To cat or not to cat???????

I am in process of fixing broken head studs and I have the motor out of the car and I was wondering if it would be of any benefit to me to take the catalytic converter off and replace it with a straight pipe, for some crazy reason, I thought that if the cat was removed, it would result in increased air flow and possibly more HP or response. Thanks alot guys, I am new at this and I am smart enough to know that Dr Porsche and his team know a little more about the exhaust on these things than I do and I just wanted your feedback. Thanks again guys. Emissions are a non issue for me!!

no cat = more horsepower. when you need the cat for inspection, just stick it back on, then take it off after the sticker gets put on. as much as people don't believe that is how it should be... that's the way it is.

enjoy!

obin

I have heard reports going both ways. When I bought my 78SC it had the cat off and a by-pass pie installed so I can't personnally testify to this. One thing is certain, however, if the Cat is clogged, removing it will increase flow. Most everyone will swear that the greatest gains are found in backdating the exhaust to a pre-74 system or installing SSI's. I choice the pre-74 system for cost purposes, I don't live in a rust promoting environment and I am infomed there is minimal weight difference between the two. Bruce Anderson in the previous issue of Excellence stated that a pre-muffler (not a Cat) used on UK cars actually increased performance! But this was not the same as with the Cat and the pre-mufflers, which could be used to "pass" a visual smog inspection, are very difficult to find. Interresting, but it does demonstrate that just because an additional "muffler" is installed, it does not mean the exhaust is more restrictive.
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Paul
78SC Targa

Hmm - pre-muffler increases horsepower. There are several Europeon exhaust systems for sale on this board. If these include the pre-muffler vs. the cat I'm guessing that is the only difference from the US spec exhaust. Anyone know the HP difference between the Cat and pre-muffler?

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Rob Fix
'78 SC Targa

NO CAT! I just removed the cat off my 83SC
and you will not notice a difference in performance but my car is running much cooler. When I changed over I discovered that the 02 has not connected and I replaced it. I don't know if the difference in Temp was the pipe or the 02 but it is definitely running better. I purchased the pipe from pelican and it was 02 ready.
There is a long thread on this subject just do a search under GB83SC.