hows my set up?
 

k this is the plan could some one tell me if i am missing something? and do u have any idea of the hp i will get with this.
85 LG4 305= 155 HP stock

MODS:
free flow cat
3" exhaust to a flowmaster
custom Y pipe
headers
custome CAI
K&N filter

with all that can i take the 80s z24 cavalier??? just a small goal i have to keep me goin. LOL

i think you should be able to!

80's Z24? You should be able to without doing anything...

It would be a close race if your talking about a late 80's Z24. Some of them came with v6's and can be quick if its running good. I think you would win though.;)

LG4 mods example
 

Stock 1982 LG4 -
145bhp @ 4000rpm / 165 lbs-ft torque @ 4200rpm

Full Performance Exhaust System(headers, 3"pipe)-
197.3bhp @ 4600rpm / 261.3 lbs-ft torque @ 3100rpm

Add Edelbrock Performer EGR Intake Manifold-
216.6bhp @ 4200rpm / 284.8 lbs-ft torque @ 3300rpm

Re: LG4 mods example
 

your joking right :doh:
first off, i am almost positive the lg4 was rated at 145 horsepower at the flywheel, not at the wheels. Secondly, if adding headers and 3" piping makes 197.3 horsepower at the wheels, that equals out to 246.6 horsepower at the flywheel. You are telling me you think that full exhaust on an LG4 is worth 100 horsepower??? :rolleyes:

Finally, with the addition of a smog legal performer intake you show the LG4 putting out 264.14 horsepower at the flywheel. If that were true LG4's would 13 and 14 second cars with only exhaust and an intake manifold. Please tell me you are joking...

seems a little desktop dyno'ish to me.

But anyway, the numbers are way off. I say start with exhaust. Get headers and 3" exhaust. You'll feel a difference (certainly not 100hp) and the parts can later be used on a 350/377/383/400/etc.

What Im getting at is if you want the car to see 13's, swap the motor. Its not too bad on CC Carb cars.

-Doug

on the tech page it says the motor stock is 155 its a 85lg4 enigine am i readin something wrong?

I thought brake horsepower(bhp) was at the flywheel.am i wrong?and the 52 HP gains from the ENTIRE exhaust seem to be maybe about 20 hp off,as i could see a gain of about 30 HP being about right,but 100lb/ft of torque!?! holy crap that seems to be more than a little optimistic.thats some of the riciest bench racing(bench dynoing:confused: )ive ever seen,no flame intended.

BHP stands for brake horsepower because it is measured at the brakes, or the rear wheels. at least that was how it was explained to me.

set the record straight
 

1)I don't bench dyno or bench race.
http://www.goingfaster.com/spo/carcraft325hp305.html

2) I said 1982(145HP) not 1985(155HP)

3)where did i say rear wheels? BHP =FWHP not RWHP

4)Dyno yes, desktop no

5)that difference you are feeling is something i like to call Torque

6)the numbers originally posted are not out of line. L69 305 cars are dipping well into the 14's with only cam, intake and exhaust. The major difference with the L69 and the Lg4 is a slightly upgraded cam in 1985

Not like I would know much about modifying 305s :lala:

Jeremy
moderator on MontecarloSS.com
(all 1983-1988 monte carlo SS's came with L69 305's)

Re: LG4 mods example
 

I was wrong about BHP, it is at the flywheel. However, full exhaust on an LG4 does not give you 52 horsepower and 100 ft lbs of torque. It probably picks up 20 horsepower and 20 ft lbs of torque due to the crappy stock exhaust LG4's came with.

the dyno doesn't lie....

Also, they are using the RATED numbers for a stock LG4, they didn't actually dyno it. It could of made more.

Headers alone are worth 20-30hp EASILY on LG4's and L69's. A single tube of the header is the same size as the ENTIRE stock manifold. Thats a huge difference.

Re: Re: LG4 mods example
 

If you only get 20HP from a full exhaust conversion, i will be completely at a loss for words. Stock manifolds in the 80's(all GM manifolds!) were freakin paper weights. The LG4 had a tiny y-pipe and a single exhaust size about the size of a paper towel roll.

