2nd resonator

2000se2.0 · Apr 23rd, 2003, 05:11 AM

hello.

i was thinking of adding a 2nd resonator to quiet my exhaust tone a little bit. it's getting to be anoying now.

question: will i loose any power?

at the last b15sentra/SERCA dyno day, a fellow SERCA member cemmented that my max HP on my dyno would be higher if i had more back pressure. any truth to this? and if so, will the 2nd resonator be enough?

thanks

p.s., my 2nd dyno showed only 138hp after adding the UR crank/WP pulley set.

sentrastud · Apr 24th, 2003, 02:38 AM

First off how big is your exhaust. If your running to big of a pipe your missing out on some power. If thats the case more backpressure could help out with horseys a bit.
The 2nd resonator probably wont have a huge affect on your HP but it might have some. Again this all depends on what you have on now.

If you think your dynos are low keep in mind that there are losses between the Manufactures reported HP (measure at the crank) and dyno HP (measured at the wheels). Power is lost in the transmission and the effort it takes to move the wheels.

-Nick

2000se2.0 · Apr 24th, 2003, 03:57 AM

Quote:

Originally posted by sentrastud
First off how big is your exhaust. If your running to big of a pipe your missing out on some power. If thats the case more backpressure could help out with horseys a bit.
The 2nd resonator probably wont have a huge affect on your HP but it might have some. Again this all depends on what you have on now.

If you think your dynos are low keep in mind that there are losses between the Manufactures reported HP (measure at the crank) and dyno HP (measured at the wheels). Power is lost in the transmission and the effort it takes to move the wheels.

-Nick

well, i am using stillen headers, down to stromung 2.25" midpipe with stock cat, to a stromung resonator aft of the cat, to a stillen exhaust with a 2.25" mendral bent piping to the muffler.
it's basiclly all 2.25". is that okay?

also, my concern in hp mainly comes from witnissing other sr20's putting down more hp by a factor if 5 atleast. there was a stock 98 se-r that had 146, with NO mod!!! a 2001se put down 127 with NO mod. all i have to show for is 12hp for all my upgrades?
http://sr20de.netfirms.com/images/dyno.jpg

SuperSentra4203 · Apr 24th, 2003, 12:47 PM

I stock SR20DE will not put down 146hp. It is rated at only 140bhp. So 146 at the wheels is rediculous. Its not always constant. Different tranny fluids can actually cause a difference in 1-3hp. I would remove the one resonator you have now and just put on a different muffler. The resonator for my DSM actually made it louder.

sentrastud · Apr 25th, 2003, 01:11 AM

2.25" is what I would use if i had an SR motor. Sound slike your exhaust would be pretty nice. I agree with
SuperSentra4203, remove the resonator and change the muffler.

There are many, many factors taht cause variances among engines. Simple stuff like mileage, oil type, when the airfilter was last changed, what type of sparkplugs all cause diffrecnces. The octance of the gas burned during the dyno testing will have an affect. Also elevation will have an affect. A car in Daytona Beach, Florida will produce more power than a car in Denver, Colorado. (denser air with more oxygen content in Daytona).
The dyno may not have been properly set up or calibrated correcty either. Also keep in mind that dynos measure at the wheels. This means that the size and weight of your tires, brakes, and axles as well as losses in transmission will all have an affect on the dyno.

-Nick

2000se2.0 · Apr 25th, 2003, 03:08 AM

Quote:

Originally posted by SuperSentra4203
I stock SR20DE will not put down 146hp. It is rated at only 140bhp. So 146 at the wheels is rediculous. Its not always constant. Different tranny fluids can actually cause a difference in 1-3hp. I would remove the one resonator you have now and just put on a different muffler. The resonator for my DSM actually made it louder.

actually, i got the midpipe without the resonator. after installing my headers, it was just toooo loud. i added the resonator a week later with an improved noise reduction i just want to quiet it a little more without sacrificing power.

well, i also had two different sets of rims on two different dyno days on the same dynometer shop. both types yielded same hp, just +2 after i nstalled my pulleys.

i have the stillen warm intake and muffler. i obviously run 91 octanve because of the timing, and use only dyno oil. just look at the list in my sig below.which setup will net more power? what do you guys recommend?

s13sr20chris · Apr 25th, 2003, 08:36 AM

i don't care what anyone says. backpressure does not ever help horsepower. smaller exaust may help some if you are way to big(which you are not), but a muffler or resonator could only hope in the most unbelievably perfect circumstances to have 0 loss of hp. there will never be a gain of hp from backpressure. sound however will be better. for optimal power and sound reduction it is best to have no resonator at all, but just have one really long straight through muffler. the straight through design will minimize hp loss but the length will give the most sound reduction properties. multiple changes in diameter of the pipe(as in multiple resonators/mufflers) will hurt considerably more than one very efficient single muffler.

2000se2.0 · Apr 26th, 2003, 04:08 AM

s13sr20chris:

point well put. however, i do not have any space for a longer muffler. my stillen takes up all the space up to the axle where the pipes wrap around. i have noticed that more expensive, and probably better quality, mufflers like the greddy are longer and larger. i guess for now i will stick to my setup.

thanks!

SuperSentra4203 · Apr 26th, 2003, 07:00 PM

Quote:

Originally posted by 2000se2.0
i obviously run 91 octanve because of the timing, and use only dyno oil. just look at the list in my sig below.which setup will net more power? what do you guys recommend?

Don't use dino oil, synthetic is like the best insurance for your motor.
I heard using a glasspack in combonation with the muffler will quiet it down, and have the most minimum loss in power. Just make sure you get a glasspack with a perforated core, other wise it may actually cause more backpressure than a stock muffler. IF you like it how it is, do what I do, turn up the music

2000se2.0 · Apr 28th, 2003, 03:47 AM

Quote:

Originally posted by SuperSentra4203
Don't use dino oil, synthetic is like the best insurance for your motor.
I heard using a glasspack in combonation with the muffler will quiet it down, and have the most minimum loss in power. Just make sure you get a glasspack with a perforated core, other wise it may actually cause more backpressure than a stock muffler. IF you like it how it is, do what I do, turn up the music

it's too late for me. i cannot change to synthetic oil. but i still would have not used synthetic anyways. not a real believer in syntec.

SuperSentra4203 · Apr 28th, 2003, 08:42 AM

I have always been a Valvoline guy. I always used Valvoline's VR-1 Racing 20W-50 in my B12. It was the only oil that could withstand the high motor temperatures and my rev happy right foot. Since I had over 75K miles on her (bought it at 168K) I didn't use synthetic, but used it in my DSM. Good stuff, if it's not too late.

lowmileage · May 6th, 2003, 08:46 AM

I have the stock exhaust system & replaced the reasonator with a 17" Thrush glasspack (perforated core). The factory muffler must control sound very much because there was no change in my exhaust note . The 17" was 1 3/4" but you could stuff a longer one in with a diameter to fit your pipes & it would probably give you a sound you could live with. Bought mine from Jegs