Performance options for an LG4?
09-13-2006, 12:13 PM
#51
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
14 mpg and poor power indicates that something in the computer controlled system is not working correctly. Probably easiest and least expensive to find the problem and correct it, rather than swapping all new/different parts on top (carb/dist). A properly functioning ccc-qjet system is not going to keep the motor from making power.
Pointless? I average around 23 mpg in my 85 TA. My camaro with a 350 gets around 18-20 mpg with the ccc-qjet (but it's a compromise between better performance and economy).
If you want to fix what you've got, why not start a new thread? If you HAVE to remove it, four bolts and a lineman's pliers.
Pointless? I average around 23 mpg in my 85 TA. My camaro with a 350 gets around 18-20 mpg with the ccc-qjet (but it's a compromise between better performance and economy).
If you want to fix what you've got, why not start a new thread? If you HAVE to remove it, four bolts and a lineman's pliers.
09-13-2006, 09:31 PM
#52
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Car: 1998 Camaro Z28
Engine: LS1
Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
i really want to see what i can do with this 305. the previous owners replaced the engine around 15,000 miles ago so fairly new engine. hate the expense of another engine when this one is fine. should i go with three inch exhaust straight back or use 2 1/2? i am used to mustangs and they always use 2 1/2. it seems like three inch would kill torque. maybe i am wrong. thanks for all your help.
09-13-2006, 09:40 PM
#53
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Car: 1998 Camaro Z28
Engine: LS1
Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
i remember a couple of the many codes the computer was throwing around. (yes i know how to do that. lol) one said the o2 sensor read rich and another said lean at cruising. then another said temp sensor was reading low and high. i replaced that sensor. should i reset the computer if that was the problem or should the check engine light go off by itself? i dont remember all the codes. i am at work and work 24 hour shifts on an ambulance. i will post the other 400 (lol) codes when i get home tomorrow but any info on these would be great.
09-14-2006, 06:37 AM
#54
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Check engine light will go out on it's own when the code is no longer present but will continue to store the code in it's memory until it's reset. Post your other codes and we'll see.
09-14-2006, 10:10 AM
#55
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Car: 1998 Camaro Z28
Engine: LS1
Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
last night at work i reset the computer. now the only code showing up is a code 34. i thought it meant the map sensor since i notice there was NO vaccum going to it but apparently i was wrong. the other codes that were on there arent there now. i replaced that temp sensor so i wonder if that didnt fix some of the problem. according to haynes repair manual a code 34 for carbs means differential pressure sensor. went to chevy and pontiac and they dont even list one. the only thing they list is mdp manifold differential pressure sensor. and they want 83 bucks for it. i hate to spend that kinda money and not know that that is even what i am looking for. thanks again. i know all these questions must have been asked before but i really appreciate your time.
09-14-2006, 11:19 AM
#56
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Car: 1985 Z28
Engine: 350
Transmission: T-5 5 Spd
Axle/Gears: Built 10bolt w/3.73s
I believe its all refering to the same thing. I often call it a MAP sensor myself, but I think GM's term is the most correct. These cars have barometric pressure sensors located on the passenger side next to the heater core and MAP, VAC, Manifold diff press, whatever you call it, next to the brake booster on driver side.
I would recommend checking yours out first. If there is a hose remove it and check for clogs. Then reinstall it and use a vacuum guage to check for leaks in the hose and sensor. Then with the car idling check the voltage at the connector. You should see ~4-4.5V while Idling I believe. If the Hayes manual doesn't list the pinout I could look it up for you when I get home.
I would recommend checking yours out first. If there is a hose remove it and check for clogs. Then reinstall it and use a vacuum guage to check for leaks in the hose and sensor. Then with the car idling check the voltage at the connector. You should see ~4-4.5V while Idling I believe. If the Hayes manual doesn't list the pinout I could look it up for you when I get home.
09-14-2006, 01:15 PM
#57
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Car: 1998 Camaro Z28
Engine: LS1
Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
the vac hose was disconnected from the sensor near the blower on the passenger side of the engine bay. i was under the impression that was the map sensor and the other one was the baro sensor. i did not have a rubber hose to go back on last night at work so i used oxygen tubing. i don't think that is strong enough to handle the pressure but thats all i had last night. it was holding up but still the light was on. so i am guessing the sensor is just bad. i guess i will try and replace it and see what happens. all the other codes it was showing just stopped flashing after i reset the computer. i commute 80 miles one way to work. so it had 80 miles to pop back up but didnt. the car seems to run alright except crappy acceleration. i know the exhaust is worthless. my step dad rebuilt the carb. before he did it smelled horribly like gas. so maybe the com just needed to be reset. also, i do not have a belt going to the emissions pump at the bottom of the engine. is this ok? i was trying to get more power and figured it was sucking it down. thanks again.
09-14-2006, 03:22 PM
#58
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
The baro sensor and the map are the same piece, the MAP sensor, on the driver's side firewall, is connected to the carb by a vaccuum line (hard plastic). The baro sensor does not have a vaccuum line connected. The ecm takes a reading of atmospheric pressure from the baro sensor to "normalize" the map sensor readings (adjust for changes in altitude, etc.). The plastic vaccuum line (plastic allows the sensor to read more accurately because it won't flex like rubber vaccuum lines) from the map sensor (near master cylinder) should be run through convoluted tubing with part of the wiring harness, up from behind the dist into the rear of the carb.
