Spray.......Cutout?

[OneQuickV6]

I don't know if this is more of an exhaust question, or nitrous question, so feel free to move it appropriately. OK, I have completely stock exhaust, and a cutout. Now I have heard 12Second's numbers and he swears having the cutout open kills the numbers. I alo know that with nitrous your exhaust needs are greater. SO am I better off to spray with the restrictive stock exhaust, or to keep the cutout open for the spray? Has anyone been in this situation and dyno'd yet? I just wanna get the most out the squeeze. Thanks.

[mike malloy]

well last year i ran a 14.01 with my cut-out open. i don't know what my times would be if i had it closed. since then i have added a 3in cat and s-pipe, the cutout is closed and the n20 hit really hard..

[AZ3.8Camaro]

Where is your cutout?

[slacker69]

I added about .2 tenths with my cutout open so i got rid of it. I even added .2 tenth with the cutout open NA so i think it is a worthless mod might be time to get rid of the single turn down MAtt [img]smile.gif[/img]

[mike malloy]

the cutout is located in the middle of my i- pipe, i have had it closed for awhile now and i'm not planing on opening it up again.. ;)

[OneQuickV6]

Mine is right before the muffler. Thanks for the advice so far guys. I just don't see how a $300 exhaust set-up, that couldn't possibly flow much more than my cut-out, could benefit me. Unless the cut-out flows too much? I dunno, what else do you guys think?

[12secondv6]

Hmmmm, well if you had a complete bone stock exhaust system plus a cut out then I would think that you would see an improvement with the cap open.
See, our cars need back pressure.
Stock manifolds, y pipe, cat should keep the back pressure high allowing that nice huge low end torque numbers to show up.
I honestly dunno.
I know with my bird's full exhaust on the bottle I make less power with the cap open

[AZ3.8Camaro]

Can anyone reccommend a proven exhaust setup for me then? How much do I want to do???

[RaVeN1469]

Why do people keep doing cut outs if it's been proven to loose hp on our cars?

Yeah, whats a good exhaust? I'm trying to decide between catback(not sure which one), spintech w/2.75" pipe (and mecham tips w/money saved), or going with MSD DIS-4. I love the sleeper appeal my car has right now and it sounds aggressive as all hell with the lid so might go with the ignition.

[John_D.]

<blockquote>quote:</font><hr>Originally posted by RaVeN1469:
Why do people keep doing cut outs if it's been proven to loose hp on our cars?<hr></blockquote>

What would be interesting, would be to run a cutout for about 50 miles, then take it to the track.

Otherwise the pcm has optimized without the cutout, and then changing the exhaust at the track throws the whole thing off...?

So it may not be that the cutout is bad, just making a big change and the pcm not having an opportunity to adapt.

[ September 16, 2002: Message edited by: John_D. ]</p>

[OneQuickV6]

I really could never belive that on my completely stock exhaust that I'm losing power with the cutout open. Now with an aftermarket exhaust setup, and then a cutout, maybe. So I guess I will either stick with the cutout, or I will eliminate it and get a more expensive, crappier sounding exhaust system.

[12secondv6]

Proven exhaust system?
Dunno
Magnus and I have complete opposites.
I think he ditches his for the track.
He also runs 3 inch I think.
I run rk sport headers 2.5 inch y pipe, 3 inch section where they join, then 2.5 catco high flow cat, then 2.5 s pipe, then 3 inch cat back
Mine works well

[AZ3.8Camaro]

Thats frustrating. I would guess that on nitrous runs, less exhaust would be better, probably not NA though. Just a guess. For NA cars, I hear the rule is a quarter on an inch bigger, a half at the very most. Anything more and you loose power. But with nitrous, it changes everything. 12sec, next time you dyno with n2o, try the cutout again. That way we have solid evidence. I am thinking about a cutout before the cat for n2o only, and a 2.5 mandrel all the way back.

[OneQuickV6]

<blockquote>quote:</font><hr>Originally posted by AZ3.8Camaro:
I would guess that on nitrous runs, less exhaust would be better, probably not NA though. <hr></blockquote>

HMMM....I think you got it backwards? With nitrous, you are burning up that much more fuel and air, therefore there is more to flow out on the exhaust side.

[12secondv6]

Old engine nitrous dyno
Cap closed 291 rwhp 362 rwtq
Cap open 282 rwhp 335 rwtq
Nuff said :D