Butterfly valve control via external control units like greddy mss

[Woods Crasher]

So this winter the CA is getting a fresh rebuild. Among other things that I'm replacing, I think I'm going to buy a greddy mss so I can control when the butterfly valves open. Has anyone every done something like this and yielded a better curve than with the ecu controlling them?

[boost_boy]

What are you trying to achieve with using the butterfly plate system? If it;s of-boost torque this will prove be useful. But this system is inoperative after 4000rpm. Let's see idle is at 850rpm or something in that ballpark and the engine (in stock trim) achieves maximum torque at or around 4800rpm. Hmmm, the little T-thingy turbo is already huffing and puffing effectively at around 2000rpm and if you don't smash on the pedal hard, you're going to get enough air, fuel injection and timing advancement to really feel anything worth the effort of activating this system.

This system is very effective in the aspirated CA engines, but are near worthless in the DET variant. But if you are going to toy with it, don't expect any neck snapping tricks for the amount of work you're going to put in. Good luck....

Dee

[Woods Crasher]

I thought that them being closed in lower rpm, say 4500 yeild a better tq curve even when at WOT and making boost. so I was figuring that if you adjusted it a bit when you're running a different setup like a bigger turbo or a different manifold that you would be able to fine tune the tq curve by changing when the butterflies open since you'll have different CFMs with different turbos and what not.

[boost_boy]

I thought that them being closed in lower rpm, say 4500 yeild a better tq curve even when at WOT and making boost. so I was figuring that if you adjusted it a bit when you're running a different setup like a bigger turbo or a different manifold that you would be able to fine tune the tq curve by changing when the butterflies open since you'll have different CFMs with different turbos and what not.

Have fun with that, brother and I hope it works the way you want it to.

Dee

[r34 gtr]

stock trim making max torque at 4800rpm? What kind of engine are you running? every time I dynoed my stock trim CA I saw max torque at about 4000-4200, and never as high as 4800.

Dude, as far as butterflies, just ditch them. The more air you can cram in there the better. If you are planning on doing this with a bigger turbo theres no reason there should be any obstructions in the intake tract. Mine may be a little gutless but its still got more than enough low-end go for daily driving.

[Woods Crasher]

Have fun with that, brother and I hope it works the way you want it to.

Dee

It's not like I'm expecting to feel like a shot of nitrous... I'm just wondering if it could help aid spool up by increasing the air's velocity when I'm at low rpm and just starting to spool. Perhaps it will help when I run a bigger turbo too. Since I have easy access to a mss and all I have to do is hook it up to a rpm source, or even a boost sensor, and the solenoid near the vacuum tank, I think I'm gonna mess around with it when I get her on a dyno.

*edit* So yea it looks like I'm looking for better off boost, low boost and part throttle performance. and being able to adjust the mss to whatever I want(can hook it up to a boost sensor, rpm, tps, anything that puts out voltage basically, I think that I'll be able to fine to the low end tq curve.

[boost_boy]

It's not like I'm expecting to feel like a shot of nitrous... I'm just wondering if it could help aid spool up by increasing the air's velocity when I'm at low rpm and just starting to spool. Perhaps it will help when I run a bigger turbo too. Since I have easy access to a mss and all I have to do is hook it up to a rpm source, or even a boost sensor, and the solenoid near the vacuum tank, I think I'm gonna mess around with it when I get her on a dyno.

*edit* So yea it looks like I'm looking for better off boost, low boost and part throttle performance. and being able to adjust the mss to whatever I want(can hook it up to a boost sensor, rpm, tps, anything that puts out voltage basically, I think that I'll be able to fine to the low end tq curve.

I'll share this with you, mine are left open and I have a big turbo (60-1) that comes onto boost fully at or around 4800rpm. Now the difference might be the way I tune my car, but it drives beautifully off boost with power steering and A/C on. For the little that you might gain, it may notbe worth it, especially if you're using a smaller turbo because they come onto boost faster than mine do; though mine give more excitement when it comes onto boost . Give it a swing and see if you can tell the difference. It's not hard to just disconnect it, either.

Dee

[Woods Crasher]

Yea I'm gonna do it....If it proves to not really help the low end, I'll just leave it at a set rpm and hook it to the TPS as well so that they're close when I'm at say below 1/2 throttle...that should prove useful

[r34 gtr]

The problem with these things is they are controlled by a vacuum system and really just use a sort of on/off operation. What you need is to open and close them with a stepper motor so you can control the opening angle accurately. I think if you were to rig it up this way and had a separate map to control it you could see some nice gains.

[Woods Crasher]

The problem with these things is they are controlled by a vacuum system and really just use a sort of on/off operation. What you need is to open and close them with a stepper motor so you can control the opening angle accurately. I think if you were to rig it up this way and had a separate map to control it you could see some nice gains.

Well I have the stock vacuum tank and solenoids, so I just need to hook the mss up to the solenoid that switches the actuator from the vacuum tank and the atmosphere source..

[dattodude]

Did you think about using a tacho with a shiftlight output to control them?

I have aftermarket ECU, I changed my butterfly valves to open at 4800rpm with a garrett GT28/76R, because I have 270/9.25 cams. This was set during dyno testing. I'm now running an HKS GT25/30, so it might need lowering back down.

[Woods Crasher]

Did you think about using a tacho with a shiftlight output to control them?

I have aftermarket ECU, I changed my butterfly valves to open at 4800rpm with a garrett GT28/76R, because I have 270/9.25 cams. This was set during dyno testing. I'm now running an HKS GT25/30, so it might need lowering back down.

I plan on hooking the mss to the RPM source so I can set what rpm they open and close