09-14-2006, 03:32 PM
#59
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Car: 1998 Camaro Z28
Engine: LS1
Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
so don't connect a hose to the nipple on the other sensor? the one near the blower motor?
09-14-2006, 03:36 PM
#60
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Don't connect a hose to the nipple on the other sensor, the one near the blower motor. Correct.
09-14-2006, 07:18 PM
#61
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Car: 1998 Camaro Z28
Engine: LS1
Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
hey where are you at in lexington? i work in west cola at mobilecare. i used to work for lexington county ems. if you are going to be around this weekend i thought we might meet up and if you didn't mind check out my car. let me know. i will be there all weekend.
09-14-2006, 09:12 PM
#62
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
I live over near White Knoll Middle School off Kittywake. I'll be around most of this weekend. Where're you going to be at and when? As long as your TA is not black and gold I can probably break free, can't have two of them occupying the same space...end of the world stuff.
09-15-2006, 05:37 PM
#63
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Car: 1998 Camaro Z28
Engine: LS1
Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
i am in red bank. my grandparents church is white knoll baptist church. and yes my car is gold and black
aww it'll be alright! promise. you can give me a ring on my cell. i am at my g-mas this weekend with my kids. my # is 803-467-5400. call anytime. maybe we can catch up tonight or tomorrow. thanks man. ttyl
aww it'll be alright! promise. you can give me a ring on my cell. i am at my g-mas this weekend with my kids. my # is 803-467-5400. call anytime. maybe we can catch up tonight or tomorrow. thanks man. ttyl
09-16-2006, 10:03 PM
#64
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Car: 1984 Camaro Z28
Engine: L69 305 H.O.
Transmission: T-5
Axle/Gears: 3.73
I will add some info to sofakingdom's advice.
A.) If you decide to port the heads, I would pick up a pair of 601s from the wrecking yard. They are like mini 462s in the chamber, have better flowing ports than the 416s stock, and have a 52 cc chamber. That will bring the otherwise stock LG4 from 8.6:1 compression to about 9.2:1. This will add compression and flow, which will increase HP.
B.)The CCQ-Jet is VERY adaptable by changing out mechanical parts and settings. The limiters on the mixture control solenoid can be adjusted to put out the correct air/fuel ratio on the primaries. There are many different primary jet/metering rod combinations from the general. Some cars came with big jets/big rods(V8 4bbls) and some cars cam with smaller jets and smaller rods(V6 2bbl such as the 3.8). Dual Jet metering rods and jets will swap to a Q-Jet. Combine the bigger jets with the smaller rods and viola, more fuel flow on the primaries. Don't worry though as you can set the limiters. The secondary metering rods and jets can be tailored to provide the best WOT power.
C.)If you could find a L-69 chip, they are best for performance and could actually increase the fuel mileage some. Short of a L69 ECM or chip, you might find that boosting the base timing to between 4-6* will add performance and MPG.
A.) If you decide to port the heads, I would pick up a pair of 601s from the wrecking yard. They are like mini 462s in the chamber, have better flowing ports than the 416s stock, and have a 52 cc chamber. That will bring the otherwise stock LG4 from 8.6:1 compression to about 9.2:1. This will add compression and flow, which will increase HP.
B.)The CCQ-Jet is VERY adaptable by changing out mechanical parts and settings. The limiters on the mixture control solenoid can be adjusted to put out the correct air/fuel ratio on the primaries. There are many different primary jet/metering rod combinations from the general. Some cars came with big jets/big rods(V8 4bbls) and some cars cam with smaller jets and smaller rods(V6 2bbl such as the 3.8). Dual Jet metering rods and jets will swap to a Q-Jet. Combine the bigger jets with the smaller rods and viola, more fuel flow on the primaries. Don't worry though as you can set the limiters. The secondary metering rods and jets can be tailored to provide the best WOT power.
C.)If you could find a L-69 chip, they are best for performance and could actually increase the fuel mileage some. Short of a L69 ECM or chip, you might find that boosting the base timing to between 4-6* will add performance and MPG.
09-17-2006, 07:40 PM
#65
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Car: 1998 Camaro Z28
Engine: LS1
Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
thanks to everyone. especially naf. you all have been a great help. finally got it running without a check engine light (thanks again naf) and now the search continues for more power.
well, i will be here so just holla whenever. 
well, i will be here so just holla whenever.
09-18-2006, 02:41 PM
#66
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Car: 1998 Camaro Z28
Engine: LS1
Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
alright here goes more questions. on my way home today, i took off suddenly from a stoplight and after it shifted to second gear, with the pedal at wot, it started stalling like it couldn't fire anymore. i let off and it stopped but putting the pedal back down again caused the same reaction. naf, you've seen the car and engine. i take it its not the timing because we set that. could it be the coil or ignition module? wires, plugs, cap, and rotor button have all been replaced. here i am asking for help again. thanks all.
thanks all.