Experiment:
Blow as hard as you can through one of those coffee stir straws.
Then blow through a soda straw.
How much more air did you move during the same amount of time?

An engine is an air pump, the more air/fuel moved in and out combined with the faster you can do it equal more power, period. People believe that headers/exhaust/intake add HP, when in fact they remove restrictions on HP production, making the parts that are there function closer to maximum potential.

To add HP, you actually have to change internals(intake can be considered an internal, but is usually considered a bolt on).

Re: Re: Re: LG4 mods example
 

But you see, the engine has to be a performance oriented engine to want to breathe more, and well, the LG4 is not. These things you say would hold true on more performance oriented engines, but LG4 heads are ****, LG4 cams are **** and so much else on the motor lacks the ability to make the power you claim. My camaro came with an LG4 engine so its not like its something i dont have first hand experience with.

he's not claiming it, they were dyno'ed producing that......the dyno doesn't lie.

Re: Re: Re: Re: LG4 mods example
 

Back to my coffee stir straw.

Make it so I can only breath through it.
Now I will run the 40 yd dash

Do the same with gold medalist, world record holder Micheal Johnson.

Did we both lose performance? Yes.
Am I as performance oriented as he is? Heck no

As for LG4 parts, exactly how bad is a 416 LG4 head compared to a 416 L69 head? So the cam is smaller, therefore it makes more TQ down low than a bigger cam would. Cams are funny, the tend to lose TQ when you gain HP(so a bigger TQ gain may be a possibility, hum...)

While the numbers I originally posted are not my own, I have produced numbers similar on my own with my 1984 monte carlo SC. I dont think that a 185TQ(thats a stock 165TQ plus 20, like you said) has the ability to smoke a set of 245/55/15's with a th350 tranny and 2.41 posi, no power brake. My SC would all the way through first from a stop light.

Yeah he's right on those gain numbers from the exhaust on the LG4. I saw it in a Chevy Hi Performance mag where they build a 325 horsepower LG4. The first thing they did was give it headers and 3 inch exhaust. :lala: 197 hp :nod:

Geeze, what a load of crap

BHP – Brake Horse Power – basically measuring HP against a brake so that with the throttle wide open the brake (usually a water wheel) controls the rpm that the engine turns at. Usually testing is done in acceleration (the brake allows the engine to accelerate at a set rate) or step tests (the dyno lets the engine stabilize at each measured rpm before continuing to the next one). This has nothing to do with whether it is an crank or wheel #, although this is the way most engine dynos work and most chassis dynos are inertia dynos (they measure how fast you accelerate a drum with a known radius of gyration and mass).

‘Performance engine’ is in the eye of the beholder and the application. Every running engine performs somehow and even a lowly 100hp could produce what someone will call high performance in some applications. Funny, LG4 heads flowbench much better then L98 heads (to the tune of 20-30cfm better at .400” on the intake)

If you’ve ever looked at an LG4 exhaust you’d see how you could get 50hp (plus or minus some) from a good one. The manifold outlets are 1-7/8” and neck down narrower then that just inside, the crossover/y is roughly the same and crush bent, going into a cat that is worse, 2.5” single into twin restrictive mufflers (if it’s an ’82). Swap that for a set of ¾ or full length 1-5/8” headers, a nice y, and any reasonable cat back and the car REALLY wakes up.

Add the before mentioned edelbrock intake, tune right you’re easily in the low 14’s to high 13’s. Add any reasonable, mild cam and you won’t even recognize the car. This setup, using a stock LT1 cam in a ’85 iroc with and LG4 ran 13.1’s at 102, 12.0’s@116 with a 100hp shot of spray. Probably would have cost less and worked the same to go with a decent solid lifter flat tappet (to use the LT1 you need aftermarket roller lifters), or maybe a slightly bigger cam hydraulic flat tappet with bleed down lifters (trying to keep the same low end so that you don’t have to spend more money on the rest of the drivetrain to make it match)….

It was still just a lowly 305 LG4… that ate LS1’s for lunch.

