i have a mini-me, a6 bottom with a z6 head, im running 8-10 pounds off a 14b. im open down pipe right now and its getting a little too loud for daily driving lol so i was thinking maybe 3inch piping to some sort of a stock muffler off of a big car. like 3inch piping to a v8 or v6 muffler out of a junk yard. how would that do for power? or should i just spend the extra money and go for a magna-flow? i dont think im gonna run a cat either. opinions and suggestions welcome

 

up

 

i got a SOHC, 2.5 mandrel DP, 3" full exhaust mandrel to a flowmaster 40 series

http://vids.myspace.com/index....7&n=2

 

instead of a stock 3" muffler... you can use a 3" chambered muffler (such as a flowmaster).

my friend had one on his 3" DP-back exhaust and it was a lot quieter than my car with a straight through 3" magnaflow.

 

I have a full 3" exhaust with 3" magnaflow muffler and it's not outrageously loud. No cat or resonator.

 

ya thats what i was thinkin was a magna-flow, somethin kinda quiet but opens up when u get on it

 

you won't be flowing enough on that motror and turbo combo to need a 3" a 2.5" will work just fine for your needs.

 

what makes u say that? 8-10 pounds should flow plenty. iv always heard boosted motors r opposite when it comes to exhaust, u dont want any back pressure instead of all motor cars that need the back pressure. i could be way off tho

 

eh everyone has an opinion. Just go three, and when you want more power your exhaust will be ready for it.

I run three inch, with a race style muffler, now acting as a resonator, and a flowmaster muffler i think. Its no where near as loud as the side pipe no muffler i was running...

 

maybe ill just go 2 5/8? or 3/4

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by oscarmayer &raquo;</TD></TR><TR><TD CLASS="quote">you won't be flowing enough on that motror and turbo combo to need a 3" a 2.5" will work just fine for your needs.</TD></TR></TABLE>

Someone needs a lesson on how turbos work. Turbos work on a pressure differential. Pressure differential is the ratio of pressure before the turbine blade and after the turbine blade. The greater pre-turbine pressure compared to the post-turbine pressure, the greater the amount of work can be transmitted through the turbine/compressor shaft. The larger the exhaust, the larger the pressure differential can become. Increasing the area of the exhaust gives the exhaust gas much more room to expand. Hot gas wants to expand as quickly as possible. This is why you want to have the largest area possible for the exhaust gas to expand post-turbine. What this means to you is increased horsepower and spool up with a larger 3" or even 4" exhaust regardless of how much your motor or turbo combo "flows."

 

someone needs a lesson in volume metric flows and designs before they try to correct others.

The turbo is he is using is a tiny one, and the voluem and cfm floes are extreemly small compaired to a larger t3/t4 unit. anyone who understands these things can tell you that he does not have to have a 3" exhaust in order to accomplish the same tasks. I ran a greddy kit wich the turbo I think may even be jsut a hair larger and I used 2.5" exhaust and out down 248 wheel pwoer at 14lbs of boost w/o any hint of flow issues.

you seem to think ryay, that jsut ebcause you read in a magazine somepalce it has to be true. I'm running 3" on 20psi-28psi GT30R and it will flwo jsut fine for those purposes.

the size of turbo he is running a 3" will not yeild him any results

The biggest flaws you left out and the turbo itself. the turbo's wheel is so small it will have more flow issues trying to get past that tiny wheel than it would with even a 2.25" exhaust system. it comes down to volume much more than flow rates when it comes to turbo charging. a 1000cfm rated turbo (like a t88 ot something) gets it's power not from flow but fomr volume or amount of air it can move.

 

I will give you my recipe..

3" piping from the downpipe all the way to the rear....No muffler.. Just put a 3" resonator in place of the muffler.. It will sound great and considerable lower than Open Downpipe and since its a resonatos in there it wont suck as much power as a restrictive muffler.

Here's a pic of how mine looked

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by oscarmayer &raquo;</TD></TR><TR><TD CLASS="quote">someone needs a lesson in volume metric flows and designs before they try to correct others.

The turbo is he is using is a tiny one, and the voluem and cfm floes are extreemly small compaired to a larger t3/t4 unit. anyone who understands these things can tell you that he does not have to have a 3" exhaust in order to accomplish the same tasks. I ran a greddy kit wich the turbo I think may even be jsut a hair larger and I used 2.5" exhaust and out down 248 wheel pwoer at 14lbs of boost w/o any hint of flow issues.

you seem to think ryay, that jsut ebcause you read in a magazine somepalce it has to be true. I'm running 3" on 20psi-28psi GT30R and it will flwo jsut fine for those purposes.

the size of turbo he is running a 3" will not yeild him any results

The biggest flaws you left out and the turbo itself. the turbo's wheel is so small it will have more flow issues trying to get past that tiny wheel than it would with even a 2.25" exhaust system. it comes down to volume much more than flow rates when it comes to turbo charging. a 1000cfm rated turbo (like a t88 ot something) gets it's power not from flow but fomr volume or amount of air it can move. </TD></TR></TABLE>

My information does not come from "some magazine" it comes from probably the most reputable Honda tuner there is, Jeff Evans. You can go to his forum and search for it if you want. I would recommend you search for it in fact, because apparently you couldn't comprehend my explanation of pressure differential. If you were to dyno a 2.5" exhaust and then a 3" exhaust on that 14b I guarantee you spool up will be faster and you will make more power with the 3". Yes, with a larger turbo the gains will be better going from the 2.5 to the 3, but the gains will still be there with the smaller turbo. Just because you made 248whp at 14psi on your Greddy turbo does not mean your 2.5" exhaust was ideal. You might have made 255whp with a 3". I'm not sure how you determined there were not any "flow issues" anyways.

 

ya im pretty sure ill go with the 3". so resonators arent as restrictive? do they make it much quieter?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lsvtecSIrex &raquo;</TD></TR><TR><TD CLASS="quote">ya im pretty sure ill go with the 3". so resonators arent as restrictive? do they make it much quieter?</TD></TR></TABLE>

i believe they do make the exhaust quieter. 22inch resonator ftw?