After scouring the Rennlist on the topic of supercharging my 3.2L 911 (which is in a 1977 911s chassis), I was pleased to find some posts on the topic which were quite helpful. I still have some questions for those knowlegeable about my engine (1987 3.2L) and transmission (1977 915).

1. Does anyone have actual dyno figures from a supercharged 3.2L carrera motor. Also, dyno figures from the same motor, prior to supercharging. Which supercharger was installed, was it intercooled, and were there any other modifications to the motor?

2. Will my 1977 915 tranny handle the power. Will it be suitable for track use. My Tranny has been recently rebuilt by a local Porsche mechanic, and works great.

3. Can, or rather, should I install this system on my motor (which has approximately 65K since a rebuild of unknown quality. I currently get some blue smoke at startup, but no smoke once warmed up, and no smoke at the track. Rebuilds are so expensive, and I'd rather wait until it is more necessary. Is this reasonable, or should I get the engine rebuilt prior to a supercharger install (notwithstanding lowering the compression for a higher pressure supercharger kit). I am considering the lower pressure paxton system which helps the engine produce a "claimed" 350HP.

4. Does anyone have an opinion on Supercharging of Knoxville as a company based on their experiences with them. How is their customer and technical support. How about their HP claims, do they seem reasonable?

5. Are their any other reasonably (similarly) priced options for gaining similar amounts of horsepower as supercharging my 3.2L motor. (Please note that selling my car and buying a turbo car is NOT an option). I should be able to get 300+/- HP from my engine with a proper performance rebuild, exhaust, mass flow intake... per my mechanic, but it costs approximately twice as much as the supercharger kit.

I would greatly appreciate the advice of anyone with experience on this matter of supercharging their 3.2, or even feedback with how it went with their 3.0 or 3.6...

This is my first post, and I look forward to your responses.

Jason

 

Jason,

If you haven't already, you may want to look at Paul Frere's "911 Story", Bruce Anderson's "911 Performance Handbook", and Tobias Aichele's "Porsche 911 Engine History and Development". All talk to what changes Porsche made to their turbo engines for longevity, and Frere (maybe Anderson) discuss the hp capacities of the 915 transmission. Bruce Anderson also talks about options you have for rebuilding a 3.2 into a more powerful engine.

You've probably already factored into your budget that with larger engine horsepower increases you'll likely want to upgrade your suspension and certainly the brakes (track saying: Before you can go fast you have to be able to go slow). Here's an article on a brake upgrade that may be of interest: <a href="http://tech.rennlist.com/911/pdf/Upgrading_Porsche_Brakes.pdf" target="_blank">http://tech.rennlist.com/911/pdf/Upgrading_Porsche_Brakes.pdf</a> In addition, VCI has some good information on their web site about other upgrade options: <a href="http://www.vehiclecraft.com" target="_blank">www.vehiclecraft.com</a> .

 

i have an 3.0sc and was interested in getting in the 300 horsepower range and the only way was to supercharge. but after dealing with superchargers of knoxville i decided to just drop a turbo motor in the car. i did not like the way i was treated buy SOK so i would not buy a anything from that company. maybe other peaple have had better results.

 

Bill:

I appreciate the advice on brakes/suspension, and am acutely familiar with the fact that these systems are currently/and or will be upgraded from stock. I've read Bruce Andersons Parformance Handbook (and have since lost it!), and am aware of the rebuild options for my engine from talking with various (reputable) Porsche mechanics in my local area. Based on discussions with them, it tends to cost $10,000+++ for the proper rebuild with upgraded internals etc... for higher HP. Based on this, supercharging appears to be a viable option (however will likely speed up my need for a rebuild)

I'm trying to either talk myself into or out of supercharging my engine by using the knowlege and experience of the people in this forum.

Thanks for your reply, and any other advice is greatly appreciated.

Jason

 

Jason,

There's another thread similar to this one going on now. If more hp is the goal, you may want to consider selling your engine and installing a 964/993 3.6L engine. You get a 250-280 hp in a modern, solid package. In a lighter chassis, the benefits are magnified. And there's lots of expertise around, as this has become more common place. Just another approach....

 

Bill:

I understand that a 3.6 is an option for me but...

1. Dont I then need a G50 Tranny,(which requires modification to my car to install) My car is a 1977 911S.

2. Won't I incur an additional weight penalty over my current 3.2L motor. If so, do you know how much?

Thanks for your reply.

Jason

 

Jason,

I believe 915's can be hooked up to 3.6L engines. Check out Dr. Timmin's page which is mentioned in another current post on Rennlist. The 3.6 engine weighs around 515 lbs and the 3.2 weighs in around 482 lbs, so yes, you've got around 30+ pounds of difference. But remember the 3.6L engine was pushing around 3080 lbs vs your '77 weight of around 2575 lbs. 500 lbs is a big difference. Jack Olsen, in another similar thread on Rennlist today, has a 3.6 and I'll bet his has a 915 in in it. You might ask him. Thom Fitzpatrick also has a 3.6 hooked up to his 915, as I think about it.

 

You don't need a G50 if you put a 3.6 in, and it adds about 90 pounds of total weight.

In my own research, I've come across too many supercharged engines that have, for want of a better expression, 'blown up.' In fairness, though, a lot of guys love the superchargers.

A 3.6 will give you factory reliability.

 

I´m very interested about this question of superharging a flat six in a nine eleven.
I have a 911 SC 1979.
180HP is´t enough and I know 3.6 conversions don´t need G50.

Unluckily enough I live in Sweden, a small country far away from big sweet US.

Any tips to me?.

Where can I get a 3.6 in europe?.

 

I know of a good source for 3.6's in Germany. Email me if you're interested.

jackolsen@attbi.com