Most poweful 928?
I think the record is around 650 crank horsepower with all genuine porsche and I think the reason nobody has gone higher is because of the transmission. Of course 650 hp will get you around town at a pretty good clip so maybe there is little point to going higher.
Trending Topics
The Best Porsche Posts for Porsche Enthusiasts

He has since ran a 6.1 stroker, at a boost level I cannot remember. This is the “sister” motor to the one Tim Murphy is selling. Custom crank, rods, pistons, bored out etc…
https://rennlist.com/forums/928-forum/271335-6-1-liter-stroker-short-block-for-sale.html
His current motor is using stock crank & rods with 110mm bores to the tune of 6.1+ liters (I cannot remember the exact numbers) at 15psi while the motor brakes in. I’m sure the boost number will increase slowly as he tests the motor.
Once he is confident this motor is working well, he will remove it to increase the stroke on the 110mm bore motor for a 7.1 liter supercharged engine.
He has talked about making a 7.4 liter high compression normally aspirated race motor to drop into an S4 chassis he purchased last year.
Keep in mind he performs 95% of the work (including the machining) in his garage.
So far he has not reported any issues with the stock Automatic transmission in his car. I would also like to point out the car he is using for this project has 150,000+ miles on it. If he has rebuilt the trans since purchase, he has not told me about it.
Sitting in his garage next to the 928 is a motorcycle he built from scratch. Powered by a supercharged type 4 VW engine putting 350+hp down to the ground at the back tire. Ever since I met Todd (over 10 years ago) this bike is his daily driver when the weather permits. Before starting the 928 project, he was carving a new crank for his bike from scratch – since he could not find a current VW crank to suit his needs.
First visit to his garage he was making 911 cylinders on a lathe for a race motor he was building. He said none of the aftermarket 911 cylinders were good enough, so he decided to make his own.
Some info on his current motor:
https://rennlist.com/forums/928-forum/239222-110mm-bore-928-engine-project-plans-for-a-7-4-liter-in-the-works.html
IIRC he has over 3,000 miles on this engine already – it is now his daily driver, said the bike just doesn’t “do it” for him anymore. So if a lightweight aluminum 7-speed motorcycle with 350 rear wheel horsepower doesn’t cut it, I can only imagine what his S4 is like. Last time I went for a ride it was only the 5.0 24psi motor. Usually I drive myself or ride with Tim Murphy (it gets old watching multiple 500hp 928’s pull away).

https://rennlist.com/forums/attachme...hmentid=&stc=1
DonsDyno.jpg
Last edited by Louie928; Mar 18, 2008 at 01:11 PM.
I wanna say thats a 1/8 mi time...but the trap speed is other-worldly...unless someone is playing games with the results reported. The host of this vid has several others up- Aussie or NZ, I think.
928 Drag Vid
Edit: Ah, which means that speed & dist is probably in Km, but still....
Gotta love Don's torque curve...or 'table'..
Last edited by SMTCapeCod; May 23, 2006 at 11:58 AM.
I wanna say thats a 1/8 mi time...but the topspeed is other-worldly...unless someone is playing games with the results reported. The host of this vid has several others up- Aussie or NZ, I think.
928 Drag Vid
Edit: Ah, which means that speed & dist is probably in Km, but still....
Gotta love Don's torque curve...or 'table'..
Don's engine runs pretty strong.....must be the 52mm individual throttle body intakes that makes that much power!!




