Piping size.
 

Hi guys, I've been reading a lot from this forum and finally I got the cash to get some mods. I bought the OBX header/downpipe and I've installed it, I love it but I have a question. With the header/downpipe, the Injen CAI and the UDP what size would be better for the piping, 2.25 or 2.5?

I don't care about the sound, I'm thinking of taking off the stock resonator. I already have a HF muffler. If I would like to install a resonator what size would you recommend? And IYO what size is better for the muffler?

Right now, I'm very excited about performance but if you could give me 2 size options would be great, the first one looking to get the best performance out of the mods and the second one, regarding sound.

Thanks,

2.25, you dont need to go any bigger unless you go turbo or other manners of forced induction. any bigger than 2.25 while the car is N/A with bolt on and you'll loose back pressure and lose torque.

Agreed I ran a 3inch on my eclipse before I went turbo and it felt like I was driving a 73 pinto running on 2 cyls. I would stick with the 2.25!

Thanks both of you for the answer, I read that with 2.5 I'd gain hp but loose tq, I'm just wondering, how much hp would I gain and how much tq would I loose? Or am I wrong?

BTW English is not my first language so there are still a lot of things that I haven't been able to translate. I've seen that you have a 2.5 exhaust, is it just the muffler or the piping also? Is exhaust called from the cat to the muffler?

Exhaust is the whole assembly coming off the motor out to the muffler, it goes through your header to your cat to your muffler to outside. Usually most people upgrade the exhaust from the catalytic converter to the muffler.

Do you think you will go FI on your lancer?? If not, just get a 2.25 exaust front to back. The only thing you have to change is the downpipe, the cat and the muffler.

If he wants to I see no problem changing the headers as well if he's going to do the downpipe. Regardless if he goes FI then he's going to have to change both of them anyway. But 2.25 sounds about the right size.

IC, thanks.

No, I'm staying N/A. Header is not that necessary?

Ok, since the header and the downpipe I've installed are both 2.5, I thought about upgrading the whole exhaust to 2.5 to keep the same sizing, but I guess I'll follow your suggestions and install a 2.25 exhaust.

Has someone with a header/downpipe installed a 2.5 piping?

The upgrade for a header is not bad but it's not significant. You will not notice the difference between stock header and aftermarket but the downpipe, you really feel it. When RRM was seeling the header and downpipe separatly, more people were bying only the downpipe for that reason. But the combo is not bad. It's a great mod with a cat back.

just 2.5 muffler, my exhaust is 2.25 all the way back.

Also i would like to add that it is the muffler that was on the car when I bought it used, and I had them take money off the price since they sold it to me without the stock parts!!

Just came back from the exhaust shop, I was determined to install the 2.25" piping with the resonator and I asked to take a look of the piping and I remembered some wise words, look for the piping to have the mandrel bends and NO they haven't the mandrel bends, so I asked for them and they didn't even know what I was talking about, I've looking for them since them and I can't find them. I live in Mexico City so I'm very disappointed. Here's the difference:

http://www.warpspeedperformance.com/huth7.jpg

If I install a 2.5"piping w/o the mandrel bends. Would that compensate for the 2.25" that does have them?

Thanks

im sure it would

try eBay. theres mandrel bent exhaust piping of different pipe diameters, angles and material. if you need a certain angle and length im sure they can make you one