i've heard that it changes a/f ratio. i was thinking about taking off the muffler part. just the muffler when i go RR in august. would that send too much heat to the gas tank? if i dont do that, i might just take off the cat and run open header. i run the stock muffler to not get attention. i wont be doing this on the street. it's just stupid to do that. will the heat coming from the header be heating up the front car of my car too much? the cat would be the easiest. just 6 bolts and it's off. if i had to do the muffler, i think i'd have to do some welding, which is why i'd rather do the cat.

i am also boosted, which is why i am trying to free it up as much as possible. the tiny oem muffler piping is not helping me at all.

if u have suggestions or anything, im open to them.

 

I doubt it. You change your A/F tuning due to incomming/internal changes not exhaust/outgoing changes so I doubt it. Its all backpressure. Know what I mean?

And on too much heat going to the gas tank. Its a possibility. But only if you push it really hard. Depending on the weather as well. If its cooler outside it will take more to heat things up. If it is just quick 10--15 sec runs it'd be no big deal.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by h23sleeper &raquo;</TD></TR><TR><TD CLASS="quote">I doubt it. You change your A/F tuning due to incomming/internal changes not exhaust/outgoing changes so I doubt it. Its all backpressure. Know what I mean?

And on too much heat going to the gas tank. Its a possibility. But only if you push it really hard. Depending on the weather as well. If its cooler outside it will take more to heat things up. If it is just quick 10--15 sec runs it'd be no big deal.</TD></TR></TABLE>

It might change some since the exhaust is moving faster, it should allow the intake to pull in a little more air also

 

Yes, it will a bit; that's why some people tune their big turbo mills for an open-dump tune and a street full exhaust tune.

It shouldn't be that much, though, provided you have a fairly free-flowing exhaust to begin with. Just do it

 

hes got the stock exhaust right now so it will be a big difference....

i think you ought to get two tunes like said above, and just pull the cat on the track....

 

i just have the stock muffer. 2.5 inch piping and an open dump tube. i will be road racing..not dragging my car. so it would be ~20 minutes of heat.

 

it will make a good size difference, boosted setups can lose 30whp from just the cat, let alone the stock muffler...i would get the 2nd tune, and would also goto a muffler shop and maybe have a bent pipe made that goes from end of header to side of car, although youre at 40+mph at least on the track, 1000 degree temps im sure do not play well with the bottom of teh car....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by h23sleeper &raquo;</TD></TR><TR><TD CLASS="quote">I doubt it. You change your A/F tuning due to incomming/internal changes not exhaust/outgoing changes so I doubt it. Its all backpressure. Know what I mean?
</TD></TR></TABLE>

A exhaust that flows more will typically lean out the A/F mixture a bit, as the engine is able to pull a bit more volume in with each intake stroke.

 

im not sure of your setup but with a stock honda computer the whole map is tuned very well so you will not run lean

the only reason that people run lean when runing open down pipe on a turbo setup is because with a grater presure differentail accros the turbo it spools quicker and makes boost in earlier rpms where the map was not tuned as well more like in those areas it was guesetimated.

if your not turbo i wouldn't worry.. the key comes down to manifold presure vs rpm. if the map is tuned well you will have no problem

taking the exhaust off just allow different manifold presures to be seen earlier in the rpm band

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prelittlelude &raquo;</TD></TR><TR><TD CLASS="quote">im not sure of your setup but with a stock honda computer the whole map is tuned very well so you will not run lean

the only reason that people run lean when runing open down pipe on a turbo setup is because with a grater presure differentail accros the turbo it spools quicker and makes boost in earlier rpms where the map was not tuned as well more like in those areas it was guesetimated.

if your not turbo i wouldn't worry.. the key comes down to manifold presure vs rpm. if the map is tuned well you will have no problem

taking the exhaust off just allow different manifold presures to be seen earlier in the rpm band</TD></TR></TABLE>

i am boosted, but i will most likely just make it run richer and get a pipe welded. ill find a 3 bolt flange and weld a pipe angled to the side of my car so it will shoot out near the door or something. it will be easy because when i am ready to drive home, i can just take off the 3 bolts and put the cat back on and not get pulled over.

another reason why i have the cat on the turboed setup is because i hate sitting in my car with the windows opened and smelling gas. it was REALLY bad. it was like taking a bucket of gas and sniffing it.

