I may now be keeping my 1994 Convertible. Its only covered 51 000 miles so believe would be an ideal candidate for an aftermarket supercharger kit. What is available as COMPLETE bolt on kits and what sort of power would it produce @5/6 psi. Will auto box need upgrading?, I have work shop facilities and have carried out turbo conversions to 4 cylinder engines and played with V8 conversions so can stand some fabrication work if necessary ie upgrading to a larger throttle body, moving air con pipes etc? but would like to keep iron manifolds....

 

Currently, the only "complete" supercharger kit in production is the one from www.blowerworks.net

his name is Greg Carol, and he'll take good care of you and help you determine the right kit for your power needs.

the stock bottom-end with the appropriate supercharger can develop anywhere from 380-430rwhp between 6-10psi... (with and without water/alky injection for intercooling).

The stock automatic can support the power. There really isn't any fabrication involved. Greg's kits are complete (with the right injectors, tune, upgraded brackets, etc).

otherwise, vortech use to make a kit (recently discontinued), and procharger "might" still make a kit for the c4.

 

I've never been able to find a twin screw supercharger for these cars...if anyone could provide me with some info or a link you would make my day.

 

Kenne Bell
makes them for C5 & C6 <<>> lets get together and request Kenne to make some for the LT1

 

I've seen them for the LS engines, but not for the L-98. My friend has a supercharger on his v-6 car, and told me it would work on mine if I got a different intake manifold. I didn't think twin screws went on that way...

 

Here's a setup that Magnacharger used to make. I don't know if this was C4 specific, but obviously based on this photo the system fit under the hood of a C4. I also don't know about availability; I can't imagine there were too many of these installed.

 

Guys-

The positive displacement supercharger option has been discussed several times recently, and some sound information can be found using the search engine.

Long story short, Eaton/Magnuson makes a small-block intake manifold for the positive displacement superchargers; however, the kit is relatively expensive and it's a small head unit (likely will not satisfy the majority of boost hungry c4 owners).

Otherwise, there was a guy out of Canada that was taking the time and expense to develop an intake manifold that would allow the LT-x owner's the ability to run a variety of roots style and twin-screw superchargers. Last I heard he was going to install a 175AX from Whipple. He was installing it on an F-body Lt-x, and those guys are clearance limited too (as far as keeping everything under the stock hood).

Keep in mind that the "head unit" (the actual supercharger itself) is relatively expensive! Especially when you start talking about twin-screw superchargers (Kenne Bell and Whipple). I'm sure a lot of people that have the resources to develop a kit like this have backed out due to over-head costs (developing an intake manifold that will provide room for the injectors, belt drive configuration, Retain the existing TB, and most restrictive- the tune).

A "cheap" kit would probably still be around $5,000+ ... once the "experts" determined this, they probably realized there isn't much of a market for it.

A stonger bottom is higher recommended with a positive displacement blower, larger injectors will definitely be the smart move, larger fuel pump, and if you don't have a 94' and newer c4, you'll have a harder time tuning the car... i.e. possibly needing a stand alone computer (there goes another $2,500).

the best person to talk to about a roots/twin-screw supercharger concept is Alvin at "pcmforless.com", he had one (I hear) on his F-body, but eventually got rid of it for a centrifugal combo (vortech, paxton, procharger, etc.)

I truly wish I had the resources to develop such a kit, it would be AWESOME, but over head and development cost along with low demand (true buyers) make it a poor business move.

 

This looks like a much older c4, and it's also running carb's... still cool, but over-kill (on complexity).

 

My son installed a ProCharger kit in my 95 which included an air intercooler. The throttle response and power was awesome. After 200 miles I begin to experience belt slip. The belt was new and tightening it only helped for a short while. The problem was solved by the addition of a second belt and a dedicated idle tensioner. This was done and there was approximately 60 percent more contact between the new belt and the supercharger pulley. At 4000 rpm the gage showed 10 psi boost. Larger injectors are a MUST (42 lbs)
and with the addition of some minor mods ie 58mm throttle body and 3 inch exhaust with headers we were able to exact 519 hp at the wheels by tuning on the dyno. Fuel economy is still decent if driven carefully. My car is a 6 speed and will average 25mpg in 6th gear at 70 mph. I originallypurchased this kit for my 94 w automatic but my sons insisted on putting it on the 95 6speed. My best guess is that on a stock 94 and a good tune one could expect 420-450 hp at the wheels.. the air/fuel ratio at max should be approx 11.7-1

 

ncChris,
Can you detail specifically what you did to prevent belt slip?

I have a 96 with the exhaust done, low compression pistons, and a small blower friendly cam, stock heads. With a P1SC head, I get 7-8 pounds at 6000 RPM but I do not think I am getting slip since the boost rises smoothly and does not jump around but I am curious as to how you were able to get 10lbs at 4000 RPM.

