2.5 or 3 Inch Exhaust??

['87quest]

I'm looking at a new exhaust system for my car and I don't know if I should go with 2.5 or 3 inch? My car is mostly stock.. any info will be appreciated!

 

Thanks, Drake

[SOTTY]

2.5" is all you need , 3" to big

[Dred_85.5_TSI]

for a stock car that will stay stock (or near stock) 2.5" will be fine. If you intend to modify it in the future 3" will give you more room to grow.

[88-cnqst-tsi]

http://www.racetep.com/tips.html#exh makes a good point for exhaust but a tone of people go for 3" and stock I remember measuring it at 2.25" so if ya go 2.5" get it as straight as possible and get it mandrel bended for best results. But check out what others have to say

[scott87star]

A 2.5" even without a muffler is eerily quiet, a 3" and it sounds like a gurgly tractor no matter what muffler. My opinion, of course, but getting to a meet and listening to what other guys are running helps lots.

[Eirewolf]

2.5" is all you need , 3" to big

This.

[NikoFab]

http://www.starquestclub.com/forum/index.php?showtopic=138062

[RonnieJ]

3" Downpipe and mid pipe to a 2.5" catback is my personal fav. Nice response without the annoying noise of the 3"

[psu_Crash]

3" to the glasspack, then into dual 2.5"

 

Personally I like the sound of 3" but 2.5 is really all you need. Or like Ronnie suggested is probably a nice setup

[NikoFab]

3" Downpipe and mid pipe to a 2.5" catback is my personal fav. Nice response without the annoying noise of the 3"

3" to the glasspack, then into dual 2.5"

 

Personally I like the sound of 3" but 2.5 is really all you need. Or like Ronnie suggested is probably a nice setup

 

I hope it's a nice setup...it's exactly what Ronnie is doing for me!

[ZPI28]

2.5 is plenty but i really liked the sound of my 3" with a dynomax bullet on it.

[TexasQuest]

for a stock car that will stay stock (or near stock) 2.5" will be fine. If you intend to modify it in the future 3" will give you more room to grow.

+1

[RonnieJ]

 

 

 

I hope it's a nice setup...it's exactly what Ronnie is doing for me!

 

With the HKS catback its so tame. You just hear turbo spool until you go WOT. That's when the fun happens

Edited July 18, 2013 by RonnieJ

[Trouble_07]

I was thinking of going 2.5" down pipe on mine with a 3" mid section and 2" duals out the back. Has anyone done this before? How was the sound? Ill be running all straight pipe.

[Technology]

Ladies love 3" pipes. Do you like keeping the noise down and the comfort up, or are you an American Patriot who won't settle for second best? Get a 3" system with a high quality muffler. Magnaflow makes an offset in/out straight through muffler that is very nice and keeps the noise to a minimum, but still allows high horsepower. I had that and it was not too loud. The cam made it louder. Stock cam, 3" with no cats and straight through muffler, and a tip that exits past the bumper will be really quiet in the car.

[MikeMeyerhoff]

Depends on how its bent. I wouldn't run a 2.5" with crimp bends.

[Dred_85.5_TSI]

my car 3" downpipe, exhaust, resonator, TenzoR muffler. Hx35W .7 A/R bullseye housing, 296 cam.

[RonnieJ]

Too loud for my taste but other will like. Ive had full 3" on a 500hp daily driver. Never again. 2.5" catback is tame enough and will make 400whp no problem. 3" is too damn annoying IMO

['87quest]

Wow Thanks everybody! I went down to a local shop and the guy there said if I bought a downpipe he could make a 3 inch system off of that and would put a good high flow Magna flow muffler on.. that sound like a good idea? I want a good deeper tone not a fart cannon ricer sound Haha

[kev]

A conquest will never sound like a fart can honda no matter what type of exhaust tubing and muffler you put on it.

 

But I agree with what the others say...I had a 3" with a dynomax ultraflow. The drone was downright annoying. Not bad driving down the freeway but stop and go city traffic drove me nuts. The Magnaflow mufflers have less drone than the dynomax...which is good but not enough in my opinion.

 

Also, you are putting a larger diameter pipe on there....it has to travel under the forward-most rear cross member and there has to be some clearance or it will rattle....ie it reduces your ground clearance significantly. I bottomed my 3" exhaust out on multiple occasions with a stock height suspension.

 

I'd go with 2.5" and a magnaflow.

 

Kevin

[Technology]

Ken just said this as I was typing it: The quest motor can't really produce the same tone as a honda which has the standard "fart cannon" sound. The turbo works as a little muffler too. Magnaflow makes a freaking nice muffler. You won't be disappointed, but if you are going for maximum performance, the magnaflow will have to be the "straight through" kind where if you held it vertically, you could drop your keys through it and they'd come out the other side. Kind of a funny idea, but it's true.

 

And I had my car dropped nearly two inches from stock height in front and 1-1.5" in back. As long as you drive smart and avoid speed bumps/humps, you won't bottom out. I rarely scraped my exhaust.

 

And as I said before, the point where the exhaust tip sits will greatly affect the sound inside the car. That is where it matters, not outside, cause let's face it: If you were going for subtlety, you wouldn't have bought a quest in the first place. The further past the bumper you have the tip, the quieter it'll be inside. My 3" system with a big cam, MPI and a bigger turbine housing was VERY reasonable inside. I could talk on the phone, have a normal-volume conversation, hear new rattles and listen to music at a lower volume than with the dynomax and forward-of-the-bumper exit. Designing the system wisely makes a huge difference.

[Technology]

http://i.imgur.com/ZFyId.jpg

['87quest]

I didn't know that made such a difference.. but I have to say I like the looks of the muffler better when it is placed forward of the bumper rather than sticking it out like that ^

 

Soo for the best sound and best performance 2.5 or 3 in????

 

Thanks again for all the help guys!

[RonnieJ]

Depends on power goals and noise level you want. We did 413whp on our shop FRS with a 3" Downpipe and 2.5" the rest of the way back. If you arent looking for big numbers I would do the 3" to 2.5" combo

[Fuze]

Ahh, this used to be a debate between Top End Performance, and Custom Network Motorsports (CNM) back in the day, CNM sold a 3" mandrel exhaust and TEP sold a 2.5". TEP was fond of saying 3" was too big, until James from CNM called them out on it with dyno results on stock and lightly modified cars for his 3" system vs TEP's 2.5" system.. After a while, TEP started selling 3" systems after CNM went out of business.

 

First, let's rule out cats and assume you'll run a straight thru muffler.

3" is the size you want on a turbo car for best performance and to make sure you don't outgrow the exhaust system. 2.5 will work just fine, but 3" will work better at minimizing backpressure. I have had an HKS (60mm, less than 2.5"), a 2.5" with TEP downpipe, a crappy 3" KayDM system, and a full 3" MK1 SS system. None of the other ones compare to the MK1 system. Get it and forget it.

Edited July 18, 2013 by Fuze