09-19-2006, 09:19 AM
#67
09-20-2006, 08:24 AM
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Car: 1998 Camaro Z28
Engine: LS1
Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
naf, i forgot that you said it looked like the fuel line to the pump was leaking. that could very well be the problem. i am thinking about switching to an edelbrock pump anyway. by the way, i lost your number. call me back sometime so i can lock it into my phone. thanks:-)
09-20-2006, 11:27 AM
#69
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
You can pull the fuel line off at the carb and check for flow and pressure while it's idling (should idle a minute or so with fuel left in carb). Should put out around 5.5-6.5 psi (with vapor return line clamped) and about a pint of fuel in 30 seconds. I'd hate for you to replace the pump to find out the filter was clogged.
If you have to replace the pump, you can pick one up a AZ or the equivalent for around $15. Save the money towards something that will make a diff.
If you have to replace the pump, you can pick one up a AZ or the equivalent for around $15. Save the money towards something that will make a diff.
09-20-2006, 05:11 PM
#70
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Car: 1998 Camaro Z28
Engine: LS1
Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
cool. i will definately try that. i think i will try just pulling the fuel lines off and putting more teflon tape on them. i think it is leaking a little bit and if it is sucking air then that will definately make a difference. thanks
09-20-2006, 05:52 PM
#71
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Car: 1985 Z28
Engine: 350
Transmission: T-5 5 Spd
Axle/Gears: Built 10bolt w/3.73s
Don't put any Teflon tape on the fuel lines, it won't do anything but make it harder to tighten. I used do that too.
The sealing surface is the 45 degree inverted flare at the end of the tube that mates with the carb's flare. If its leaking I would tighten it a little bit.
The sealing surface is the 45 degree inverted flare at the end of the tube that mates with the carb's flare. If its leaking I would tighten it a little bit.
09-20-2006, 05:56 PM
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09-20-2006, 06:25 PM
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Car: 1998 Camaro Z28
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Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
well, i gotta work tomorrow so what better time to check that stuff than at work
i will definately check both of those out. thanks again.
i will definately check both of those out. thanks again. 
09-23-2006, 11:09 AM
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Car: 1998 Camaro Z28
Engine: LS1
Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
here we go again. my car just started throwing codes 14 and 15 again. that means the coolant temp sensor is showing low and high readings. how is that possible? plus i just replaced that sensor. what is wrong with this piece of junk? heeeeeeeeeeelllllllllllppppppppppp!!!!!!!
09-23-2006, 12:10 PM
#76
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Loose wiring or bad connector to CTS is likely. The connector gets beat up by the hoses that run right by it. You can short out the two connector leads and "confuse" the ecm into thinking the temp is good. Clear codes, run it a little and see if the trouble light comes on. This would rule out the CTS as it would be disconnected.
09-23-2006, 10:12 PM
#77
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Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
I can see the clutch fan taking 10 RWHP off of an engine at 4,500, IF it is engaged. In cooler weather without the airplane effect going on, I doubt that it takes 2-3 HP to turn. 10 RWHP is what it did to my 350 in 105* weather. Took the clutch fan off and made another dyno run (fan-less) and it was 10 RWHP stronger. Before you decide to go electric, let me note that the clutch on my engine is a HD type that engages sooner and more fully and I have a 20" 7 bladed fan from a 454 on it.
09-24-2006, 08:26 PM
#78
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Car: 1998 Camaro Z28
Engine: LS1
Transmission: 4L60E. Right now.
Axle/Gears: 10 bolt, Torsion diff, 3.73 gears.
well again, i find out that you are all much smarter than i. i realized that naf was right because the old connector was broken and not making good contact with the sensor. i went to oreilys and bought a kit with a new sensor and the new connector for only 15 bucks. changed the wiring (because i already bought a new sensor) and voila, no more check engine light. by the way, advanced auto did not even have the wiring in their system. next time you need something that az or aa says cant be gotten, try oreilys. pretty good people and parts, even if they do cuss a lot
lol. til the next dumb question.........
lol. til the next dumb question.........
09-25-2006, 06:30 AM
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01-26-2007, 08:47 AM
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Car: '10 Subaru Forester
Engine: 2.5 Boxer
Transmission: 4EAT
Axle/Gears: 4.44
I can see the clutch fan taking 10 RWHP off of an engine at 4,500, IF it is engaged. In cooler weather without the airplane effect going on, I doubt that it takes 2-3 HP to turn. 10 RWHP is what it did to my 350 in 105* weather. Took the clutch fan off and made another dyno run (fan-less) and it was 10 RWHP stronger. Before you decide to go electric, let me note that the clutch on my engine is a HD type that engages sooner and more fully and I have a 20" 7 bladed fan from a 454 on it.
The one big advantage of electrics is being able to run a manual fan switch to help cool off the radiator between drag runs.
Last edited by ChillPhatCat; 01-26-2007 at 09:03 AM.
01-26-2007, 09:53 AM
#81
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
I've recently swapped to the single electric fan on my LG4 and there are benefits aside from freeing up horsepower. 1) my clutch fan was on the way out so I would have had to replace it anyway. 2) less noise from the engine compartment, there was a noticeable difference 3) seems to warm up a little faster on cold mornings 4) that big thing isn't blowing on you every time you're working on it. 5) Seems to cool off faster (or run at lower temps) when the fan motor is engaged.
