After I finished my tuning; I hit 330whp on 14psi with 3" downpipe to my 2.15" (mm to inches) HKS hiper exhaust.

On the SAME tune I managed to hit 410whp by just unbolting the exhaust.

I had planned on getting an "ecut out" and I wanted a 3" cut out due to my down pipe being 3". Well (hear say; Im going to talk to them tomorrow directly) QTP says that with a 3" DP you don't a 3" cut out because it would still flow the same because the exhaust is still going out through the exhaust system. This doesnt make sense to me... Wouldnt you want that FULL 3" so EVERY last bit can exit?

Anyhow, I heard QTP units weren't that good in the first place, and I think Im going to send it back either way. I paid $184 after tax for this ~2 1/2" cut out.

Is there an informational thread on cut outs? I found it hard to search for. Is the only way Im going to achieve this 410whp I hit with an open DP going to be just dont run exhaust at all?

Thanks guys!
Any input is good; even if your going to tell me to search for something!


Modified by jDMJeRk at 12:57 PM 10/4/2005

 

Instead of getting a E-cut, why not just get a 3" exhaust?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by green_GSR &raquo;</TD></TR><TR><TD CLASS="quote">Instead of getting a E-cut, why not just get a 3" exhaust?</TD></TR></TABLE>
I thought about that as well but you would think it still isnt going to have the same effect as the ecut out.

Only one company makes a catback 3" system for my car and Im not sure how good the quality is either. (Thermal)

TTT

What other brands do I have to choose from; I've heard the QTP ones arent the best

EDIT: I just called QTP and they have no idea why anyone would put a 2.5" cutout on a 3" DP... Interesting.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jDMJeRk &raquo;</TD></TR><TR><TD CLASS="quote">
What other brands do I have to choose from; I've heard the QTP ones arent the best
</TD></TR></TABLE>

http://www.mccordcg.com/mpp/mpp.htm
http://www.atpturbo.com/
http://www.dmhperformance.com/ A friend of mine has these on his '69 lemans.

Or a DIY throttle body set up.

 

Hands down, the DMH is the best. It has a 4 year warrenty... You cant beat that!

Its what Im using, just my opinion tho...


Blaze

 

i went with the dmh...


...well i should say i ordered it 4 weeks ago, and im hoping its in the mail. the product looks to be badass though, and better for a street car than a 3" turboback, cause i can run stock exhaust to keep the cops away when im not blowing it

 

i too went with dmh.

28whp gain opened vs closed
(small setup so no need to tease, im sure your gains would be much larger)

 

Thanks for the input guys; I gained 80whp from an open DP instead of my HKS Hiper exhaust. I just heard the QTP were a bad design and they were crapping out on people; main CRPTurbo...

Next step; where do I buy one?

Thanks guys!

 

dmhperformance.com

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jeterkm02 &raquo;</TD></TR><TR><TD CLASS="quote">dmhperformance.com</TD></TR></TABLE>
Is there anyone that sells them cheaper then what is listed on there site?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jDMJeRk &raquo;</TD></TR><TR><TD CLASS="quote">
Is there anyone that sells them cheaper then what is listed on there site?</TD></TR></TABLE>

199 shipped isnt bad if you think about it. i mean a kteller 3" weld together is 200, not including shipping, a muffler and actually having it welded together

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blackeg &raquo;</TD></TR><TR><TD CLASS="quote">199 shipped isnt bad if you think about it. i mean a kteller 3" weld together is 200, not including shipping, a muffler and actually having it welded together</TD></TR></TABLE>
I was just trying to save myself some $$$ and help out a sponsor if anyone knew of one; Ill just have to pick one up from the site then.

 

i'm getting the DMH ecutout. i already talked to jason about it too. all you need to get is the ecutout unit cause he already has the flanges. so just 179shipped. cant really beat that now can you?

 

i was planning on using a cut out but then deciden not too. because it will through off your tunningdepending on weither it was tuned open or closed. i decided to just build a quiet sleeper 3". 2 resanators, cat, dynomax superturbo muffler. the muffler is going to be tucked under the rear bumper with only the turndown showing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by downeyballz &raquo;</TD></TR><TR><TD CLASS="quote">i was planning on using a cut out but then deciden not too. because it will through off your tunningdepending on weither it was tuned open or closed. i decided to just build a quiet sleeper 3". 2 resanators, cat, dynomax superturbo muffler. the muffler is going to be tucked under the rear bumper with only the turndown showing.</TD></TR></TABLE>

true but if you tuned for open dp...youd be a lil bit rich closing it up...so you tune 2 seperate maps...once you have the basic curve of the motor under boost you just add/subtract fuel dependent on the open/closed dp senario....or you tune both maps...and have 2 chips and flip of a switch at off positione changes the eprom...and then you follow suit w/ ecutout switch...

 

Mccord makes a nice E-cutout. In Google do a search for Mccord Powerplate.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jDMJeRk &raquo;</TD></TR><TR><TD CLASS="quote">I had planned on getting an "ecut out" and I wanted a 3" cut out due to my down pipe being 3". Well (hear say; Im going to talk to them tomorrow directly) QTP says that with a 3" DP you don't a 3" cut out because it would still flow the same because the exhaust is still going out through the exhaust system. This doesnt make sense to me... Wouldnt you want that FULL 3" so EVERY last bit can exit?

