My gauge holder..

[kermit]

It's an electric cutout.

It can go from quite full exhaust to loud wide open exhaust in the flick of a switch.

[mhillis]

Not trying to be rude, but what is the good of it?

[kermit]

It allows you to run a full exhaust on the street that isn't too loud so you don't get pulled over and you can pass emissions. Then you open it up when you want the extra power and let 'er rip!

It's electric so that you can open it up without having to get out of the car like a standard cutout.

[mhillis]

roughly how much extra power? Sorry for the hijack.

[Timmay2]

Perfect way to make your car perform worse... tune it in, let the computer get used to that air fuel mixture, then throw it off completely by opening the exhaust.

Otherwise, cutouts might have a better purpose than making your car loud.

*shrug*

[kermit]

Probably good for a few horse... I think that your biggest improvement would be in the decrease in turbo lag.

How exactly would this worsen your performance? You're computer is constantly monitoring your air/fuel and making adjustments.

[Timmay2]

These computers are not that fast, it takes miles and miles to adjust properly based off of averages.

Worsens performance because your car will go excessively rich once the exhaust is completely opened. If you like to not get a complete spark, carbon buildup in your cylinders and on the valves, by all means, use cutouts.

This isnt 1960 anymore and electronics dont like drastic changes.

You need to tune for the exhaust difference, or run them open all the time.

[impuresoul2k3]

How would it go rich?

[kermit]

Hmmm...I'm not buying that. Eveytime that the throttle moves, or even flutters more/less air is let into the engine and the O2 sensor detects this and adds in a some more/less fuel.

[speeduphoria]

I think your both mistaken, as @WOT the computer goes off pre set tables and no O2 info. It would go slightly leaner if anything since the motor breathes better. It would depend on how close to the edge your tune is when going through the full exhaust.

[kermit]

I wasn't talking about WOT... When you aren't at WOT the computer monitors the output of the O2 and uses it to determined the air/fuel.

But yes, when you are at WOT your computer determines air/fuel from table values. If you were doing things right, IMO, the tune for WOT should be done with the cutouts open, since that is when you want "no holds" all out performance. Then you're tune would be perfect then and a tad rich with the cutouts closed. In my opinion, that would be just right because you probably don't want to be riding so much on the edge on the street when the cutouts are closed.

@ Tyingbe... How quick is the response time on the cutouts from open to closed? I think that it would be cool to mount it to a pedal switch so that when you floored it, it would close the switch and open up the cutouts automatically.

[speeduphoria]

Quote:

Originally Posted by kermit I wasn't talking about WOT... When you aren't at WOT the computer monitors the output of the O2 and uses it to determined the air/fuel. But yes, when you are at WOT your computer determines air/fuel from table values. If you were doing things right, IMO, the tune for WOT should be done with the cutouts open, since that is when you want "no holds" all out performance. Then you're tune would be perfect then and a tad rich with the cutouts closed. In my opinion, that would be just right because you probably don't want to be riding so much on the edge on the street when the cutouts are closed. @ Tyingbe... How quick is the response time on the cutouts from open to closed? I think that it would be cool to mount it to a pedal switch so that when you floored it, it would close the switch and open up the cutouts automatically.

I have a McCords cutout on mine, it takes maybe 2-3 seconds to open. If you want to do that they also have boost opperated ones that open at a certain psi using something similar to a WG actuator. Then again they used to have(but only saw 2.5") ones from Summit or Jegs that use a cable like a parking brake.

[kermit]

Quote:

Originally Posted by speeduphoria I have a McCords cutout on mine, it takes maybe 2-3 seconds to open. If you want to do that they also have boost opperated ones that open at a certain psi using something similar to a WG actuator. Then again they used to have(but only saw 2.5") ones from Summit or Jegs that use a cable like a parking brake.

Darn! ...like with all my good ideas, beaten to the punch (and the patent, no doubt )!

[tryingbe]

Quote:

Originally Posted by kermit @ Tyingbe... How quick is the response time on the cutouts from open to closed? I think that it would be cool to mount it to a pedal switch so that when you floored it, it would close the switch and open up the cutouts automatically.

4-6 seconds for the valve to completely open and close.
Pedal switch is bad idea, race is over before the valve is even fully open.

I use my cut-out for addition of noise and vibration purposes, it's a music to my ears. I don't know if it increase performance, and I don't really care to find out either. My wideband says I'm safe on A/F ratio with it open or closed, and that's the important part.

[ZachT]

i like the guages in the tona, those are pretty sweet too. he just used plastic for the mounts then? like 1 piece and drilled 3 holes in it?