SEEMS faster, right, but probably not enough to notice. I spend nearly all my time below 4000 rpm in this thing anyway. The engine will load some when the fan is engaged at idle, so with the fan motor on there's probably near zero net gain. I haven't put an amp probe on it yet to see what it's drawing but I am curious.
SEEMS faster, right, but probably not enough to notice. I spend nearly all my time below 4000 rpm in this thing anyway. The engine will load some when the fan is engaged at idle, so with the fan motor on there's probably near zero net gain. I haven't put an amp probe on it yet to see what it's drawing but I am curious.
01-26-2007, 11:18 AM
#82
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The HP difference is at high RPM; keep in mind that the fan's power consumption goes up in proportion to THE SQUARE of the RPM change; i.e., double the RPM, power goes up by a factor of 4.
It's a noticeable gas mileage improvement too supposedly; although I have no numbers to substantiate that. Still, a mpg or 2 over a long period of time and lots of miles, continuously every mile, has a tendency to add up to some $$$.
It's a noticeable gas mileage improvement too supposedly; although I have no numbers to substantiate that. Still, a mpg or 2 over a long period of time and lots of miles, continuously every mile, has a tendency to add up to some $$$.
01-26-2007, 12:05 PM
#83
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
"The HP difference is at high RPM; keep in mind that the fan's power consumption goes up in proportion to THE SQUARE of the RPM change; i.e., double the RPM, power goes up by a factor of 4."
Not quite as straightforward I would think, don't forget about the clutch, it's efficiency loss and the coupling/uncoupling at different temps/rpms.
I've only driven it back and forth to work a couple of times now as I still haven't gotten the plug out of the pass side head to install the temp switch. I may eventually need to remove the manifold on that side to get it out. I know, should have done that first, but the clutch fan was starting to rattle and I had accumulated all of the pieces/parts for the swap a few months ago. (and the weekend is only so long) Anyway, during my 35 mile commute the engine temps have remained low enough for the fan to remain disengaged so I would definitely expect some gains in mileage. Maybe not so noticeable at the pump but averaged over the 15+k a year I do? This is with air temps in the 50's.
Not quite as straightforward I would think, don't forget about the clutch, it's efficiency loss and the coupling/uncoupling at different temps/rpms.
I've only driven it back and forth to work a couple of times now as I still haven't gotten the plug out of the pass side head to install the temp switch. I may eventually need to remove the manifold on that side to get it out. I know, should have done that first, but the clutch fan was starting to rattle and I had accumulated all of the pieces/parts for the swap a few months ago. (and the weekend is only so long) Anyway, during my 35 mile commute the engine temps have remained low enough for the fan to remain disengaged so I would definitely expect some gains in mileage. Maybe not so noticeable at the pump but averaged over the 15+k a year I do? This is with air temps in the 50's.
02-05-2007, 09:43 AM
#84
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I got a LG4 that was rebuilt 2 summers ago all stock, if dropped the Comp XE256 in it would the lifter kit have to be installed as well to operate properly or will it still be fine just putting the cam alone in? Also, I might not have the facilities to do this myself so I'm probably going to get it done at the local performance garage, so just out of curiousity, how many labor hours are usually charged for a cam replacement and how much of a performance difference would I be looking at?
02-05-2007, 10:02 AM
#85
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
You always need to install new lifters with a new flat tappet cam. It's also recommended that you run GM Engine Oil Supplement along with a diesel type motor oil (Rotella T is often recommended and I use it) on start up for initial break in. If you haven't done anything to the exhaust you probably won't get the max benefit from that cam. Otherwise it's a good choice for the LG4. On the shop hours, IDK. I'd just call two or three different shops and ask for a price.
02-15-2007, 06:43 AM
#86
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Car: 1987 SC/1985 TA
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Transmission: T56
Axle/Gears: 3.27 9-bolt
So far, three tank fulls through the 85 stock lg4 after the electric fan conversion and I can report an average of 23.5 mpg which is an increase from the 21-22 mpg I usually average this time of year. I suspect a part of the increase is due to the engine warming up faster (less time rich with choke on) as this is the mileage I usually see in warmer temps before it becomes necessary to run AC constantly. The mileage average is during my 70 mile round trip commute to work, so route and conditions are fairly constant.
Stupid me, can not put an amp probe on a DC circuit...I am often reminded why I did not choose EE.
and why does funky punctuation in this window open a search feature this morning and move me to another page? The apostrophe did it every time? Weird.
Stupid me, can not put an amp probe on a DC circuit...I am often reminded why I did not choose EE.
and why does funky punctuation in this window open a search feature this morning and move me to another page? The apostrophe did it every time? Weird.
