exhaust question

[94"Che-rolet"Z34]

ok i finally found someone with a madrel bender that'd do an exhuast for a fairly good price. and then i got to thinking... is a 2.5 exhaust for a 94 Z34 going to be too large and just bog it down... anyone done this? anyone know anyone thats done this? i dont forsee it as too much of a problem(i am going with an all new cat and dual mufflers). but im just checking before i get into something.. thanx in advance!

[jeffcoslacker]

Originally Posted by 94"Che-rolet"Z34

ok i finally found someone with a madrel bender that'd do an exhuast for a fairly good price. and then i got to thinking... is a 2.5 exhaust for a 94 Z34 going to be too large and just bog it down... anyone done this? anyone know anyone thats done this? i dont forsee it as too much of a problem(i am going with an all new cat and dual mufflers). but im just checking before i get into something.. thanx in advance!

2.5 duals are too much for a stock V8. 2" is the largest recommended without loosing low end torque. Anything bigger is worthless without a performance cam(s).

[94"Che-rolet"Z34]

ok quick side note... the Z34 came with a 3.4l V6... no v8. another note... its a split exhaust (splits right b4 the mufflers) and last note(someone correct me if im wrong) but i believe that it comes stock with a 2.25" exhaust anyways... maybe i shoulda been a little more specific but i guess you cant assume everyone knows what your talking about. so my bad.... but input would still be really appreciated...

[jeffcoslacker]

Originally Posted by 94"Che-rolet"Z34

ok quick side note... the Z34 came with a 3.4l V6... no v8. another note... its a split exhaust (splits right b4 the mufflers) and last note(someone correct me if im wrong) but i believe that it comes stock with a 2.25" exhaust anyways... maybe i shoulda been a little more specific but i guess you cant assume everyone knows what your talking about. so my bad.... but input would still be really appreciated...

Right. I understood. I was just saying that 2.5" duals on a V8 originally equipped and tuned for single exhaust is enough loss of backpressure to loose any benefit of exhaust scavenging that helps low end torque. So I wouldn't think you'd want to do that to a V6. It may have some effect on high rpm, WOT performance, but how much time do you spend driving at WOT? Off the line and midrange power is much more useable for a street car.

So what I'm thinking is, the best route would be to go with maybe 2", and be sure there is a crossover, maybe in the form of a single free-flowing cat designed for this purpose. If you want the beefy look, just have them put some 2.5" resonator tips on it, it'll look tough and have that echo to it. Most people don't realize that the crossover is very important, and is figured into the tuning of the flow of stock configured engines. Without it, they suffer a lot in the bottom end.

At any rate, I don't know what you have on the intake end, but if you open up the exhaust, you gotta be able to flow more in the front to get much benefit from it. Otherwise you are just creating a "pressure bias" in the overall system, and that doesn't do anything, except waste gas and sound better than it runs.

My friend has a Ford Contour, with the V6, quite overpowered, really, for that size of car. It ran pretty good, and had great throttle response. He wanted to hang duals on it. I gave him this speech, and of course, he didn't listen. Now he hates it. It's loud and obnoxious, slow to pick up from a start, throttle response is rubbery, and his mileage sucks.

[Jonn]

Originally Posted by jeffcoslacker

Right. I understood. I was just saying that 2.5" duals on a V8 originally equipped and tuned for single exhaust is enough loss of backpressure to loose any benefit of exhaust scavenging that helps low end torque. So I wouldn't think you'd want to do that to a V6. It may have some effect on high rpm, WOT performance, but how much time do you spend driving at WOT? Off the line and midrange power is much more useable for a street car.

So what I'm thinking is, the best route would be to go with maybe 2", and be sure there is a crossover, maybe in the form of a single free-flowing cat designed for this purpose. If you want the beefy look, just have them put some 2.5" resonator tips on it, it'll look tough and have that echo to it. Most people don't realize that the crossover is very important, and is figured into the tuning of the flow of stock configured engines. Without it, they suffer a lot in the bottom end.

At any rate, I don't know what you have on the intake end, but if you open up the exhaust, you gotta be able to flow more in the front to get much benefit from it. Otherwise you are just creating a "pressure bias" in the overall system, and that doesn't do anything, except waste gas and sound better than it runs.

My friend has a Ford Contour, with the V6, quite overpowered, really, for that size of car. It ran pretty good, and had great throttle response. He wanted to hang duals on it. I gave him this speech, and of course, he didn't listen. Now he hates it. It's loud and obnoxious, slow to pick up from a start, throttle response is rubbery, and his mileage sucks.

Right, 2 inch for V8's if dual exaust, what people say for like my 5.8 litre in my truck is a single 3 inch, they claim its better than small duals, i dunno. I used to be a die hard dual guy, still love the sound over a single, but id rahter now have a right size single, right muffler than duals, not to mention its sooooooo much easier to run it under the car/truck

[94"Che-rolet"Z34]

well it would be a 2.5 single exhaust for a 3.4l... all it does is split at the very end b4 the mufflers... im getting the brand new cat and mufflers. its not a dual exhaust. im not that much of an idiot. i know thats way too much for a 3.4 v6. its just a single cat back w/cat and then splits b4 the mufflers... now that ive explained it in a little better detail can someone plz answer the question...