 

The cat isn't going to make THAT much of a difference of gas smell, chances are you are just running too rich as it is.
Running open DP can be dangerous since it affects spool rate. I wouldn't do it if I were you, or I'd just spend a few hundo to get an exhaust system and tune it. If you can afford turbo, you can afford that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by homesauce &raquo;</TD></TR><TR><TD CLASS="quote">The cat isn't going to make THAT much of a difference of gas smell, chances are you are just running too rich as it is.
Running open DP can be dangerous since it affects spool rate. I wouldn't do it if I were you, or I'd just spend a few hundo to get an exhaust system and tune it. If you can afford turbo, you can afford that.</TD></TR></TABLE>

hrmm, probably going to throw on my gutted cat on track days. ill go find a cheap muffler then.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eMpAtHy &raquo;</TD></TR><TR><TD CLASS="quote">

hrmm, probably going to throw on my gutted cat on track days. ill go find a cheap muffler then.</TD></TR></TABLE>

let me warn you even more, i have a strait thru 3 inch exhaust wich offers very little restriction with a open dump tube and i should only have 9 psi but due to the very free flowing exhaust i see boost spike at 10 and 11, yes i know not a major problem

however take my friend for example drumking15 on here, he has a plate block off a 3 inch open down pipe and then t'd off of it to run it thru the stock exhaust, with the stock exhaust and the open downpipe plate on there to block it he runs a SOLID 7 psi with out any creap what so ever. we took off the exhaust just befor ethe cat and drove it still not open DP and it creaped to 8-9, then we took of his block off plate and when were were doing a 3rd gear pull as it crept up to 10psi when the wheel broke lose i saw the boost gauge spike at 14-15 psi! .. this is on a built motor and he is only on a stock map sensor that reads to 11 psi

this probablycreated a dangerously lean condition.. you have to be very aware of how much of an effect that the presure differential accross your turbine can have on boost.

 

Even on N/A setup, removing the exhaust WILL alter A/F ratio.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prelittlelude &raquo;</TD></TR><TR><TD CLASS="quote">let me warn you even more, i have a strait thru 3 inch exhaust wich offers very little restriction with a open dump tube and i should only have 9 psi but due to the very free flowing exhaust i see boost spike at 10 and 11, yes i know not a major problem

however take my friend for example drumking15 on here, he has a plate block off a 3 inch open down pipe and then t'd off of it to run it thru the stock exhaust, with the stock exhaust and the open downpipe plate on there to block it he runs a SOLID 7 psi with out any creap what so ever. we took off the exhaust just befor ethe cat and drove it still not open DP and it creaped to 8-9, then we took of his block off plate and when were were doing a 3rd gear pull as it crept up to 10psi when the wheel broke lose i saw the boost gauge spike at 14-15 psi! .. this is on a built motor and he is only on a stock map sensor that reads to 11 psi

this probablycreated a dangerously lean condition.. you have to be very aware of how much of an effect that the presure differential accross your turbine can have on boost. </TD></TR></TABLE>

good information

 

I run open headers everyday on the streets.. Have been for over 1 year already.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1997Accord &raquo;</TD></TR><TR><TD CLASS="quote">I run open headers everyday on the streets.. Have been for over 1 year already. </TD></TR></TABLE>

Im sure that sounds just fantastic.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1997Accord &raquo;</TD></TR><TR><TD CLASS="quote">I run open headers everyday on the streets.. Have been for over 1 year already. </TD></TR></TABLE>

You sir are an idiot.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1997Accord &raquo;</TD></TR><TR><TD CLASS="quote">I run open headers everyday on the streets.. Have been for over 1 year already. </TD></TR></TABLE>

Good for you.

 

isnt it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1997Accord &raquo;</TD></TR><TR><TD CLASS="quote">I run open headers everyday on the streets.. Have been for over 1 year already. </TD></TR></TABLE>

are u trying to be sarcastic? u live in san jo. the cops there are bitches. i dont know why u are being an *** about this. i am doing this on the TRACK. not on the streets. if u didnt read, i run with a cat and the stock muffler on the streets.

 

I really believe that the open header system for a turbo'ed car is great. I know someone who has a electronic cut out system on their tubo'd prelude and spools much quicker and gets all that extra turbo gases out.

If I were you, I would spend some money on getting a Electronic Cut Out system so you can go open header whenever you like, and then press the button, and you're stock again.

Consider it, everybody has their own opinions on open header.

 

Which company carries the cut out system? any website?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BLACKISWHACK &raquo;</TD></TR><TR><TD CLASS="quote">I really believe that the open header system for a turbo'ed car is great. I know someone who has a electronic cut out system on their tubo'd prelude and spools much quicker and gets all that extra turbo gases out.

If I were you, I would spend some money on getting a Electronic Cut Out system so you can go open header whenever you like, and then press the button, and you're stock again.

Consider it, everybody has their own opinions on open header.</TD></TR></TABLE>

 

I stand corrected. Thanks. Nice to know.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BLACKISWHACK &raquo;</TD></TR><TR><TD CLASS="quote">I really believe that the open header system for a turbo'ed car is great. I know someone who has a electronic cut out system on their tubo'd prelude and spools much quicker and gets all that extra turbo gases out.

If I were you, I would spend some money on getting a Electronic Cut Out system so you can go open header whenever you like, and then press the button, and you're stock again.

Consider it, everybody has their own opinions on open header.</TD></TR></TABLE>

it would be a great idea, but i only plan on doing this at the track and i wouldnt need a cutout.