what engine in the avenger? if its a 2.5 mitsu thats amazing..my 3.0 mitsu is hard pressed to get 24 mpg.[:@]

 

The Avenger has the 2.0 w/ a 5 speed. I get 28-29 in the city and 36-37 on the highway. Usually with all around driving I get 30-34 just depending on waht the driving condition are.

 

Ah, you have the Neon motor, they respond fairly well to mods.

BadStratRT:
What is the whole mandrel bent hole?[sm=smiley5.gif][sm=smiley24.gif] They have been dyno and track proven time and again to increase power over both standard wrinkle bends and the slightly better compression bends. If they were not effective they wouldn't be as popular as they are and wouldn't be coming standard on so many cars now. It's no different than porting and polishing your heads on intake, it serves the same purpose, to free up and smooth out air flow.[sm=exactly.gif]

 

71.i simply dont buy into it. im sure that on a car moving 1300cfm through the engine and it has 2 inch exhaust valves and 4 inch collectors, yes, that slightly smoother bend makes a difference...my exhaust on the mirada doesnt have any bends, it was all cut/welded. and i ran 12.80 with it bolted up..i cant see a certain kind of bend making any difference...same with the RT...my exhaust was bent in a regular bender, and i think it sounds very good,and it is Very loud. on the other have, ive met a few other guys with RTs who have paid out the *** for a mandrel bend, and they ask me"where did you have yoiur exhuast done? i wish mien soudned like that."

the only people ive ever heard make regular "mandrel" comments are ricerboys..ive heard the follow comments on many occassions at the track...(always about cars faster than theirs) "look at his exhaust...its not even mandrel bent"

to each hsi own,but like i said..i dont buy it..a bend is a bend...i can see it making alot more of a difference on an intake pipe,or the exahust of Very high flow cars..but not any normal car...and im sure people have dyno sheets that show they gained 0.0246838 hp at 5000rpm with the mandrel bend, but the ends dont justify the means..IMO

 

In the case of optimally sized pipes, or the exact size you need for a particular application, there is a difference in the type of bend. Let's say your cars optimal size is 2". WHen you use a compression bender the pipe gets smashed to a smaller diameter causing a restriction. In the same situation you don't have the neckdown problem with the mandrel pipes, obviously, so no restriction. What can be done to overcome this is to oversize the pipe to say a 2.25" pipe, that way the restrictive areas are still the same size as the optimal pipe size. Another shortcoming of the compression bender is the ripples it puts in the pipe. Ripples = turbulence that effectively reduce the diameter of the pipe when gases are passing through them.

badstratrt. I don't think the mirada is a good example in this discusion due to the pipe size your running, 3". You don't need that much of a diameter. Optimal size for your car and engine set-up is 2.5"

 

i would think the opposite...the mirada runs faster with open headers, leading me to believe that a bigger system would allow more flow. backpressure isnt an issue because of the amount of low end power with the open headers...and i think it would sound terrible like 2.5"...all nasal like the "pony" cars..

 

That's your first mistake.[sm=smiley2.gif] A few years back a study was done on exhaust pipe length. The study showed that for every inch or so of pipe beyond the collector took away one or more HP. So what your talking about isn't related so much to the bends as the length of pipe itself. Or in the case of the Mirada, the compression bend length of pipe. LIke 71RR said, it's been proven. Believe it or not.

[sm=itsok.gif]

 

well, studies dont mean sh** to me...

here is an example of another study..CMU published an article about a study that said "maintaining a steady level of alcohol in the bloodstream helps the brain retain information." if that was the case...id be smarter than dr steven hawkin.

thats like saying "C&D said this or that...so it has to be true..."..its paper racing..

the bottom line is i have time slips that show the car is faster without exhaust, and last time i checked the super pro guys, and for that matter, nhra top fuel guys, dont run exhaust.

now when it is an item like headers, i can see a need for the mandrel bends, because of the cramped nature, but with exhaust, where it is such a subtle change...it sounds like over priced ricer nonsense.

 

If you can see it here, why not further downstream? The only thing that changes from the individual tubes to the pipe is the volume of gas being carried and the temperature of the gases.

You need to understand more about fluid flow and temperature changes to really understand why it's better. Maybe I'll try and explain it to you at Norwalk between rounds. I'll bring my crayons to draw some pictures.

 

while i can imagine some flow being affected by the ripples, open headers are just that, wide open...so anything is causing some restriction, could be significant... with full exhaust you have a muffler, and with the restriction caused by even the best muffler, i cant see how the tiny amount of turbulance could make that big of a difference.

and ill explain track time, burnouts, etc.....