Horsepower Estimate

gt_diesel · 07-18-2006, 11:43 AM

I was wondering about a horsepower estimate for the engine in the Porsche I am buying. It is a big bore 3.4 Liter, Mahle Pistons and Cylenders, 7.5:1 compression. Group B cams, K28s Turbocharger, Heads have been ported. It has a custom intercooler, crankfire ignition, B&B headers... etc. The engine currently pulls 1.1 bar....

The engine is in a lightened 86 911 Turbo Widebody (930) and weighs in at about 2700 lbs. It is running a 4 speed trans.

Any ideas????

I am thinking about throwing it on the dyno after I get it to see what it puts to the wheels.

asphaltgambler · 07-18-2006, 11:51 AM

I would think in the 400hp range (flywheel) with those goodies

jdm61 · 03:25 PM

wouldn't 375-400 be about the natural limit without some pretty serious mods to the fueling system? That engine in your car sounds a lot like a mid-80's Ruf BTR which was good for 375-380, right? and with the wide body, about a 175 mph top end maybe? i know the narrow bodied one tested at 183mph

gt_diesel · 07-18-2006, 03:27 PM

I forgot to mention, the fuel system has been completely gone thru and updated. I am not sure what has been done to it, but I am told it will support 600 horsepower without any issues.

jdm61 · 07-18-2006, 03:31 PM

Quote:

Originally posted by gt_diesel
I forgot to mention, the fuel system has been completely gone thru and updated. I am not sure what has been done to it, but I am told it will support 600 horsepower without any issues.

I don't think a K28 will flow enough air for 600. I read a while back that most of the "600hp" engines actually put out somewhere in the 400+ range when you actually get them on the dyno. You car kinda sounds similar to the standard big bore Andial upgrade. I';m sure it has more than enough horsepower to be an inherently dangerous vehicle in the hands of someone, oh, like me!!!!! lol

gt_diesel · 07-19-2006, 07:06 AM

How much HP will a K28s support on a 3.4 litre? I have a buddy that is claiming 550 horse with a K27.... Is that possible?

Craig 930 RS · 07-19-2006, 01:58 PM

1.1 bar on a CIS engine is idiotic. Sorry, no way around it other than that comment.

I hope it has never ever seen a track day. Has it?

gt_diesel · 07-20-2006, 12:58 AM

sorry if I sound stupid, but what is CIS? and what makes that idiotic? the car was built as a track car....

Craig 930 RS · 07-20-2006, 06:11 AM

We need some stats and pictures, gt. I'd recommend you do a lot of reading and learning about 930s/Turbo air cooled Porsche cars to learn what you are getting into......and what not to do.

CIS is the quasi-mechanical injection system - it typically cannot support more than about 450 crank HP without fairly serious modifications; ie fuel head or better yet, EFI.

1.1 bar on a non-EFI engine is really pushing it. What are the AFRs (air fuel ratios) on the dyno? I hope they are 12.3 or less all the way up.

gt_diesel · 07-20-2006, 06:31 AM

I am new to the Air Cooled Porsche world, but I have a really great Porsche guy who will be doing all my work for me... I am in the process of buying the car right now, and as I understood it, the fuel system had already been changed out to EFI.... I will know much more about the car as I go thru the paperwork and find out more and more. My Porsche guy seems to think it will be a great car for what I am looking for.

The motor was just built about 10k miles ago. For right now I know it has a 3.4 Liter Kit with Mahle Cylenders and Pistons, Group B Cams, The heads have been ported. It has all new valves and valve train. A K28S high flow turbocharger. I believe it is 7.5 to 1 compression, but I do not know for sure yet, it may possibly be a little higher. It has a 1 Bar Spring, which allows for about 1.1 bar according to the RUF Boost Gauge. It has Carillo Rods, it has been O-ringed. The fuel system has been updated ( I am assumeing EFI ) It has a custom intercooler and custom oil cooler. Bolt in roll cage, Sparco seats. The trans was just rebuilt with new sycros and such. It has fully adjustable coilovers all the way around. Kenesis K58 Wheels. Tires are pole positon SO-3's. It has carbon fiber fenders, wing, and front spoiler. The brakes are the Big Red Twin Turbo brakes.

I am hoping it will be a blast to drive... I have drag raced for 10 years and have done some track days and stuff with my M3, and figured it was time for somthing a little different.

I am hoping to have the car by next weekend. I will have to give some driving impressions and I will let you know what I end up with on the Dyno.

Craig 930 RS · 07-20-2006, 07:07 AM

Hmm, nice setup. All that is left is to find out if you have the original CIS vs. EFI system...this is a biggie.

The rest of the stuff done to your car = A1 good stuff!

rsrfan · 07-20-2006, 08:44 AM

Have a proper ppi performed, and ask specifically what has been done to the fuel system to support high horsepower claims. As Craig can tell you, bad things happen when these cars are run at high boost without proper fueling. If these cars are built right, 1.0 bar is all you will need. Trust me, things happen REAL fast at 1.0 bar boost.

JP

gt_diesel · 07-20-2006, 03:42 PM

Did some more research, the compression ratio is actually 8.3 to 1, and the Fuel system is a programmable setup and has been tuned to the car.... I think the higher compression would change the HP numbers a bunch.... What do you think?

Craig 930 RS · 07-21-2006, 09:25 AM

8.3? That is quite high.
We really need to know exactly what fueling it is to help you.