Gateing stock VGT

[sweetdiesel]

Is tuning the vane not a option that you want?

Larry and I both got are DP very close to 1:1 just with tuning. It wasnt just vane posistion that worked but it is still capable with tuning.

Maybe im missing something here?

 

[Redbowties88]

well ive yet to install a DP gauge but im working on it,,, however ive never really heard of anyone with a stocker on a race tune with near that good of a ratio

 

[LarryJewell]

well ive yet to install a DP gauge but im working on it,,, however ive never really heard of anyone with a stocker on a race tune with near that good of a ratio

See below response Yes, on acceleration drive pressure will exceed boost pressure, but not by much, at least in what I am seeing on my gauges. Hitting 5th gear my vane position is almost fully open (1-5%) and drive pressure and boost pressure is pretty much 1:1, you have to tune more than just the target vane tables though, all the vane tables do work together.

Is tuning the vane not a option that you want?

Larry and I both got are DP very close to 1:1 just with tuning. It wasnt just vane posistion that worked but it is still capable with tuning.

Maybe im missing something here?

 

[JoshH]

This was with the single stock turbo? What kind of boost are you able to hit with the vanes almost all the way open?

 

[LarryJewell]

This was with the single stock turbo? What kind of boost are you able to hit with the vanes almost all the way open?

No mine was with a 71.5 Cheetah, both as a single and with twins, I think Simon's was with a stock turbo

 

[Redbowties88]

yea but if i open mine up any more at wot ill be losing boost...IRRC for fun i tried 4-5% once and i didnt make much more then 20psi and wot in 5th... it was a slug

 

[HogAssWild]

This would help my dp drastically right?

 

[sweetdiesel]

This was with the single stock turbo? What kind of boost are you able to hit with the vanes almost all the way open?

Ive seen as high as 37 psi ( higher spikes ) with the stocker.....It never helped being that high though. DP would start to rise and so would EGT

 

[JoshH]

Ive seen as high as 37 psi ( higher spikes ) with the stocker.....It never helped being that high though. DP would start to rise and so would EGT

I understand that, but what kind of boost do you see with the vanes practically all the way open. Kind of makes me want to do some logging to compare between MAF, boost, and vane position. I ought to put a driver pressure gauge in my truck to, just temporarily. I do have an extra 100 psi boost gauge laying around.

 

[sweetdiesel]

I understand that, but what kind of boost do you see with the vanes practically all the way open. Kind of makes me want to do some logging to compare between MAF, boost, and vane position. I ought to put a driver pressure gauge in my truck to, just temporarily. I do have an extra 100 psi boost gauge laying around.

37

here is a old post Josh.....you really need to install a gauge and even better log it.
http://www.duramaxdiesels.com/forum/showthread.php?t=1115&highlight=ghetto+drive+pressure

 

[duramaximizer]

So what's wrong with 37 psi of boost?

 

[Redbowties88]

im making 37ish-psi now.. .with my current vane positioning

did you have fueling mods?

 

[JoshH]

37

here is a old post Josh.....you really need to install a gauge and even better log it.
http://www.duramaxdiesels.com/forum/showthread.php?t=1115&highlight=ghetto+drive+pressure

37 lbs of boost with the vanes at 5% to 7% closed? With 20% vane position, my boost jumps to just a shade under 32 at about 2500 RPM just after the 4 to 5 shift and falls off to about 28 by 3400 RPM in 5th gear. I'd like to see what kind of drive pressure I'm running like that.

The MAF sensor is showing almost 70 lbs/min at the top of 5th.

 

[SteveFord]

37 lbs of boost with the vanes at 5% to 7% closed? With 20% vane position, my boost jumps to just a shade under 32 at about 2500 RPM just after the 4 to 5 shift and falls off to about 28 by 3400 RPM in 5th gear. I'd like to see what kind of drive pressure I'm running like that.

The MAF sensor is showing almost 70 lbs/min at the top of 5th.

Josh, on one of my lbz logs mine vanes actually hit 0% closed on my 3-4 shift with the boost at 32psi from what I can tell. I can send you the log.

 

[sweetdiesel]

So what's wrong with 37 psi of boost?

Better question is what is good about it? I never seen any benifit from anything over 33psi jmo


Josh i wouldnt be so concerned about dropping vane to zero....You need a DP gauge and then go from there. Myself found more benifit from adjusting target VS des vane. Timing also played a big roll

 

[duramaximizer]

Fair enough, I am going to a dyno sometime to get it dialed in I just haven't made it. I was wondering if I would be better off running less boost? You can PM if you want I would like to hear more.
:coolspot:

 

[LarryJewell]

Honestly gating a vvt for me probably isnt needed, I think I may have a pretty good setup here. here are 2 screen shots of my drive pressure and boost gauges. The first gauge on the left is the drive pressure gauge, the middle gauge is total boost and the one on the right is boost from the big turbo. Both of these are just 3/4 throttle runs right before shifting to 5th gear.

 

[Redbowties88]

yea but thats with a cheeta...i think that would have a little better flow characteristics then a stock lly charger

 

[LarryJewell]

Just trying to say that good drive pressure could be done without a gate, people have complained of drive pressure problems with after market singles too, I really dont think that the Cheetah would be that much better than a stock turbo with the tuning dialed in, and you can do that for free :thumb:

 

[JoshH]

Wow! So you run 30 lbs of drive pressure at 40 lbs of boost? Is your DP gauge still tapped in the manifold?