we just took my gf/s bird to the track friday night and I drove my stang and she ran the bird.

The cars previous best time was 16.9 at I believe somewhere between 81-83. That was with me driving. She took the car once since then and couldnt do better than 17.2.

The time that she ran I had the swaybar off/ drag springs in. drop base open air filter and 1/2 tune up.

Then I added hedman shorties and their chesey Y-pipe, with 3 in from their (where the cat goes) and the 3in Hooker catback ($200 jeggs for 82-85 cars). We also changed plug wires, cap and rotor.

She then drove the car to a 16.5 first run then I told her to put the shifter in 2 and leave it there which she did and went 16.195 @ 85.89 on the 2nd and last run.

I tried to adjust the timing at the track but couldnt get the hold-down loose. The exhaust also leaks pretty bad at the Y-pipe flange I believe. Once I fix this and play with the timing (and maybee drive it myself) It could go 15.9 with no other mods.


Next up: subframes(which ones?) 3.42 and zexel posi. Maybee some LCA relo brackets and maybee some new wheels and tires.

The 2.73 open dif and 6in wide bald street tire isnt cutting it with the amazing 2.4 60's.

Just thought Id share.

good gains. was there a cat on it before you did the exhaust swap? almost sound slike the cat was beat and partially clogged if you go that big a gain from the exhaust.
the posi and gears will help a ton. while you are welding on the relo brackets get yourself a 2 inch wide piece of strap steel adn weld it into the bottom of the control arm to box it in. it really helps a lot and only take sa few mins.

later
tim

Exhaust helps out a lot no doubt. My friend greg got similar gains with his dynomax headers/y-pipe/cat/catback. I did the cat, cat-back and headers at different times so I dont know how much a full 3" from the y-pipe back alone helped.

Breakin that hold down bolt was a bitch the first time I did it, too. We had to rig up a wrench because there was no room back there, but once you get it the first time its easy.

My holddown bolt is stuck again. I lost the bolt so I had to get a new one. It was to long so I put washers under it...now its really stuck. By the way what size is that bolt 14mm? And I need to like bend a wrench so i can get the closed end on it.

Yea, its 14 mm. What I aucutally ended up doing was getting a wratchet socket that was a 14 mm wrench head, then we put a long extension on it and use a wratchet to break it loose. Worked pretty cool.

I've used a 14mm crowsfoot wrench connected to a 3/8" ratchet, extension, and u-joint to get that bolt loose.

This may be best for the transmission threads but since you brought it up I would just like to ask. Ok your saying that your girlfriends car was able to go at least 85.89 on second gear, if so why is it that my camaro can only go around 50-60 on second gear? would you say that there is something wrong with my engine or transmission?

You shift according to the power band of your engine and the effectiveness of the ratio of your gears to use that powerband. Once you leave that powerband, you shift to the next gear to put you back in the powerband of your engine.

Example: I shift manually from 1st to 2nd and 2nd to third at roughly 5300-5500 rpm and finish the 1/4 mile at almost 4000 rpm in third gear. I finish at 89 mph avg and in around 15.8 avg times.

I have 3.23 gears in my car which for a stock engine is great because at peak roughly 4000 rpm, that's 92 mph in 3rd gear. Still well within power range of a stock engine.

On 2.73 gears which were normal gears for the lo3, you'll never see that peak because the load is so high on the engine with that ratio...

Heck in second you are well within the power band with 2.73 gears at the end of the 1/4 mile that I wouldn't be surprised to see a lo3/2.73 combo do 1st and 2nd only and get better times.

To make best use of power you want to be running in a 1:1 ratio by 1/4 mile's end since the driveshaft and engine would theoretically be at 1:1 ratio (slip occurs on automatics so there is a small loss compared to a manual clutch).

An engine with 2.73 gears and pulling into the high 80's low 90's is making a respectable amount of power at the engine. I'm running a basic stock engine, but making better use of the power from that engine. For those that have modded the engine, cam, heads, TBI, intake etc and think they haven't done a thing, remember it takes a good amount of torque to motivate a 2.73 ratio so you are making good power. Just gotta work on using the increase more efficiently.

I could easily hit 85-90 in second. Maybe your camaro has a higher rear end gear?

Hey Slade1

I have every thing stock in my LO3 Camaro with a 3.08 differential and I never see my tach go beyond 3500 RPM's on any gear every time I shift. I try as much as possible to make my engine red line but it never does. I still don't understand what's the problem. Thanks for your help.

on the stock engine it probably does rev a little bit out of the powerband but If it goes into 3rd then it is way too low in the revs to make power across the line. once new gears go in It will go across in 3rd of course. (and be faster, et wise at least)

If I let the car shift on its own, it shifts at 4500 rpm everytime.. that took some adjusting of the tv cable more than anything to get that working ok.

I manually shift it when I hit 5300 rpm though at the track.

Yeah I'm pretty sure the LO3 stock gears are good for 80-90 mph in second gear.

90 mph with a 2.73 gear with 27.8 mph per 1000 rpm for a 2.73 gear and 25.5 inch tall tires, and a 1.63 ratio in 2nd, that's 5200 rpm which a stock lo3 should be able to make with no problem.. heck my lo3 can pull to 6000 rpm in 2nd.. just doesn't mean I make any real power after 5300 though since it surges like mad after that rpm.

Yep I've changed my gears to 3.23 gears, I busted my 2.73's after 30 runs on the track...

I pulled 17 runs at my last track day lol... shows you how much I like to do 1/4 mile runs...

I expect another 10 runs at the least this coming saturday.

It'll be the last time my car runs with a stock engine, mods for the coming year are rockers, cam, heads, intake, tbi, lca, springs, panhard rod, sfc, torque arm, shocks, strut tower brace etc...

I'm going all out once this job works out the way I want... I got two offers each with respectable salaries... 6 figures etc.. debated the 4th gen thought, but will build up the 13 sec or better TBI for the least amount of cash first and document it completely to leave no doubt that it is easilly done if planned right.

im hoping to add some picks. lets see if it works.

I guess its working straight from my cpu.

Let me know if it works and you want to see more.

vroom305: sounds like you are heavilly restricted by intake and exhaust... as suggested before perhaps a clogged cat if it bogs at 3500... another issue is intake, your air filter could be really dirty... the stock lo3 engine should rev to at least 5000 (in 1st and 2nd) without much thought. With the little mods, half ultimate mods (injector spacer, air cleaner ring, thermac) and a dynomax cat and flowmaster, I was able to push the rpm range up around 5400 rpm, after that it's pretty restricted by the headers, it backfires somewhat...

under 3rd gear load, it backfires as early as 4400 rpm... definitly backpressure from the headers and cat... increasing fuel pressure just makes it run rich, I tried various settings up to max fuel pressure 15 psi and no change from 11 to 15 psi...

I tested this on a dyno too if you're wondering. I'm sure with headers I could free up the rpm range, not much torque difference mind you but if I get access into 5000 rpm range I should be at 170 rwhp... right now I'm at 156 rwhp, and its now made at 4200 rpm vs the stock 4000 rpm.

Dan those headers should help quite a bit. I wish I could get some headers.. no more $$$ at the moment..

First of all I really appreciate your help on this topic because I have tried to trouble shoot this problem (TBI, transmission, exhaust, engine, ect) from every angle that I can possibly think of.
Second was another *theory* of what may be restricting my engine so much because I just got an open element 14x3 K&N air filter and a Random Technology Cat but stock exhaust and intake maifolds...now here's the *theory* could it be that my O2 sensor is not working properly?

Thanks again

PS sorry for changing the topic of the original thread...