Mongo

Did anyone just catch the latest issue of Excellence in their mail?? (has 4 911 RS cars on the front of it) It has an article featuring a great story behind the loved 1987 928 S4 that set the land speed record of almost 172 mph on the salt flats of Bonneville.

It's a great article that tells how much torture this car had gone through after setting the record and ends at falling into the hands of a man who restored the car into a track monster. What was interesting was the power gain stated just by allowing the engine to aspirate more. He had claimed 400 HP on an otherwise factory specified engine but had Devek Stage II headers, 3.5" piping leading to a Borla XR-1 race muffler. The intake tubes leading to the airbox have been widened with larger diameter ducting. Is this possible to get that much power out of an early S4 with just intake and exhaust modifications??? Because, thats a lot of power here and we all love power.

Andy

hacker-pschorr

http://www.erik27.com/pca/Mark%20Kibort/

Fastest928

We have had a GTS making 342 rwhp using our Level 2 headers, 3.5" exhaust with cats and RRR. A gain of over 45 rwhp...a rare case as the usual gain is around 25 rwhp with cats, close to 30 without. Most S4's go from 275/280 to 300 ish. Each engine is a bit different due to cam timing. Best to nail the cam timing spot on or a tick retarded....cam timing is worth about 10-12 rwhp.

Best S4 was 313 with cats, and best GT was 329 rwhp...or about 400 hp! using 17% driveline loss.

Mark K's engine is a healthy one!

Marc
DEVEK

hacker-pschorr

marc, what kind of a power gain do you see on the 16V cars with your headers?

Mongo

Marc is the cat you are using the factory? or did you guys fabricate an aftermarket one yet? Great power gains on your amazing headers!

Andy

Mongo

oh Marc one more thing. I see that you sell a complete exhaust for the 928 S4. Does this include the headers? Stage 1 or 2? Catalytic converter included with it also?

Andy

IcemanG17

<<Most S4's go from 275/280 to 300 ish. Each engine is a bit different due to cam timing. Best to nail the cam timing spot on or a tick retarded....cam timing is worth about 10-12 rwhp.

Best S4 was 313 with cats, and best GT was 329 rwhp...or about 400 hp! using 17% driveline loss.>>

Marc
When you quote an S4 is that with the automatic or 5-speed?
Thanks
Brian
I have to get my car on a dyno!

m kibort

Seems to be right in line. my 335 rear wheel was its best. last 3 dyno days over the last 2 years have shown a bit less, down to 318-320. remember, i also have a very loud exhaust, no MAF screens and a very open air box. Ron's GT racer put down almost the exact same, but with mufflers, and no cat.

I would imagine that the 313 Devek saw with cats , would do about the same as mine. No reason mine shouldnt make this much, as it is a pretty new but old (ie 29,000miles, but 19years old)

we started with 285 at the rears with a cat bypass and by the time we were done with adding equal length devek stage II headers, we were up to 335hp originally. (or approx 400hp flywheel)

Not bad for an almost 20year old porsche without a bolt turned on its engine since it left the factory almost 20 years ago. (and 3 full race seasons to boot!)
(knock , knock, knock!)

MK

Mongo

good to know your car is still running ship-shape Marc! It's amazing how much of a power gain you got from the exhaust still....makes me wish I had the $$$ to put a full Devek exhaust on right now I trust we'll be seeing you more on Rennlist hopefully since this forum is growing about as fast as the rabbit population Keep us updated on your progress with that infamous beauty!


Andy