Q1: For those of you running turbo, did you have any problems with the stock exhaust system being too restrictive? I have a freshly turbo'd S with stock exhaust, and the car "falls on its face" when VTEC turns on. I had a very reputable AEM EMS tuner try to tune my setup with the stock exhaust, but he couldn't get rid of the drop in power after VTEC. As an experiment, he removed the exhaust entirely (open 2.5" downpipe), and gained almost 50 HP at 9000 RPM. It sounded a little ridiculous to me at first (how could such a high revving, high flow car have a restrictive exhaust?), but he showed me the dyno results, and it appears to be correct. Has anyone else encountered this?

Q2: Obviously I can't run open downpipe in California, so I need to find a less restrictive exhaust. Most of the exhaust systems on the market have 60mm (2.38") tubing, but that is that same size as stock... Other than "bling factor", what kind of improvement could that offer? Are there any 3.0" systems on the market, designed with turbo in mind? I want something that is quite, emissions legal, and less restrictive. Any ideas?

-Mike

 

yank the damn thing and run open downpipe them tell me whats up!

ultimate-racing 3.0" stock look



they also have a single setup in 3"

 

single 3" full exhaust.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by all mOtor h23 &raquo;</TD></TR><TR><TD CLASS="quote">single 3" full exhaust.</TD></TR></TABLE>

there u go. no cat. 3 inch piping ALL the way. test pipe. maybe a resonator and a single muffler.

 

any where from 70mm to 80 is good for turbo

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fknfast &raquo;</TD></TR><TR><TD CLASS="quote">yank the damn thing and run open downpipe them tell me whats up!

ultimate-racing 3.0" stock look



they also have a single setup in 3"</TD></TR></TABLE>


Sure, if u wanna burn your valves

hondas require backpressure, they "aint no american cars"

 

and how would a bigger more free flowing exhaust burn valves???? this is for a turbo setup...andything under 3" is not making power.

 

the valves burn whe there is no back pressure, u need at least a certain amount, to run it with solely a downpipe would let zero back pressure....a certified honda mechanic told me this

 

thats speculative bullshit.

no offense to you, but your honda mechanic is confused.

i can agree that running no exhaust at all on a naturally aspirated car can cause burnt valves, but even still many people feel that it is not that terrible of a risk when compared to the power gains. when it all comes down to it, you have to make comprimises in power if the car is to be used a great deal of time. personnally i can not say for sure<U></U> one way or the other, but i can say that most people out there are very confused on the subject of backpressure, and they commonly throw that word around to represent other properties of exhaust gas flow.

excessive backpressure causes power restriction. we all know that, but not having enough back pressure can cause complications as well.

simply having some type of exhaust piping will be sufficient in providing the back pressure that you need to keep from burning up valves on a NA car.

i think it would be safe to assume that the pressence of a turbo would provide a substantial amount of backpressure. think about it like this. when a turbo car lags, it is because the exhaust gas is having trouble overcoming the inertia of the exhaust turbine. that seems to me that it would create a little back pressure. at least enough to prevent the problem listed in the post above.

i would reccomend 3 inch all the way, but i think that if you went with an open downpipe your valves would be safe.

I am simply basing this off of other peoples words, dont take this as gospel and feel free to offer a rebutal

also i would like to add that being a honda mechanic is not that great of an accomplishment. i worked in a couple of honda dealership, and it is down right scary how little these mechanics actually know. Honda has an in depth online training course that most of the certified honda mechanics that i know have all cheated on, not to mention the fact that they arnt required to pass any of those tests before they actually start working on your car. they can work on your car right out of the gate, they just dont have the title of "certified". In addition the honda mechanics that really do know what they are talking about still may know very little about doing aftermartket stuff to a honda engine.

its amazing to me how no one trusts salesmen at a dealership (rightfully so) but they trust the service department infinately more. they are just as crooked, and they also get paid off of commission. And take it from me, they make more money for the dealer than the sales department.


have you ever talked to an average guy who supposedly knows a lot about cars. 99% of the time they are completley full of ****. unfortunatley these guys often become mechanics.

 

sport rider mike...

lets assume that the difference between stock exhaust and no exhaust is 50 whp.

3 inch and a freeflow cat are good for 30 addtional whp.

its not quite 50 but its better than stock and its legal.

 

TELL HIM he is full of ****. I worked for honda for 18months and I know its bs. I have ran a open dowpipe and run a 3in all day long

 

yes as stated before your honda mechanic is obviously not familiar with a little thing called a turbo...turbos do not like backpressure at all it is not their friend and will crap out on you if your exhaust is small.

 

f it.. get a 2" exhaust and let it ride!