you only gained 10rwhp from a lid and a cutout...somethin is wrong there. lol

 

One more question.

We agree that cutouts decrease bottom-end a little. If I would keep the cutout closed on the launch at the track (to take advantage of the bottom-end) and then open it uper after, say, the first shift, would that help any or does the cutout have to be open or closed only for the entire pass?

 

You'll gain more then a catback plus its alot cheaper

 

I haven't read through the entire thread and posts, but I'll throw in my $0.02.

On Hypertech's dyno, cutout closed was 317 RWHP and cutout open was 330 RWHP

 

I talked about this with a friend. We had a little different idea than yours but...it's just not worth the trouble.

 

the guy who makes the gmmg told me their ls1 made like 433 rwhp with the gmmg and other mods and then they tried it with a cutout and dynoed 434 rwhp so they only lost 1 rwhp with the gmmg, so i doubt i would benefit from a cutout attached to the end of my y pipe

 

You can agree ... but you can't prove it ... the gain at the bottom end isn't as great as it is at the top end ... but there is a gain.

 

I think if you could get a dyno that records under ~2000 rpm, you might see a loss of torque by opening the cutout, but IMO, that loss would be so small that you'd be wasting your time messing with opening the cutout on the fly. I say open it and leave it open. Pretty much once you take off, the motor is over 2500 rpm anyways.

 

If I'm not mistaken... I don't believe you technically 'lose' any torque low-end, the powerband is simply shifted upwards a bit with the more efficent exhaust flow?

Like the guy above me said, I don't believe you'll be in the lower RPMs for very long if you're racing anyways