Midpipe & Resonator - Don't Flame!!

[Slip_Angle]

Ok, before anyone flames me... YES I have done many searches on this topic but it's all over the place. Does anyone agree on gains to be found with a midpipe? I couldn't find solid information for my question / setup. Are there any real concrete numbers for this combination?

Short Ram Intake
Midpipe with resonator still attached
All else = stock


...should I duck? :)

[chubbychu]

im not a tech guru, but from being around here. you will get some gains from SRI. The resonated midpipe might help a little but not as much as a non-resonated. But yours will sound a lot quieter and less raspy when cold.

[Peking]

Originally posted by CDN-SiR-02
Ok, before anyone flames me... YES I have done many searches on this topic but it's all over the place. Does anyone agree on gains to be found with a midpipe? I couldn't find solid information for my question / setup. Are there any real concrete numbers for this combination?
Short Ram Intake
Midpipe with resonator still attached
All else = stock
...should I duck? :)

What would you consider to be real numbers? with this set-up you will make a few HPs. What else do you have planned?

[fsugatorbait]

The gains in the exhaust come by changing out the midpipe.

[KeNnYtAkEr]

For our ride it's Mid-pipe more then exhaust dunno why but thats what I've read from a few dyno tests. So don't go cheap on a midpipe.
T1R mid-pipe is 2.36" thick tested for maxium power gains by Spoon.
I heard if u go 2.5" and u don't have a turbo u'll lose power. Goodl uck ;)

[ConeCrazy02]

The resonator is just a resonator, it keeps the exhaust noise down.

Think (pressure(A))(volume(A))=(pressure(B))(volume(B)). The resonator section has bigger tubing, and that will decrease the pressure (The flow of exhaust gases will be the same).

It is basically a tube with holes, then a layer of steel wool, and another bigger tube over all that. The resonator also work like a second muffler (muffle out sounds). The outer walls of the muffler is supposed to be thicker and that limits the vibration of the tubes (less noise). Unless your resonator have baffles, it should not affect the performance.

[Siman]

go 2.25 piping and no resonator and a good quality muffler i.e.: HKS, Apexi, Veilside, Blitz etc....the muffler will cost more than the piping but you gain nearly 10 HP extra and it sounds good( with a quality muffler);)

I spent only 350 on my HKS Hiper muffler and 2.25 piping from the cat back...I got it done at a local muffler shop for 80 bucks, the muffler was from optauto.com options auto salon:cool:

[Siman]

oh and I ran over a concrete parking log thingy at Subway and bent the muffer...which i sold to a friend for 30 bucks....:'( but he sold me his ES' tuning oval muffler from jdmhondaparts.com :cool: SOUNDS LIKE FUJITSUBO POWER GETTER!:confused:

[rs_1101]

you cant leave the origional resonator attached if you do a B pipe replacement. youll need anothre one (60$) and it wont really take hp away.
conecrazy is right: as long as its a straight through resonator it wont take hp away. the sri+B pipe is just about as good as a full cat back system, for half the money.

[Slip_Angle]

Hmm, ok...

rs_1101: Why can't you keep the same resonator? Haven't some people done that? If it doesn't restrict flow, I want to keep it. If it has a different pipe size, I'm sure a shop can adapt it right?

I really don't want the raspy/farty sound everyone gets when removing their resonator.

Last thing: I'm reading that I will get gains from changing the "B" pipe but it's not real specific. So, I'll clarify. I have a SRI and that's it. Does anyone have a dyno of a SRI and 2.25" "B" pipe?

Peking: I have nothing else planned at the moment, but I imagine by the end of this summer I will have headers..

Thanks for all the info!

[ConeCrazy02]

Those raspy/farty sound is due to the fact that the walls of the custom b-pipe is too thin.

If you want a quiet exhaust, you can wait for the R*SR to come out with one.

All of those bolt-on mods will give you only minimal gains. If I were to guess, those two mods will give you about 8 hps.

If you want your car to be fast, you must devlope the suspension first. If you do that first, you can get the most out of your current setup.

[Slip_Angle]

ConeCrazy02: Thanks. I didn't include my suspension mods for the purpose of this discussion. I'm researching power gains right now.. My suspension mods are: Eibach Sportlines, 19mm rear sway, ES100's and Hawk HPS pads.

On that topic though. From what I've read about the mid-pipe, it increases HP in the higher end of the rpm band but decreases torque. I'm thinking this would be a disadvantage for Auto-X (Which I do) -- At least for the short courses anyways.

I've always felt that our engine when at WOT, has a stepping feeling during acceleration. Does the midpipe help this? Do you know what I mean?

Comments appreciated!

[Peking]

Originally posted by Siman
go 2.25 piping and no resonator and a good quality muffler i.e.: HKS, Apexi, Veilside, Blitz etc....the muffler will cost more than the piping but you gain nearly 10 HP extra and it sounds good( with a quality muffler);)
I spent only 350 on my HKS Hiper muffler and 2.25 piping from the cat back...I got it done at a local muffler shop for 80 bucks, the muffler was from optauto.com options auto salon:cool:

Yes, this is a good plan. Yet I went with the Skunk2 muffler, saved me about $300 dollars at the time. I don't think you will get 10HP, exhaust alone. Got my muffler from Nopi, yet you can also get it at inlinefour.com


Originally posted by CDN-SiR-02
I really don't want the raspy/farty sound everyone gets when removing their resonator.
Peking: I have nothing else planned at the moment, but I imagine by the end of this summer I will have headers..

With a good muffler you will not get a raspy/farty sound. I had always got great feedback on my custom exhaust. Cool, what headers you thinking?


Originally posted by CDN-SiR-02
On that topic though. From what I've read about the mid-pipe, it increases HP in the higher end of the rpm band but decreases torque. I'm thinking this would be a disadvantage for Auto-X (Which I do) -- At least for the short courses anyways.
I've always felt that our engine when at WOT, has a stepping feeling during acceleration. Does the midpipe help this? Do you know what I mean?

It is difficult to say considering how everything is objective. So you shouldn't notice a negative effect when auto-x.

[rs_1101]

someone dyno'd this once.. i believe that the gain from b pipe alone was 2.5 hp. however, with a freer flowing intake and exhaust, it balances out some pressure differentials in the motor which can INDEED increase your power by maybe 10hp total. someone coined the term... "synergetic mods" in that one mod will help the other for a higher total gain. i think part of it is our egr system, cuz at a point in the cycle, both intake and exhaust valves are open. by freeing at both ends of those valves you create a balanced pressure and then get more power cuz of it.

you cant re-use your stock resonator: heres why
our cat outlet is 2.25 in
b-pipe is about 1.5 in i think
resonator, once you cut it open youll see its like 1 inch.
muffler inlet is 2.25 in again

the idea of getting a wider b pipe is to create a more linear flow, without restrictions, which is why keeping the stock resonator wont work. it squeezes the exhaust. the resonator itself isnt the problem, its the diameter of the pipe in the resonator.
conecrazy is right, most custom pipes make fart cuz theyre thin walled, and bang against the frame, cauzing raspiness. other than that, the ep releases a very good exhaust note. very crisp and hollow sounding, not terribly farty at all.