Kuhn Performance Technologies 32V 928S4 Twin Turbo Nearly Complete

[Herr-Kuhn]

Good observations on the fuel economy. I'm hoping I can still get the 20-22 on daily drive...that is darn near what my 5 jug S4 gets back and forth to work (I tap into the boost a lot though). This is the true bueaty of the turbo, there is nearly zero penalty when cruising, even at high RPMs and low loads. It sits quietly in the background until you drop your foot and call for it. Your docile, well mannered 928 then becomes a real blast of a ride. With the way my 4.5 and 4.7 builds have turned out and knowing this car has so much more potential....let's just say I have high expectations out of it.

Regarding weight...I have not actually weiughed all the bits up, but I'm sure total there is some weight added. However, this is nothing 0.2 psi won't take care of in a hurry. Induction plumbing could be made of aluminum to shave weight. I don't think the additional is enough to mess up the balance of the car though.

In the case of my dog's stainless rear end, it was a shattered leg between the knee and the hip. The biggest piece was just one inch long...the rest was shattered. He got an erector set plate and was back in business after 6 weeks!

[rhjames]

Yeah, the Indy motor isn't quite a "street" engine, at least the one I was thinking about. 16:1 CR isn't quite streetable, but they do make a 605 ci motor at 10:1 (750 HP--775 ftlbs torque). Then again, I think I'd just drop the CR on the 655 down to get it streetable.

I was just curious if Herr had thought about a total engine weight including his turbo setup.....

Everybody had no problem putting a Chebbie in a 928 (ala Renegade kit), but I was toying with the idea of dumping an all aluminum big block Mopar in one. (What the heck, it costs the same as Phil Threshie's 6.4L 32V stroker, but makes a lot more power---I've not seen any dyno reports of his making more than 500hp.)

Dimensionally, I believe it would fit. Then it's nothing more than fabbing up adapters for the clutch and torque tube inputs..... motor mounts are easily fab'd using aluminum motor plates on each end of the block, bolting them to angle pieces welded to the frame (same way we build a drag car). No EFI to mess with, no computers to limit what you're doing, just raw power.

Fun discussion, these things are, but when you're looking at the cubic dollars to do it (which ever way you go), one has to look at all of the possibilities.

Of course, there's always a HEMI in that mix as well.

Mmmm......750 hp to start with, then add a turbo setup.

That would be a deal.

Speaking of weight reduction:

Changing from the 16 inch tire/wheel combination I had, to my current 19 inch tire wheel combo, had a net weight reduction of over 45 pounds. Now there's weight we can all afford to lose, if we're trying to go just a little bit faster.

regards---rhjames

[rhjames]

By the way Herr,

you might fix that wiring issue on your right front. looks like the ABS wiring---

Such a nice setup to have a busted bunch of wires showing.....

I didn't notice any mufflers (?), and what size are the pipes you're using?

Keep it up--looking very nice.

regards---rhjames

[Herr-Kuhn]

Yes, my doner car has some miles...but this was planned...wanted to make sure the car could handle the boost with high miles.

For now the exhaust is stock, minus the rear can. The downpipes are 2.25" diameter. Longer term, I might upgrade to a dual 2.75" or so. My goal was to not have to upgrade the full exhaust on this car to make good numbers. KISS concept.

Once the brain gets back from Ott's I'll be able to turn the car over...JUST as the weather is shaping up! Nothing like good timing!

Cheers.

HK

[T_MaX]

Herr-Kuhn, do you have a website, how can you be contacted?

[sonett3]

T-max you can email him at herr-kuhn@netzero.net . He is out of town right now he will be back nexted week.

[ceedee]

Originally posted by sonett3
T-max you can email him at herr-kuhn@netzero.net . He is out of town right now he will be back nexted week.

your OB twin turbo set up is needed here. can i have it?

[jsbc]

Im interested in doing this to my euro 85 16v but will probably have to drop the cr(10.?) whats your cr and max boost

[Herr-Kuhn]

The 16V cars run well on 8:1 The 32V cars shoudl be able to run decent boost on the stock compression because of the superior design of the combustion chamber.

I'm starting the tune on the 32V twin turbo today.

[Zimoludek]

Hi, anyone know where I can buy those black filter adapters. Those that go on top of the radiator. PM me please or text 973 930 6164

Originally Posted by Herr-Kuhn

Greetings,

I've come here as a new member to share some of my work to other 928 enthusiasts out there. My project was to take a garden variety 928 S4 and add the best form of forced induction, namely turbocharging. To further this, the system had to be top notch in its method of approach, both from a technical and aesthetic standpoint.

The 928S4 twin turbo system offers the following:

2 Garrett GT series liquid cooled ball bearing turbochargers 750+ HP capacity

2 Air to Air bar and plate front mount intercoolers 10"X4.5"X8"

High energy pulse flow designed exhuast manifolds, ceramic coated

Dual Bosch compressor bypass valves

Split exit downpipes, seperating wastegate exhaust flow from turbine discharge, ceramic coated

Dual air filtration and inlet snout system

Proprietary MAF junction box

JDS Porsche SUPER MAF

Shark Tuner massaged EPROMS, fuel and ignition as required

Run delay turbocharger water circulation system allowing water circulation through turbochargers after engine shut down.

This, that and the other...

This has been a very argued about project for the last 3 years. I promised to bring back a full blown (no pun intended) twin turbo system for the Porsche 928S4. Why? Beacuse the car is worth such a system and this is the way Porsche would have built it. I have been working with turbocharged Porsche 928s since 1990 and it has always been a dream to build the ultimate 5.0 liter 32V 928 street machine for me. I also grew really tired of hearing that a Centrifugal Supercharger was the "top dog" way to go for the 928 and that "turbos don't work on a 928" Some people claim this is an imaginary project, or won't work, won't outperform a supercharger, is too complex, etc. Not true as the below pictures show.

I investigated the "rear mount" turbocharger system for the 928 well over two years ago. I could never draw myself to even remotely warm up to that setup because the turbocharger is designed to extract the raw heat energy from the exhaust pulse. Additionally, mounting the air cleaner(s) under the vehicle was simply unacceptable to me. That meant front mounting was the only option for me, as it is for any factory setup or top notch tuner working in this field. Furthermore, splitting the bank loading with twins is the natural layout progression for a turbocharged V8 and is Porsche and Audi's choice for nearly all of their new turbcharged vehicles. In fact, BWM has seen fit to equip the new 3 series with twin turbos. The value is in generating an extremely responsive system, one which can deliver an ultra-wide powerband, not just a peak, chest-pounding dyno number. The widest powerband per pound of boost was the ultimate goal. I expect this setup to run circles around most new high performance cars on just 5 psig.

I attach some pictures of my project. In the next 3-4 weeks I will be putting the finishing touches on the system and running the car in. The first setup will run a low 8 psig, but I'm expecting some serious performance at even these low boost levels. After all we are chasing 5 full liters of displacement here with the latest in Garrett turbocharger design.

To date, this project represents 1000+ hours of investigation, engineering, fabrication, installation, etc. My motto has always been to do it the best way possible.

For those willing to write the check I can be willing to supply the systems. More information coming by February, 2007.









[img]
http://forums.pelicanparts.com/uploads9/IMG_2173+copy1167966275.jpg[/img]