:hail: LG4 :eek:

looks like i should sell my 330 horse 350HO and go buy my LG4 back :rolleyes:

you guys kill me, why is it i know a ton of people with LG4's with intake, carb and full exhaust that are in the low 15's? you guys can bench race all day long, and read bs out of magazines that is hardly true, and hear things from other people who heard it from someone else whos friend ran whatever. DID YOU SEE HOW MUCH **** Chevy High Performance had to do to get their LG4 into the 13's???

BASELINE, 2.73 GEARS: 17.45 @ 78.64 mph
K&N, Flowmaster, timing: 17.21 @ 80.40 mph
Holley fuel pump, Edelbrock
Intake, air cleaner: 16.75 @ 84.25 mph
Edelbrock TES headers,
dynomax high flow cat: 16.29 @ 86.59 mph
3.73 gear and posi: 15.82 @ 86.74 mph

So why didnt CHP's car run 15's???

:D I should really go down to the dyno to see what my pos puts out with the mods I have. It goes good for what it is but of course I want more ;)

Swapping the right parts >< speed power or even a good running engine. Tuning and knowing what you’re doing has TONS to do with it.

As a side note, of the 3rd gens with 305’s that I’ve spent a lot of time working on (immediate circle of friends, long before this internet thing):
’83 LU5 (crossfire) TA (mine) A4
’83 LG4 Z28 M5
’84 LG4 Z28 (got a L69 for a little bit but blew up and we built a 350) A4
’85 LG4 Iroc A4
’87 TPI Formula M5
’90 TBI RS

all have run deep 14’s with headers and cat back (my LU5, Hedman headers, custom dual cat y, Iroc 2.75” intermediate pipe, 3” Dynomax race magnum, stock tranny, gears 3.23, converter etc, etc…)
In addition (on top of the exhaust):
’83 Z28 ran 13.4’s with the addition of an intake, cam and gears (11.0’s with a ’92 ‘vette LT1 +ATI)
’84 Z28 ran 13.7 with the addition of a cam, otherwise stock, 12.6’s with 75hp N2O
’85 Iroc (already listed above)
’87 TPI formula 13.43 with edelbroc TES, dynomax catback TB airfoil and SLP cold air

I’ve run a 13.6 with nothing but a cold air, TB airfoil and SLP cat back on my ’87 L98 formula.

Maybe it’s something in the water… These times are pretty much interchangeable at the 3 local tracks, never seen more then a .15 difference between them.

my 84' Z28 100% bone stock with the LG4 went 16 flat at 85mph. it has a peg leg rear with 3.23s. and he didnt gain 100 ftlbs from exhaust... look closer at the numbers. do you really think a LG4 came with 165 ftlbs? i thought it was more like 250? in that case he only gained like 15ftlbs.

i believe those #s, if youve ever seen exhaust from one of these cars (especially the 82 - 84s) youd know that so much can be gained from a full ehaust swap

my stock carbed 82 Z would run neck and neck with my friends 89 Z24, a turbo sunbird and a turbo probe used to eat my lunch. the other neck and neck I remember was this guy had a honda 350 motorcycle from the (70's?) we raced about 100 times it got to be obligatory on race night to check to see if one of us could beat the other.

Yes, I do believe that it only had approx 165Ft Lbs. The L69 had better flowing exhaust and a better cam and could only had 230Ft Lbs

For those interested, I plugged an LG4 into DD2000 last night and got a 145HP/and 263TQ. Hum... Does not look anything like the numbers i put out there originally. And it also shows WAY more TQ than an L69 motor. Desktop Dyno can't estimate low performance stock motors worth a crap. Add the headers and exhaust and the HP went up to about 190 and the TQ went to about 325. Just by changing the exhaust. now these numbers are way off. The numbers posted originally are much more in line with reality.

Unknown, dont sell your new 350. Jerk the heads off, machine the spring seats, port the heck out of them(like Dave Vizard did) and drop in a bigger cam. Do all this and your HP will be in the 400's.

Why they are in the 15's? Hum...
1) Cause they suck at driving?
2) Got rear suspension mods?
3) mismatched drivetrain parts?
4) no, i did not see how much stuff it took CHP to get a 305 into the 13's. I dont pay attention to car mags and racing(they pretty much suck at it). I really only look at car mags for engine build info and dyno tunes as well as interior and paint schemes.

