86TransAMsbc305

How much horse power comes on a stock 86 TA with a LG4 305 carbureted???

Sitting Bull

About 160 hp.

TransamGTA350

iTrader: (2)

I've seen ratings for 160hp and 165hp for the Trans-am. Subtract 10hp for the base Firebird due to the base timing at 0 BTDC instead of 6 BTDC. Whether it's 160 or 165, it's really not much to write home about, but it does have significant potential with upgraded exhaust and cam, and retuning of the Q-jet.

Sitting Bull

Yup, if you follow the mods in my sig (which is also a 1986 LG4) you'll have a good 300 hp, which is mid-14s in the quarter

TransamGTA350

iTrader: (2)

250hp will get you mid 14's. With 300hp, you should be inthe high 13's.

86TransAMsbc305

about how much horse power do I have??

I took out the egr and the computer, put in a 50,000 volt coil, put a 3" flowmaster catback on, and put a 1" spacer under my carb...other than that, it is stock.

All of this is on my 86 lg4 305

Mark A Shields

I'll estimate 15-20hp at the most.

Marshall89ws6

he means 300 at the flywheel im sure.... you are right 300 hp would be around high 13s.... but 300 at the flywheel is something like 270 at the wheels... and you have to factor in that it doesnt have as much tq as a 350 would with those mods... also driving style is a factor.

Mark A Shields

I would think 300 engine HP would be more like 240RWHP. Granted we're both just guessing, just sayin.

curt86iroc

base timing for all LG4's is 0* BTDC.......

EvilCartman

iTrader: (1)

Nope, mine was 6*

ME Leigh

QUOTE]he means 300 at the flywheel im sure.... you are right 300 hp would be around high 13s.... but 300 at the flywheel is something like 270 at the wheel[/QUOTE]

300 at the flywheel should be about 240-210 rear-wheel.

Sitting Bull

300 at the flywheel should be about 240-210 rear-wheel. [/QUOTE]

I agree with ME Leigh.

300 - 30 (alternator, water pump, etc.) = 270

270 - 20% (auto tranny loss) = 216 hp or so.

Roughly 220 hp gets a 3600 lb Camaro through the quarter in the 14.5x range.

todd200

If he still has the CC Quadrajet and CC distributer and he removed the computer wouldn't he lose power due to no timing advance?

Mark A Shields

I agree with ME Leigh.

[/B][/QUOTE]

did anyone not see my reply before ME Leigh's?

Sitting Bull

did anyone not see my reply before ME Leigh's? [/B][/QUOTE]

He was closer than you Mark, but we'll let you squeek in, too

Momar

With the 350 ho conversion kit which made 308 hp they ran high 13's. I would think if you had 300 hp you would at least run low 14's. https://www.spoperformanceparts.com/...119&CATID=1099

Ben

Mark A Shields

He was closer than you Mark, but we'll let you squeek in, too [/B][/QUOTE]


Oh please , I could have put 240- 110 hp too

Sitting Bull

Ben,

Here's the general formula and it is correct.

300 - 30 (alternator, water pump, etc.) = 270

270 - 20% (auto tranny loss) = 216 rwhp or so.

Roughly 220 rwhp gets a 3600 lb Camaro through the quarter in the 14.5x range.

The ZZ4 that they are referring to has 350 hp at the flywheel, with all accessories accounted for. The 308 hp figure they cite is without question at the rear wheels. Probably a standard tranny, too, which robs less power.

Ed Maher

A true 300hp at the flywheel engine should have no problem running high-mid 13s, even if it's not a 350. I mean, Cmon sir, my basically stock 305 has run 14.10, and i can assure you it would be lucky to make 250 at the flywheel. Granted thats with a nice converter, but it still went 14.38 with a stock converter on it.

But if your 300hp number came from desktop dyno then i guess mid 14s or worse would probably be a good guess.

Sitting Bull

Ed,

You have done a lot of traction mods, IIRC. Mine is stock, for now

Momar

Ok, then how come Stock 350 tpi's that made 240 fwhp run low 14's when in good tune?

240 - 30 (alternator, water pump, etc.) = 210

210 - 20% (auto tranny loss) = 168 rwhp or so

So acording to your formula 168 rwhp will get a car into mid-low 14's.

Also, I think that car that I posted a link to made 308 at the flywheel and ran 13.83. I think something is a little off here huh.

Ben

Sitting Bull

Well, I'd say it has to do with the additional torque a 350 makes over a 305.

Also, a 350 L98 has 240 SAE hp--that is at the flywheel with ALL accessories accounted for.

Mark A Shields

Yup, HP isn't everything.

Momar

Have you actually dynoed your motor or is this a destop dyno number? I am just curious where you are getting 350 hp from.

