upstate bob

by coincidence, dropped in to my neighbor's shop this evening where his (talented) son was setting up the computer on his LS1 powered 72 el camino SS. 383 cu in, AFR heads, comp cam, LSX FAST 102 intake/induction.
he had the laptop on the roof and explained a few of the lines of data to me.
then touched the switch... !!!!! bang! fuggettaboutit. just get your 928 in perfect stock condition. no comparison. that intake alone is $1000.

Madturk

I have a friend who is doing a LS1 swap with his old Jag. Nice project but not for the 928 if you ask me.

SMTCapeCod

check out tony77s project sometime.

http://www.ccstreetscene.com/forums/...ad.php?t=39376
or

I thought 928 sp were referenced as NLA in a different thread?

BC

I have had 12 928s, and probably driven....25 of them. Not nearly as many as some here, but I will say that an over-arching concept is people say "Its in great shape" (and its not sellers I am talking about) - and its simply not. This is why people may seem to not be taking some of what you say as gospel.

Its a tough crowd sometimes for new people.

Also, unless you have a great relationship (not a stealer) with a great mechanic, then when you don't work on your own car, **** just doesn't go well.

I had a friend that had an early USA model stuck at a mechanic here locally. The guy says he could not get it started for the life of him. Starter solenoid was replaced, battery was replaced, tons of "wiring" was checked, and they were completely stumped. I walked up the car while my friend was chatting to the mechanic, popped out the horn relay and stuck it in (I forgot) where it needed to be swapped for, L-jet or whatever, and it started fine. I just looked at the mechanic and walked away as he said to my friend "What did he just do?"

Honestly? Some cold hard facts? The depth and breadth of knowledge here on this board about this particular car (let alone some others by the same people) is not common to find on the internet. Its quite uncommon and actually stunning to see. I would stop saying you aren't an expert and that you are not getting any info and open your ears to what people are saying, and do some further reading in other threads.

I am on other boards for my other interesting cars. Other than old-timer Big block people on Yellowbullet (and that place is a good-ol-boys area, the info is there but its hard to sift through the abject lack of grace) - this is probably one of the best. On AMG boards.... Well, I've digressed.

bureau13

Maybe it would help if the OP put the complete list of what has been done to refresh the car and when it was done...if it really is complete, folks would know and stop being suspicious of how pristine the car is REALLY. Conversely, if something important is missing, they could point that out, so that it gets done.

As for the info on which to get...I'm not sure what more is wanted. There have been a couple posts that pretty clearly recommended the Murf as the top choice. There was one or two that mentioned some advantages of the other one, I think mostly involving the ease of removal to stock...but the recommendations are there, with fairly clear justifications. I'm sure all three of the available kits have their advantages and their disadvantages, but you did get recommendations.

jorj7

Erin,

I was one of the early Murf Supercharger adopters. I installed the kit in 2004 with the help of Bill Ball and Tom Cloutier. The kit was a little rough at the time, but Tim Murphy was a great help working through the problems. I was doing Open Road Racing (ORR) with my stock 928 S4, running in the 145 mph average class. I had already done the water pump/timing belt change, replaced the hall sensor and in-tank fuel pump as well as have local experts check out the car. After the install, I started running in the 155 mph average class (172 mph tech limit). This was the first supercharged 928 to compete in ORR. At the time no one knew if it would hold up. I ran 4 races in the 155 class and then 5 more in the 160 class (Unlimited tech). It was on the 5th event I had my first failure, the oil dip stick blew out and all the engine oil proceeded to be pumped out of the engine. The oil return line from the supercharger feeds into a Y on the oil dipstick tube. The problem was the o-ring on the dip stick had broken and so the seal was not tight allowing the dip stick to blow out of the tube.

Anyway I think the supercharger proved to be well worth it. I had put about 30,000 miles on the car from the install to the engine failure, including the 8 1/2 ORR events (2004-2007), which I drove to and from (~500 miles each way). Tim has continued to work on the kit and improved it significantly. He supports his product and has been a great help to me and my car. I would recommend him and his supercharger kits to anyone that is interested in "upgrading" their 928 S4. Oh and the current Murf supercharger kits don't return the oil to the engine through the dip stick tube...

I don't have much experience with the other current supercharger vendors, but I did run Bill's supercharged 928 S4 in the 150 class at the 2009 Nevada Open Road Challenge. He was running the 928 Supermodel kit from Andy. It didn't have any issues running at that speed, for that distance, or to and from the event. So I think if installed and tuned correctly, a supercharger is a great "power adder" for our cars.