Look at it this way, bolt a 720HP 572ci big block in your car and run the 1/4. Then come back and ask me why you ran it in 13 sec?

(traction,suspension,mismatch torque converter, mismatched rear end gears, bad tune, and last but not least driver error)

We have a member of the SS site that is currently run a best of 14.85 in the 1/4 with a K&N and a set of Edelbrock TES headers on his stock L69 monte carlo SS.

Some of you guys will never get it. I could come there and beat you with a modded LG4 305 car and you would make me tear the motor apart in front of you to beleive it. :rolleyes:

are you absolutely 100% sure? cause the 2.8/3.1 V6s had similar torque #s. im almost positive the LG4 had somewhere in the 240/250 ftlb range. 165 is just way to little for anything with 8 cylinders

Even if you ripped it appart in front of them it woudn't help, some people around here are so hard headed about how low performance a 305 is that they'd spend months discussing how you tricked them.

What it comes down to is simple, get the air in and out of the engine and you'll make power. More cubes only lets you do it at a lower RPM (which I will agree will be more streetable to a point, but that is not the issue here). If you want to do it badly enough you could make just about anything run fast...

BTW, I don't know where you guys got your torque #'s, but the gm # in '85:
LG4- 245@2000
L69- 240@3800
'83 LU5- 250@2800

i used to have a video of a supercharged 305 obviously it was built but it ran a 10.35 and a best of a 10.0 or something like that, it was a thirdgen and street legal, has anyone seen the video it is a maroon camaro?

Heres the reason why car crafts LG4 was making 197 hp.
When the LG4 was dynoed at the factory, GM was useing the "NET" rating ( the way all the auto companys have been since 1972), What this means is that GM dynoed the LG4 with all the smog equipment, the single snorkle air cleaner and paper filter, all of the accesorys (AC, smog pump, alt., and simulated PS pump), an exhaust with stock manifolds, cat, and muffler, and they rated it through the transmisson NOT at the flywheel.
Car craft dynoed their LG4 on an engine dyno A.K.A. the "GROSS" rating method (as used by the auto industry '71 and earlier)what this means is Carcraft didn't use an air cleaner and accesorys, it was dynoed with an open exhaust, and it was dynoed at the flywheel Not through the trans.

An Lg4 with an exhaust and headers would make more like 160-165hp on a good day.

When I get done building my car Im tellin everyone its a 305.

haha not a bad idea, but having that fast of a 305 is not impossible......

THANK YOU :hail:

thanks to this little debate goin on i learned everything i was wondering, and i no now that lg4s are not a lost cause.

I really dont know, all I hear from the LG4 owners are that their cars are dogs. This would be about 8/10 of them. I just dont think you can get that big of gains from a complete exhaust, we are not playing Grand Turismo here. It comes down to hearing so many people say that the LG4 is a dog, compared to a few people who say that the LG4 is a fine peice of work. And the L69 in the F-bodys were supposed to run 15's flat because the early years they were in the f-body they came with 5spd and 3.73's, so that seems to help a bit.

Man, there is enough of this anti 305 crap out there, especially on this board that I'm SOOOO tempted to build a 305 just to shut people up (I'm sure if i did people would either react with 'you didn't run that' or 'prove that it's a 305.') It's almost too bad that my 'project' car is a 70K original mile L98...

For some reason i think a lot of people here are confusing LG4's and L69's.
Honestly, I owned an LG4 and it was the biggest dog I ever drove.

I never once said 305's are crap, I am saying that low compression, crappy headed, crappy cammed LG4 305's will not run the times a lot of you are claiming. Chevy High performance barely got their project Z28 into the 15's with intake, headers, high flow cat, cat back exhaust, posi, 3.73's K&N and a fuel pump. Don't give me the tuning BS either. I agree that not all magazine writers/contributors are the brightest when it comes to cars, but we are talking about a team of guys who buildup motors and cars and write about it for a living who couldnt get an LG4 into the 14's or 13's with the exact mods you said it would take to get it there.

Is there really a point in all this arguing over a few hp?

Heres what we know...

