Supercharging a 928S4....

[Yellowb1rd]

Fellas,

I'm seriously considering supercharging my 928S4 before next summer, and I would like some input from anyone who has gone through the process. Carl at 928 motorsports sells a pretty nice kit, and from what I can see, it's a weekend job to install for even the weekend mechanic. That ain't bad.... BUT, it's also a 5400 dollar kit for the 87-95 era 928.

1.) Anyone here ever purchase and install this kit on their S4? How long did it take? Any dyno numbers to support 928MS claims of ~400 HP at the tire? Is there a big performance difference?


2.) Does anyone have the low-down on alternatives. Perhaps a custom setup that can be done in the 2-3K range? The more detail, the better in regards to the setup - the specific components, process/instructions, and the dyno results.

3.) With either a custom fabricated setup, or the pre-fabbed ones, will the transaxle or anything else need to be beefed up to handle the extraHP/torque? This is an auto-trans equipped car.

...it would be nice to have a 928 be able to overtake even a Hyundai Genesis, if need be......

[5l32v4c]

Wow, that's a big pile of cash. I know the 928 is a well-engineered car and the engine should be pretty strong but should you be putting that much stress on an engine of this age?

What are you going to do if you blow your engine? If the engine goes, the car is pretty-much worthless, right?

I dunno, man. Seems like a premature death sentence to me but I don't have alot of spare money right now for my 928 so I tend to look at thing differently, I guess.

Having said that, it would be VERY cool, while it lasted.

[chitown944]

Victor 25 did an install of his kit at Sharks in St. Charles last month. Very sweet looking kit. Give him a jingle him at Porsche Supercharger Kits | VCB Engineering

[Fixer]

A Fellow who goes by IMO000, built his own kit and took detailed photos for the DIYer, I would take a look at that first.

I don't think superchargers stress motors all that much, just make them more fun

[victor25]

A Hyundai Genesis won't have a chance once you get supercharged!! Oh and that trans & drivetrain can handle 500hp no problem. Basically your good to 450+ before you have to worry about replacing things

We cant do 2-3k, but give me a shout when your ready, and I'll see if I can help in some way

https://www.facebook.com/pages/VCB-Engineering/429040613809336

Victor

[harborman]

I saw an S4 here with it this summer. Unfortunately the owner did not have much time but he opened the hood and I had a look. It looked like a neat install. I never found out where he got the parts. He said he could plug in his computer and adjust things. He hangs out on RENN list, but I just can't remember his ID now. I suppose it would be fun to try but a considerable amount of $$ and then I wonder about any problems. Not sure I would do this if I wanted dependability.

[Yellowb1rd]

Thanks, everyone for the responses! Victor, what is the best way to get in touch with you? You can message me directly with contact info.

[Herr-Kuhn]

The 32V M28 engines have been proven reliable to well past 550 HP at the wheel. My system has supported over 700 WHP on a stock long block, no internal modifications, though I don't recommend running it that high without internal modifications. There are no free lunches though, as you have to do the job right. I have a write-up on my website regarding the various forms of supercharging and what makes them all tick, including the gas driven turbine variety.

Turbo or Supercharger? | Kuhn Performance

Also a write-up on which 928s are the best to add forced induction to:

Best 928 to Turbocharge? | Kuhn Performance

Be aware of what you are buying before you make a purchase decision. The above write-ups are based on well over a decade's worth of experience in forced induction for 928s. From a street and all-out performance standpoint, centrifugal superchargers have been, and always will be the bottom of the barrel...the math doesn't lie here regardless of the sales tactics. Positive displacement pumps may not may as high a peak HP, but they are typically stronger across the engine's speed range and are a much better solution, specifically for a daily driven car. The turbo out performs both and does it at lower manifold pressure and with less stress on the engine. Making 400 WHP with a turbo on an M28 32V is like falling off a log.

We're currently fitting two GTX3576 to the M28 32V engine for much higher power capacity (800 WHP+). To do 400-500 WHP right you should expect to spend at least $6-$8K. Intercooling is a must and it has to be designed properly...some people are peddling junk so my advice is to read up on what you are looking at to make sure it is what people claim it is.

If you can find a left over twin screw system that is the way I'd be looking to go if you are set on SC.

I'm available to discuss options if you need advice.

[Flint Ironstag]

I don't have anything technical to add to the discussion, but Herr-Kuhn: your twin turbo system is a work of art.