Exhaust Piping Dimensions

[Unity112]

I just wanted to do an analysis of our current header/exhaust system. Starting with the header, what size piping are the tubes leading from the engine, down to the collector. Then what is the diameter of the collecter. Inlet and exit diameters for the cat. B-pipe sections, and the assorted bottlenecks here and there all the way through the muffler. If anyone knows these numbers then let me know. Thanks.

[Unity112]

So nobody has done any measurements for the stock system? Okay, at least least help me figure out the inlet and outlet for the cat. Thanks very much.

[kaioshin]

Well, I was looking under the car the other ( I was having TRD struts and springs installed) and noticed the exhaust piping got to it's thinnest right after the cat, I think. stayed that way until it hit the resonator. Not sure of the exact diameter but it looked around 2.25 in.??

Someone correct me if I'm speaking outta my ass

[LEDmod]

I've heard it was aruond 2 and 1/4
Dont' know the exact dimension...

[EzRidA]

Okay the exhaust piping from factory is 2.55" inches. That's on a GT-S I don't know if it varies on a GT. As for the cat section it's considerably larger. I never meassured it, but I would guess around 3 1/4-4inches. Next time my car is on the lift I'll check it out. Unless someone has the answer.

[knightridergts]

hmm 3.25 inch i highly doubt it unless you pushing 400 whp and you dont step down with exhaust sizes because it creats backpresure and loss in flow velocity, most stock exhaust systems come with 1.8 or 2' inch diameter tubing with 1.8 inch at the flanges. i think 2.36 or a 2.5 inch all the way threw including cat the exhaust system would produce best results with the gt-s, i am searching allover the place for these specs with toyota celicas. we need some hardcore tech gu rus to show up somewhere on these boards hehe, sorry im use to chattin with all the honda techs about these issues

hmm edit, tomorrow (tuesday) i will go into the lab and try to find these specs

[Unity112]

Wow this is dug up from the grave. Thanks, I'd like further investigating. I was very curious.

[knightridergts]

ya well i was in the lab and went on all data and the toyota puter line and found everything about the exhaust system cept the freakin dimensions and sizes, does anyone know especially GRIFFIN or could measure, this is so important that i find out ive emailed TRD and got no response, please someone help me so i can figure out which exhaust to buy for my setup