08-22-2007, 11:48 AM
#87
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Location: Grand Terrace, CA
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Car: 88 Camaro
Engine: 310 LG4
Transmission: 700R4 w/2200 stall
Axle/Gears: 3.42
Re: Performance options for an LG4?
all you need right here
http://www.popularhotrodding.com/eng...cks/index.html
enjoy. I built up my LG4, making about 320 at crank, but i did everything I could (except new heads, just modded the stock 416 heads)
they got 372hp from their motor with not too much money either. 372hp is enough to satisfy most.
http://www.popularhotrodding.com/eng...cks/index.html
enjoy. I built up my LG4, making about 320 at crank, but i did everything I could (except new heads, just modded the stock 416 heads)
they got 372hp from their motor with not too much money either. 372hp is enough to satisfy most.
Last edited by 88_Import_Slaye; 08-22-2007 at 11:52 AM.
08-22-2007, 03:32 PM
#88
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Join Date: May 2007
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Car: 1984 Trans Am
Engine: LG4
Transmission: 700R4
Axle/Gears: 3.23
Re: Performance options for an LG4?
No, no one. Ever.
Seriously...
The choke points in that setup are, in the order they should be fixed:
1. Exhaust
2. Cam
3. Air cleaner
4. Electric fan
5. Gears
6. Heads
7. Converter (if it's an auto)
Notice that at NO POINT did I mention the carb, intake, or ignition system; hacking off any emissions eqpt; aftermarket "chips"; add-on ignition boxes; or other typical wastes of money. The reason those are wastes of money, is that THEY ARE NOT THE THINGS LIMITING THE CAR'S PERFORMANCE. Note also that I said "car", not "engine"; as not all of the things that make those slow, are under the hood.
1. Exhaust - needs to be replaced, as an entire unit. Every piece from the heads to the back bumper. The replacement MUST NOT be designed to fit LG4; because if it is, it will PRESERVE the LG4 exhaust bottleneck, namely, the itty bitty Y-pipe. Get one of the quality brands of headers SPECIFICALLY for one of these cars, BUT NOT for the LG4; get the ones for a TPI 350. Get a high-flow cat such as a Catco from Summit, and your choice of cat-back. All of this for something like 89 TPI 350 without G92 (single-cat setup). This will retain emissions legality (except for the EFE valve).
2. Look at cams in the 210 - 215 degree @ .050" range on the intake, with a larger exhaust lobe. Comp's XE256 and XE262 are known to work well. Crane has cams of somewhat similar specs that also give good results; I think it's the Energizer 272 but I could be wrong. Lunati's new Voodoo series is the right design for this, and may have something in the right duration range for it. Whatever cam you pick, avoid choosing it based on "sound"; any cam that "sounds" "good" will probably be too much for the rest of the engine and car. Replace the valve springs and their hardware, and the timing set, along with the cam. DO NOT try to use a modern cam under stock springs; you'll probably break something.
3. Get a dual-snorkel one from L69. This will give several HP over a typical open element, since it will give the motor cold (dense) air instead of hot, thin underhood air.
4. If your car has a clutch fan, it uses a good solid 12 HP just to run the fan. An electric fan will give you back those HP. Watch the classifieds on this site for a used fan setup.
5. Those cars were always the "sacrificial lambs" to CAFE in the V8 F-body product lineup. At the time they were new, the people who bought them were looking for the "image", not the "substance", of performance. Since anybody that was buying a new car and was seriously interested in performance avoided those like the plague, I guess GM figured they could nut them as much as they wanted to get their fuel mileage up, and nobody that bought them would care (might even like them better in fact, if they were cheaper to drive; no matter how slow). So they always got crappy gears. The best they ever got, standard, was 3.23; and most years they got 2.73 or the like. 3.42 or 3.73 makes an AMAZING difference to a 2.73 car. If yours already has 3.23s, it's not quite so urgent; but once you get the motor to breathe, it will benefit from 3.73s. In stock condition though, 3.73s will force the engine RPM so quickly up into a range where the motor has no power, that it won't really be any faster than stock; even though it will feel like it has this huge launch off the line.
6. The heads themselves are fine, entirely adequate for 305; except that they can use some porting, and larger intake valves. There is a great deal of HP available here.
7. This is like gears. The stock converter pins the motor to a very low RPM range, especially from a stop. Once you get it to where the motor has some higher-RPM power, letting it rev up when you punch it will give it a much harder "leave".
I cannot emphasize enough, RESIST THE TEMPTATION to un-bolt and re-bolt big shiny things that sit up there where everybody can see them, on top of the motor. There's an old saying you'll hear at the race track, from the people who WIN: "Chrome don't bring the money home". People who spend their limited cash on "dress-up" are choosing the path to a slow expensive car that loses races.
The parts that produce performance are INVISIBLE. Don't let that discourage you from doing the right thing. Spending your money on things you can "see", will produce little or no results; except maybe, the car will be lighter, because the driver's wallet will be thinner.
Which reminds me of another whole set of things you can do to make the CAR faster; and that is, lose weight. I don't advise hacking stuff off; few things make me puke as bad as all the people who hack off their AC, for example. But, any time you replace something, make an effort to get something lighter in its place. For example, a "mini-starter", a plastic/aluminum radiator instead of copper/brass, an aluminum drive shaft, lighter wheels, lighter flywheel if it's a 5-speed, aluminum bumper support to replace the steel one, the 82-83 "composite" hood, etc. etc. etc. You can shave an easy hundred pounds off of it that way, maybe more.
