91 Z28 vs 92 Z28 Who Wins?
 

A little background, for those who don't know my best friend of 50+ years has a 92 Black Z28. G92, 5 speed. I have a 91 no package auto vert. Both 305's of course and both have 3:42 rear ends. Both have the cats removed. Both TPI's. His has about 150K, I have 85K. So who wins? does his performance package offset the weight difference? Does the faster shifting auto make up some difference? Maybe some aero advantage at the top for the hard top? Less miles worth anything? What do you all think?

Re: 91 Z28 vs 92 Z28 Who Wins?
 

A heavy convertible with an auto vs a 5spd hard top with G92? It'll be a slaughter.

Most of the convertibles got the lower output 305 TPI, with restrictive exhaust and salt flat gearing. All the convertible reinforcements and the mechanical roof add weight over a similar hardtop. Give the hard top G92 and it's not even worth accepting that race for the fun of it.

Re: 91 Z28 vs 92 Z28 Who Wins?
 

I do have a 3:42 gear and the low performance 305. I always thought the convertible weighed less but I can see where all the extra parts and such could make up added weight. I also have some free mods done and we all know the power increase that comes with those!

Keep the answers coming, I will reveal the winner after a few more guesses.

Re: 91 Z28 vs 92 Z28 Who Wins?
 

In 91 the only thing that is different about the 305engine in the auto car vs the 5spd cars is the exhaust. With your mods I imagine you have closed the gap quite a bit. Still I predict you turn 14.7s in the 1/4 , 9.4s in 1/8. I say the 5spd car turns 14.5s in 1/4 and 9.2s in the 1/8.

Re: 91 Z28 vs 92 Z28 Who Wins?
 

We raced before I did the mods. The only free mod difference is my AIR pump has been fully removed. You are right, I have the crappy exhaust, and we both have the dronemaster muffler.

Re: 91 Z28 vs 92 Z28 Who Wins?
 

So tell us how the race went down the suspense is killing me Vinny..

Re: 91 Z28 vs 92 Z28 Who Wins?
 

Wait! Don't! This is fun.

G92 cam is waaaay better than peanut cam.

Cats out almost even the exhausts out IMHO.

Assuming both limited slips are working, and assuming your friend drive's a manual like a 50-year old.

Removing air pump doesn't do squat IMHO.

Depends on how your friend drives. G92 T-5 should have you pretty handily. But a difference of half a sec in the quarter is a slow shift.

Lastly, at the age of these cars, 150K miles is a lot more than 82K. The lower mileage one will be fresher.

I'll bet you got him Vinny!

Re: 91 Z28 vs 92 Z28 Who Wins?
 

I want to...it is killing me also not telling :lock:

Re: 91 Z28 vs 92 Z28 Who Wins?
 

Didn't the 91 and 92 get the same cam? I don't believe there is a difference. My buddy drives the piss out of his car so if anything the miles will hurt him more than we may think, here sure does not drive like a 50 yr old.

I really thought more would have chimed in by now as this was a real race and pretty much apples to apples or as close as you are going to get. It was close either way!

Re: 91 Z28 vs 92 Z28 Who Wins?
 

Same cam in 91-92 305-350 TPI

Re: 91 Z28 vs 92 Z28 Who Wins?
 

Oh, well then. You definitely got him. Unless he's an expert driver.

Re: 91 Z28 vs 92 Z28 Who Wins?
 

Ding Ding Ding! We have a winner and it is Tootie and me! Yes I did get him by about 3/4 of a car. His bumper was @ my rear wheel when we let off as a car was entering the 4 lane hwy we were on.

He got me by about 1/2 a car on the start but I quickly closed the gap. He shifted 3 times during the race so maybe a 1/8 mile or so was the distance. Every time he shifted I gained a little, but I would pull him slightly anyway so even if we had the full 1/4 mile he would not have gotten me.In fact I would have opened the gap more if we had more road. The gear is the equalizer IMHO. If that "salt flat record setting" gear that came in the car was still in there I would have been toast and probably got beat by 3 car lengths or better. It was also a good gauge of the old adage ringing true that nothing shifts faster than an automatic It was cool to see the fall off as he shifted and he was slamming those gears.Stick for the track, auto for the strip IMHO.

It was a fun race with 2 old friends that was totally impromptu with 2 almost identical cars. Fun times for sure, brought that kid out in both of all over again. :D :burnout:

Re: 91 Z28 vs 92 Z28 Who Wins?
 

Very cool. I would have figured the weight difference would have put him ahead. After your intake work id love to see a track time or dyno.Good deal Vinny.

Re: 91 Z28 vs 92 Z28 Who Wins?
 

I really think the difference in miles on the car is what made up the weight difference. IMHO

After I get this exhaust complete, and the hooker cat back system arrived yesterday, I think there is a test and tune date in my future at PBIR. I will post up the times Dustin. Maybe I can drag Scott (my buddy) out with me!.

