Gretch

EVERY one of the 850i cars that I have ever come up against, I blew the doors off of.......they are not quick.......and they are not as fast as a 928 gt.

bcdavis

Quick Carl's is the main provider of superchargers for the 16v cars, until Andy Keel gets his kit up and running.
Carl has a lot of info on his site, if you want to look at dyno charts, torque numbers, etc...

http://www.928motorsports.com/parts/superchargers.html

Carl Fausett

All the numbers I gave you are from Dyno-Jet dyno runs of actual 16v 928 SC installations that I have done.

Herr-Kuhn

Ask to see what a centrifugally supercharged and intercooled 3-spd A/T car will do in terms of real world performance, not just on the dyno. I plan to do more performance testing sometime soon and I might even strap the Goldmember into place and make a few pulls, but for now it is just a cruising machine to and from work. I'll just mention that a Lancer Evo III could not pull away from this car in a straight line.

You will be hard pressed to match the turbo's performance addition with a CS system. Is it more involved, of course it is....but so is making a birthday cake from scratch as compared to out of a box.

If you are handy, you could make your own system. The manifolds are the hardest part.

Shane

There is no magic bullits for the early 16v engines. You pay for Hp either way, be it a 32v 928 or a supercharger, or 10k for some turbos. Like the early body style buy an '85-'86.5, and get 288 hp. Add supercharger to that and get 400hp. It really just depends on how much money you are willing to spend. All this other nonsense is a waste of time.

Carl Fausett

May I explore this twisted logic:

"don't buy a supercharger kit based on dyno numbers - use "real world" numbers instead..." Wow. Real world?

a) I left the Holideck or the USS Enterprise a long time ago - there were no chassis dynometers there. All the dyno's I have used have been VERY real world.
b) Like stop light runs against undocumented cars? You never know WHAT is in that other car. ...who wants to buy a HP solution based on hearsay of great street victories? Get real (world).
c) Dyno's have their fallacies, its true - just fewer of them. At least you can compare a dyno run in NC with a dyno run in SoCal and have some apples-and-apples to look at. Other than shipping the one car to the other coast its the best way I know of. Even 1/4 mile times are skewed by tire hookup, driver reaction time, etc - so instead of knocking dyno sheets as a source of comparison, please propose something better. I do not know any.
d) like "real world" results? here are some results of a SC 928 vs race cars equipped with race drivers on an open road course with no traffic lights - does that work?

results are at bottom of this page:
http://www.928motorsports.com/2002track.html

results are at the bottom of this page:
http://www.928motorsports.com/2003track.html

Next twisted logic topic: "Supercharger Lag" Please. "Lag" has long been associated with turbos as in the phrase "turbo-lag". I think it is well accepted that one of the benefits of superchargers over turbochargers is the elimination of "lag". This is one of our strong-points.

My boost comes in at 3k (on purpose, I could move it, but I like it there). I run her up to 6k and shift to the next gear - I'm at 3500 RPM in NEXT GEAR. I run her up to 6K and shift again. I'm at 3800 now, and accelerating again. Repeat. repeat. Repeat.

I am never NOT under boost in this driving (dare I say "real world") situation. What lag?

Tim's 32 v kit and My 2 different 16v kits are not on under boost at: idle, and at: partial-throttle cruising. Good. We avoid tip-in detonation this way, and can pass sampling emissions inspections with the SC kit ON.

Sorry for the satire, but COME ON. Some of us have spent the time and the MONEY to document EVERYTHING and have MANY DYNO CHARTS and offer VIDEOS and have written SEVERAL INSTALLATION MANUALS all so that our customers know we are the real deal in the REAL WORLD.

Lagavulin

'Hard pressed'?

If I remember correctly from an earlier thread, it was shown that Carl's centrifugal setup was slightly quicker than your twin-turbo setup, and just as importantly, cost HALF as much. The question is, why would anyone in their right-mind want to spend TWICE as much for something that could be had for HALF that, and to top it off, is quicker than the TWICE as expensive twin-turbo option? Finally, the centrifugal setup is much simpler.

'Hard pressed'? It looks like to me that YOUR version of a twin-turbo setup is 'hard pressed' to match the performance of a 'lowly' centrifugal setup.

John, don't you remember that thread? I am not exaggerating, unlike you (..as usual); all someone has to do is dig it up...

Adam C

Plus last time I checked, there is no long promised turbo kit or anything like it - and no dyno sheets.

It's pure vaporware.

James-man

Not quite vaporware. It actually exists - it is just not in kit form or stocked on a shelf.

Herr Khun is proud and enthusiastic about the performance of his turbo creation. I think that all boostards have similar feelings.

Too bad these things always seem to turn into neener-neener fests.

Herr-Kuhn

Hey, this guy asked which was better and I gave my opinion with facts and on the road performance figures to back it up... which is more than can be said for what we have seen for a CS strapped to an 80-82 AT 928. Where is the CS 4.5 liter 3-spd car pulling better performance? Please show it to me. Or, show my that system on a 5-speed 4.5 liter car with on the road performance. I've already proven the turbo makes more power and torque lb. per lb. and I've shown with the Goldmember what a dramatic improvement the turbochargers can and do make. Those are the facts without hiding or stretching the truth whatsoever.