Seriously...
The choke points in that setup are, in the order they should be fixed:
1. Exhaust
2. Cam
3. Air cleaner
4. Electric fan
5. Gears
6. Heads
7. Converter (if it's an auto)
Notice that at NO POINT did I mention the carb, intake, or ignition system; hacking off any emissions eqpt; aftermarket "chips"; add-on ignition boxes; or other typical wastes of money. The reason those are wastes of money, is that THEY ARE NOT THE THINGS LIMITING THE CAR'S PERFORMANCE. Note also that I said "car", not "engine"; as not all of the things that make those slow, are under the hood.
1. Exhaust - needs to be replaced, as an entire unit. Every piece from the heads to the back bumper. The replacement MUST NOT be designed to fit LG4; because if it is, it will PRESERVE the LG4 exhaust bottleneck, namely, the itty bitty Y-pipe. Get one of the quality brands of headers SPECIFICALLY for one of these cars, BUT NOT for the LG4; get the ones for a TPI 350. Get a high-flow cat such as a Catco from Summit, and your choice of cat-back. All of this for something like 89 TPI 350 without G92 (single-cat setup). This will retain emissions legality (except for the EFE valve).
2. Look at cams in the 210 - 215 degree @ .050" range on the intake, with a larger exhaust lobe. Comp's XE256 and XE262 are known to work well. Crane has cams of somewhat similar specs that also give good results; I think it's the Energizer 272 but I could be wrong. Lunati's new Voodoo series is the right design for this, and may have something in the right duration range for it. Whatever cam you pick, avoid choosing it based on "sound"; any cam that "sounds" "good" will probably be too much for the rest of the engine and car. Replace the valve springs and their hardware, and the timing set, along with the cam. DO NOT try to use a modern cam under stock springs; you'll probably break something.
3. Get a dual-snorkel one from L69. This will give several HP over a typical open element, since it will give the motor cold (dense) air instead of hot, thin underhood air.
4. If your car has a clutch fan, it uses a good solid 12 HP just to run the fan. An electric fan will give you back those HP. Watch the classifieds on this site for a used fan setup.
5. Those cars were always the "sacrificial lambs" to CAFE in the V8 F-body product lineup. At the time they were new, the people who bought them were looking for the "image", not the "substance", of performance. Since anybody that was buying a new car and was seriously interested in performance avoided those like the plague, I guess GM figured they could nut them as much as they wanted to get their fuel mileage up, and nobody that bought them would care (might even like them better in fact, if they were cheaper to drive; no matter how slow). So they always got crappy gears. The best they ever got, standard, was 3.23; and most years they got 2.73 or the like. 3.42 or 3.73 makes an AMAZING difference to a 2.73 car. If yours already has 3.23s, it's not quite so urgent; but once you get the motor to breathe, it will benefit from 3.73s. In stock condition though, 3.73s will force the engine RPM so quickly up into a range where the motor has no power, that it won't really be any faster than stock; even though it will feel like it has this huge launch off the line.
6. The heads themselves are fine, entirely adequate for 305; except that they can use some porting, and larger intake valves. There is a great deal of HP available here.
7. This is like gears. The stock converter pins the motor to a very low RPM range, especially from a stop. Once you get it to where the motor has some higher-RPM power, letting it rev up when you punch it will give it a much harder "leave".
I cannot emphasize enough, RESIST THE TEMPTATION to un-bolt and re-bolt big shiny things that sit up there where everybody can see them, on top of the motor. There's an old saying you'll hear at the race track, from the people who WIN: "Chrome don't bring the money home". People who spend their limited cash on "dress-up" are choosing the path to a slow expensive car that loses races.
The parts that produce performance are INVISIBLE. Don't let that discourage you from doing the right thing. Spending your money on things you can "see", will produce little or no results; except maybe, the car will be lighter, because the driver's wallet will be thinner.
Which reminds me of another whole set of things you can do to make the CAR faster; and that is, lose weight. I don't advise hacking stuff off; few things make me puke as bad as all the people who hack off their AC, for example. But, any time you replace something, make an effort to get something lighter in its place. For example, a "mini-starter", a plastic/aluminum radiator instead of copper/brass, an aluminum drive shaft, lighter wheels, lighter flywheel if it's a 5-speed, aluminum bumper support to replace the steel one, the 82-83 "composite" hood, etc. etc. etc. You can shave an easy hundred pounds off of it that way, maybe more.
about how many Horsepower would this setup make without the stall and with 3.23s?
I want at least 200 horsepower and to be running 14's or lower with mine, and everyone keeps telling me to use the old motor as a boat anchor and get a 350, which is fine, but I want to keep the original motor. (especially because it only has 71,xxx miles on it)
This setup sounds way better than a swap.
Last edited by freebird779; 08-22-2007 at 03:40 PM.
12-18-2007, 12:06 AM
#89
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Location: Gulfport, Florida
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Car: Toyota Slowica
Engine: 2.2 liters of raw muscle
Transmission: 5 speed stick
Re: Performance options for an LG4?
No, no one. Ever.
Seriously...