Did you go with an 8 rib setup? Is the procharger head a P1SC or D1SC?

Also curious on your mods to get past 500RWHP. Did you do cam and heads?

I agree on the procharger power gains, car feels like it has a big block in it at part throttle, and has run with a couple of bikes and a newer Viper coupe.

 

The Procharger advantage is the step-up ratio (4.10:1, compared to the lower ratios offered from Vortech)... However, belt slip can be resolved primarily by contacting Greg and Blowerworks.net, he's definitely had his share of experience with this combo and has a variety of options to resolve it...

The procharger kit for the c4 was originally a P600B and/or a P1SC


*edit* you can also increase boost with a smaller supercharger pulley... Once again, Greg can help you with this. Keep in mind that if you've got some work done (less restriction in the system) you will see less boost.

 

I second contacting Greg at Blowerworks. I switched over to his modified bracket for the Vortech unit and the system has never worked better! I used to have an issue with the tensioner pulley hitting the frame once the belt stretched a little bit. Now, with his modified unit, everything fits better and, I get more boost! The way the system should have been designed.

 

This is the 12-rib version of the 8-rib drive referenced above--look very similar. No belt slip, no cog belt teeth issues, and no motorcycle chain waiting to rip the crap out of something/someone...just consistent boost!

 

I also recommend Greg at Blowerworks. He is truly a one-stop shop for supercharging C4's.

 

[QUOTE=djxib;1575687786]I also recommend Greg at Blowerworks. He is truly a one-stop shop for supercharging C4's.[/QUO

I did not see the unit for an L98.

Have 1990 A4 with bolt ons and stock bottom end. How difficult is the install and then how does it affect the tune and emissions?
I would like to install myself and have done exhuast and intake aftermarkets on my car ( i.e level of skill)

Also about what do these cars run ( 1/4 mile) with the SC and the stock bottom? I would say I am about mid 13s now

Thanks
Flatbush862

 

[QUOTE=flatbush862;1575711346]The kits might not be listed on his site, but I'm certain he has kits for the L98's...

I believe you might be running a high 13 right now (nearly stock- standard vette'). With the supercharger (depending on a dozen variables; i.e. boost, tune, head unit) you're looking at easily being in the 11's. Usually the problem is traction, or learning how to drive the vehicle with the increased power. The MPH is usually there with boosted cars, but it's getting it down the track efficently that gets you ET's.

There is a guy on the forum that could get 10's out of his nearly stock LT4 with just a shot of nitrous; however, he's a hell of a driver!

 

A much older C4? Because the much newer C4's looked that much different under the hood?!?

Apart from the revised A/C compressor introduced in 1988, the larger radiator and slanted radiator shroud introduced in 1990 (along with elimination of the MAF sensor), and the different intake manifold/plenum on the LT1 introduced in 1992, all C4's look pretty much identical under the hood.

Besides, tehcarguy asked for information regarding a twin-screw supercharger application on a C4. What difference does the age/year the C4 in the photo make?!?

 

If you go to the BlowerWorks website and download the C4 Supercharging Guide (PDF) all the kits which they sell are listed inside, including the L98 kit(s) available. The guide breaks down exactly - part-for-part - what's included in each kit. There's even a section in this guide for optional items like hidden/integrated boost gauges, ignition system upgrades, etc...

And given your skill level, you'll be able to handle the install of a BlowerWorks kit without much hassle. I have an early kit from BlowerWorks (from back when the company was called The Carroll Supercharging Company), and I can attest that it is VERY complete! If you budget about a weekend for the hardware install, you should be fine.

 

To eliminate slip we purchased a separate idler and pulley which accomodates 2 belts. The supercarger belt now makes contact with 180degrees of the blower pulley. It is a
p1sc and gets about 10-12 lbs boost at 6000. Heads are mildly ported and pistons are
hypertechtic with standard LT1 compression. Cam is a mild lingenfelter. Prior to adding the blower the car made 348 hp at wheels. To get 519hp on pump gas took a lot of tuning on dyno. With 42 lb injectors she started to lean out at 5800. Fuel pressure was raised to 50 psi and at 6500 the injectors were running 90 percent duty cycle and A/F was 11.7. We purchased the idler setup from Brand-x then in Florida.. He has since moved and to my best knowledge to Texas. During this time we did speak to Blowerworks and he was extremely helpful..In fact I was seriously planning to use his water/alcohol kit instead of the intercooler. Once you get setup then you must get an expert tuner to finish the job.
feel free to contact me anytime and dont hesitate to call Greg at Blowerworks.. He is the real Guru on the subject