1.the dyno numbers were from a modified L69...not a stock LG4.
2.No matter what happens to the block, the car will run 14's at best...chances are with mods it'll still be in the 15's.

Lets give some good advice, not start a p!ssing contest about a few hp.

If you want to be really fast (for a little $$)you need more cubes.

-Doug

um how can u say 15s best when baddest 305 is runnin 11.6's, hes got 475hp. and he has a lg4. how can people keep sayin it cant be dont when this guys did it!! i plan on gettin atleast 300hp out of my lg4 just give me till july this year and if it dont turn out i will drop the 350. but i am never go to no unless i try. and this debate it driven me crazy, get hopes up then go right back down then up. i'm gunna find out 4 my self.

ill post this again so you guys can go over it... my 100% BONE STOCK LG4 went 16.0x 3 times in a row when i took it to the track. its an auto, with a peg-leg rear containing 3.23 gears. the only thing i did to it was manually shift the auto trans at 4500rpms (the factory shifts at 4000), and removed the air cleaner assembly. any LG4 in good tune can go low 16s stock. anyone who is stuck in the 17s with one either cant drive worth a damn, or cant get a car to run properly. my car is living proof

now, is this engine good for building for hp? id say not. my Vette is a much better starting point for that. i just wanted to see what my daily driver could do in the quarter

15's with only intake and exhaust, fricking READ before you post.

Nobody said 305's couldnt make horsepower.

i did read it and this is who i was talkin 2, not 2 YOU!!! i dont no how 2 do tha quote thing so i just copyed it<its B low>. unless i missunderstand what he is sayin but i think he said no matter what, its gunna be 14s. $hit u take this post thing a bit far dont u think?

2.No matter what happens to the block, the car will run 14's at best...chances are with mods it'll still be in the 15's.

LG4, so misunderstood
 

you know, i bet alot of people said those darn turbo regals were slow too in 1982. Change some parts over the next few years and *POOF*, the fastest production car built by GM in 1987.

icebird_1981:

You are on the right track with your mods. Some people have no faith. You can make approx 87% of the power of a 350 with a 305.

Take a 1985 LG4(9.5 to 1 CR)
Port and bowl blend the heads(polish the exhaust)
Add 1.94 intake valves
Add the Xtreme Energy 262H cam
Add Edelbrock Dual plane intake
Add 1 5/8 headers, highflow cat, and large Catback system

All the parts would cross over to a 350 block, even the heads.

Do this to an LG4 and you won't recognize the motor.

Re: LG4, so misunderstood
 

is that an LG4 with an intake manifold, headers and full exhaust???? no. You are stating exactly what i was trying to say long ago, it takes more than just an intake and an exhaust to make an LG4 or any low compression smog motor to go fast.

Re: Re: LG4, so misunderstood
 

Since when is 9.5 to 1 a low compression motor?

As for the list above, of course it is more than exhaust and intake. I wrote it as a list of things that could be done to push the motor to about 300HP.

Too bad you can't take a ride in my N/A low compression(7.8 to 1) smogger 350 car. Its a street lethal LT1 killer. I am going to bump the compression and drop on a set of vortec heads this summer and watch out LS1 cars. BTW, the 350 has a ported stock manifold, full exhaust and a cam. Still runs stock 76cc chamber heads.

Dont tell me that a smogger motor can't be fast.

I said, as you quoted me saying, it takes more than intake and exhaust to make a low compression smogger motor fast. 9.5:1 is not low compression, however the majority of LG4's are.

Personally, I think there is a big difference between the younger years of the LG4 and the later years. I had an '85 TA with the LG4 and I now own my '87 Formula, with the LG4. I'll tell you what, there is not even a comparison. I ran them side by side (both were completely stock), and my TA couldnt even put up a fight. Granted, there was some weight differences, but the TA also had lower gears and a shift kit (forgot to mention that). Still, the point is, I think there are many varying-HP'd LG4's out there. And I'm not talking about the L69, I know what the difference is thanks.

Also, it seems to be a lot of people's opinion that anything performance related is always going to be TPI and/or 350. I can't believe it. I'm not saying I know everything myself, or even a lot, but I think that a lot of people on here just go around looking for LG4 owners to knock on their cars. Not speaking for all, but I know a lot of them do.