</TD></TR></TABLE>

they are wrong, there is a difference.

I run a thermal exhaust and an ecutout
nice combo. thermal still flows alot, and the cutout flows even more!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Red Bull &raquo;</TD></TR><TR><TD CLASS="quote">Mccord makes a nice E-cutout. In Google do a search for Mccord Powerplate.</TD></TR></TABLE>

no they dont. its a piece of ****. DO NOT BUY IT!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drumking15 &raquo;</TD></TR><TR><TD CLASS="quote">

true but if you tuned for open dp...youd be a lil bit rich closing it up...so you tune 2 seperate maps...once you have the basic curve of the motor under boost you just add/subtract fuel dependent on the open/closed dp senario....or you tune both maps...and have 2 chips and flip of a switch at off positione changes the eprom...and then you follow suit w/ ecutout switch...</TD></TR></TABLE>

hmmm...turning off the car to switch maps is a inconvience IMO if you're on the street. maybe tune it closed and so when you open it up it just flows a lot better?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drumking15 &raquo;</TD></TR><TR><TD CLASS="quote">true but if you tuned for open dp...youd be a lil bit rich closing it up...so you tune 2 seperate maps...once you have the basic curve of the motor under boost you just add/subtract fuel dependent on the open/closed dp senario....or you tune both maps...and have 2 chips and flip of a switch at off positione changes the eprom...and then you follow suit w/ ecutout switch...</TD></TR></TABLE>
Just tune the car with the cutout closed to be safe; I tuned my car with the exhaust on and by just taking off my exhaust in between ONE run i made 80whp extra without adjusting the A/F ratio. No problems at all. A/F was just fine with and without exhaust.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by undercoverdc2 &raquo;</TD></TR><TR><TD CLASS="quote">hmmm...turning off the car to switch maps is a inconvience IMO if you're on the street. maybe tune it closed and so when you open it up it just flows a lot better?</TD></TR></TABLE>

ok this has finally got to me....no one understands the whole concept....if you have an ecutout and know your going out to cause havoc....before you start driving switch over to your tuned open dp map....so you start driving closed dp...youll be a tad rich but not horrible...you see someone...open the dp whamo tuned map for ever last bit of power....end of fun...close the dp...drive on....now say your going to work and know your not going to be out tryin to sqeeze every last bit of power....you switch back to the org. stock exh map...to save gas...

and to people who say switchin between stock exh &gt; open dp doesnt effect a/f ratios obviously somethng is very wrong w/ you car....every setup ive seen fluctuates not a lot but around .5 a/f leaner when the dp is opened if tuned for closed dp....similar concept to why a car runs leaner when puttin on a header...you increase the flow of the exh..makin more power...more power = more air which in turn needs more fuel!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drumking15 &raquo;</TD></TR><TR><TD CLASS="quote">ok this has finally got to me....no one understands the whole concept....if you have an ecutout and know your going out to cause havoc....before you start driving switch over to your tuned open dp map....so you start driving closed dp...youll be a tad rich but not horrible...you see someone...open the dp whamo tuned map for ever last bit of power....end of fun...close the dp...drive on....now say your going to work and know your not going to be out tryin to sqeeze every last bit of power....you switch back to the org. stock exh map...to save gas...

and to people who say switchin between stock exh &gt; open dp doesnt effect a/f ratios obviously somethng is very wrong w/ you car....every setup ive seen fluctuates not a lot but around .5 a/f leaner when the dp is opened if tuned for closed dp....similar concept to why a car runs leaner when puttin on a header...you increase the flow of the exh..makin more power...more power = more air which in turn needs more fuel!</TD></TR></TABLE>

All I was trying to say was this; I had my car tuned with the dp CONNECTED to my exhaust. AF was around 11.5 to 12. With the exhaust NOT CONNECTED; the AF honestly stayed about the same. Maybe it was like 11.2-11.9. Im thinking that still a safe zone.

Reguardless what you decide to do for your personal setup, as long as your aware of what your running and your monitoring it; you shouldnt have a problem!

UPDATE: Still no word on any sponsers that sell DMH products?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jDMJeRk &raquo;</TD></TR><TR><TD CLASS="quote">All I was trying to say was this; I had my car tuned with the dp Reguardless what you decide to do for your personal setup, as long as your aware of what your running and your monitoring it; you shouldnt have a problem!
</TD></TR></TABLE>
well then you exh system must be very un-restrictive...because usually when you change the flow of the system it changes the fueling requirements....also when you tested your theory...im assuming you tested closed exh 1st....then opened the dp....the heatsoak of the car w/o iat correction could have gotten these results...because as the air heated up....youd obviously need less fuel....so the heated air offseted the a/f difference....its not redicilously huge...maybe .5 a/f at most

 

any one have pics of a electronic cut on there prelude i want to put one on my 4th gen but i want to use a three inch header and can't find one

 

Its a old thread....
Any updates??