Michael H

I've approached a local mechanic in Switzerland for advice on my 3.2 (US model)that is now using about 1 liter every 350 miles. I want to keep the car as close to stock as possible, yet get some performance improvements. This is what he suggests:

1. Change the Alusil cylinders/pistons for a Nickasil set that he has which came from a car with only 30,000 miles. This would raise the compression to Euro spec.

2. Valve, springs and valve guide replacements

3. Change the mass air flow filter for the newer model which he says is much more efficient

4. Add a cat bypass

5. Reprogram or rechip the car (not sure which) and tune it on a machine he has that they use for track cars (rolling road / dyno)

He says he this will yield about 250 horses. My question is would I be better off with reringing my current pistons, replacing valves and dumping the cat --- or does it make sense to make the cylinder/piston/compression change and/or add the new mass air flow system?

thanks in advance for your advice

Ed Bighi

Actually, the pistons in your car should already be nikasil. Though they are of a lower compression than the european ones. Also, if I were to get pistons for that rebuild, I would think about using the 98mm ones for a 3.4 displacement. I say that because if you are already considering buying pistons, you might as well. Unless he wants very little money for his pistons. Then again, in my experience, you will be grayer and maybe with a little less hair by the time that rebuilt engine becomes tired. And long before that time, you will have long forgotten about the cost of the rebuild and parts. I base that on my sc which still hasn't been rebuilt with 210,000 miles and years and years of track time. As for the valves, new ones with new guides are usual. Springs are cheap enough that it makes sense to put in new ones. The cat in your car right now does not do much for your car. Not much for the environment either since these cars run clean enough without them. It also weighs more than a bypass pipe. So get rid of that cat and use it as a paperweight. As for everything else, it is up to you.
I also think you are a very lucky man living where you do. I love your country.

Chris Martin

I am no expert, but I am not sure of the Mass Air conversion. Reading the sales literature makes them sound great, but after a little research I am not sure the HP increase is worth the high cost. Check this thread for some info:

<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=1&t=001130" target="_blank">http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=1&t=001130</a>

Whatever you decide on, good luck! I hope it turns out as you wish.

Bill Gregory

Michael,

No matter which route you take, be sure and replace the piston rod lower bolts with Raceware or ARP or equivalent. On 3.2L and later engines, Porsche went to 9mm (from 10mm) rod end bolts. At high rpm the stock bolts can become stressed, and won't offer much, if any, protection if over reved. The results aren't pretty....

PMNorris

I have been looking into doing a Mass air flow conversion and top end rebuild for my 3.2 Carrera (it's already UK spec so I am just going with a stock rebuild). Check out <a href="http://www.auto-amd.com/filmstar.asp" target="_blank">http://www.auto-amd.com/filmstar.asp</a> and <a href="http://www.auto-amd.com/91132.asp." target="_blank">http://www.auto-amd.com/91132.asp.</a> I am probably going to include a gas flowed throttle body at the same time.