My friend just bought a Thermal R&D 3 inch exhaust for his GSR. We haven't put it on the car yet, but I've heard that it won't bolt up to the stock cat convertor since the stock cat convertor is like 2 inch or something?

Is there any way to connect the thermal to the Cat convertor or do u have to get a high flow that that goes from 2.5 inch (downpipe) and flares to 3 inch?

Give me all the options , thanks!

 

Well what he needs to do is cut the 3" flange off of the thermal cat back than get a flare that will take the pipe from 3" down to 2 1/4", 2.5" or whatever size the stock exhaust pipe is, weld that onto the thermal exhaust than just get a 2 bolt flange that mates up to the factory cat weld it on to the flare and hook you exaust back up..

That should do it..

Adi

 

goto a 3inch custom downpipe eliminating the cat all togheter, with an extra o2 sensor for wideband tuning. what i did.

 

Hmm...anyone else?

 

Anyone here know if both of the O2 sensors are on the cat convertor on a 97+ gsr?

friends too lazy to go outside to check his car in this cold weather

 

I'm 99.9% sure that one of the o2 sensors is on the cat and the other one is somewhere on the B-pipe..

Adi

 

They are both on the cat...

 

yes they are, but now mine are connected right after my flex pipe before my thermal 3in. if your friend connects his thermal to a stock cat, he just wasted $600
Get a test pipe, go to a muffler shop they have pipes that flare from 2.5in. to 3in. hope you got a flex pipe also.

 

OT but does anyone know where to get a 3" flex pipe for a good $$$? Thanks and BTW dont let your friend bolt that Thermal to a stock cat...He might as well get a greddy ot some other garbage 2.5" exhaust..its defeating the purpose of a 3" exhaust.

 

Sorry I was wrong about the O2 sensor location before 4 Stroke.....

http://www.turbo-performance.com/ has some cheap 3" flex sections usually...

Adi

 

You can get a 3" Testpipe made pretty cheap with O2 bung from http://www.testpipes.com

 

I believe Thermal Sells a flange to weld on to the converter. I have a Thermal 3" and welded a 3" flange to the 2.5 inch cat and 2.5" downpipe and added an 02 bung. Mated great with no leaks.

 

the whole point of going 3 " is for maximum flow, even a high flow cat would kill that,
high flow cat=BS, i dont care how high of a flow cat it can be, they all are just restrictions, get a test pipe and youre good

 

Thanks....