I'm thinking ahead to a possible future project which would be some "tweaks" to my '89 C4 Corvette. I'm retired and am always considering what to build next. Since I already have the "almost daily driver" C4 I'm thinking why not just do some modifications to it rather than adding yet another car to the fleet. I don't want to go really wild, but wondered about adding a turbocharger, but thinking I wouldn't want to go beyond 5 or 6 pounds of boost.

Doing some research I've found that there at least used to be some companies that produced turbo kits for the C4, but through searching I haven't found any of them. Is it possible that with the age of the C4's that they've all moved on to producing only kits for later generation Corvettes, or maybe have completely gone out of business.

FWIW, I am 70 years old and have been a car fanatic most of my life. In recent years I've had a couple dirt circle track cars and have built '23 T Ford roadster and '30 Model A Ford Coupe hot rods from the ground up, I'm currently building a nostalgia front engine dragster again starting with a pile of tubing on the floor. Not bragging, but just pointing out hot rodding is in my blood and I know my way around a tool box.

Suggestions and input are welcomed!

Thanks

Lynn

 

Why not go supercharged instead? Alot less fab work...

 

Good point but I'd prefer to go turbo to just get the boost when needed/wanted. I found an old article about a kit that retained the stock injection and the turbo blew through it, but can't find anything current on them...HP Performance in NM or AZ. I'm guessing they have moved on, changed their name or gone out of business.

Lynn

 

You will have to fabricate or send to someone who will. A rear mount is probably easier, but I don't think any would be worth it for only 5-6 pounds, just do heads/cam.
If you want to go all out, send to NRE.

 

There are no off the shelf turbo kits available for the C4. You'll have to fabricate it yourself of you want one. I built a twin turbo setup for my 85. While I really like it, I would suggest looking at a remote turbocharger kit unless you like the work of fabricating your own manifolds. (Boost + TPI is a lot of fun.) STS Turbo makes a couple of kits. You'll have to do some fabrication to fit it but nowhere near what I did. 6 pounds of boost would add approximately 100 horsepower to a stock L98.
If you do decide to add boost you need to figure some additional costs in: You'll likely need bigger injectors, a larger pump, and some dyno tuning by a competent tuner. Depending upon how much more power you want to make you'll need drive train mods as well.

 

I am pretty proficient at fabricating so I don't think that would be an absolute deal breaker although the exhaust manifolds could get pretty complicated it seems. If they had to be fabricated from scratch it would probably be best to have a SBC on an engine stand to do mock-up rather than trying to do it in the confines of the engine bay of the car. That would also allow a great deal of fabricating to be done without tearing the car apart right away.

I have a friend who has done quite a bit with turbos. We talked just briefly yesterday and he greatly de-mystified turbos and the basics of HP to be expected at what boost etc. I'm sure when it gets down to actual turbo sizing and design it will get much more complicated. The tuning would be foreign to me. I'm an analog guy living in a digital world. I guess it wouldn't hurt to try to learn something new.

This is all just speculation and dreaming right now. I have another major project going at present and don't want to put it on the back burner.

Thanks!

Lynn

 

I've built two systems for car. The first was a single T4 and the current one is a pair of T28s. The single T4 performed well, I was just having issues with where heat was getting under the hood so I built the twin setup to fix that.
Link to the current setup is here https://www.corvetteforum.com/forums...is-better.html
Garrett has a good tool for picking the right size turbo(s) on their website.

 

Do you have any pictures you could post? I’m thinking of doing the same on my 1990

 

I don't have a remote mount system on my 85.