I see it all too often, someone will mention "LG4" and immediately, there will be a response similar to "....drop that POS and get a 350..." or something along the lines. Most of the time, the only good, positive and helpful responses come from the most knowledgable and understanding people on this site. People who actually give good positive information, not people that go around looking to start piss matches with others of lower-performance cars.

Another thing. It is unfair to compare the LG4 to the LB9 stock for stock because of all the crap that the LG4 came with stock (air box, exhaust manifolds, exhaust, cam, CR, etc..). How can it even be compared? Put all the crap that the LG4 came with on a TPI 305 and see what kind of numbers it will produce. I guarantee it wouldnt be pretty.

Regardless, I beleive that the LG4 (as well as any other 305) has lots of untapped potential. Thats what I'm doing to mine right now, and I'm happy with it, and if anyone else on this board wants to do it and is happy with what they are doing, then excellent. I respect anyone that can take a 305 and make it fast more than someone that just 'drops in a 350', which seems to be the easiest and most common way out for some reason. I'm not arguing that a 350 has more advantages, I'm just saying, for some people that is not always the best route. Some people like more of a challenge, some like to be able to say 'ya, its a 305' after they just toast someone, others just take joy and pride in working on what they have, and making the best of it.

Not everyone has money to just blow. Ya, I'll admit, in the long run, it is probably comparatively cheap to just mildly build up a 350, but not everyone has time/space/money to just up and do it. So we work on it when we do have the time/money/whatever. Little by little, at least thats the way it goes for me, and I enjoy what I do. I do my own work on almost everything too, so that makes things a lot cheaper also.

I dont care what anyone says, a 305 (not leaving out the LG4) can be fast with a little work. And it don't take a rocket scientist. I do believe that maybe some of the stuff people post on here about HP gains with the LG4 may be a little overly-optimistic, but they arent the only ones I see doing it.

So what it may take a little bit more money in making it fast, so be it. I am definitely not regretful of putting the money that I have in my 305, cause personally, I'd rather not have a 350, but thats just me. Just to get it out in the clear, I am not afraid to take my car up against any of my friend's cars (Camaros, 'Birds, stock 'Stangs). I'm not saying I win every race, but I usually give them a good run for their money, and I dont even have anything major aside from my headers and exhaust and K&N.

Not that this is going to change anything, and like it hasnt been said a million times before, if you dont have anything productive to say, dont say it. You can post your opinions, but you dont' have to knock someone every time LG4 is mentioned, damn. Sometimes while reading through this stuff, it makes me about sick how much people argue and piss and moan on this site about stupid issues such as this.

Now all he originally asked was how his setup looked, maybe some advice. If you dont have anything productive to say, take it elsewhere. And I know someone will come back and say "oh well this is a public forum, opinions are allowed in here, its America, I can say whatever you want" well I suppose you can, whatever. I'm just saying, all he wants is help and info on his setup, not a war.

Sorry for venting, it just seems like everyday, this is all I ever get done reading. Argument after argument. What gets accomplished from arguing? Nothing, people are still gonna have their opinions, so why argue? Just help with what needs helped, if not, leave alone you know? It's simple.

87formula4bbl,

Dont be sorry, you did give some good advice and make some great points.

Check my sig...Ive been through building a 305, and if I could go back in time, I would have swapped out the motor right off the bat. That is why I advised icebird to do so.

The fact is that there are only a few sets of decent flowing heads (essential for making hp) that can be used on a 305. They are not exactly cheap either.

A set of iron heads (mildly ported would be nice) with 2.02/1.60 valves, a small street cam, headers, and an aftermarket intake and carb would do wonders on a 350 block. That combo should be good for at least 13's (depending on cam size and heads) in a thirdgen.

And whoever said baddest305 is using a LG4 is on crack. Its a 305...thats pretty much the only thing in common with that setup and a LG4.

And a LG4 (as far as I know) doesnt have 9.5 : 1 compression. The LB9 does, but uses flat top pistons unlike the dished found in LG4's (or at least the ones I've opened up).

-Doug