6G Celicas Forums

Is there a rule for the exaust set up? When I say that I mean Power = Size of Piping?

Also anyone give me a idea 2 what piping and effect each celica engine would have.

ex. 7afe, 5sfe, 3sgte, etc.

well i guess it will make a little more power because of less bends, more free flowing. i have 2.25 in. piping on my 7a
For a N/A small motor i don't think it will real noticeable effect opposed to rear exit Exhaust.

any N/A car should probably run 2.25" but there are people with 2.5" on theirs. the 3S does nicely with a 3" exhaust.

7A- 2.25"
5S- 2.25"- 2.5"
3S- 3"

What about the size of the outlet?
2.5"? 3"? 4"?

So I assume for every 100 HP another inch of piping

7afe : 105 - 2.25
5sfe : 160 - 2.50
3sgte : 260 - 3.00

What is stock 1"?

I didn't feel a noticeable difference in my celica when I got mine ether. I can really feel it once I get 45 mph and going.

Would a header and a high flow cat give more power or tourqe to the 7afe? Or would it be a waste of time and money?

most likely a waste of money, and aftermarket exhaust isnt going to help a stock 7a much (we just dont flow that much air to make a difference) and it can actually hurt the low end torque. stock is 2.25in, it needs to stay that diameter to maintain sufficient exhaust velocity, anything bigger will actually hurt your performance (unless its boosted of course ).

This post has been edited by celicaST: Feb 11, 2006 - 11:30 AM

Are you sure that stock is 2.25? What is the point of getting 2.25 cat back exaust set up then? I could of swore stock is like 1" to 1.75" or something around there.

no matter what size you get. just get mandrel bend piping

here are a couple threads that talk about piping size... back pressure... reasonance and all that good stuff that you need to know about

http://www.6gc.net/forums/index.php?showtopic=30025&hl=

http://www.6gc.net/forums/index.php?showtopic=32117&hl=

http://www.6gc.net/forums/index.php?showtopic=30286&hl=

i take it you are planning on getting a cat back system so there are a few things to consider

lots of good men were injured in these heated battles over the controversial theory of exhaust so dont take this information for granted

Where did you get those 5S and 3S numbers... they're far from accurate. A stock 5S has about 135 and I think a 2nd gen 3S-GTE has approximately 225.

2nd gen usdm 200.... jdm 225.... but 3" is by far the best for a 3s motor ... 5sf the best I have heard is a 2.25 and a 7a... now thats just silly.

yep 2.25, (1"? go look at a ruler, an inch is tinier than you think, even the 7a couldnt breathe with that small of piping), and im just curious how come you are asking this when your profile say you have a custom catback exhaust already?

Best for loud noise. If I was getting a 3sgte and keeping it under 250whp, I would go with a 2.5" exhaust in a heart beat. At levels less than 300whp, you lose LESS than 5 whp from a full 3" exhaust. Its dyno proven.

i got this from recneps:



the exhaust piping is dependent on a lot of things.

a larger piping size and or more free flowing exhaust will push your peak torque up in RPMs, assuming youve got the cams for it. a smaller and less free flowing exhaust will push your torque band down in the RPMs.

if your peak torque is higher in the RPMs its going to result in more horsepower, this relationship is easy to see with the formula for horsepower.

hp = (peak torque * the rpm you got it at) / 5252

i think 5252 is right.

its up to you if you want nice topend and more horsepower but not so hot bottom end



you might lose 1-2whp on the dyno by pushing your tq down in the rpm range.

but really that could be dyno error

I forgot what they where and I was guessing.

Yes I do have the 2.25 catback custom exaust. I was stupid back then when I hit it on it and was misinformed that it would do great power for it. Im just trying to get it strait, because Im wanting to try out the 3stge swap and I don't wanna **** anything up.


My celica maxes out at around 107mph. I dono if that is right or not. I never tested anything before the exaust.

This post has been edited by o0black0o: Feb 11, 2006 - 6:58 PM

http://i5.photobucket.com/albums/y166/o0black0o/exaust.jpg

This is rather fascinating, I've only recently bought my celica ssIII with the 3s-ge engine(3rd gen) and am finding some interesting things about it. I made a few phone calls regarding exhaust systems and Toyota Racing Development recommend a 60mm (2.34 inch) pipe with a 100mm tip (4 inch). Going to a larger pipe size than that will actually reduce performance because it reduces backpressure required to maintain torque. You can't have added horsies without torque...IMO, TRD spend tens of thousands of $$$ developin these systems and know what they're talking about. And as for the cat...in New Zealand we are currently still allowed to remove the cat and replace with straight through piping (+10% more power for me ).

10%? I highly doubt that.

Actually, my last car, A 1985 Toyota Corona GT, Had the 1st gen 3s-ge and celica running gear in it (completely factory btw) (and if your interested it had the ST162 frame...try finding that on a 4-door sedan corona ) and it had a dramatic increase in power after removing the cat. I greatly miss that vehicle as it only weighed 1,010kg and would out-drag my current celica easily. Let's face it, you can mod your cars as much as you like but it's still power to weight ratio that counts.

true, but its not like the 6g is a very heavy car still relatively light.