Exhaust setup opinions

[MRX]

Alright i'm gonna break down and buy an exhaust setup. What i'm thinking is a combo of:

glass pack inlet/outlet of 3" but $99

or
A thrush glasspack with 2.5" inlet and outlet -$19


Stainless steel 3inch mandrel bent piping -$235

or crush bent at a local muffler shop cause its cheap and not much of the inside diameter is compromised $125

To the Ractive MT217C - $90


I'm not going for the most badass exhaust ever created, i'm looking for sublteness, comfort, better flow, and most of all sound quality. Tell me what you would do in my case. Although there are no emissions laws here in FL i'd like to cut up the exhaust piping the same size as the stock cats' location, and throw in some flanges so i have the option of putting the cat right back on in case emission laws change.



But i'm open to suggestions

[WiKKeDV16]

you already know my opinion
3"kteller cat back
no cat
have the muffler shop attach ur downpipe to the rest of the exhaust system
as the muffler shop themselves told u..
3" setup will be quiet with the muffler ur using
u already know that the turbo itself is a muffler.. then ur secondary muffler if u will will reduce sound even more.. i mean.. its not a canister it actually is a muffler

so my setup for u is

3" catback
3" crushbent from downpipe to catback
ractive muffler

[BustedLX]

Well deffinately going to choose the red cherry bomb baby you know that shit

Better flow?? The crush bent just went out the window. You're going to be using this exhaust for your boost project right?

What Turbo have you chossen? That will make a difference in what setup you eventually choose.

[mickey_601]

Sorry

hey midnight it's this guy off of honda-tech that is selling that fuel pump w/controller for like 65 shipped. Sorry to get off topic

[WiKKeDV16]

Originally posted by BustedLX
Well deffinately going to choose the red cherry bomb baby you know that shit

Better flow?? The crush bent just went out the window. You're going to be using this exhaust for your boost project right?

What Turbo have you chossen? That will make a difference in what setup you eventually choose.

i feel u on how crush bent isnt best choice.. but then again its not crushbent.. i mean the only really crushbent part is the bend to meet up with the catback..
the rest is just straight..
i dont see him losing TOO much flow from one crush bend.. also.. hes on a budgetizzle..
so i see that as his best bet..

[MRX]

Re: Sorry

Originally posted by mickey_601
hey midnight it's this guy off of honda-tech that is selling that fuel pump w/controller for like 65 shipped. Sorry to get off topic

pm'd u...np about getting of topic


The turbo is a t3/t04e....wikked wants me to kill the trees...even wants me to run open wastegate from a dump tube...WHAT ABOUT THE CHILDREN HUH WIKKED!? WHAT ABOUT LITTLE SUZY AND BOWLEGGED TIMMY LMAO!?!?!

I'm just gettin others opinions on this

[WiKKeDV16]

dood.. weither its coming outta a dump tube or routed back into the exhaust UR STILL KILLING TREES AND LIL SUZY.. SO STFU and run that open Dumptube..!

[rcleghorn]

My suggestion:

3" Turbo DP
3" Magnaflow Cat
3" Catback exhaust
3" Magnaflow Muffler

Also make a 3" straight the same length and flanged the same as your cat and run which ever you choose. This is my suggestion because this is what I will be running very shortly. If you do plan on boosting, i would not run anything smaller than 3". Magnaflow works well and is cheap. You can get the 3" cat and muffler for around $100. My .02

[BustedLX]

Running an open dump tube off the wastegate is one of the worst things you can do for turbo efficeincy and you could encourage detonation. You can't dump hot ass air into the engine compartment for the tubro to pick up and compress. The turbo already makes the air hot enough with out the super heated exhaust gas. Plus you want the turbo to pick up clean air, not exhaust gas.

As for the crush bent, You don't want your exhaust flow to be turbulant. Having a turbulant exhaust flow is no good. And having crush bent eblows makes for some nice turbulance.

As for exhaust size piping. A popular misconception is that since you go Turbo you no longer need any sort of back pressure. Nothing can be further from the truth. You still need to maintain a degree of back pressure in order to preserve torque and help the turbo spoll. If your turbo only has a 2.5" exhaust exit then that's what it needs, Not 3". My recommendation there would be get a 2.5" DP till the cat then after the cat you can open up to 2.75" or 3" if you wish, But give the engine some form of back pressure.

Last I heard you where using a small DSM turbo. A 2.25" DP would be fine for that, Maybe even 2.5" would be allright. The reason I bought my Bullet brand cat-back 2.5" mandral bent is because at one time I was planing to go boost and that's what I was going to use. Unless you are moving massive amounts of air liike from a 60-1 a large diameter exhaust pipe is not needed and could end up hurting you.

