RE: Porsche 944 V8

[will_968]

posse948 said:

Hi I am racing a 924 with a 928gt engine in swedish endurance series.
I would like to know what modifications that where made on the Kelly Moss 928 engine,
I have heard that it benched more than 700hp.
Any one with some info regarding
Bore/pistons?
Crank / rods?
Camshafts ???
Regards
Jan

Drop Bret928S2 a PM - he's your best bet for either knowing, or knowing someone who'll know.

[Cheburator mk2]

posse948 said:

Hi I am racing a 924 with a 928gt engine in swedish endurance series.
I would like to know what modifications that where made on the Kelly Moss 928 engine,
I have heard that it benched more than 700hp.
Any one with some info regarding
Bore/pistons?
Crank / rods?
Camshafts ???
Regards
Jan

Hi Jan,

You should check out the rennlist forums, where there is a lot of info on many powerful 928 engines. I don't think Kelly Moss ever fitted the engine in a 944 and made it work. I think the most powerful Porsche V8 at present is the 6.5ltr ITB stroker as found in Louis Ott's GT with 550Bhp+ at the rear wheels.

HTH,

Alex

[MartinD]

Cheburator mk2 said:

posse948 said:

Hi I am racing a 924 with a 928gt engine in swedish endurance series.
I would like to know what modifications that where made on the Kelly Moss 928 engine,
I have heard that it benched more than 700hp.
Any one with some info regarding
Bore/pistons?
Crank / rods?
Camshafts ???
Regards
Jan

Hi Jan,

You should check out the rennlist forums, where there is a lot of info on many powerful 928 engines. I don't think Kelly Moss ever fitted the engine in a 944 and made it work. I think the most powerful Porsche V8 at present is the 6.5ltr ITB stroker as found in Louis Ott's GT with 550Bhp+ at the rear wheels.

HTH,

Alex

As Alex says, use the search function on http://forums.rennlist.com/rennforums/928-forum-69.... Louis Ott is on there.

From Louis's web site http://www.performance928.com/cgi-bin/page_display...
The engine is 6.5L. It has 968 intake valves & mildly ported heads, 11.4:1 compression ratio. The cams are Devek B1, Devek headers and dual 3" exhaust. The intake system is individual 50mm throttle body using my adapters to mate the TBs to the cylinder heads. Rear wheel horsepower is 578 and torque is 523.8.

BTW . Devek are no longer in business.

Alex, what about Mark A's race car ?

[posse948]

Thanks for yor quick answers.
Do you know how he reached 6,5liters ?
Is it 104mm bore with pistons from a 944s2 or custom made pistons ?
(anything that can be ordered somewhere?)
Crank is it the 928 GTS crank or a custom made ?

I am running (but at the moment totally smashed) a 928 GT 5,0liters.
With camshaft regrounded with a smaller basecirkel ( I think this is about the same as the B1)
intake lift is just 9,6mm = 0,378 inch.
Solid lifters. Std valves, ported head.
Home made headers 1 3/4" to dual 3", dual 4" catalysators (Swedish regulations for racing since 2007)
Modified 50mm throttle bodies from a BMW M5 E34.
Autoverdi dry sump, with crankscrapers windage plates.

Regards
Jan

[MartinD]

posse948 said:

Thanks for yor quick answers.
Do you know how he reached 6,5liters ?
Is it 104mm bore with pistons from a 944s2 or custom made pistons ?
(anything that can be ordered somewhere?)
Crank is it the 928 GTS crank or a custom made ?

I am running (but at the moment totally smashed) a 928 GT 5,0liters.
With camshaft regrounded with a smaller basecirkel ( I think this is about the same as the B1)
intake lift is just 9,6mm = 0,378 inch.
Solid lifters. Std valves, ported head.
Home made headers 1 3/4" to dual 3", dual 4" catalysators (Swedish regulations for racing since 2007)
Modified 50mm throttle bodies from a BMW M5 E34.
Autoverdi dry sump, with crankscrapers windage plates.

Regards
Jan

Jan
All your answers are on Rennlist & a lot more info besides. Rennlist 928 forum
Without looking it up its 104mm ,968 pistons & custom crank & rods
The crank & rods are available from Greg Brown In the USA (find him on Rennlist)
Lots of info on this thread
http://forums.rennlist.com/rennforums/928-forum/47...

I thought the GT cam lift was 10mm, S4 9mm ? with reground cams running 11mm lift.

