t.p.

85 Carrera. Just installed cat-bypass, SSI's, Autothority chip, and K&N cone filter. How much power increase can I expect? I was thinking around 35 HP over stock.

carnut169

Um, cat bypass and SSI's? Don't think so....

Martin S.

Referencing Bruce Ansderson's POrsche Performance Handbook, I think you are safe assuming 35 HP as a result of the mods you mention. I put the SSIs and the Bursch muffler on my 80 SC and the Dyno said it was good for 20HP. I can't swear by this particular dyno...check out Bruce's book.

Jay H

t.p.:

Excellence Tech Notes from a year ago has a tech note (written by Bruce A.) about modifying a 3.2 engine.

One test (that matches your mods to some degree) on an '89 Carrera was done with the AutoThority chip, SSI heat exchangers and a '74 muffler. Max torque was 207 ft lbs (up 12 ft lbs. from 195 ft. lbs. in stock form) and max hp was 225 (up 11 hp from 214 hp in stock trim).

Hope this helps a little,
Jay

richard glickel

T.P.,

Sorry, those mods will not result in a 35 h.p. gain . . . maybe 8-14. You'll pick up a little more with a sport exhaust.

Richard
'87 Carrera-3.6L <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Jeff Curtis

How are you running a catalytic bypass and SSIs at the same time? If you have converted to SSIs, that would insure removal of your catalytic setup and would concern me if this wasn't done in conjunction with a factory or aftermarket performance muffler.

If in fact you do upgrade with SSIs, a sport muffler and chip/filter, I would imagine you would be knocking on the door of 20-25HP or so. Opening up the exhaust is the key to any HP upgrade.

t.p.

I haven't put in SSI's yet. Just wanted to see what people would value all those mods at. I expected they would fit in exactly like the O.E. heat exchangers. If not, then I wasted good money on that bypass.

JackOlsen

You wasted good money. But check your local smog laws before you waste more on SSI's. If you have a visual inspection (to confirm that the cat is there), you'll fail with the SSI's.

Chris Blum

you really haven't wasted the money. You can sell the cat bypass when you upgrade to the SSIs. For me it was a question of $100 vs $1000 in a year when i was spending a lot of money on other stuff.

David_M

[quote]Originally posted by Chris Blum:
<strong>you really haven't wasted the money. You can sell the cat bypass when you upgrade to the SSIs. For me it was a question of $100 vs $1000 in a year when i was spending a lot of money on other stuff.</strong><hr></blockquote>

Hi Chris,

I just purchased a 86 Carrera coupe here in San Diego. I am looking at the cat bypass mainly to reduce heat and gain a little performance. What are your experiences with the bypass?

Thanks,
David

Chris Blum

David,

re: cat bypass

The cat bypass is being done in conjunction with so many other mods that it will be near impossible to tell what effect it will have.