[MRX]

Ok, now we're talking. My current setup consists of a t3/t04e with 35mm wastegate, and a 2 7/8" downpipe that already has a tube running out of it for the wastegates' gases. I need more info on why the dump tube method is a bad idea. The temperature problem can easily be solved by routing the end of the tube right underneath the firewall area so that the moving air flushes all the gases underneath and to the backside of the car without it ever entering the engine bay or cabin. The back pressure issue i'm convinced doesn't exist(stay with me on this one). There is however a pressure issue i'm more concerned about but its with velocity. Just as low rpm's having a high velocity intake charge (small diameter piping) promotes more torque and power in the lower powerband so does the exhaust velocity correct? When increasing the diameter of the intakes diameter you automatically slow down the charge but are able to add more air in correct? Same should happen with the exhaust. I don't believe in backpressure i believe in velocity. Backpressure to me is a myth concerning valves seating properly. Think about it, our valves go down into the combustion chamber, having back pressure would make it harder for the valves to come back up and seat properly. Its the positive pressure exerted by the pistons combined with piping diameter and design that determines the speed of the existing exhaust gases. I'm trying to find a nice equilibrium between the two concepts. My manifold is log style which already impeeds flow at higher rpm's but i'm not to worried about that. Please enlighten me on your theories sir and experiences you've had with similar setups seen.

[BustedLX]

Ok, I made a mistake in regards to the dump tube. What I meant was using a wastegate with NO dump tube. What I meant was that you can't have a wastegate dumping into the engine compartment without having a down tube to channel the hot gasses away from the engine compartment.


Now to you exhaust. My experiance with Turbos is mostly from working on Tubro Diesel engines and lately with boosted B series engines and a few SOHC Vtec Turbos that I've done for my brother and his friends. But it's mostly from what I learned while working with diesels and I just applied it over to the Honda work and I've had great results.

I don't know the whole technical reasons why you need back pressure it's just something I know... It's hard to explain but I'll try. Engines with to little back pressure will have a larger tendancy to backfire and when they do they pull cool air in (since all the warm exahsut gass is gone) and they run a risk of burning a valve. It's true that having less back pressure will help you top end power band but having to little will also hurt you.

Basically you have to find a middle ground that you are comfortable with. I've applied this knowlegde basically with every honda I've worked on boosting and had good results. For example a friend of mines B16 with a 60-1 2.75" DP to cat and 3" exhaust made 278whp and 243 ft. lbs at 10 psi and the power band was real smooth. That's what I'm intrested in, Smooth power band, flat toque, flat AFR, and good numbers. This isn't a car that is going to be fast as hell and blow up in 10K miles. It's a street racers that's been runing for over two years now.

Another example I have is a friend of mines 02 Super Duty 7.3 Powerstroke. Factory has a 3" DP. Started working on the trcuk made a custom exhaust with a 4" DP, new intake, minor goodies. The truck got faster ran a 15.40. Then this dude in an Excursion pulls up and runs a 14.50, My mouth hit the floor. Ended up talking to the guy (who really new his shit) and he sad that the 4" DP was just to big, The engine doesn't have enough backpressure. So I was like ok makes sense. We mad a new 3.5" DP and bought a whole new exhaust that the guy recommened also (very nice looking tip). The truck has allot more bottom end now, yo ucan esspeically feel it while towing. Haven't gotten it back to the track since we've been focused on the race car but it deffinately feels allot better.

So just think it over. If I can put my back pressure thought into words better I'll post again.

[MRX]

please explain your definition of back pressure. I am very understanding of this subject but its really never been explained in scientific terms (something i'd understand).

[WiKKeDV16]

Originally posted by BustedLX
Running an open dump tube off the wastegate is one of the worst things you can do for turbo efficeincy and you could encourage detonation. You can't dump hot ass air into the engine compartment for the tubro to pick up and compress. The turbo already makes the air hot enough with out the super heated exhaust gas. Plus you want the turbo to pick up clean air, not exhaust gas.

As for the crush bent, You don't want your exhaust flow to be turbulant. Having a turbulant exhaust flow is no good. And having crush bent eblows makes for some nice turbulance.

As for exhaust size piping. A popular misconception is that since you go Turbo you no longer need any sort of back pressure. Nothing can be further from the truth. You still need to maintain a degree of back pressure in order to preserve torque and help the turbo spoll. If your turbo only has a 2.5" exhaust exit then that's what it needs, Not 3". My recommendation there would be get a 2.5" DP till the cat then after the cat you can open up to 2.75" or 3" if you wish, But give the engine some form of back pressure.

Last I heard you where using a small DSM turbo. A 2.25" DP would be fine for that, Maybe even 2.5" would be allright. The reason I bought my Bullet brand cat-back 2.5" mandral bent is because at one time I was planing to go boost and that's what I was going to use. Unless you are moving massive amounts of air liike from a 60-1 a large diameter exhaust pipe is not needed and could end up hurting you.

i meant dump tube as in.. running pipng from the wastegate out of the engine bay under it.. not staying in the engine bay.. how stupid do i look.. i told antonie about this already.. not leave it in the engine bay thats just stupid.. and antonie u hit the head on the nail on what i wanted u to do..

secondly.. ive seen dynographs and a few people on some forums feel greatly towards giving the WG its own exit tube instead of rerouting it into the exhaust.. they have gained spool time and some power as well..the reasons for this i havent looked into.. i dont know why when the WG is routed into the exhaust system again it becomes some sort of a restriction sometimes.. but running the WG alone ive seen to improve the previous wg/exhaust setup

[WiKKeDV16]

example of what i meant..

[BustedLX]

Originally posted by WiKKeDV16
they have gained spool time and some power as well..the reasons for this i havent looked into..

Because there is more back pressure without it. The more volume your exhaust system has the less back pressure you'll have.