Installed cat by-pass today...
 

What a rare painless project this was today. Of course, my exhaust bolts and gaskets are only 2 mos. old, so they came out with no problem. Amazingly, my O2 sensor (84k miles old) came out with no problem. I used just a crescent wrench, breaker bar and hammer, while holding the cat between my knees. I used anti-seize goop on the bolts again, tightened her real snug, got the O2 sensor in there and went for a very spirited test drive.

I immediately liked the lower growl in my exhaust note. Once I was at op. temp., I took her to 6000 rpms in gears 1-4 and I must say it was quite a boost. I have a chip and K&N too, so I guess the pipe completed the circuit. I'm happy now and hereby give up my boost addiction/search - well until I sell my house and use some equity for a 3.6 conversion.

I notice a little popping noise, though, when pushing in my clutch to upshift. The pop I used to get going from 3rd to 2nd is now gone, but replaced by these new pops. I assume they are small exhaust leaks. They're not too loud or frequent. Any cause for concern?

Congrats and glad to hear it went well.

Just think, earlier today you could have been locked up for speeding but tonight you are sleeping softly knowing that you have ended your boost addiction/search (for the time being).

Yes, that was as close as I've come to jail since the last time I really was in jail. Good thing that was a few hours before I had more boost bolted on.

Me to....monday
 

Richard,
Doing the same thing tommorow using the Fab Speed Euro pre-muffler + new Dansk 1/2 SS Sport Muffler + reprogramed Autothority chip. Cone filter already in place. Can't wait for the test spin. Also curious on any weight savings. Will take old & new next door to my wrench for a weigh in on a shipping scale. That will be it for quite awhile...budget shot for the time being. Hmmmsell the house; now there's an idea!....Nah

Cheers
Ted in So. Fla
86 Carrera Targe Blk/Blk
More fun than a barrel of alligators

Hello Richard

Are you saying you have more power as a result of the cat pipe, or a different exhaust note?

stuart 87 carrera

See, I told you those O2 sensors aren't always that hard to remove. Maybe it's just the antiquated SC's that have some corrosion issues :D :D

Stuartj, yes, there is a noticeable power increase. It seems to have a little more low end torque. My chip only added high-end torque. But this pipe is a very nice complement to it. It may not work on everyone's car, but it sure does on mine. I'm very happy so far with this mod.

Richard,
Which cat pipe did you use?
How much?

I got it from Carsinc.com. He sells on eBay a lot and he had it custom made or salvaged or something. It's not pretty, but it does work. I got it for $88 including shipping.

Richard,

I did the same in my 87. Bursch cat pipe into a Borla SS exhaust, with a Europroduct chip and K&N intake.

My only concerns are the "back-fires" when shifting under moderate to full throttle.

Do You experience this?

I get very small backfires sometimes when depressing the clutch to upshift. I have only driven about 10 miles or so since my install.

I put the Fabspeed Euro pre-muffler and the GHL single in dual out with 3"tips on my 83SC.
Results:
Excellent low end torque.
HP gains are noticeable.
Sound level aggressive.
No loud DROAN noise.
Looks kick _SS
Driver is a happy camper :D

Just imagine how light and fast your car will be when you take out the back seats, replace bumpers and all of that. My car is like lightening in a bottle, seriously.

And I'm probably going to put in sport seats to lose another 40 or 50 lbs...this thing'll be competing with 914 on the scales!

I saw a real bare-bones 72 911 with a 3.6 conversion yesterday at the track. That car was soooo awesome. But I need a few creature comforts in my 911.

An exhaust leak could be causing the backfiring, but I understand that another cause, common when pushing in the clutch to shift is from an over rich condition. I guess the theory is the engine is pumping a ton of gas in because you have the throttle really cracked open and then the throttle is closed, but it takes a second to stop the gas, or something like that...

So do I need to adjust the mixture? I changed the plugs 2 mos. ago and the old ones were clean as a whistle. How do I measure this? Please don't tell me I have to go to a pro wrench for this. I never want to leave my car at a shop again.

I lost some kick with the loss of the Bursch though, I'll say that--of course with the other mods, it's still faster than it was with bursch.

As I have said, it is faster than ever..I spanked a new Firebird no problem..he actually gave up. And I was playing with a Honda S2000, and even though he took off first, I was on top of him immedately and 10 feet ahead before he changed lanes and went on his merry way. No doubt, an s2k would go down now. And stay down. With the high torque, 3.2s will usually jump out ahead..the only problem was staying ahead past third. Now, I feel although they might gain ground from 2nd to third, the lead would be insurmountable.

If you can handle the backfiring a bursch is nice if you don't already have something else.

I also want to say, the K&N cone back in definitely made a difference. I'm not insane, I'm not hopeful, but for guys like me who drive the car every single day, and push it every single day, I know this car inside and out...I can tell very subtle differences in performance just from familiarity. When I put the cone in, I also took out the pad, because the pad takes up a lot of air space back there, and I'm very please. Every mod helps on these cars--

Huh? You're worried about an S2000...but you spanked a new Firebird? U sure that firebird was a V8? :) The V8's are pretty mean cars (stock).

Brad

Kurt - You talking about the sound deadening pad under the rear window? Yanked mine a few months ago as it was falling apart. No difference in sound in the car and it does seem more spacious in the engine compartment. Never thought that it gave more air.


My 3 yr old wont have me yanking the rear seats! I need some other weight saving techniques!

Richard,
Jim and I also installed a Vertex cat-pipe when we did the clutch job last weekend. I like the exhaust note more and noticed a little quicker push through the RPMs to 6K. As for the backfires, I haven't experienced any (Vertex chip installed as well, standard air box with 1.5" holes drilled out) but couldn't that be due to a slightly rich mixture caused by the chip?
Just a thought.