Last of the Twin Turbo conversion videos are uploaded to youtube
 

For those who are interested, I have uploaded the last of the twin turbo conversion videos up to youtube. These have been on my camera since July and I've been busy pulling my shop together since then so the videos went onto the back burner.

YouTube - HerrKuhn928's Channel

All in all, the car turned out very well and there can be no dispute that turbocharging on these cars is a viable and very desirable option.

This entire conversion was done on a stock 928S4 engine with about 70,000 miles on the clock. No internal modifications to the engine whatsoever.

Sure "LOOKS" Nice, but how come no actual running of the engine and/or some wicked spooling up noises?

Throw down some of the Car and Engine running.

See part 16. Trust me, this car runs well and has already posted well past 600 HP on the tarmac on the stock engine.

Wasn't a trust issue, but I was looking at the vid and didn't see anything running. I just assumed a final video would be a "all hell breaks loose" vid of it doing it's thing. Let me go back to your Youtube channel and look at part 16.

Nice run on a hot humid day. An "honest" 550. How about we make your last video of a run on the street. The throw in a little Bill Ball SC Burnout down the whole block.

Now that would be an awesome last video of your Twin Turbo Project. Sure wish I could see you car in person. Don't your kids need to make a San Diego Sea World run pretty soon? ;)

Bill Ball S/C burn out was a one wheel willy burn out .:D

I would have gotten some street videos of the car, but the owner was very anxious to get it back to New England. He literally got in in the day after I finished it up and drove straight through. Car did fine and got 20-22 MPG on the 900 mile trip.

I still have my car so maybe more videos are needed? I intended for the video series to cover all the details of such a conversion and to cut through all the BS spread over the years on turbocharging a 928. Now it's all out on the table for the world to see.

John,

Stayed up until about 2 AM this morning watching all the videos in bed. Wife was HAPPY about that!

Are any significant changes necessary for say an '86.5? I know the manifolds would need different flanges. Also I was talking to John at P9 about his stuff, and said I should get with you about what you and John Speake had found for a car like mine. Mainly for tuning, knock control, etc.

The 86.5 question is one I often get asked. If people call me and they don't own a car but want to purchase one with the intent of turbocharging then the answer they always get is the S4. There are many reasons the S4 makes a better platform and I will list these:

More base power to start with
Bigger brakes (though does no apply to 86.5)
Knock control in the EZK...a good thing to have for a turbo car
Ability to run large injectors on the LH...up to 60 lb/hr (earlier cars can only run like 36 lb/hr...you have to tune the rest with a RRFPR)
To upgrade the clutch is less money as it is single disc

I'll refrain from making styling comments, because beauty is always in the eye of the beholder and styling holds no merit on this topic.

With all of this said, the S4 and newer cars are a much better starting platform for a conversion. I don't currently have anything that will bold right up to the S body cars, but I have done some sorting on a mid mount car with new intercoolers and upgraded fuel management with full boosted control of the EZF so you have timing control rungs under boost and vacuum.

I always tell people the best path on this venture is to sell the early car and buy a clean S4 to do the conversion on. The differences seem subtle, but they run pretty deep into the car and are hard to really get around unless you want to spend a lot more money. For example if you wanted to run 60 lb/hr injectors with the LH2.2...well it won't be possible, so you have to go to stand alone ECU or go smaller injectors and trim the top with a rising rate regulator. Either way is just a lot of hassle in my opinion.

I hope this helps to clear up the differences in the cars. With that said, I have the ability to re-write the chips for the early cars as well as the newer cars (not L-Jet though). I have also developed a clever way to map the boosted range on the EZF system. After all, you don't really want the same timing at atmospheric conditions as you do under 12 psig boost.

Glad to answer any more questions you might have on here or via phone.

Thanks,

JK

I'm already "in it" with the '86.5! I suppose I can just make my next 928 an S4, the headaches seem like they might not be worth the hassle on the early 32V. I REALLY love the S3 cars.

Thanks for taking the time to answer though, I'm sure I'll be on the phone before long with you.

No worries...but just remember, you didn't put a ring on the 928's finger...it might be okay to take a look and see what elese is available. Never too late to add another 928 to the stable either. If you want a track/street car there is a guy here with an 87 S4...rough but a good platform. Car can probably be had for high 5K range.

Cool, nice Job and some great HP out of a other wise stock engine.

I'm really impressed that you got all that stuff crammed in there AND looking so good. It must have taken forever to work all that out. I played mega-millions tonight. so you may be hearing from me. I live in NE too (30 miles from Boston), I hope I run into that car so I can check it out in person. nice work. .... but wouldn't it be easier to just put in a chevy crate motor ;)

The development took about 1000 man hours to figure out and implement. I'm currently talking with a potential customer who is building a 962 replica and wants to consider putting the 5.0 twin turbo into the car. That would be a really nice package, but could be totally different due to having more real estate back there. You could make full headers and go even bigger on the turbos, plus dry sump the engine. I guess those cars when finished weigh in at about 2,000 lbs. 600 HP with 2000 lbs is a little over 3 lbs/hp....that's hyper-fast territory.

Pete...I used to live up your way. From 1980-1992 I lived in Amherst, NH and graduated from MASH in Milford in 1989. If you are 30 miles from Boston, then you must live on the border of NH and Mass.

I'm sure Tuomo would welcome poeple looking over his car, I know he takes it to several shows up there. He is very open about discussing the car and the system.

Here's one new updated video:

https://www.youtube.com/watch?v=cxn-LxwsrnU

Results from that day:

https://picasaweb.google.com/lh/photo/Pj_YXeTIUdXHJZe11waREeFU7TCHMCAd9lnQulb4eyg?feat=d irectlink