The choke points in that setup are, in the order they should be fixed:
1. Exhaust
2. Cam
3. Air cleaner
4. Electric fan
5. Gears
6. Heads
7. Converter (if it's an auto)
Notice that at NO POINT did I mention the carb, intake, or ignition system; hacking off any emissions eqpt; aftermarket "chips"; add-on ignition boxes; or other typical wastes of money. The reason those are wastes of money, is that THEY ARE NOT THE THINGS LIMITING THE CAR'S PERFORMANCE. Note also that I said "car", not "engine"; as not all of the things that make those slow, are under the hood.
Seriously...
The choke points in that setup are, in the order they should be fixed:
1. Exhaust
2. Cam
3. Air cleaner
4. Electric fan
5. Gears
6. Heads
7. Converter (if it's an auto)
Notice that at NO POINT did I mention the carb, intake, or ignition system; hacking off any emissions eqpt; aftermarket "chips"; add-on ignition boxes; or other typical wastes of money. The reason those are wastes of money, is that THEY ARE NOT THE THINGS LIMITING THE CAR'S PERFORMANCE. Note also that I said "car", not "engine"; as not all of the things that make those slow, are under the hood.
12-18-2007, 12:24 AM
#90
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Join Date: Aug 2007
Location: Gulfport, Florida
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Car: Toyota Slowica
Engine: 2.2 liters of raw muscle
Transmission: 5 speed stick
Re: Performance options for an LG4?
I can see the clutch fan taking 10 RWHP off of an engine at 4,500, IF it is engaged. In cooler weather without the airplane effect going on, I doubt that it takes 2-3 HP to turn. 10 RWHP is what it did to my 350 in 105* weather. Took the clutch fan off and made another dyno run (fan-less) and it was 10 RWHP stronger. Before you decide to go electric, let me note that the clutch on my engine is a HD type that engages sooner and more fully and I have a 20" 7 bladed fan from a 454 on it.
changing energy from one form to another (from kinetic to electric to kinetic again) causes a loss in total energy (lost as heat) so unless the clutch unit and fan weighed quite a bit more than the electric unit (I have never actually lifted them) you would actually lose power that way (unless the electric fan spins slower than the original unit).
of coarse you could get the same effect with a lightweight version of the original fan unit with a slightly less aggressive profile.
12-18-2007, 01:05 AM
#91
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Location: Winnipeg, MB, Canada
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Car: 1984 Camaro Z28 T-tops
Engine: 350
Transmission: T-5
Axle/Gears: 3.23
12-18-2007, 06:29 AM
#92
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Location: Michigan
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Car: 1987 Trans Am
Engine: LG4 (I desire a 383)
Transmission: 700R4
Axle/Gears: Stock?? 1.0? :)
Re: Performance options for an LG4?
Yes, he was referring to the air cleaner assembly, going from SINGLE snorkel to either DUAL snorkel or open element. From there it flamed and I don't think there was ever any agreement on which is better. Dual snorkel will run roughly $150-$300 depending on seller and condition. Open element seems to be cheaper and simpler, on my setup I don't know how I could route the passenger snorkel through the plethora of emissions CRAP in the way.
As for the intake, yes he was referring to the intake manifold. Using context clues, one can figure out what he meant. Given the original post was almost 2 years ago, I wonder what good it does to point this confusion now. It seems as though if it were a real issue then someone would have brought it up sooner.
As for the intake, yes he was referring to the intake manifold. Using context clues, one can figure out what he meant. Given the original post was almost 2 years ago, I wonder what good it does to point this confusion now. It seems as though if it were a real issue then someone would have brought it up sooner.
12-18-2007, 06:59 AM
#93
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: Performance options for an LG4?
one thing you all forget is it increases the load on the alternator thereby making it harder for the alternator to turn.
changing energy from one form to another (from kinetic to electric to kinetic again) causes a loss in total energy (lost as heat) so unless the clutch unit and fan weighed quite a bit more than the electric unit (I have never actually lifted them) you would actually lose power that way (unless the electric fan spins slower than the original unit).
of coarse you could get the same effect with a lightweight version of the original fan unit with a slightly less aggressive profile.
changing energy from one form to another (from kinetic to electric to kinetic again) causes a loss in total energy (lost as heat) so unless the clutch unit and fan weighed quite a bit more than the electric unit (I have never actually lifted them) you would actually lose power that way (unless the electric fan spins slower than the original unit).
of coarse you could get the same effect with a lightweight version of the original fan unit with a slightly less aggressive profile.
12-18-2007, 10:09 AM
#94
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Join Date: Apr 2003
Location: Grand Terrace, CA
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Car: 88 Camaro
Engine: 310 LG4
Transmission: 700R4 w/2200 stall
Axle/Gears: 3.42
Re: Performance options for an LG4?
The fan on my truck (2001 dodge ram 1500 5.9l) sitting at idle will suck papers (or other trash that might be too close) to the grill and keep it there while sitting at idle. That fan pulls a lot of air, and it IS further from the radiator, but that is why you use a fan shroud, that prevents the fan from pulling air from around the unit instead of through it. As far as the electric fan unit putting load on the alternator, you can get an aftermarket solution like i did. The unit is called a DC Controller (DC is the company) and it ramps the fan up and it does one hell of a job keeping it at the set temperature no matter what and since it ramps up the voltage, it doesnt strain your alternator. The unit is all self contained, just give it power and attach it to your fan and your done. Never worry again.
