1985 c4 horsepower??
Thread Starter
Cruising
Joined: Dec 2017
Posts: 11
Likes: 0
1985 c4 horsepower??
I have an unmodded 1985 corvette with 160,000. I would like to get between 400 to 500 horsepower. My question is, what parts would I need and how much would it cost? Also, would it be worth it due to the high mileage of engine. Any input would be great, thanks.
Team Owner
Joined: Jul 2004
Posts: 28,472
Likes: 3,290
From: Hartford WI
Worth is determined by YOU. IMO, it isn't worth it to me at this point. I'd have sold it and gotten something that uses an LS engine for easier modifications. OTOH, if you are absolutely in love with the car, it might make it easier to shell out that kind of money. IF you are like me and the car is a tool to get your jollies, perhaps not.
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,218
Likes: 1,174
From: Southlake, TX
IF it is auto, probably have to rebuild the trans to take the load and also a D44 rear end. Now we are talking 6 to 9 thousand on a good motor, couple grand for intakes and headers. Then you need someone to tune the thing so give or take $1000.
Worth is determined by YOU. IMO, it isn't worth it to me at this point. I'd have sold it and gotten something that uses an LS engine for easier modifications. OTOH, if you are absolutely in love with the car, it might make it easier to shell out that kind of money. IF you are like me and the car is a tool to get your jollies, perhaps not.
Worth is determined by YOU. IMO, it isn't worth it to me at this point. I'd have sold it and gotten something that uses an LS engine for easier modifications. OTOH, if you are absolutely in love with the car, it might make it easier to shell out that kind of money. IF you are like me and the car is a tool to get your jollies, perhaps not.
So, rather than focus on a HP number, what do you want the car to accomplish or feel like? Remember HP is a dyno number, you can get a lot done with a lower HP number with a great combo.
350-375 is very doable with the L98 without breaking the bank and without major power train modifications.
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
You will need all the block work done, note you have 2 pc rear main seal from the factory and a hyd flat tappet cam, not a roller.
You must have new heads, yours are junk. You must have cam changed, and then a custom chip tune for the 85 which is different to tune than later cars.
You could reuse the factory TRW Forged pistons unless you have it bored out, which you will probably want to do.
You will have to get rid of the TPI intake to get close or beyond 500chp. You will want Superram, miniram, etc.
Labor, install, all that will add up with the machine work.
So whats the budget, whats the car intended to do for you, etc.?
Instructor
Joined: Oct 2006
Posts: 223
Likes: 5
a couple of options
Burning Brakes
Joined: Oct 2017
Posts: 823
Likes: 106
From: Somewhere near Fort Wayne, Indiana
For that much power I'd consider a turbo or supercharger. You're looking a 100% increase in power.
Or, an LS swap considering the time and money to get 400 hp from an l98.
Or, an LS swap considering the time and money to get 400 hp from an l98.
Team Owner
Joined: Jul 2004
Posts: 28,472
Likes: 3,290
From: Hartford WI
For his year, assuming he wants to spend the time and money, that might be viable. He'd have to get mounts and the ECM and harness and a fabricator to make it all work. Not to mention a tuner.
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