Red rooster

Garrett376,
I guess you have the answer now ! On Euro spec 964 a Cup pipe or straight through silencer can give up to +10 bhp flywheel .Final silencer +2/3 .Cat bypass almost nothing but the car feels so much more responsive especially at less than 4000.Trickey old things these motors.
Geoff

forklift

I think his info. shows +14 with the cat bypass, which is impressive and almost enough for me to break out the checkbook.

Red rooster

Go for it!!

Geoff

garrett376

Yeah, I'm with Geoff - make the order forklift!!! I am glad to see that the system I am running is the best from Tom's findings. Luck of the draw! Actually, the G-pipe was cheaper when I was shopping around and I wanted the greater weight reduction from the secondary removal.

agentpennypacker

Is anyone running primary and secondary bypasses and leaving the cat on? Any thoughts on this?

Wachuko

Thank you!! Any plans of testing a different primary?

Stock headers, fabspeed cat bypass, aftermarket primary, secondary bypass(G-Pipe): ??? rwhp If hp stays the same at least we should loose some weight with that change...

Can you share how much $$ was the cat-bypass? Was it this one?:


I current have

Stock headers, stock cat, stock primary, and secondary bypass (G-Pipe)...

Thanks again for the tests done and sharing the data with us... you just saved a few of us time and $$.

Wachuko

I will have to search on a few topics that discussed this... but if I remember correctly the lack of back pressure made the car loose hp instead of increasing it...

ronone10

I am a new tiptronic 964 owner and would like to know if the horsepower gains are the same for a tip equipped 964? I am happy with the stock performance and the only mod on my list is to lower it to euro specs. But, I may get the bug down the road....

Ron
'93 C2 Guards Red

Tom W

Jaime: That appears to be the cat bypass I have. I have no plans to replace the primary as I've spent enough time and effort going nowhere with what I've already tried. I will not do a primary bypass due to sound restrictions at tracks I like (especially Laguna Seca). Yes, I may be able to loose a couple more pounds of weight, but at this point I'm going to concentrate on driver skill as a method of improving lap times.

Scooter92

Not to hijack the thread, but I have some questions directly on point. I recently picked up a full B&B exhaust system for a really great price, and now I have to decide about installation. I currently run a primary bypass and chip from Steve Weiner and was thinking about the cat bypass when I found the B&B. Questions after the installation of B&B: 1) how should my car act, relative to my current setup (i.e., torque, hp, etc)? 2) if I remap my chip, should I get even more power? 3) should I pass emmissions without a problem? 4) any downside to going with aftermarket headers?

I am expecting to get the performance Tom got in his test, maybe more with a dialed in chip. I got such a great deal on the B&B, I had to buy it. Given what I am running now vs. the B&B, I am expecting a noticable difference.

Ron, I may sell my primary bypass if I get the result that I am looking for. Being local, it may be a good opportunity for you to upgrade.

H964

hi, iam in the process of running a cat bypass and a primary bypass. thats the best set up i think based on reading countless threads here on rennlist, but now iam all confused again.
i thought the primary was a lot heavier than the secondary?? right??

garrett376

The primary is heavier based on published info, but when you look at the total weight saved (the primary BYPASS is heavier than the secondary bypass) for the installation, the secondary bypass comes out saving more weight.

Wachuko

Thank you... one more item on the wish list

Tom W

Scooter: You can talk to Steve about the chip and if he recommends a different one for the different exhaust. I doubt you will pass emissions with the cat bypass. My car is a track only car and not a general street car, so I don't care about emissions. The only way to find out about power is to do a dyno run (it's the moral of my story - lots of claims are made about chips and "free-flowing" exhaust but the dyno is the only way to know).

Scooter92

Given the advice here and my research, it looks like the B&B would not be the best choice for me. I already have the primary bypass and chip, so I am thinking about the cat bypass or premuffler. Should I expect some hp/torque? Should it be a little louder? Better choice - cat bypass or premuffler?