Bischoff exhaust - modification

[Tp81]

Hi,

Looking for some advice in relation the std exhaust that was used on 1974 /75 cars. I was hoping to modify the existing box to give a more sports purpose sound without going overboard. I have had the silencers on all 993 cars opened and for all intensive purposes ‘hollowed out’ Gert from Carnewal does this and calls it the RSR conversion.

Is there a similar procedure for the early sausage exhaust? 2 in 1 out unit.

I am hoping there is a tried and tested route to extract a more mechanical / metallic rasp without going overboard.

Thanks

Tom

[911hillclimber]

Google what you are after.
The is a great line dia game which shows what to do.
I have not tried it, so unsure of the result.

[Nine One One]

Here you go, half way down this page - Ian

viewtopic.php?f=2&t=54063&start=165

[defianty]

This is worth watching too.

https://www.youtube.com/watch?v=-aKN0ujaQcY

I'm going to be doing this myself soon.

[210bhp]

Here you go, half way down this page - Ian

viewtopic.php?f=2&t=54063&start=165

But that’s a 2 in 2 out solution which I don’t think is what Tom is after as per original post.

Regards
Mike

[Nine One One]

I thought as most standard exhausts are 2 in ONE out, he meant 2+2 in the post, and was just a typo? But obviously just wants to keep the standard appearance, with ONE output- never mind - leave you to it

[Tp81]

Thanks for the replies, the diagrams in the threads will be useful and I will have a proper look at these when I get a chance. To clarify, I was looking to try and retain the std look of the exhaust with only one outlet.

I am assuming that some changes internally would allow the exhaust gases to move more freely and removing some of the baffles would increase the noise without going overboard. Just hoping to get a tried and tested method.

Thanks

[Nine One One]

This shows you what bits to cut out, the restriction in air flow (back pressure) would appear to be the two tubes connected at he right hand side of the back box, opposite end to the tail pipe.

http://forums.pelicanparts.com/porsche- ... anted.html

Some boxes seem to have packaging inside, others not, or a mouse or two!

[911hillclimber]

As I have said on other recent similar threads, Turbo Thomas will tailor something for you in Stainless, but hard to describe the 'boost' you want.
Dansk do a large outlet pipe 2in/1out that might do the trick, but expensive.

[Tp81]

Have opted to retain the stock exhaust and have ordered a Turbo Thomas 2 in 1 out. Nice guy Richard very helpful, I am having a rolled steel pipe on the end to retain the original look.

Just need to wait now. Thanks for the advice.