[sunshineracer]

sorrie...i know his has been covered thosands of times before....and yeah....i've read the other posts about it...but i'm not sure if i got the answer i was looking for...so please bare with me.....

my question is....i want to get a hi flow cat....most likely the carsound cat....but i have no aftermarket headers.....i do have a greddy evolution exhaust though....its on a 97 GSR....and i'm planing on goin supercharged...so what i'm tryin to get answered is...what size cat should i get....??? cuz i want to get the kamikaze headers later on when i put in the supercharger....so should i get a 2.5 inch cat and put it on now....or just get a 2.25 inch cat and put it on....and then wait until i get the supercharger and then get a 2.5 inch cat...??? isnt the kamikaze header a 2.5 inch opening....??? so does that mean i get 2.5 inch cat....?? but then my greddy exhaust is 2.25 inches rite...??? so what do i do....???

so please help.....in short....what size cat should i get for my present set up....intake...stock headers....greddy evo exhuast...???

and what size should i get for my future supercharged setup with kamikaze headers and greddy evo exhaust....???

or is it better to just wait until i go supercharge and get a 2.5 inch cat...???

thanks...and sorrie for bringing this subject up again...

 

[IntegraBad18c]

If you supercharge your car and if you get the Kamikaze header, you need to have the rest of the exhaust system sized at 2.5", too, or will restrict exhaust gas flow. You will have to get rid of your greddy evolution and go with a 2.5" or 2.75" catback.

 

[dragontegz]

okay, first off, it's a header. not headers. okay? unless you have a v6 or v8 under the hood of your teg. (one of my pet peeves)

if you want to go SC in a near future, i'd hold up on buying new stuff for your car for now. without FI, the oversized exhaust system will hurt your performance. with a SC set up, you should go with a kamikaze header (please note the singular form of this noun), a 2.5" ID cat, and a 2.5" or 2.75" OD exhaust. Keep in mind that going from 2.5" ID to 2.5" OD, you'll be stepping down instead of up. stepping down is usually not recommended. i would go with a 2.75" OD exhaust but i'd be pushing 8 lbs of boost instead of stock 6 lbs anyway if i had a JRSC. (2.75" OD exhaust seems a bit oversized with 6 lbs of boost. perhaps someone with more experience with SC setups can answer this better)

like i already said, if you're going to go SC, just save up your money for everything - SC, header, cat, exhaust, and other things to insure the reliability of your SC setup. and then when you have all the components needed, put them all in at the same time. if you change the header, the cat, and the exhaust first, you would lose a lot of performance.

good luck and drive safely.

 

[MichaelDelaney]

what he said....

man, you guys are makin my job easier around here....maybe I'll put my feet up now...ahhhhh....

hopefully we can get the discussion up to the next quantum level since everyone here is on the same page....

 

[sunshineracer]

so basically i'll need to get rid of my greddy exhaust....??? cuz i'm plannning on running 9-10 psi....and get everything 2.5 inches....???

so when you guys mention 2.5 ID cat and 2.5 OD or 2.75 OD exhaust....so does that mean the 2.5 OD exhaust is actaully 2.25 ID....and the 2.75 OD exhaust is 2.5 ID...???? i thought everythin was measured ID...??? so when people say 3 inch exhaust for turbo...that means 3 inches ID rite...??? and not OD...rite...???

i'm confused with these terms...sorrie...

 

[dragontegz]

sunshine -

the term "piping" is misused. piping is measured by inside diameter. the exhaust "piping" should really be called exhaust "tubing" for it is measured with OD by convention.

that being said, i thought the cat was supposed to be measured with OD as well until dave at SMSP told me that car sound cats come in ID instead of OD. i guess the cat is the only exception to that convention when it comes to exhaust systems.

the difference between ID and OD - most people would recommend that you use 16 gauge steel although it is heavier than 18 gauge for its strength and durability. 16 gauge is 0.065" thick. so what you can do to calculate the ID from the OD is to double the thickness of the pipe and subtract that from the overall outside diameter.

example:

assuming you're using 16 gauge:
2.25 OD => 2.25 - 2(0.065) = 2.12 ID
2.375 OD (2 3/8) => 2.375 - 2(0.065) = 2.245 ID and so on...

i hope this clears things up a bit. if you have anymore questios, please feel free to PM me.

sung

 

[IntegraBad18c]

hopefully we can get the discussion up to the next quantum level since everyone here is on the same page....

But we don't have any power!!!

 

[MichaelDelaney]

wadda ya mean , no power?

 

[Teg2nv]

I'm a doctor not a mechanic! LOL

 

[nospeedlimit143]

check into Random Technologies.... good kittie...

 

[MichaelDelaney]

I'm a doctor not a mechanic! LOL

damn it Bones, just give me the stimulant! I just need to hang on for another 2 min.! LOL

Random is POS....