Lag, you should stop mixing and matching....like I already stated the Goldmember with the 3-spd AT will beat my callaway off the line by 0.3 seconds 0-60...so when you make statements like this are you referring to "my system", or the callaway car I upgraded? Please get you facts straight and stop misleading people. This guy wanted a straight answer on forced induction and I gave it. It is the same answer you will get from any high end tuner that knows anything about pressure feeding an internal combustion engine.

Please do tell all of us how much boost you can make at 3000, 3500, 4000, etc up to redline...i.e. what does the boost curve look like? I've asked this many times but I never get an answer.

I'll remember comments like "real deal in the real world" the next time someone inquires with me about forced induced 928s, or fuel systems, or the like. That is all I'm going to say without mentioning any names. The R&D I've put into 928s is every bit as involved (if not more so) as anything any of the rest of you SC guys have done and you know it.

Cheers

tammons

Personally i think its just preferential as to if a person like turbos or superchargers. I guess the reason I like turbos is on the highway cruising they are just idling along and are not tugging on the crank all the time and I guess they seem a little more exotic. The twin setup is much more complicated though. After building 3 928 turbo setups, I would have to say that the 928 has to be one of the most difficult cars to twin turbo charge. Since it is so difficult it does make sense to use a supercharger that is much more of a straight forward type bolt on setup. Other than that i think a Single turbo setup is just a viable and is a lot less complicated than a twin and can make just as much power. Actually any of these setups if well designed , twin T, Single T, or Supercharger can all make the same sort of power. Stuff more air in and more fuel, and thats about it. A super charger does take more power to drive it. A turbo has constant back pressure so really I think its have dozen one or the other.

If you keep boost at a level where the engine and drivetrain will live a normal life you can expect to pick up 120 - 150 hp and probably 150 ++ ft/lb of torque out of either system. Also A good V8 turbo setup just does not have the same sort of lag as something like a 4 cyl turbo. Both my 928 T cars spooled up very quick and made a lot of torque from 1st gear and up.

Herr-Kuhn

Yes, I agree the SC works but the only no-lag supercharger is the positive displacement type. The centrifugal is a whole different piece of machinery and has the longest lag time to full boost of any method of force feeding. That is fact and can't be disputed. I'd bolt a supercharger on one too, but it would be like Andy has done. You are after area under the driving curve, and that is where the turbo outshines everything else....mid range and top end is what you are after in a car like the 928. The CS uses a centrifugal compressor that can't change speeds based on engine load like the turbo can. Like I said, running down the highway with 15 in hg and boot it and you have full boost in no time flat. The positive displacement supercharger is a whole different machine...hence the name.

I agree, you can make just as much power with the single turbo as with twins. For me, the twins are the way, it is elegant and if you open my hood the car looks virtually stock. Very stealth. Aesthetics always count. No it wasn't easy, but it can be done and can be reproduced reasonably if you put the work into doing it. Lately I have not had the urge to do so.

Have you run any performance figures on your single setup? I'd be curious as to what you are seeing with that setup as well as what wheels and trims you are using. I ran some performance figs on my twin...check the board.

Carl Fausett

From Rob Roy -
The fuel pump on the K-Jet CIS delivers higher pressures and volume than the L-jet setup, but that is because the mechanical injectors in the K-Jet require that.

One of the reasons the K-Jet and the L-Jet "max out" their fuel systems is the single 7.5 mm solid fuel line they use from the back of the car to the front. While large enough to over-supply the Naturally-aspirated early 928 at WOT forever, Helmut's fudge-factor allows us to run about 9 psi in our systems before his fuel system just cannot keep up.

This can be cured with tandem fuel lines (or a single larger line) and twin pumps, etc etc, but now this becomes (for us) no longer a simple, easy-to-install bolt-on kit, but a more involved project than most of our customers want.
That's why we do not talk about it much.... we do not want folks to think that they "gotta" do this to install our kit or supercharger their 928 - they don't.

Comparison: supercharged 1/4 mile race cars running V-8's over 600 HP often have 1/2" or larger fuel lines from tank-to-front. A 1/2" fuel line is 12.7 mm - quite a bit bigger than our 7.5 mm fuel supply line.

If our customers want to start at 9 psi with our kit, and then go up from there and modify the gas-tank-to-front-of-car fuel system, they certainly can. We can produce a LOT more air.

Hoyo

16v enthusiast...there is hope...

In Sweden there is a clever fellow that is installing a Twin Screw on his 1979 928. He has taken away the K-jetronic and fitted an aftermarked electronic fuelsystem.

You really should go to this page http://my928.kicks-***.org/Fries/

I am impressed.

Geir

Carl Fausett

Lagavulin - I ran out this morning to get some fresh G-Force numbers to compare to John's.

I just posted my 1/4 mile times side-by-side with John's on this thread:

"Real World Goldmember Results"
https://rennlist.com/forums/showthre...00#post2089800

Pretty damn similar, thought you'd like to see them. Thanks for your support.