thanks i just sent him a e-mail. so what other mods do you have done. and how noticible where the headers? my goal for my r is when i hit warrenty at 7 years or 100k i am going to fully build and blueprint the enitre motor tranny redo suspension and probly convert it the jdm at least the seats and front end possibly even right hand drive but i think that might be a bit to costly to make it right hand drive just for looks really. anyways right now i just have aem cai. after i get the headers i am looking at getting a 2.5 inch exhaust i am looking at the kakimoto type r exhaust its 2.7 all the way through full cat back and ss through out. http://www.kakimoto.co.jp if ya want to check it out.

R #858
last R sold in the southwest area

This R is Debadged and Dewinged, just plain black, no attention till I cross the finish line!

Any questions?

Generically there are 3 design types for import exhausts: straight through vs chambered vs 2 pass design .

Most important: pay attention to the B pipe, and in muffler tube diameters for your engine combination:

2-1/4" up to 210HP @ the crank
I find that most of you have engines with bolt-ons only so look for a 2.25 in. exhaust not a brand. If you begin to think about big cams, 2.5 in. collector headers, and pistons then go up to the next level in diameter.

2-3/8" (60mm) up to 235HP @ the crank
2-1/2" up to 265HP @ the crank
2-3/4" up to 325HP @ the crank
3" big big HP (FI)


Some people with >190 whp step the diameter after the cat to 3 in. anyway to get an antireversion effect.

Pay attention to what is used as a sound absorbing insulator material. Stay away from fiberglass or what's called a glass pack. Fiberglass melts with heat over time and guess what? you become loud as **** and it's not due to more power..it's due to a failed muffler.

Pay attention to materials if you live in a snowbelt area that uses road salt: get aluminised coated or stainless steel.

Pay attention to tube thickness or gauge. The 18 gauge thick steel is lighter than the 16 gauge thick steel which is great for performance high performance street and road racing but it has less durability and the risk of denting or cracking may occur more easily over time.

quote:
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Originally Posted by SMSP
FYI, 2.50 in. OD exhausts with 16 gauge steel (.065 in. thick) is 1.69 lbs/ft and 2.50 in. OD exhaust with 18 gauge steel (.049 in.) is 1.28 lbs/ft. The typical Integra exhaust will have about 7.25 ft. of tubing, not including the resonator and muffler. That equates to 12.3 pounds of 16 gauge tubing versus 9.3 pounds of 18 gauge tubing.
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Pay attention to fitment and hardware provided like gaskets and areas for the hangers to hook on to.

I agree with the reply above: please don't obsess over an exhaust because it makes around 2-4 whp in bolt-on only < 190 whp combinations.

A Newbie Misconception: More Loudness Equals Power Gained...

loudness (not extraction performance) depends on these: muffler length, presence and length of a resonator tube in the B-pipe, muffler absorption material, whether the muffler has louvers or holes , tip size/length , and the design : straight thru with resonator vs chambered vs 2 pass (number of passes...the 2 pass Mugen exhaust without a resonator is quiet). If you want a non-coffee can quiet throaty sound, look for the characteristics I listed..a longer muffler is a good start.

Power depends on how the exhaust works with the engine combination you have in terms of compatibility to help maintain a high exhaust gas velocity out of the head for the volume of air you are dumping in...most experts agree that the exhaust flow should be at least 80-85% of the intake flow (if it's more than this...even better). So for exhausts as related to power?: pay attention to diameter, diameter, diameter that will suit your combo. A big rice newbie misconception: My exhaust is loud so it must be great! wrong.

Big huge diameter tips are better? :
another newbie misconception. You design the tip size to fascilitate where you want the bulk of your power to be along the rpm band.

If the exhaust has the characteristics that work for you and is cheaper, get it. There's not much separating exhausts these days in terms of 2.25 in. straight thru exhausts. Be forewarned: the Tanabe G-Power and Racing Medallion have a 3 in. long bottleneck that is less than 2.25 in. diameter at the B pipe just behind the cat flange...not good. I just found this out on mine and will be chopping that part off.

The Backpressure Myth: As you get more advanced in your engine mod combination you want less to no backpressure. Stock backpressure is around 16 psi in a GSR. Good aftermarket exhausts yield 3-5 psi backpressure. Bolt-ons only engine combinations use exhausts with some backpressure since there is this myth that it prevents the intake charge from shooting into the header at cam overlap during low to midrange rpms. No backpressure was thought to result in a midrange power drop due to loss of intake charge into the header much like our turbo tegs using all motor long duration cams. This need for backpressure no longer exists when you have a properly tuned (timed) engine and a good stepped header. In fact, increased backpressure may lead to reversion where the exhaust travels backwards into the combustion chamber and dilutes the fresh intake charge at overlap. So ignore the "you should have at least some backpressure" sales pitch for an inferior incompatible exhaust.It's all about the energy of the exhaust pulse leaving the exhaust port and maintaining that velocity.

as eloquently stated by Larry at Endyn on the Backpressure issue:


quote:
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Just changing back pressure is a bogus way of trying to create the "ideal" pressure in the system. The exhaust system should work like a correctly conceived header. It should extract the exhaust from the header, to minimize pumping pressures.

The only way to create a system that will serve as an extractor is to properly size the tubing to allow the flow velocity to create a sort of "vacuum" behind it.

Just as with headers, creating a system that will provide the best of all worlds at all throttle positions and rpm ranges is impossible. It's all going to be a trade-off.

You can tune for the throttle positions and rpm ranges where you desire the greatest performance, but you'll sacrifice performance at the other end of the scale.
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Know where and how wide your power band will be along the rpm range and choose a system that facilitates that goal. You may get more midrange but give something up at the top or want more power up top with some compromises at the midrange...this is what we are talking about when it comes to the old saying you want some backpressure. Yes you get more midrange with some backpressure in a bolt-ons only teg but at what cost at the top end? will this cost be liveable for your tastes?

hope this can go in the search archive now and we can dispense with any more exhaust polls.

This R is Debadged and Dewinged, just plain black, no attention till I cross the finish line!

LOL, sideways, with the windshield wipers going

Sorry, autocross joke...