Supercharging

[RSGulp]

I'm toying with the idea of a winter project to while away those dark nights...

I've always liked the idea of building a 'wolf in sheeps clothing car' to upset a few more modern and quicker cars on todays roads. My younger sister's just ordered a ClioSport 182 with a better power to weight ratio than my SC!

Has anyone any experience of supercharging an SC? I remember a copy of P&911World a couple of years ago with a feature but I think it was referring to a modified 3.2 carrera. I vaguely remember a kit purchased in the states and I think AmD or Autotune may have been involved in fitting the kit and dyno testing it.

Just a few points for discussion...

- any engine/gearbox/driveshaft mods needed to cope with increased bhp?
- would the exhaust need modifying to flow more freely?
- any ideas of overall cost and power improvement to a 3.0 SC?
- an any ideas of additional cost or potential problems with (honestly/legally) insuring a modified SC?

Thanks in advance,

Rich - Team Gulp Racing

 

[bones]

If you supercharge an SC Richard you will turn it into an animal, you need to look at uprating the brakes. If I was attempting that project I would make sure the suspension was up to scratch too. John Bellringer will chime in here soon and probably give you all the advice you will nedd on supercharging. The strength of the gearbox may be an issue if you are silly in how you use the power. Ideally you should have early heat exchangers and a freer flowing exhaust, I think John B runs a H&S system.

 

[Guest]

John Bellringer will chime in here soon

No I won't.

 

[bones]

Oh yes he will!

 

[Guest]

Super charging has been done many times, if you check out anderson Porsche 911 performance hand book (pages165-171) he covers converting a SC and a C2. I remember a web page in the usa specifically for super charging (www.superchargersonline.com). Anderson gives a couple of names including techart here in Europe. It seems that you have to change the ignition system.
I would have thought the biggest problem would be the 915 gearbox. Check with the Turbo guys but to handle the extra power the turbos used the 930 gear box (4 speed) and at the least the 915 gearbox would need an oil cooler to be fitted.
If you do not have the book I could fax you the pages.
Could be an awesome conversion I seem to think adding a super charger is the same as increasing the capcity by 50% making the SC a 4.5 litre!!!!!!!!!!!! Hence the gear box concern
Rats

 

[Guest]

OK Bones, I relent.

The power produced depends, of course, on the boost level. My G50 box takes the power with no problem, as do the clutch/brakes. I tend to drive mine at lower revs, as there is more power (power band really gets going at 3,000 revs), so the stresses on the engine/transmission are less, and fuel consumption is the same as the normally aspirated car.

No lag, but less low down (1,000 - 2,000 revs) power, as the s/charger takes about 40 bhp just to turn it, I have been told. Still pulls away in third, on level ground, at tickover.

Engine mapping changed, but runs as per normal if s/charger belt removed.
Needs more fuel at higher revs; runs an intercooler.
Fun.

 

[bones]

I think you should consider fitting EFI first as this will make the whole conversion more user friendly, CIS is not an easy system to work with on modified engines.

http://forums.pelicanparts.com/showthread.php?s=&threadid=139422&highlight=cis+to+efi+kit.

If you don't want to bother changing the gearbox consider tuning the engine to give a useable increase in power rather than something that will destroy the tranny and drive-shafts. On a dyno at AMD or similar if you tuned it for 250-275 bhp you would have a very quick 911 as your power to weight ratio would be so much better. Put the car on a diet simultaneously and that would be a seriously quick 911.

http://forums.pelicanparts.com/search.php?s=&action=showresults&searchid=920903&sortby=lastpost&sortorder=descending&perpage=25&pagenumber=2

 

[Richard Pottle]

Not quite what you were looking for but here's a web link of someone who has either a 3.2 or SC and has put a 993 supercharged lump in it - nice

http://www.instant-g.com/Cars/BlauCarrera/BlauCharger/

 

[Guest]

and has put a 993 supercharged lump in it - nice

The pictures refer to a 964 engine. But, neat installation, and no intercooler.

 

[Richard Pottle]

Yep - whoops 964 engine - procedure the same on a 993 engine though- purpose of my previous email was to show that a supercharged later engine can fit into an earlier car []

 

[Guest]

If you only want occasional power what about a nitrous oxide kit?
Have a look at the Pelican tech forums, there's some great threads on the subject or try NOS systems on the web. You could dail in a few pounds when you wanted and still have a drivable car in the wet etc. From the Pelican forums it seems some one in Canada (nothing else to do?) put a supercharger and a nitrous kit on an SC f............! be patient reading the threads as they do get off the point occasionaly to have ago at each other.
Rats

 

[Guest]

I read somewhere that all the engines from 2ltr to 3.6ltr air cooled were based on the same external dimensions/crankcase/barrels, so have always assumed that they would fit.

Trouble is, when you add the cost of the s/charger to the cost of the new engine (with all it's extra wiring/plumbing, it must get really dear.

Nitrous oxide ? Bit too short term (in terms of on time) to make it really practical.

 

[Richard Pottle]

When my 993 engine was fitted to my SC it had to have an RS pulley fitted in order that it could fit in the engine bay - the airbox had to be replaced by a cone filter and the heater blower had to be removed also. Other than that then I see where you are coming from.

 

[Beaky]

Hi John, did you fit or was your car fitted when purcased with forced induction?

Secondly was it Turbo or a Supercharger and roughtly how much did it cost?

Thx

 

[Guest]

I had it fitted in 1994, when I bought the car, at a cost of approx. £4,500.00 (allowing for memory degredation). It was modified at a later date (intercooler added, oil cooler for the s/charger etc., but can't remember the extra cost, if any).

It is a Paxton SN92 supercharger, belt driven from the same pulley that powers the air-con compressor - rather a long belt, as it wanders from side to side of the engine compartment.

If you want to know any more, just ask. Assuming that my PC, which is sulking a bit at the moment, still talks to me.

 

[Beaky]

Hi John, nice one,

Next time you at at a regioanl meet, ACE? maybe we can have a little, chat, I'm potentially thinking about a supercharging as a 2005 project

Regards

 

[Guest]

Well, now that my car is back from the nice repairing people, and I can get to the Ace under my own steam, and the next meet that I can make will be December (?), just jog my (failing memory) nearer the time.

There are also a few pics. in the gallery section of www.911online.co.uk - must get round to taking some more, as the installation is subtly different now.

 

[Beaky]

Nice one John, see you at the ACE in December

 

[Guest]

Here`s some pictures of my newbuilt 3,0 litre engine with Turbo and Intercooler, expecting approx. 300 Hp when finished, using DTA fast (http://www.dtafast.co.uk/)
Otherwise, no uppgrades of brakes etc. is done at this moment, but i will look into it when I got the car on the road again. There should not be a problem using the 915 gearbox, just be careful when shifting fast for 1. gear to 2. gear and depends how you otherwise use your Hp [] The air intake is from the 3,2 litre, this gives me a fuel rail for the BMW 745 fuel nozzles Enjoy []

 

[Guest]

These people with nice clean, painted, engines, makes mine look really tatty !

Big intercooler !
And from a cabrio, I see.