Re: 91 Z28 vs 92 Z28 Who Wins?
 

This was fun.. We should do more of these threads! Unless one is an expert driver, an auto trans is just too easy and makes up for a lot. It just isn't nearly as fun IMHO.

Re: 91 Z28 vs 92 Z28 Who Wins?
 

I know Tootie, I smiled every time I got a reply. :waveman:

Re: 91 Z28 vs 92 Z28 Who Wins?
 

Vinny did you put the better manifolds and y-pipe on that car I thought I remember you talking about it? I have a set but also some hooker headers and haven't totally decided which to use when I do my swap.

Re: 91 Z28 vs 92 Z28 Who Wins?
 

I have not yet. I have them and the Magnaflow y-pipe and now the 3" cat back Hooker system, all I need is a 3" "test tube" for where the cat would be. I just found a shop yesterday that will make the pipe. I still have the crappy 2" mannies and the terrible y-pipe coupled with the massive 2.25" intermediate pipe!

I would go with the HO manifolds for your build. Just my opinion. Your car has such a stock look that the headers might look out of place. Plus I really think the maybe 10 hp you may be given up just won't matter in the end, The 350 alone will be a big upgrade in your performance. Are you putting the AIR pump back on?

Re: 91 Z28 vs 92 Z28 Who Wins?
 

something is definitely wrong with your friends car or he cant drive .. his car is lighter , the 5 speed will always be faster , and he has 25 more horsepower than you cause of the cam .. did you put the 3.42 gears in your car ?

Re: 91 Z28 vs 92 Z28 Who Wins?
 

No, I bought the car and it had it in already. My son and I counted the driveshaft revolutions. I knew when I bought it was not stock as the speedo is off and it turns 3k @ 75 MPH. The cam is the same, he has more horse power cause of the N10 exhaust. I used to ride and drive his car all the time in the 90"s and I always thought it fast for a 305.He rode in mine when I first got it and smiled when I gassed it. I really think the miles has caught up to him, he drives that thing hard.

How much weight difference am I giving up?

Re: 91 Z28 vs 92 Z28 Who Wins?
 

from what ive seen over the years probably 100 pound difference .. what do you think you have the same cam ? the 305 autos came with the peanut cam and the g92 5 speed 91-92 camaros got the 350 cam

Re: 91 Z28 vs 92 Z28 Who Wins?
 

the only reason i said that about the cam cause its in the tech section on this site

Re: 91 Z28 vs 92 Z28 Who Wins?
 

From the research I have done and others on here I don't think there is a cam difference in 91 and 92. I could be wrong as I am definitely not an expert. I do know that you are correct in the 25 HP difference. Do you feel that twice the mileage could be a factor? 25HP does not seem to be an unreasonable falloff over the years and the miles?

Re: 91 Z28 vs 92 Z28 Who Wins?
 

ya his motor could be whooped , who knows .. most of the people ive talked to and tech data that ive seen shows that there are different cams , again who knows .. if you go to the top of this page in the tech section it shows 2 different cams ..

Re: 91 Z28 vs 92 Z28 Who Wins?
 

one thing that is for sure is ive owned over 20 third gens and have driven a ton more and they all seem to run different .. and back in the late 80's when they were pretty much all stock there were some that were screamers and some that were dogs with the exact same combo and year .. and i lived at the track when there were alot of third gens there and there times were all over the place ..

Re: 91 Z28 vs 92 Z28 Who Wins?
 

This guy knows and it looks pretty definitive that I do have the peanut cam. Looks like there was 2 cans used and I looked @ my Tach and it is a 4500 yellow and 5K red, just like listed. I will look at Scott's tach the next time I am over there and see if his is a 5500 red line. Wow look at the lift specs, not even in the .4's. No wonder these 305's get a bad rap. Looks like a Cam swap needs to be added to my mod list!

http://gmtips.com/3rd-degree/dox/tips/cams/cams.htm

I do think his motor, drivetrain is tired, I rode with him the other day and it did not seem like the same car I remember 15 yrs back. Didn't sound the same and rode rough. I told him I want to swap cars for a weekend so maybe I can get a feel for what is off on his ride.

Re: 91 Z28 vs 92 Z28 Who Wins?
 

i also knew but didnt feel like arguing about it .. and as far as your friends car they did put the peanut cam in the 91-92 non g92 5 speed cars .. check his tach

Re: 91 Z28 vs 92 Z28 Who Wins?
 

Nice work Vinny!

I thought I read that the convertibles weighed about the same because the hatch is pretty heavy...

Sometimes 25hp doesn’t make up for an auto beating a stick...

My Vert chirps second gear at WOT and shifts pretty hard... I wonder if it had the Corvette servo installed...

I have raced people in a stick and lost ground on every shift... it’s a crappy feeling... But driving a stick in general and controlling the torque ripping around town is super fun..