7rrivera7

iTrader: (1)

Bought a Del Sol with a rebuilt but stock B16 which supposedly has S2 Tuner 3's installed on a semi-built head. She pulls hard after VTEC up to 9k - more than I'm used to "feeling" so they might be T3's afterall but I'm not planning on pulling the cams to find out.

Anyway, the car's exhaust (header, straight thru to Magnaflow muffler) is too loud so I was planning on throwing in a resonator and noticed the tubing is 2.25" which may or may not be too restrictive?

Since I was thinking of "eventually" modding the engine for AM, I thought of installing a 2.5" mandrel kit from VRS along with a high-flow resonator and a Vibrant muffler. Or should I just throw on a regular no name $20 2.25" resonator (not high flow of course) for now to get rid of the loud tone?

todahead

go 3'' it will be ok if you use big resonators.

7rrivera7

iTrader: (1)

Dude, it's an all-motor B16!

Coler

with stage 3 cams go for a 2,5"

mar778c

iTrader: (1)

Lol, I guess B16's can't benefit from reductions in back pressure.

kyosoeg6

iTrader: (7)

all you have to do is pull off your distributor to see any markings on the intake cam.

DDTECH

3''. Its been proven and its been well discussed. The less backpressure the better.

You're allowing the motor to breath easier, it'll make the power.

OMG

Can a car lose HP from going from exhaust to straight header (infinite, way bigger than 3")?

todahead

obviously no

7rrivera7

iTrader: (1)

wow, all along I thought going too big would kill torque and horsepower but if ALLMOTOR says 3", I can't argue based on his rep...

OMG

What about putting a device at the end of the header that gradually slows down the exhaust to avoid turbulent flow and also create a reflective negative back-pressure wave to create a tuned cancellation of exhaust-valve reversion? That might be better than a straight transition into said "proven" Monster 3" exhaust.

DDTECH

Everything after the final merge collector is either for emissions or evacuation, and is a restriction.

Just trying to help, search, its been discussed and debated until people are blue in the face. The noise is about the only draw back to running a bigger pipe diameter. Could careless about "street" credit.

BMo Tuning

Stuff some fiberglass(or maybe some argyl socks) in your exhaust.

Restriction = power

OMG

Taken to its logical conclusion, no header works best.

vmshaw2

Go for a 2.5,

flavio

in my case i'm runing a stock b16 block stock head, itr cams, itr intake mani/TB w/ cai chiped ecu and 2' ex.. stock ex header
but i have a 2.75 ex here at home..
2.75 will make more power than 2'?

DDTECH

Always.

flavio

next week i do the feedback :D

mar778c

iTrader: (1)

That logic works only if the laws of physics have been suspended.

mhax

People that think back pressure is a myth are missing some understanding of the physic behind fluid dynamics...Some people will also tell you that the second butterflies in the gsr intake manifold is bad because it is restrictive! The word restrictive is probably the only word they can understand! The intake problem is quite a simplier problem, but still some people won't understand it. The exhaust air flow is alot more complex since the fluid dynamic behind it is completely different.

Some people really think that engineers working for bmw and other car company are stupid and that they put dual butterflies intake and variable exhaust muffler just because they want the engine to make less power...sigh...Anyway i could continue this text forever, but that would probably be useless!

Ridewithme38

What about Exhaust scavenging? Don't pipes that are too large cause the exhaust to slow down and actually screw up flow?

mhax

It's all about volume! Some race car model will use a variable exhaust which will modify the back pressure in order to keep the volume optimized with the rpm. Since we don't have such a system in old honda/integra, going to a high volume exhaust piping will kill the back pressure at low rpm (because the volume won't be enough to flow efficiently), resulting in a loss of power and torque (edit: at low rpm). The opposite is also true, going to a low volume exhaust piping will kill the flow at high rpm, because the volume will be restricted. The best exhaust to have also depends on if it is going to be used on the road or on the track. If the exhaust rarely see low rpm/low volume because it is only used on the track, then a high piping size can be used. If the exhaust rarely see high rpm/high volume because it is a road car, then a standard piping size should be used. Since i usualy drive my car on the track and on the road, i would prefer something in between.

7rrivera7

iTrader: (1)

Got some good people on here commenting. Thanks for all the feedback!