I was at the track yesterday with my friend. He was running an 89 Turbo Trans Am. He ran a 13.2 then opened his dump pipe and ran a 12.9

I am wondering if the open header is what gave him the extra 3 tenths?

What differences have you guys noticed when running open header?

What where your quarter mile gains? Did anyone try it on the dyno?

Just curious....

Miguel

 

nope. . . you will get better low end torque, but will lose in top end . i tried it already didt work too good.

 

unless , , you got a potent *** all motor set up . but im talking real potent

 

Interesting, thanks for the info.

A while back I had a DC Race Header. I only had it on for a few minutes....(WAY TO LOUD) I noticed a loss in low end torque but the high end did seem a noticeable difference higher. I guess the trade-off does not help in the 1/4 huh??

Miguel

 

hey migeul, your next dyno tuning session pull the header on your last run. see for yourself if it works. i am curious about this myself.

 

I gained about 4 WHP from taking out my testpipe and B pipe completely, right out the header.

The gains were steady from VTEC right up to the top. I also have the JDM 4-1 Header.

This is how I run at the track (I have a straight pipe that dumps right before the gas tank, downward)

 

C5.... I hope you're right, I'm gonn give it a try.

rodney... I'm gonna do that... I wanna dyno one more time before I do the work to my motor

Chris 4 WHP is not bad at all. Almost as good as popping of the power steering on some cars I'm gonna have to give it a try.

Thanks fellas.

Miguel

 

I gained 3whp just from unbolting and running open header w/ spec b's - went from 185-188whp and gained 2-3wtq too... On the dyno.

 

If you have a "proper" cat back, you will see minimal gains by running open header.

 

Yea. But most do not! I was refering to the Stock B pipe in my post.

 

I was refering to the Stock B pipe in my post


true,true

 

I don't know most tracks won't let you drive with open header due to noise violations. I believe ours is 112dB and I've heard some loud as 120+ and there normally told they can not drive unless they put a muffler on that car.

 

At Raceway Park in Englishtown, NJ you can run UN-Muffled on Wednesdays.

Miguel

 

Ditto. My gains were from open header vs. stock catback.

 

So then there really wouldn't be too much of a gain over a 2 1/2" exhaust with no cat and a E-S Muffler? What the hell, I'll give it a try anyway. It's easy enough to do

Miguel

 

Hey Miguel, when I got your DC header I put it on and my car ran super lean. That is almost open header, I dont know if something was wrong with my car but when we modified the header to fit the exhaust it was still a little lean but it was much better than with no exhaust (I have mugen exhaust). I dont know if I would run the snot outa the motor if there was a chance it would run super lean up top, especially with big cams like you have. you may wanna run it on the dyno open header first.

scott

 

On the dyno.. i dynoed 225 with an open header (SAE corrected) and i dynoed 219 with a full exhaust (2.375" only) so thats a gain of roughly 6 hp. on the dyno comparison of the two, the low end were exactly the same up to roughly 6500 rpms.. where vtec (top end) is fatter, better top end. I dunno what you guys consider a bad *** NA motor, but my dyno is below.

 

Most tracks out here are out in the middle of the desert. or no-where.. no limits (none that I have been told of) except Laguna Seca..89dB

 

well, lemme know if you want to go to the place upstate. they have night appointments, so i could meet up with you. give me a call when you want to go.

 

Hey SIINSI, Did you buy that car from one of the guys from JDM Hondaparts and had it shipped to ny? I met you at dunkin donuts in union one day. Also saw you at the track. The 1/4 mile times definatly improved since the last time I saw the car run. Good Job man, shoot me an im sometime, when you are goin to the track.
EVIL

 

I saw little to no gain at all on my B20/B17...
but then again I have SMSP quality from the header to the rear bumper all the way through!

 

i actually lost time at the track . i unbolted the b pipe and hung it to the side. i lost top end . just didnt feel right, that s was with the stock header though.
i was looking for any kind of free hp i could get and that wasnt there for me .
at english town , they dont give a **** , they say they do , but thats where i ran it and all the rotaries and **** there are no where even close to muffled. but my car sounded like one of the rotaries it was funny.

 

Agreed, it depends on your setup.....but remember these 3 tenths were on a FI car. They aren't as fussy about back-pressure. Our NA cars is.....

Just my 2c.

Later.

 

well im gonna try it with the nitrous this year to see if that makes a diff. . .im always down to try . ill let you know . i got an even t in a couple weeks

 

Skunk2's Steve Rothenbuehler's B20VTEC with Greddy catback on



and with it off: