Jim, the irony here is I first found Rennlist when searching for "supercharged 928" a year or two ago. I had watched and watched the F_A_S_T website for several years waiting for a critical mass of production and customer installations for validation. At the time I had some money but needed more evidence. Eventually the website became stale without updates and somehow I chose to lose some money in the stockmarket instead. Uh, oops.
The boost/stroke history has been interesting, sometimes entertaining, sometimes annoying. My position is: anyone that has the courage to innovate and actually puts serious effort into it should be worthy of respect whether they succeed or not. Others can learn from the failures of others or be inspired to do better. Those that learn and succeed are creating our viable options for keeping our 928s interesting for us. All of these folks are important to me, and I respect their efforts.

I like to see new posts of old topics. It provides a forum to compel developers to give the latest updates on what is going on and keep the competitive energy bubbling. A little pressure doesn't hurt anyone.

Should I change my name from James-man to Ramble-onner? Geez I get tired reading my own junk...

 

Incidentally, when I belonged to rennlist years ago and had my old S4 supercharging seemed to be way out there. After being out of the scene for four years, I can't beleive there are at least half a dozen supercharged cars on the list - maybe more.

I think supercharging makes a lot of sense. I'm going to bring up the AMG example again - they hardly make a non supercharged car. And they are all positive displacement incidentally.

My boss drives a CL600. This is a twin turbo, 6L v12 mercedes - it makes 500 horse. He took it to Brabus and added their t12 package - made another 70 hp.

Point i'm trying to make is that soccer moms are driving around in their 500 HP Mercedes S55 sedans and we are still talking numbers in the 300-400 hp range. The 928 has much farther to go and you could bet that in the world of 500 hp v-10 M5s and 469HP e55s we would see Porsche marketing the 928 as at least a 500 hp car.

I don't think the stroker is agressive enough for the money. Just my 2c.

 

very true James, but only if ones legitimate question and post isn't deleted from a forum so that others cant see potential problems or issues they also may have .
That gets everyone no where and in the meantime the products manufacturer looses a tremendous amount of credibility in the process. Taking one step back to make 2 steps forward is OK.

 

".....I can't beleive there are at least half a dozen supercharged cars on the list - maybe more."

Double that, anyway. Hell there are at least 6 Supersharks in existance, and I am in contact with two more who just pulled the trigger with Tim Murphy. Andy has sold several also, only he knows how many, but I bet with these two guys, plus Quick Carl, F.A.S.T. and Joe Dyer's car, there are maybe as many as 24 supercharged 928 cars out there.

And in case anyone is wondering.....I am still a very happy Supershark owner and satisfied customer of Mr Tim Murphy. My 928 GT Supershark is rock solid, and still the quickest thing on four wheels I have ever driven. It is SICK fast.

 

Add Marcus Hut. 85 , the Denver? S-4 sold on E-bay to Illinois, Texas S-4 from a few years ago , "Tilo" race car, There are many supercharged 928s. And they just keep getting better and better. I too was a "Doubting Thomas" when the question of forced induction was in the early stages of development concerned about too much compression, detonation , cooling, adequate fueling , head gaskets, belt drives . But Tim , Andy,Tony, Rob,the Fast boys,Eric ,Turbo John , Marcus Hut. Carl ,focused on the positive potential and pushed forward addressing the issues if and when they occurred. I have to admit that I may have overestimated the potential problems and definitely under estimated the skill and determination of many of the people involved. To each and all who have contributed to this explosion of knowledge of forced induction on a 928 , I admire your resolve and dedication . You have come a long way !........ Now Andy, where is that blower for the very brown 1980 ?

 

Yeah Andy whats up with the old bugger kits?

I have one SC 928 and will be adding another soon as I get the kit bolted on.

 

forget about all those old cars andy, tell us GTS owners (engine anyway, in pieces..) about a workable solution!

 

Nick there are far more 78-84 928s than GTSs far , far more

 

Adam,

How much did that 570 HP cost him??? Just curious. I bet he spent over $100,000 more than I did for mine

Remember what Porsche was up against when they built the 928. 300 HP was the right number at the time.

 

I know that there are strokers making the 400rwhp that you mentioned. Those are more than 6.0 liters, which requires boring, etc, and/or are using high flow heads. I was talking about base stroker installations, on an otherwise stock engine. That's what the 318rwhp stroker in the catalog and the 298rwhp one one the Devek web site are. I realize that those may be somewhat old, but there wouldn't be anything different in a base stroker built on an otherwise stock engine today, would there? If so, what would it be that would create an addition 80-100rwhp on the same basic configuration?

I thought that the base stroker configurations on an otherwise stock engine would be the most relavent configuration to compare to a base supercharger installation on an otherwise stock engine. I mean if a comparison is going to be made to a stroker with bored cylinders, bigger pistons, high flow heads, different cams, etc., it should be to a supercharged engine with those other similar modifications done to it as well.

Perhaps one day you'll actually have a grasp on what's really going on, but I am losing hope in that.

I think you may have suceeded, as there are some on this board that are of the opinion that your bag is definitely full of it.

Yes, and the Pro 5.0 Mustang guys are getting 2,000+ hp with CS superchargers. There are street Vipers with centrifugal superchargers making big power and running in the 9's in the quarter mile.

Are you sure you didn't just hear that on your 8-track player or Betamax?

I was thinking that there would be a good comparison made in Wichita. Quick Carl was there with a centrifugal supercharger and you were there with the "Goldmember". I saw Carl put his car on the dyno, but you never showed up at the dyno.

That's exactly what I've been telling people. And when you do shift, the RPMs will drop to a point where the centrifugal still has it's advantage. The big torque low end of the positive displacement supercharger or stroker will never be seen once you get past the first part of first gear, where you probably can't use all of it anyway because of lack of traction. The centrifugals already make enough down there to light up the tires. You can have 1,000,000 more ft/lbs of torque down there and you will not be accelerating any faster if the tires are already getting more power than they can put to the ground. If you just want that big wheelspinning torque right off the line in first gear, forget about strokers, turbos, and superchargers. Just put in lower rear gearing and save yourself a lot of money.

The best choice depends on the specific application and what the car will be used for. People make statements about turbos being best because that's what's used by Porsche and others on their race cars. If you're going to run the 24 hours of Daytona, a turbo setup is a very good choice. Turbos make a lot of power when spinning at speed, and they do have good efficiency then which will help with fuel consumption. That means less fuel to carry and less pit stops. The turbo lag isn't an issue because you'll really only experience the worst of it when pulling out of the pits from a stop. Once going the time it takes for the turbos to spool up is irrelevent.

I don't drive in the 24 hours of Daytona though. Living in a metropolitan area, if I tried to drive like that on the street I'd more than likely run into something or be arrested before I got very far. I'm more interested in drag racing like performance. That is not to say drag racing specifically, but rather "drag racing like", which means sudden bursts of high acceleration, either from a dead stop or from some cruising speed. I've driven turbos in situations like that and I was tempted to just drive into a wall to end my misery at waiting for the turbo lag to end. Of course by the time I was going fast enough to actually get to the wall I could have changed my mind back and forth a bunch of times, changed the radio station to some soothing music, turned up the A/C, reclined the seat, and relieved my stress. Then the boost would kick in and there would be a rush of acceleration. I do not like that off/delay/on full throttle power delivery.

Drag racing wise, the world's fastest pump gas car is claimed to be a 1969 Nova. It weighs 3400lbs, and has run the 1/4 mile in 8.18 seconds at 170mph on 91 octane pump gas. It uses a centrifugal supercharger and an air/water intercooler.
8 second Nova

Tim, promise me you won't ever give John a ride in your car unless I'm there to see the look on his face.

 

Hacker, let me remind you the Goldmember went from concept to reality and was DRIVEN 800 miles to Kansas the day after completion, the same day it smoked a Lancer Evolution wearing the KY plate "BYBYV8". Six weeks start to finish. All talk? You think I can't do it Hacker, you think I won't? Just wait, good things come to those who wait. I do have a NA 944 race motor to build this winter, but that is cake.

Tim, now that was a great comment, you get bonus points for that one for sure. I was laughing hard, great stress relief from a crazy day at work! Big Postal visit next week, $20 million contract, lots of stress! I'm sure Goldmember and "TS" Supermodel would be quite pleased with the "results" of this meeting as well. But, the question is this; Will your 5.0 liter Super Shark be ready when "Fat Bastard" hits the pavement? lb per lb of boost, no BS, no 6.0+ liters, no nitrous. Twin Garretts, lots a boost, bla bla bla. Answer this, if the CS is so great, why are all you guys now chasing displacement? Sounds like BIG Bucks to me. Imagine, just for a moment if you could have full boost as you enter each higher gear while hammering it out! Translation...50-70 more ft-lbs of torque up the middle...heck Andy could tell you all about that. I do think dropping the cast pistons for this level of power is a must, so you guys are doing well there.

Personally, I think the turbo setup is worth a premium over the CS setups, there is no doubt in my head about that. How much, I can't tell, but it is worth more. Of course, nothing is worth more than it can be sold for. Also, remember my first post on this thread never mentioned the turbos...someone else put that into this equation. But I love you guys just the same.

Jeez, I feel like we are one big 928 family again!

Oh and before I forget to mention it, the Banks guys are able to squeeze 800-1100 HP out of the Chevy TT without a header system....straight old fashioned cast iron manifolds. Cast iron is the best material selection for a turbo street car. I believe Lag calls them "Briggs and Stratton" style. Can't this work for the 928?

 

I wasn't joking John - did you read my post? Can you respond here please?

 

John, that you? you must be on your meds man.......I thought fer sure the ****e was gonna hit the fan......getting mellow in your old age, cool man.....welcome to the "seniors" section.

 

Hey Z, you can talk all day about turbo lag but ask yourself this...would you rather wait 1/4-1/2 of a second between gears to make full boost or wait til redline to make full boost with the CS? Those are the facts. You see it on the magazines and on the strip and think it is best. Turbos clean up most races, they are simply better technology.

Exponential boost build with your peak at the redline, it is that simple and unless you find a way to vary the compressor speed as a function of load, it won't change. Drag racing---high stall converters close gears. Yes it works, but an equal boosted turbo car would crush it. It is a proven fact.

You can't use all the boost in 1st gear that the CS makes...and most turbos won't make it all there anyway. Another reason to use the turbo. By 3rd gear the difference in performance is obvious. Your CS explanation has major flaws....the higher the gear the longer you have to wait for full boost. That is infinite lag in my book. Your compressor is linked to the crankshaft and your boost is a function of RPM, not engine load. 3rd gear, drop the hammer on the turbo car and you have all the boost you can handle.

Why don't you guys go to Europe and sell Porsche, RUF and MB on the CS? Surely you must know more than they do by now. As it turns out, MB is moving heavily towards turbo. Mr. Bell tells me they are eliminating the SC from their product line.

 

I think you will all be surprised when on equally prepared 928s, with the same weight, tires, etc, one with a TT setup, and one with a CS setup, turn out pretty similar 0-60 and 1/4 mile times.

Since the difference will be so minimal, I think most people will go for the cheaper and easier answer.

If you are looking for maximum power, and maximum bragging rights, then it won't matter what the cost is, because you will have to build pretty custom engines, heads, cams, etc, to handle the power. If cost is no object, and speed and horsepower numbers are the goal, then just spend $50,000 and stick a jet engine in there. Or buy a McClaren. Or a drag bike. Or a top fuel dragster.

For most of us, the goal is a fast 928, that kicks *** over most other cars on the street.
I think a stroker, a TT, a CS or a Twin Screw, will all do the trick...

So what's the price tag?