I agree, but i dont think so that 2x3'' pipes are too much for a swapped gt-four. In the photo, the left pipe is fake but i have diferrent plans about it.. Both pipes will be working of course and they have to take care of a decent horsepower, so i dont think that anyone will say that it is wrong...
OEM knows better how many pipes should a celica have but a lot of celicas have 50+ % horsepower than the oem engine, so you have to think about a totally different exaust system to take care of the extra power that the engine produces.. In my case, except from the extra hp that i ve got, I have also removed the catalytic converter so the pressure from the exaust gas is too high for a simple muffler. So, in order to avoid the uptake, to minimize the flames and of course to keep the db low, i have to split the rear tube to a twin muffler, or better to different mufflers. I am sure that when my project will be finished you will love the hand made rear exhaust system and mabe you will change your mind about the two different mufflers. I believe that at least in my case, i will have a gain of +15 hp with this system. Lets hope that the dyno will agree with that!!

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Agreed, if you need to get rid of the gass then go ahead.
You Us guys peobably won't know the ford Ka, but here in UK it's a popular runaround cheap small car.
They have now released a sport version, but before that I had one and wanted more power (only comes with a 1.3)
so I got a turbo conversion for that, on the rollers it went from 56bhp to 86bhp... I know you're all laughing and saying what's th point but I liked the car shape and it handled great.
My point is that removing the CAT and replacing it with a much biger one from a 1.7 ford, plus upgrading to 2 1/4" exhaust all the way put the 86bhp up to 96bhp, a considerable difference by just geting rid of the extra gas.
If you need a big pipe, get one!
My problem is with the stuck on jobbie on the left of that photo that isn't even linked up!
Rant over.