ZR-1 Net Registry Forums - LS1 vs.LT4 vs.LT5 vs.LS6 vs.LS7 etc. discussion continued

A compare/contrast thread to avoid the off topic (yet fascinating) chatter of a different thread.

We Gone
I also had a 96 LT4 and many times my son and I played around with them. At the time my 91 only had headers, flowmasters and chip. The LT4 had a custom tune and muffler eliminators. I will say this the LT4 did a great job up to 100mph after that the ZR-1 started to wind up and 100 to 150 I was a good quarter mile plus ahead I had to slow down for him to catch up.

Edram
c5's are not slow. ever drive a fixed roof coupe 6 speed? very quick and light. these cars can be easily modified to make big horsepower. my c5 automatic made 525 to the wheels. no meth injection or nothing just blower and cam. stock automatics are a bit slow but great driving and cruising cars. c4 zr1 feels more like a race car and the lt5 howls. Corvettes for the most part are fast compared to other cars in general. My two favorite power plants after the l88 is the lt5 and the ls7 427. The ls7 427 505 hp 470 ftlbs torq and idles like grandma's 1968 chevy nova going to the market. No gas guzzler tax either and revs to 7k. A marvelous engine.

8cam
Good luck the Z is an incredible car. I've been into euros my whole driving life, and it's the first American car I've owned in more than 20 years. I love driving it hard. Other Corvette guys who have ridden with me are flat amazed at the difference, just a completely different animal from a pushrod car. Guy with a C6 at the last autocross rode with me for a run, and he talked about how different it sounded and how hard it pulled all the way to 7500, couldn't believe it. It's my kind of engine.

Paul Workman
Couldn't say it better! Nothing convinces the pushrod crowd like pairing up with a 4-CAM DOHC and having their socks blown off! :dancing The Zs always attract a crowd at the local annual 1/4 mile Corvette Shootouts after taking a thrashing from those obsolete motors...:mrgreen:

Kevin
experience tells me different. Been showing stock and lightly modded ones my tail lights since 99. Sure they can make big power modded and for a lot less but stock or near stock forget it

Hog
I have the impression that the LT4 and C5 LS1 cars are on par, and the LT5 cars smoking both. All stock of course.

5ABI VT
From my experience the LS1 6 speed traps slighty higher than the LT4. Given that the C5 is lighter it sure lends some credibility to the LT4 being slightly underrated. Ive seen 2 LT4s trap 106-107. My friends LT4 I went to the track with with nothing but a B&B (newer restrictive system) just last year trapped 106 mph. Back when I had bolt ons on my 93 LT1 I was trapping around 111 and Stock 6 speed LS1s were slightly slower at 108-109. The only car I went up against was in 1999, and it was a stock 97 6 speed with a Borla stinger cat back and he was 109.

I guess just for comparisons sake I had Long tubes and Corsa with a haibeck chip and I was just under 118 mph. My friends LT4 car only has a chance when im not paying attention :-D

Csavaglio
My CE LT4, which was stock, trapped between 108 and 109 consistently and, as I mentioned, usually ran 12.7. All uncorrected and actual numbers.

I never dyno'ed that car, although, from the dyno sheets I've seen of other LT4s, they seem to vary quite a bit, but usually higher than the rated hp numbers would suggest.

Personally, I think the LT4 is one of the most under rated (both by people's opinions and the hp numbers) corvette motors.

I agree 100% with WeGone. Up to 100, stock to stock, the LT4 keeps right up with the LT5. But 0-100 is the LT4's game and not the LT5's. Two very different powerplants with two very different personalities.

5ABI VT
Theres a lot of variables when it comes to track times. I only compare what ive seen at my local track and what ive run side by side. My brothers ss for the life of him couldn't crack 14.0 on street tires totally bone stock. Went to Englishtown and ran 13.4. no changes at all. Different track.. differet altitude and all the other variables etc etc.

Im not knocking the LT4 but Theres been a ton of bs about hp numbers over the years. There was one thread about how some were 370 hp even 390hp for a few %. SOrry but that is :censored: . If a 390 hp Lt4 existed.. weighing in 200 lbs less than a zr1 we would see trap speeds over 116-117 mph rivaling c5 z06s. Just not happening. Ive never seen an LT4 factory fresh run over 110 mph without some mods like headers or gears intakes etc. My 93 trapped 104 mph stock. I knew a guy who hung out with us that we went to the track with in a 96 LT4 like I mentioned earlier and he trapped 107 mph. 104-107 mph is about 30-40 hp. Right on par with GMs ratings.

I can definitely see why the LT5 may feel slower at lower speeds. It has longer runners tuned for certain rpms. at part throttle and certain rpms it only runs on half the runners. It can make for a soggy feeling engine at low speeds. GM also didn't add any gear to it. For a motor making higher torque and hp it sure could have used it. On top of that it weighs 200 lbs more. all those contribute to the slower low end feel.

Kevin
I think I did 116-118mph back in 00 at the gathering in my stock 90

From this thread
http://zr1.net/forum/showthread.php?t=24070&page=4