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Discussion Starter #1
I have a O\R H pipe with pypes Catback exhaust if i cut the mufflers out would i gain or lose performace? up comming mods are equal lenth headers custom CAI ported intake manifold and 100 shot of zex nitrous? what are everyones thoughts on straight pipes?
 

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i think you would loose to much backpressure and hurt performance a little.
 

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Discussion Starter #3
alright thanks ..also can i run long tube headers with a auto tranny?
 

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I've seen a dyno with and without mufflers and it did loose power without mufflers. not much, but it did.
Go ahead and stick 3" exhaust all the way on there or just run longtubes with no midpipe or catback and see how it feels.
 

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I've seen a dyno with and without mufflers and it did loose power without mufflers. not much, but it did.
Go ahead and stick 3" exhaust all the way on there or just run longtubes with no midpipe or catback and see how it feels.

There you go, thats the problem. The Dyno numbers. Dyno is only a tool. It can not measure how fast a car gets down the road. Wonder why so many guys run open headers at the track?:headscratch:

The longer the exhaust system, the more restrictive. No way around that. The Smaller in diameter the exhaust system, the more restrictive. No way around that.

Then what about exhaust scavenging? Pumping looses?

To put it simply, the better the car can exhale, the better it can breath.

Hope your next response, isnt "This is not a track car".

A car is a car. Exhaling and breathing are the same.

Unless its electronic:D
 

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if i were you id leave the mufflers on because it says you have an aftermarket catback so theres no point in puttin it to waste itll sound better the way it is...
just my opinion
 

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No mufflers will make it sound like a tractor.
 

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All those stupid drag guys at the track running open headers when they could make more power with a mufflered system, especially those slow fools running NASCAR. :shigrin

Seriously, there are almost no properly tuned engines around that make more power with more restriction. An engine would have to have a design problem like an A/F ratio error or excessive exhaust open time without proper backpulse to make more power through mufflers or other restrictions (like looong pipes).

A well-tuned engine that makes more power through mufflers or long pipes is a rare freak. The only way to have that happen is if a good tune was never made for full breathing, or the thing had way too much exhaust valve open time to the point it was drawing clean mixture into the pipe and there was no backpulse to ram it back into the cylinder.

The NORMAL way an engine is designed to use large exhaust time is to used a tuned pipe to ram the drawthrough back into the engine. Never build a motor based on a freak result.

Tom
 

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hey old man, if ya gonna run it on the street ya gotta run murfflers. so sayeth mr. popo. in my passed, i've burned valves on extended street driving. what ever the dyno says, it is what it is. if ya gonna trailor it, cut 'em off.
as it has been said, exhale is a crucial part but, don"t forget inhale. (air intake)
 

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Discussion Starter #14
thanks for all the replys everyone i reason i asked is because i am going to be running nitrous and a few people at the track told me the less restrictive the exhaust the better.
 

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Discussion Starter #15
Also 89coupe has a very good point.. a dyno is just a tool i don't know about anyone else on here but ive seen car that dynoed over 900rwhp and car that have dynoed at 600rwhp but the funny thing is some of the cars that dynoed lower in HP had better track time. the dyno isn't everything.
 

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WhiteGT, your are correct. Dyno should only be used as a tuning tool. That's it. I have also seen cars lose Power on the dyno, but pick up ET at the track. Peak Power, is not as good as Column Average of Power.
 

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thanks for all the replys everyone i reason i asked is because i am going to be running nitrous and a few people at the track told me the less restrictive the exhaust the better.
The less restrictive the exhaust the better it is for anything. Don't get sucked into the myth plugging up the exhaust makes more power in a properly tuned engine.

Look at the headaches people have with exhaust using a turbo. The backpressure of the turbo causes all sorts of exhaust temperature problems. When you plug up the exhaust temperatures go way up, and that can damage valves and other things.

The less restrictive the better. Especially with something like nitrous that raises temperatures.

Tom
 

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Look at the headaches people have with exhaust using a turbo. The backpressure of the turbo causes all sorts of exhaust temperature problems. When you plug up the exhaust temperatures go way up, and that can damage valves and other things.
I agree but turbos actually need a certain amount of Down pipe behind them. Other wise there is a huge pop flame on shifts that will burn up the compressor wheel and damage bearings. Running a turbo with no exhaust is like running an engine with no headers or manifolds. Yeah, it works great but not for long.

The less restrictive the better. Especially with something like nitrous that raises temperatures.
Very true. However, be sure the exhaust pressure is equalized before dumping (IE some sort of crossover:Ypipe, Hpipe, Xpipe) especially when running juice . Equalizing the pressure between the 2 banks of cylinders if advantageous for sound and power.

Consider the firing order:

1-3-7-2-6-5-4-8

3 out of the first 4 cylinders to fire: fire on the left bank.

Oh and strait pipes sound like a$$ with out resonators.
 

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Discussion Starter #19
thanks every for all your help :bigthumbsup
 

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try glass packs or an slp loudmouth set up.
fyi your offset in/out muffler design will make it suck to weld a straight piece of pipe in there.

actually if i were you... do cutouts before the mufflers. if your gonna hit the juice, open the cutouts.
 
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