I'm about to install my QTP valve on my borla and got to thinking about how I could do it differently. This is what I came up with. Opening the valve before a street race is a pain and also a dead give away of your possible potential, so I'm building a circut to open it for me.

When armed the valve will open when two things happen. 1: the engine revs above 3k (or what ever you want) 2: the throttle goes beyond about 80%. When these two things happen the valve open fully by its self. While it takes both to open it, only one or the other is required to keep it open. When the revs come down and I let off the throttle the valve will close by it's self after a 2-3 second pause, this will keep it from closing should I have to let off for a few senonds.

What do you think?? Other than the RPM switch, it should be cheap to build. A few relays and a timmer chip from Radio Shack. I'm trying to build a sleeper type car and I think this will add to the image. It could also scare the hell out of the other guy when the quiet car he was about to race wakes up.

 

3 seconds after you peg WOT, the valve will be fully open. By then you'll already have shifted once, if not twice.

 

Why not jut use a standard electric cutout and a switch? Just flip the switch as you nail the gas and boom, car goes from quit to really loud. It would be cheaper, and it adheres to the K.I.S.S. philosophy.

 

The valve will open by it's self immediately, it will pause 3 seconds before closing after I let off it.

Yea, I could use the switch, but I've always gotta improve things. I figure with this setup I could leave it on all the time. Set up the way I'm thinking it would only open a few times a day. It's just an idea I'm playing around with. It started when a friend gave me a MSD RPM switch. Gotta find something to do with it.

 

Hehe, I love it! I had thought of doing the same thing with a DMH electric cut out. Keep me posted.

Jason

 

you also have to think about the time it takes for the valve to fully open if you are looking for max performance etc. I know my DMH takes about 3 sec to fully open but only .5 to get really loud.

So you have to ask yourself are you just doing this because you want it to be like that or do you want it to make more power? I am going to be testing my cut out this spring to see if it makes an diffrence with the borla open or closed as far as et's.

But my vote is for the K.I.S.S. rule

 

The electric method is going to be of limited effect, the slow valves will respond too late.

I have the QTP and if I floor it and hit the switch I'd be in second gear before it opens. On the street I'd like something faster.

I'd go mechanical.

A simply way would be a flap valve with a spring. As the back pressure increases, the valve would overcome the spring and open. As you cruise the valve would close as the spring overcomes the lower pressure in the pipe.

OR

Use a blow off valve.... When your vacuum drops because of the open throttle, the valve would snap open. This would operate the same as the above spring method, but would have a quick definite open snap to it.

Just thoughts turned into words.