Thinking about getting one of the QTP electric cut-outs; does this offer any real/noticeable power gain or is it merely something for those who enjoy the loudness of it all? Also, what is the optimum location for it's placement?

Thanks in advance.

94 Z28 M6

 

depends on how restrictive your catback is On my flowmaster it makes a .3 tenth diffrence from open to closed

 

I know I have seen some really big gains on the dyno before on LT1 cars that just had the flowmaster muffler. Gains in the 12-16 hp believe it or not

 

yea, guys/gals running flowmaster and the spintec mufflex have said they have seen numbers in the teens w/ the cut-out open compare to closed. i just installed mine last week and didnt notice anything except for its extremely loud now.

 

460rwhp closed,480rwhp open

 

whats ur torque like?

 

I noticed gains as well...i would go ahead and do it if thats what your thinking about

 

Uncapped - about 20-25 avg gain netting 500rwhp/445tq N/A on my 396 build, w/dual 3" ss QTPs. It's a worthy mod.

 

i just installed one last week. i guess i have to take it to the track to see if i got anything from it?

 

i havnt had a chance to dyno my car but, i can feel a big difference. so much of a difference that i decided that im gonna start with an intake and a cutout on the next car i start modding.

 

I ran back to back at the strip closed and then just uncorked the headers and gaind a few hundredths and less than 1mph. Now the LT1 Caprice did come stock with true duals so I am a step ahead there far as ease of a great system install. I have 2.5" everything after the headers x-pipe to Dynomax Ultraflos and Dynomax glasspacks as resonators tucked in the quarterpanels with the tips welded on. This is just a modified dynomax UltrafloSS system for a b-body I added the x-pipe. Think most would agree my car makes good power too.

 

I am interested in reading the feed back of the members. Logically it makes sense that you would gain power. Interestingly, I have heard a lot of bad results (meaning no significant gain) with the cut-out. I admit, I may do one myself for my car but more for shock value. I hope the majority of people who have this cut-out do gain something measurable.

 

I had a gain of 12HP to the wheels with mine open and .2 tenths faster average in the 8th mile. It is just as noticable in the seat of the pants power region. Not only can you hear it when it is open, but it feels much faster. I placed mine where the factory cat was under the passenger seat. My exhaust was loud already, but with it open it is awesome. I don't usually open it open on the street. But I have been known to pop it open when some unsuspecting imports want to try me.

 

you can get some HP on a mild set up but the crazier the set up the more HP gain you will get

 

Spend half the money on a better muffler. All the power without the noise, and without having to flip a switch.

Mike

 

http://www.mofbody.com/blkchevyz/web...6hpnumbers.htm

 

I would say my car proves you wrong and to backup what engineermike said I actually get comments on how quiet my car is. My setup is mild as far as drivability but is making pretty good power for a heads cam motor. As I also said though since the LT1 b-body came with true duals it is a lot easier to run a proper exhaust on one of these which is likely why f-body guys post decent gains because they have crappy exhaust.

 

Yep. I made 545 rwhp quietly through a 3" Hooker Aerochamber. I pulled it off and only gained 5 rwhp.

 

I think cam selection plays into this as well exessivly tight cams are known to be exhaust sensitive. My cam is tighter than the off the shelf stuff and wider than some custom grinders are specing.

I think your case is different from an NA or even blower car too, a little muffler induced backpressure after the turbo is nothing compared to what is on the otherside of it.
I also think people do not understand area of a circle a single 3.5" pipe will outflow dual 2.5"

 

I stand corrected