Exhaust Cut-outs w/ remote cable actuators

[Pyro]

Originally posted by Dominick32
I figured the best placement for exhaust cutouts would be directly before the cats. After header/exhaust manifold connection to h-pipe.

Wouldnt the maximum power goals be achieved using this method. (and sound goals for that matter)
I do understand you didnt have the room to do it. But then why do it?

Dom

That IS the best place to put it. I put mine where I did because it was the most convenient place to put them. It bypasses the mufflers and about 6+ feet of piping...which is better than nothing. All I know is that at first, it did not seem to have any gains but the sound is very deceiving. After about a month of driving the car with the open cutouts, I closed them and I swear, it felt slower when closed (more restriction). What makes the most sense is that with them open, the power gains should happen up top at higher rpms and that's exactly what it feels like. Also, my gas mileage is better when they are opened. Then there's the fun factor when I mess with the ricers and their blow off salute. The open cutouts puts a quick stop to that.

 

[postban]

Originally posted by Pyro
That's hard to believe. In short, you are saying that with less restriction in the exhaust, you loose power? Doesn't sound logical.

The HP and TQ simply moved up on the curve. You gain more on the top end.

I lost PEAK HP/TQ and area under the curve. Also note that these were STOCK MACH1 FACTORY mufflers, very resrtictive, the car liked them better.

To each his own on this one.:bored:

One more note, this is a very consistent dyno, back to back runs frequently within 2 HP/TQ. Better than 10 pulls on it for past various mods or dyno days.

 

[cgriff97cobra]

i posted twice oopps :bash:

 

[cgriff97cobra]

I didnt gain anything from my cutouts but didnt really lose anything either besides my hearing. I got mine cutouts removed from my car. Have a story though, i was riding through town and i was going down a hill on the main strip of town and i was in fourth gear with my cutouts open. THey were rumbling really loud and i saw a cop behind me so i push the clutch in but i starting gaining speed very fast coasting and i didnt want to ride my brakes all the way down the hill so i put it back in fourth and it was so loud. The cop pulled up beside me and i was like, oh no he is going to bust my tail. He got beside me and i looked over and he said "your car sounds good" and i was like thanks!!! I really didnt know what to say, so i got into the throttle a little bit so he could hear it a little better, but i was so surprised that he didnt pull me over for my car sounding like dale jr's race car.

GO Dale JR!!!!

 

[BlownShift]

Originally posted by Pyro
That's hard to believe. In short, you are saying that with less restriction in the exhaust, you loose power? Doesn't sound logical.

The HP and TQ simply moved up on the curve. You gain more on the top end.

I cut the mufflers off on my car when I first got it and ran straight pipe. I lost alot of low end power... but it pulled harder and faster in the upper end. The car was a dog around town (under 4k rpms). But if you're racing, you're not racing below 4k, you're racing in your powerband so it doesn't matter. The car ran it's fastest time with that setup.

I got tired of the noise. Put Flowmasters on. I got all my low end back. It was peppy around town but I lost a little top end. It didn't pull as fast or hard above 4k rpms.

Wiith no mufflers, the higher the revs went, the faster it revved. With mufflers, the higher the motor is reving up, the slower it revs up to redline.

Less restriction - more top end, weaker bottom end. More restriction - stronger bottom end, weaker top end.

But there is probably a point where if the exhaust becomes to freed up, you start losing top end along with bottom end. Which is probably what happened to Postban... as he has no cats as well.


my theory anyhow....

 

[BlownShift]

best thing to do is test it out at the track.

use the same lane... take a run with them closed.. then one with them open.. then one with them closed, etc

I bet you run 1 to 2 tenths faster with them open