mattman

I have been lurking here for quite a while. I am a 560SEL Mercedes owner that is looking for a new vehicle in the next 12 months or so.

I have typically been a sedan owner and am currently looking at the late 90's BMW 540, an E420 or a CL500 or similar. I have begun to look at the 928 more and more lately. What I have decided is that the power outputs of all these vehicles is not enough by today's standards and I possibly might like a manual as all my previous V8 cars have been auto's.

Whatever I buy will get suspension, rims, a brake upgrade and a supercharger. Ideally I would like around 350KW which is about what the current gen of boosted vehicles produces and what the next gen of aspirated motors will make.

I have tried to understand the various models of 928 available and also the different supercharger systems as well however I am having trouble aligning them all and understanding the pro's and con's of each.

I am after some suggestions as to model and supercharger setups that will get me a very late model ie early 90's 928 with the necessary setup to produce around 350KW safely and reliably. I would also like to do a little bit of track work so it would have to be durable.

I don't want to start a debate on the pro's and con's of each manufacturers systems, all I can say is that the 928 crowd seem to have a strong aftermarket following which is cool.

Any owners who can share their setups and lesson's would be appreciated. I have read nearly every supercharged thread posted here, there are some wicked cars.

Thanks in advance.

Matt.

AO

Matt
Welcome. It depends on your budget. But I'd say you best bet for availability and reliability is going to be an S4 or a GT. That means 1987 or later. I suppose you could go for a GTS, but you'll need to spend $35k or more just for the car. Best value will be an S4 5-Speed, but they're kind of hard to come by as 80% of them are autos. Whatever you do, read the FAQ at the top. A PPI (pre-purchase inspection) is a must on these cars. And it REALLY helps if you can turn your own wrench. If you search the threads I started you'll see I have a very detailed PPI list that will get you through most of the PPI if you know your way around a car. Otherwise pay someone to do it for you. Good luck.

BTW, where are you located?

mulik51

I think MB could be a good choice becouse there is an AMG version probably, so no custon work. Talking about 928, you could get up to 450RWHP on stage 3 SC from Carl(16 valve), or you can get more then 500RWHP on the 32 valve cars with superchargers from Andy.
Klim

hacker-pschorr

Best bang for the buck - easiest to install as well:

https://rennlist.com/forums/928-forum/219892-new-stage-i-supercharger-dyno.html

https://rennlist.com/forums/928-forum/187494-murf928-supershark-stage-one-supercharger-kit-and-85-86my-status.html

http://www.murf928.com/

Gretch

89 GT, KING of the BEASTS + Murph Iron Lung = Super Shark.....

mambodoc

Questions from the peanut gallery...Are 90/91 GT's as well as newer GTS's a good base vehicle for the Murph...also...as far as a transmission...auto or manual preferred to maximize on the installation, or is there no difference?...no racing here, just street play. Thanks in advance!

Jim_H

The GT is most excellent for Supercharging. The exhaust valves stay open a bit longer in the GT's making them a better candidate than the S4 motors, as I understand it.

m21sniper

I thought the 5.4 liter motors had oiling problems.

No?

Vilhuer

GTS has oiling problems and 10.4:1 compression. Together these make it difficult canditate for high boost setup unless something is done to pistons and conrods. Average S4 is little better than GT as CR is maybe liitle less. '87 S4 would be best because of oil squirters in the block.

DFWX

Consider a super clean 80 - 81 model. They weigh under 3200 pounds, have the stronger dual disc clutches, and much lower compression. While a 16V motor and a few ccs smaller, they also have lower compression - thus allowing higher boosting. For the $10,000+ you will save in buying the car, you have a lot of play money then for customizing or motor work-up. You could add big port 2 valve heads that likely will flow better than the 32 valve, and virtually everything you do will be cheaper. To manage the fuel injection, go to a TEC-2 or other engine management system. Just an alternative course you could take - and one that would put you into a supercharged 928 for under $20,000 ttl for the entire project.

Tony

Agreed, but depends on the type of SC on the GT though. Issues of "Tip-in" with the Twinsscrew is what i always hear ?????

Fastest928

Any that utilize the twin screw .....

Absolutely amazing results per lb of boost.

mspiegle

I'm actually working on a mini-project to solve that tip-in issue on a GTS. If it works, then the same idea should work on GTs....

mattman

Thanks for all the replies guys, I will go through them in more detail and come back with some more questions!

Cheers
Matt.

Bill Ball

Good that you warned people not to get into a pros and cons of the types of SC kits, even though I see a few small attempts here. That's been beaten way beyond death. Which car is the best candidate is a far better question as well as how to modify the car and tailor the setup for even better response to the blower. Good thread developing, although it may not have the drama and bloodshed of the gladiator wars.