Hope this helps,
__________________
George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com

Dan87951

Check out Murf. IMO he makes the best kit. Everyone I have talked to has been really happy with his service and support. Not to mention the Murf equipped silver 928 I rode in at Sharks in Hell was wicked fast and performed flawlessly.

Carl Fausett

ptuomov and Lizard: Yep - thats what you guys keep saying. Which makes me think the Murf kit is incomplete in your eyes. If so, consider the cost of the Murf kit PLUS the $2400 dollars for the Sharktuner. That's what I have always been opposed to. (that and the big alternator you will need to keep up with all those fans). I know the kit comes with a generic EPROM with some timing pulled out. Hardly a "tune" IMO.

Just wish you would either compare the two kits (Murf and 928MS) AS SHIPPED, or the two kits BOTH with a Sharktuner.

Just want to point out: the 928 Motorsports kits are compatible with the Sharktuner too. I have always said the Sharktuner works. It does. But you don't need one with our kit, our kit is complete out-of-the box. If you have access to one, all-the-better.

Regards comparisons to Georges's early install and such: careful. Early Murph kits used V1 and V2 S-Trim and later T-Trim head units. Performance characteristics quite different than the current V3 supercharger that he is shipping.

So please... don't put up performance stats from a V1-T-Trim as correct stats for that kit currently with a V3.

Just clarifying.

jorj7

Carl,

You're right about my early install, a discontinued Stage 2, using a V2 S-Trim. It only produced ~8 psi boost, 35-50% less then the current Stage 3 kit Murf offers. Later, with a smaller pulley, I as able to get it up to 10 psi boost, which is closer to the current Stage 3.

Now I am using a V1 T-Trim Race version, sourced from Tim and "upgraded" by him and Todd. Bill and I are also now are using the Sharktuner, one of the most useful tools around for tuning a modified 928. But I wasn't commenting on the current set up.

Best Regards,
__________________
George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com

Carl Fausett

No problem, George. I hope someday to join you down there on the Silver State Classic.

ptuomov

My point is that if you have an '87 or later 928 that you like to tinker with as a hobby and that has stock computers, you should buy a Sharktuner 2. Whether or not you're supercharging the car or not, and regardless of who's kit you're using.

The price of ST2 is not $2400, at least that's not what I paid for it. It was under a grand if I recall correctly.

If you want to know my view instead of just assuming what it is, I am firmly of the opinion that any centrifugal supercharger kit that doesn't come with an exhaust driven turbine is incomplete!

Carl Fausett

My mistake.

Current prices for a SharkTuner seem to be here:
http://www.jdsporsche.com/sharktuner.html

Point being: they ain't cheap. And they are not included. And its not like you will be able to just borrow one from your neighbor.

demetan

Very interesting forum. I personally plan on eventualy SC my 89S4. I quite understant it's a 26 year old car that would, in a very high probability, show major gaps if I would throw in a 10 psi SC, right! The point here, is that I bought a machine that's new to me & that I'm learning from, as a driver & as a mechanic. I'm interested in the learning curve process regarding SC a 928...I know some of you are trying to defend they're point of views about performance & even they're business. But is there someone out there that had a bad experience with SC a 928? What is the first step, or what do you have to change or modify mechanicly speeking, to prepare the car for SC? How do I know if my car is ready for it? Do you think I should sharktune-it first or why not? Is'nt that the safest way to begin with, to know how to tune your own car & give your self the tool to do so? Can you do that with Porkenchips?
What do the turbo guys have to say? The first 911 turbos had 7:1 CR & A 928 varies from 9.5 to 10.5:1...

ptuomov

The S4 and later have 4-valve pent roof combustion chamber with central plug. They are liquid cooled with a big bore spacing. That's not close to those first 930's...

You can't consider the static compression ratio in isolation without also considering the cams. '87 S4 with stock S4 cams and the stock 9.4:1 compression ratio can take a lot at the top end and not so much at the mid range. Here's an example:

SMTCapeCod

So, IIRC '78 and S3 cams are the most uppity factory cams for normal aspiration, and that GT is similar to S3? How do these profiles compare to S4 for forced induction? Small words and short sentences appreciated. ;-) I'm good with discussions of lift, duration and cylinder fill but beyond that I'm out.