If you want to build up your LG4, there are many many options available now. Lots of packages.
If you want to build up your LG4, there are many many options available now. Lots of packages.
12-18-2007, 10:26 AM
#95
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: Performance options for an LG4?
My experience was with the stock clutch fan and stock shroud and was subjective at best. I do feel confident in boasting a 0.5 to 1.5 increase in average mileage, a little more in the winter when A/C is not calling for the fan constantly. I ran with the mechanical fan for around 30k miles, probably around 15k since the swap. Same route, 35 miles one way, to work every day.
Getting rid of the fan roar was worth the effort alone.
A voltage controller would be sweet to ramp up fan speeds. I'll look into it. The start up load for the stock single fan is already in excess of 20 amps. If it's not too much $...
Getting rid of the fan roar was worth the effort alone.
A voltage controller would be sweet to ramp up fan speeds. I'll look into it. The start up load for the stock single fan is already in excess of 20 amps. If it's not too much $...
12-18-2007, 10:56 AM
#96
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Car: 88 Camaro
Engine: 310 LG4
Transmission: 700R4 w/2200 stall
Axle/Gears: 3.42
Re: Performance options for an LG4?
the unit is about $110 and due to back orders, it takes about 2 weeks to get one. It's awesome, water proof, tons of fail safes and easy to install and configure. I needed it cause I got a ford taurus electric fan from the junk yard and that thing pulls some air baby! But like you said, in excess of 20 amps, that draw can stall your motor at times.
12-18-2007, 09:00 PM
#97
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Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: Performance options for an LG4?
one thing you all forget is it increases the load on the alternator thereby making it harder for the alternator to turn.
changing energy from one form to another (from kinetic to electric to kinetic again) causes a loss in total energy (lost as heat) so unless the clutch unit and fan weighed quite a bit more than the electric unit (I have never actually lifted them) you would actually lose power that way (unless the electric fan spins slower than the original unit).
changing energy from one form to another (from kinetic to electric to kinetic again) causes a loss in total energy (lost as heat) so unless the clutch unit and fan weighed quite a bit more than the electric unit (I have never actually lifted them) you would actually lose power that way (unless the electric fan spins slower than the original unit).
Got news for you, unless the A/C is on, the electric fans rarely ever kick on. I know in my van they only came on when stopped for 3-5 minutes in traffic and only ran about 30 seconds when they came on. Then they would shut-off for another 3-5 minutes. (A/C on is a different story when stopped or driving slowly) On the highway, they NEVER came on. I had mine wired like the OEM would do it, with an A/C high pressure switch on the back of the compressor and a thermal switch in the cylinder head. Going down the road at about 35-40 MPH, the A/C head pressure and engine coolant temperature would drop enough from the air rushing over the radiator and condensor, that the fans would shut-off and stay off.
12-19-2007, 10:29 AM
#98
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Car: 88 Camaro
Engine: 310 LG4
Transmission: 700R4 w/2200 stall
Axle/Gears: 3.42
Re: Performance options for an LG4?
the factory default temperature for the fans to come on is 230* for the camero. So if you are driving on the freeway and have a decent system then it wont come on. Mine didnt until it was under extreme load.
The fans in my Kia nor my honda ever come on until I am stopped, it depends on your system so dont make a blanket statement that isnt true.
With my new system the fan comes on all the time because it is generating more heat. Beef up that 305 like I did and you'll see.
The fans in my Kia nor my honda ever come on until I am stopped, it depends on your system so dont make a blanket statement that isnt true.
With my new system the fan comes on all the time because it is generating more heat. Beef up that 305 like I did and you'll see.
12-19-2007, 07:02 PM
#99
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Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: Performance options for an LG4?
the factory default temperature for the fans to come on is 230* for the camero. So if you are driving on the freeway and have a decent system then it wont come on. Mine didnt until it was under extreme load.
The fans in my Kia nor my honda ever come on until I am stopped, it depends on your system so dont make a blanket statement that isnt true.
With my new system the fan comes on all the time because it is generating more heat. Beef up that 305 like I did and you'll see.
The fans in my Kia nor my honda ever come on until I am stopped, it depends on your system so dont make a blanket statement that isnt true.
With my new system the fan comes on all the time because it is generating more heat. Beef up that 305 like I did and you'll see.
Then again, this is my cooling system. MONSTER BeCool radiator and Dual two speed electric fans from a Nissan Altima.
01-06-2008, 10:58 PM
#100
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Car: 2000 BMW M5
Re: Performance options for an LG4?
should i go with three inch exhaust straight back or use 2 1/2? i am used to mustangs and they always use 2 1/2. it seems like three inch would kill torque. maybe i am wrong. thanks for all your help.
You need a 3", minimum, on these cars. 2.5 will not support any kind of real HP. Even the stock 305/350 TPI cars had a 2.75" stock. Those cars were only in the low 200 hp range, so that should tell you a 2.5 is nowhere near enough.