Ben

Sitting Bull

And no, the engine you posted a link to was a ZZ4 and they make 350 SAE hp. That is how GM rates their engines. For us, we would put the engine on a dyno with no accessories, and then deduct about 30 hp to account for it, which will give you your SAE hp rating.

Momar

Ok, so

240 - 20% = 192

Even with the extra torque you are saying that you are putting out 60 more hp and still only about at the same level if not slower than the stock tpi. What trap speeds do you run?

Ben

Momar

Performance: During development of the HO 350 Camaro conversion, a prototype HO 350 engine equipped with a computer-controlled Quadrajet carburetor and all emission controls required for this application, produced 308 horsepower (at 5000 rpm) and 365 lb-ft torque (at 3500 rpm). The Chevrolet Raceshop's 1987 Camaro test vehicle equipped with an emission-legal HO 350 ran a quarter-mile elapse time of 13.83 seconds at 98 mph.

novadude

Ed is right. Hell, I can direct you to threads on the corral where stock suspension, 3200 lb, ~230 hp 5.0 Mustang is running LOW-13's. Granted MPH is low (~102), but the ET is there.

It's all about the combination, and driving. You can do amazing thing with low dyno figure if you have this stuff nailed.

Oh, and for all the non-believers, I am pretty sure Ed's car has a STOCK suspension to hit those 13's.

Sitting Bull

I think Ed will tell you he has done significant rear suspension mods.

I'm only going by average traction using Performance Trends Drag Analyser to estimate my quarter mile times.

Sitting Bull

Well, even a 350 HO is rated at 330 hp by GM, so the 308 number is something different.

Ed Maher

Sitting bull my rear suspension is completely stock right down to dry rubber bushings, and all of my best times were run on real street tires (dunlop SP5000s) not any kind of drag radials or anything.

BTW, the ZZ4 from what i have always understood is rated at 355 net hp, which means including driving it's WP, an alternator supplying the ignition and using one distributor setting (not tweaking at every sample point for best results as gross would). But it no doubt doesn't account for a PS pump, air pump as well as probaly used full length headers and no cats. I think you'll find the 47 missng hp in the GM test mules rating in the fact that it is running a computer controlled dizzy with a probably less than optimal spark curve tuned for emmisions as well as shorties and cats and the other mentioned accessories. Looking past the GM results, there are plenty of examples of people with ZZ4s both carbed and TPI running well into the low 13s at 104+ as delivered and still in what 90% of us would consider emmisions legal basically stock trim. If i had a ZZ4 and it ran 98 mph i would shoot myself in the head, or at least figure out what the hell was wrong with it. The slowest i ever saw one run was 13.8@100 and it only had a couple hundred miles on it if that so it was barely broken in. Last i knew, with no changes it was running 13.3 @ 104. OK thats not true, this summer i raced a guy with a ZZ4 and he only went like 14.4 @ 96...but he had 2 plug wires burnt completely through on that run so i'll give it the benefit of the doubt.

Whats funny as hell is this has nothing to do with the original question anyway. As to LG4 power ratings, depends on the year, and also the whims of GM that day. The earliest LG4s came with iron intakes and were true dogs. By some time in 83, all LG4s (except canadian, in fact everything i say has no bearing on canadian cars since they had different carbs and dizzys) were getting AL intakes and are marginally better. In 85 the compression was brought up and they can be almost half decent. Here's a caveat though. Throughout the years, some LG4s got a low output carb which was also shared with the boat anchor 307 olds, which has a very limited air valve opening. These are the cars that ran 17s. However, some cars got the good carb form teh L69 with almost full AV opening. I've never actually seen an LG4 with the junk carb, and i've also never seen a 17 second LG4. Damon from the carb board however has told me in the past that he has seen such slow LG4s, and he also thought that all LG4s got the severely limited AV opening carb (the discussion was releveant because apparently the limited AV carbs cannot be modified to fully open without binding the AV shaft, whereas the good carbs have no such problem in my experience.)

five7kid

iTrader: (14)

Different animals. The 330 HP 350HO is the Vortec-headed, low-bucks performance crate engine.

The "HO 350" they talk about in the conversion kit is the ZZ4 350 with aluminum heads, roller cam, PM rods, forged crank, etc. It makes 355 HP with a 650 Holley, vacuum/mechanical HEI distributor, and basically no emissions controls. Not sure if that is with headers or cast iron exhaust manifolds, though.

Sure makes you wish they hadn't used the "HO" with two different engines, but they did.

Sitting Bull

Ed,

I stand corrected. I thought you had done a lot of suspension work. Must be someone else with a 305 dipping into the 13s.

Momar

Well, what does that matter anyway as long as the power is around 300. Also it is a zz4 but it has "performance manifolds" instead of headers and the stock ignigion and carb setup(with different secondary metering rods and hanger) off of a lg4/l69.

Ben