425hp Lt1/Lt4
Thread Starter
Instructor
Joined: Oct 2003
Posts: 149
Likes: 0
From: ATL Ga
425hp Lt1/Lt4
I was looking at an LT1 to LT4 conversion and; well see for yourself below.
http://store.summitracing.com/defaul...4922130+305334
did you see it?
"The result of all of these modifications is 425+ proven horsepower"
this can't be true is it?
http://store.summitracing.com/defaul...4922130+305334
did you see it?
"The result of all of these modifications is 425+ proven horsepower"
this can't be true is it?
Last edited by bronx69; Nov 18, 2004 at 10:34 PM.
Safety Car
Joined: Apr 2004
Posts: 4,532
Likes: 7
From: Lahaina Hi
If you change the springs to the bee hive from comp cams ,No problem.
But the lt4 motor has 10.8.1 compression,if you are running a stick should run 12's with no problem.
You have an lt1 with auto with this set up you should pull 12.70 with no problem if you reprogram your computer.
With tuner cats or even hypertech it can be done easly.
But the lt4 motor has 10.8.1 compression,if you are running a stick should run 12's with no problem.
You have an lt1 with auto with this set up you should pull 12.70 with no problem if you reprogram your computer.
With tuner cats or even hypertech it can be done easly.
Last edited by REDC4CORVETTE; Nov 19, 2004 at 02:10 AM.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
That kit has stock, unported LT4 heads. For less money you can get ported LT1 heads, which will out perform those that come in the kit. Of course if you then had the LT4 heads ported they would perform better still. It's all about the $$ you want to spend.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Melting Slicks
Joined: May 2002
Posts: 2,670
Likes: 4
From: Severna Park MD
Key to this kit is the LT4 manifold. So you have the higher ports all around. It has the LT4 heads so that includes the extra valve train goodies you would get with the Hot Cam kit for the LT1. Including springs that will handle the lift and revs.
You would still be lacking some of the internal goodies that are in the LT4 block, but this is a good bolt on upgrade.
Send out the heads for porting before assembly and it will do more than any heads/cam LT1 can do, maybe 450+ crank.
You would still be lacking some of the internal goodies that are in the LT4 block, but this is a good bolt on upgrade.
Send out the heads for porting before assembly and it will do more than any heads/cam LT1 can do, maybe 450+ crank.
Melting Slicks
Joined: Jan 2002
Posts: 3,293
Likes: 79
From: Jackson MI
They have it at www.gmpartsdirect.com for a little cheaper I believe
Do a search for the conversion and you should find the website. Its been covered several times before.
Do a search for the conversion and you should find the website. Its been covered several times before.
Race Director
Joined: Sep 2004
Posts: 13,793
Likes: 0
From: St. Peters MO Sometimes you have to prove yourself by doing alot of killing or alot of dying...
Okay... I have an LT4 and I know that it is claimed to be severly underrated... but can I really expect a 100hp jump just by adding a hot cam?
Seriously.... I already have the LT4 heads and intake so all I'd need is a cam to push a 'proven' 425hp?
Seriously.... I already have the LT4 heads and intake so all I'd need is a cam to push a 'proven' 425hp?
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
Originally Posted by kwik_ta
Okay... I have an LT4 and I know that it is claimed to be severly underrated... but can I really expect a 100hp jump just by adding a hot cam?
Seriously.... I already have the LT4 heads and intake so all I'd need is a cam to push a 'proven' 425hp?
Seriously.... I already have the LT4 heads and intake so all I'd need is a cam to push a 'proven' 425hp?
Race Director
Joined: Aug 2003
Posts: 11,043
Likes: 3
From: San Jose Pat Tillman - American Hero
I pulled 324hp/325tq with the basic bolt-ons in my sig - K&N, LT headers, Corsa. That's pretty much it. Assuming a 15% drivetrain loss, that's around 380 at the crank. I don't see why another 45hp isn't possible with some more upgrades (cam, etc.) and tuning.
Aaron
Aaron
Race Director
Joined: Oct 1999
Posts: 13,298
Likes: 14
From: Somers NY
More HP does not always = quicker ET at the strip.... A car can go on a dyno & show 425 HP but still run 13's
Dyno # are only an indicator of the cars "potential" performance.. My car has had NO engine work at ALL with the exception of GM 1.6 RR
it still has the stock LT1 cam, stock exhaust manifolds & still has the cats on it.. I did use muffler eliminators, went to a Dana 44 with 3.73 gears & a 3000 converter...
I also have a Hypertech with a 160 thermostat.. I have run a best of 12.28 at over 110mph
IMO a lot of HP will give you high MPH in the 1/4 mile.. but chassis set up will give you better QUICKER ET's
and ET is what wins races not MPH (I'm speaking of 1/4 mile only)
The price I for that kit was over $2,000 I have only the price of Roller Rockers in my motor..
Dyno # are only an indicator of the cars "potential" performance.. My car has had NO engine work at ALL with the exception of GM 1.6 RR
it still has the stock LT1 cam, stock exhaust manifolds & still has the cats on it.. I did use muffler eliminators, went to a Dana 44 with 3.73 gears & a 3000 converter...
I also have a Hypertech with a 160 thermostat.. I have run a best of 12.28 at over 110mph
IMO a lot of HP will give you high MPH in the 1/4 mile.. but chassis set up will give you better QUICKER ET's
and ET is what wins races not MPH (I'm speaking of 1/4 mile only)
The price I for that kit was over $2,000 I have only the price of Roller Rockers in my motor..
Race Director
Joined: Oct 1999
Posts: 13,298
Likes: 14
From: Somers NY
Originally Posted by SPEED750
Where did you find the FREE 3:73 gears, 3000 rpm stall converter and 160* thermostat? 
Ya got me there... your correct, The converter was $650.. & the rear ran me over $1200 But I was originally speaking of MOTOR only...The converter & gears are the "main" reason I can run those #sI guess what I'm trying to say is you really dont need a "High HP" car to run mid 12's
Melting Slicks
Joined: Apr 2003
Posts: 2,150
Likes: 6
From: NS
Originally Posted by Red96Coupe
More HP does not always = quicker ET at the strip.... A car can go on a dyno & show 425 HP but still run 13's
My car has had NO engine work at ALL with the exception of GM 1.6 RR
it still has the stock LT1 cam, stock exhaust manifolds & still has the cats on it.. I did use muffler eliminators, went to a Dana 44 with 3.73 gears & a 3000 converter...
I also have a Hypertech with a 160 thermostat.. I have run a best of 12.28 at over 110mph
My car has had NO engine work at ALL with the exception of GM 1.6 RR
it still has the stock LT1 cam, stock exhaust manifolds & still has the cats on it.. I did use muffler eliminators, went to a Dana 44 with 3.73 gears & a 3000 converter...
I also have a Hypertech with a 160 thermostat.. I have run a best of 12.28 at over 110mph
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Originally Posted by Atok
Take that same car to the road course and a 6-spd would run circles around it. Don't feel bad if you can't get the same track time as an auto with the same horsepower, it's just part of the game.
IMHO I could get a faster track time with an auto but I'd be bored to tears driving my car on the street every day, so I stick with my 6-spd.
It's all in what you want to do with the car.
A friend of mine has a 93 Z-28 with a turbo 350, he makes less horsepower than me. He'll have me by half a second at the 60' mark, but I'll drive past him on the big end because of the horsepower difference. Horsepower wins in a straight line IF the race is long enough. It just so happens that sometimes that 1/4 mile track isn't long enough.
