Header & Exhaust combo for max power?
 

Any recommendations from the header back for maximum power while sticking with 1 cat for an STX build? Currently thinking a JDL header, overpipe, and catted front pipe with a perrin cat-back resonated exhaust. Opinions?

Perfect setup. I run that exactly. End of thread. I'll just save you a lot of time and you won't be disappointed.

Lol, thanks. EL or UEL header? Do you have a tune? If so, have you had your car on the dyno?

UEL, I am tuned. Haven't had a chance to dyno since all the tuning was done remotely. Probably have done at least 30 logs on the street with hard pulls, 30% to 70% throttle blips, and regular driving.

I would say I am close to 200 whp on 93 octane, but without actually being on a dyno, that's pretty optimistic. With that fuel, and my setup, my tuner said he was able to squeeze quite a bit of timing in due to the octane versus the 91 octane he had. Runs real smooth with the Grimmspeed intake as the tuning with that is much easier than a lot of the intakes out there.

Awesome. Last question: 2.5" or 3" Perrin?

2.5", 3" isn't necessary unless you're FI. All it will do is be louder, and more prone to scrape on things if you're lowered. I would stick with 2.5" all the way. The difference is very negligible between both and the trade offs for loud/possible drone aren't worth the slight horsepower gain you might see in the higher RPM's.

What kind of maximum power? Area under the curve, or peak numbers?

The nameless header will probably give you a much better powerband, but will probably be a few hp lower at peak.

Nothing against the JDL, but a 4-1 vs 4-2-1 will always come out this way.

Considering he's looking for STX, most likely peak or high RPM returns.

... but this depends on your local autocross course design. Some places like to put in courses with a lot of 2nd and 3rd gear changes.

-alex

National courses. So high second gear typically.

why are you adding in a catback, wont you just be running a track pipe? as long as you are below the sound limit it should be fine? maybe it was just the CS guys that can get away with that because of the extra cats?

I have that setup with the jdl uel header and everything 3" from the overpipe back. It is loud, but not extremely so. I daily drive it, and I think it's completely liveable. But then I like loud cars, so I may be biased. There is no drone with that setup, however there is just a little raspiness too it at partial throttle. If you don't like the rasp, you might want to try getting the resonator added to the front pipe too. It won't hurt power very much if at all, and should help bring down the volume a tad too.

As far as power goes, I'm still in the process of e-tuning it, and I've never had the car on a dyno, so I don't know what kind of a difference you will see between the 2.5" and the 3" system. Might be some small gains higher in the rpm band. I bought this exhaust with STX in mind, but also wanted to have a free flowing exhaust in case I ever add a supercharger down the road.

Obviously, the 3" system will weigh a little bit more than the 2.5" system, and as was previously stated, the 3" exhaust will be lower on the car, which means you may have to deal with more scraping if you are lowered. I'm not lowered yet, still on stock wheels and tires, and I have had zero issues scraping the exhaust so far.

I think either way you go, you will really enjoy the sound quality and performance gains from this type of setup. Hope this helps you make a decision.:thumbup:

We run a car in STX out in San Diego and some regions have lower sound limits. SD's sound limit is 93db from 50 ft. On a NA setup even a 2.5 is the most I would really go as you are going to loose a lot down low with the lack of back pressure.

We have a ton of systems available, if you know which you would like shoot me a PM or give us a call for the best pricing out there.

Cat-Back Systems

Here is the Perrin Res System - PSP-EXT-360BR Cat Back Exhaust
Resonated

We have different header options as well. Header Choices
Also Cats and MidPipes available
Cats and Midpipes here


"FT86Club" Promo code works on a lot of items on our website, if it doesn't on the system you are after contact me and I will update the pricing.

trippinbillies - check out ptuning's header. They got 200hp with header and a 3" exhaust (I think the 2.5" would be better) + a tune.

Just my opinion but I think EL is the way to go for high REV's. UEL I think is better for the torque dip (someone correct me if I'm wrong).

For STX out here, 4-2-1 all the way. Far too much time 4k+ where area under the curve is going to win out.