'90 944 S2 Cabriolet decat

[Hubbahubba]

Hi all
Recently treated myself to my boy hood dream car (before the prices go through the roof)and now want to do a couple of things to it including a decat. Unfortunately I have just got an email back from proMAX saying their kit doesn't fit a cabrio only a coupe. Anyone know of any kits that are OK for a cab. Looking to use a Dansk for the rest of the exhaust as it s the most original looking.
Cheers

[NJH]

When I had mine done I just drove into Maniflo in Salisbury and had a custom decat pipe made while I waited. They reused the triangular shape flange from the cat section. The whole thing took maybe half an hour and cost much less than the aftermarket centre sections. A few people have had similar jobs done by other outfits. Several years later the same bypass pipe is on my race car with a Dansk rear section. This makes about 91 dB in the noise tests so is still pretty quiet, using a centre silencer would make it a bit to quiet for my liking, with the OEM rear section I was at about 88 to 89 dB but the OEM exhaust was 8kg heavier than the Dansk which is a big deal on a race car. The cat section is really heavy, I think using a straight bypass pipe must have saved another 8 to 10 kg.

[Hubbahubba]

Did you have any problems with back pressure with just a pipe? I've been advised to have some sort of resonator/silencer to replace it. I would like to keep it quiet still, but a bit of pipe seems a neat. Of all the people to have near you, maniflo know all about air flow through an exhaust!

[NJH]

Mine was bang on 221 Bhp after a head rebuild using the dyno EMC use as a basis before power testing cars to comply with the PCGB Championship regs. It was as fast as pretty much any S2 out there down the straights but has bone stock original internals unlike many/most race engines. Also very smooth and free spinning. One thing to note if going the decat route is that you are supposed to put a jumper wire on two of the pins in the back of the multi-connector into the ECU, Porsche made a little plug in bit for doing this which I believe was fitted to the few cars which came without a cat but had the centre silencer from the factory. This tells the ECU you are running in cat free mode.

[NJH]

Just noticed you say you want to keep it quiet. In that case leave the cat in place as is, just putting on the Dansk system is IMHE going to make your car 2 to 3 dB louder which you will notice, TBH the original system if in good condition is a better made exhaust than the Dansk. Those Dansk boxes tend to blow the insides out towards the back of the box fairly quickly making them much louder.

[Hubbahubba]

Unfortunately for me the previous owner cut that 3 hole flange off in order to fit some nasty exhaust over the pipe. In order to change the rear I need to change the cat, so if I have to do that I may aswell get rid of the cat all together. I wondered if a non cat S2 exhaust centre would do it, if there is such a thing. Picture is upside down, by the way.

Edited by Hubbahubba on Wednesday 25th February 09:44

[NJH]

There is, Dansk make one. I doubt you could get the original from Porsche, I asked about 13 years ago and they refused to sell one to me unless I could show the car came from the factory without a cat (very rare as ISTR all of them sold here came with cats).

Have a look at Pro-9 on ebay and give them a ring, there good guys and have a lot of experience racing the S2.
http://www.ebay.co.uk/itm/Porsche-944-Stainless-St...

[Hubbahubba]

Ok cheers