Martin

Edited by MartinD on Wednesday 7th January 18:10

[Cheburator mk2]

posse948 said:

Thanks for yor quick answers.
Do you know how he reached 6,5liters ?
Is it 104mm bore with pistons from a 944s2 or custom made pistons ?
(anything that can be ordered somewhere?)
Crank is it the 928 GTS crank or a custom made ?

I am running (but at the moment totally smashed) a 928 GT 5,0liters.
With camshaft regrounded with a smaller basecirkel ( I think this is about the same as the B1)
intake lift is just 9,6mm = 0,378 inch.
Solid lifters. Std valves, ported head.
Home made headers 1 3/4" to dual 3", dual 4" catalysators (Swedish regulations for racing since 2007)
Modified 50mm throttle bodies from a BMW M5 E34.
Autoverdi dry sump, with crankscrapers windage plates.

Regards
Jan

Wow.

That is one hell of a modified GT engine I would guesstimate that you are making around 370rwhp. Can you give us more information on the engine management and how you managed to mate the E34 M5 throttle bodies to the GT heads? They are cheap to get in the UK and my GTS engine needs more power...

To answer your questions:

To get 6.5lts - you will need custom pistons and a custom crank. If you are to use a GTS crank, 944S2/968 104mm pistons and custom rods you can get to 5.9ltrs.

Can you post pictures of your car. Pretty please.

[posse948]

Hi guys,
Thanks for the advise of Rennlist, 2 years ago I was a frequent visitor but didnt find much, tried it now and there seems to be a lot more going on, thanks!

Martin I mixed up figures exhaust is 9.6mm lift, intake is 10.6mm net lift.

I will post some pictures but have them on another computer.
Here is a link to a Swedish endurance cup homepage.
http://www.slc.se/foto/bilder2008/r3/index.html we are #90 Hooka Hey Racing.
We had some problems with a electromotive tec2 system at that race and several before, after about 30min hard driving it started to put out fuel at braking so we made a lot of smoke and finally melted the catalysators. We changed to a NIRA i3+ system and solved that problem.

We are on a low budget and have built the car by ourselves so there is alot of varied quality of the solutions...
The M5 throttlebodies took a while to fit I will send some pictures.
Regards
Jan

[928tt]

Interesting there seem to be several different paths to the same destination with 928 V8s, 6.5 litres putting out 550 rwhp and on the other hand John Kuhn puts a couple of turbos on a 5 litre for 550 rwhp, I'm putting my money on turbos for nicer mid range grunt. Cheers Roy

[Jan K]

Hello

I have been building a all carbon fibre body 944 turbo for track use and now we are starting with the engine so which engine? possible candidates:
951 engine with some vitamins 450hp. good things! we has the engine. Bad things the sound and turbo lag.
928s 310hp engine with turbo +500hp. Good things! we has the engine. Bad things it's expensive and fragile.
Corvette C5 engine with supercharger. Good things! Good torq, doesn't brake much. Bad things! we has to by one, We make Porsche racers= no good pub.
Cayenne turbo engine +550hp Good things! it''s from Porsche and i like the idea. Bad things! The price 8000€ on the salvage yard
What to do?
I think we go for a Porsche V8. Wich one! it's depends on how much money we has left after making the body and chassis work on the car.

[Cheburator mk2]

Jan K said:

Hello

I have been building a all carbon fibre body 944 turbo for track use and now we are starting with the engine so which engine? possible candidates:
951 engine with some vitamins 450hp. good things! we has the engine. Bad things the sound and turbo lag.
928s 310hp engine with turbo +500hp. Good things! we has the engine. Bad things it's expensive and fragile.
Corvette C5 engine with supercharger. Good things! Good torq, doesn't brake much. Bad things! we has to by one, We make Porsche racers= no good pub.
Cayenne turbo engine +550hp Good things! it''s from Porsche and i like the idea. Bad things! The price 8000€ on the salvage yard
What to do?
I think we go for a Porsche V8. Wich one! it's depends on how much money we has left after making the body and chassis work on the car.

The 928S engine is not great for turbo-ing for 3 main reasons:

1. High compression at 10.4:1. You will have to go with custom pistons on that one
2. The LH-Jetronic/EZK cannot be mapped with a "SharkTuner" unlike the later 928 S4 engines, which have the next generation of LH/EZK units
3. The 928 engine breathes very heavily and suffers from oil surges when raced. Thus you will need a dry-sump.

Thus go with a Cayenne V8. There is a lot of 928 DNA in it anyway...

[beario]

anyone know or have a contact email for... mr xv8