Surging

[Powerstroked162]

I don't know anything about them so good to know. Also.could be the reason your having issues

After reading that write-up beef taint posted, I agree... It sounds like they are made for fine tuning and it very well could be out of whack. Biggest thing I see wrong when it comes to waste gates is people who may not understand tuning them, setting them up and even proper sizing for the application. Thats article gives a pretty good general outline, IMO

 

[madman1234509]

Yea idk what was going on with the gate. I know the plumbing I had set up works, Ive seen it work on two other trucks. Eventually Ill try it again, maybe run it with boost references like you guys suggested to see if it changes. Doesnt take much to throw it back on. Thanks for all the help guys, hopefully Ill have some good data on the setup/cam in a few weeks. Ill def be putting a converter in it soon, saw it go to 45 rpm of slip today testing. Didnt feel it but obviously its not a good sign. The converter did have some burn marks on it, but my tranny fluid looked and smelt new.

As for tuning the gate, the guy that did all the work knows tons on tuning, and I also know a good amount, coming from having other forced induction vehicles. We will look into more on why it was doing it. I dont want to say it was the gate that failed because it didnt leak on any of the tests we did on it. Might have been the springs that were in it. There are two, and they held about 20-22 psi of compressed air pushing up on the piston when we checked it, thats with no reference and no air pressure pushing down on the valve with the springs.

http://jgsturbo.com/wgpg.html

Also if you look here, jgs is testing a new mechanical, none electronic blow off valve for diese trucks
http://competitiondiesel.com/forums/showthread.php?t=126690

 

[Dzchey21]

were the two other trucks running vgt manifold turbos?

The problem that im seeing with the reference off of the exhaust side are the fact that the back pressure is always acting against the valve, therefore back pressure is always being "tuned in" to the gates, just because you are using boost referencing to control the gate, doesnt mean back pressure isnt doing some work on the gate.

Now since the vgt is thrown in the mix now everything becomes alot more sensitive, the vgt actuator reacts very quickly to changes in back pressure as needed. When you are using a reference off the exhaust side i feel that you are asking alot of everything to work in harmony and perfectly all the time.

Spartan tuning also uses pretty high back pressure tables compared to others. Generally from what i have found spartan will comand back pressure all the way up to 70psi absolute, where as alot of others will open the vanes as soon as back pressure basically reaches 40 psi, this is there way of staying on top of the back pressure to help keep it down on the top end. The problem with the spartan tuning is if the back pressure even drops a little the vanes will start to close right away thus making the surge.

IF your back pressure seams to be in check without the gate, then let it eat, no need for it anyway.

I would like to try one of these piston type gates, but i have no need for a gate right now so it would be pointless. But its definatly a cool option out there esp if the valves and seats can be swapped out

 

[CamTom12]

Beat me to it and very informative!

 

[madman1234509]

The one truck is a 2007 5.9 it has a 64 and 82 mm compound garretts. The other is an 08 6.4 running a Spartan 310, basically same setup as mine minus the cam and valve springs. Beats me. The gate isnt going to really help where I see high bp to boost ratios which is part throttle lower boost and high rpms. Boost ratio wide open with the torque converter locked is almost 1:1 so its not going to do too much for me there.

Anyone else running stock fuel besides ported rails? When I let off abruptly I get pretty high spikes in rail pressure, saw 29k via the DD today.

 

[Dzchey21]

The one truck is a 2007 5.9 it has a 64 and 82 mm compound garretts. The other is an 08 6.4 running a Spartan 310, basically same setup as mine minus the cam and valve springs. Beats me. The gate isnt going to really help where I see high bp to boost ratios which is part throttle lower boost and high rpms. Boost ratio wide open with the torque converter locked is almost 1:1 so its not going to do too much for me there.

Nothing wrong with higher back pressure than boost at part throttle that's just the vgt doing its job

 

[madman1234509]

Yea I know that. But it needs to be taken care of... Or its just what I tell myself so i have a reason for doing compounds sooner

 

[Dzchey21]

Yea I know that. But it needs to be taken care of... Or its just what I tell myself so i have a reason for doing compounds sooner

Why? That back.pressure is what's giving you awesome drivability granted a set up like mine runs close to 1;1 most of the ttime but that's the whole idea of a vgt

 

[Jeff@Spartan]

Why? That back.pressure is what's giving you awesome drivability granted a set up like mine runs close to 1;1 most of the ttime but that's the whole idea of a vgt

:whs:

 

[CamTom12]

Yea I know that. But it needs to be taken care of... Or its just what I tell myself so i have a reason for doing compounds sooner

Again, I got beat to it, but higher bp to mp ratios make for great driveability. They really help get and keep your turbos spinning at lower exhaust levels like part-throttle driving.

So long as you're seeing near 1:1 at WOT you're good to go.

But if you just want to do bigger turbos, I won't stop you LOL

 

[Dzchey21]

Again, I got beat to it, but higher bp to mp ratios make for great driveability. They really help get and keep your turbos spinning at lower exhaust levels like part-throttle driving.

So long as you're seeing near 1:1 at WOT you're good to go.

But if you just want to do bigger turbos, I won't stop you LOL

Good way to.put it and I.wont stop him either. Just don't want the misconceptions about vgts because they do work well. My truck is making 70 psi of boost with equal back pressure and no wastegate...

 

[madman1234509]

Yes the vgt set ups do work awesome and are great for driveability. But itd be nice to have lower (closer to 1:1) exhaust pressure all the time, hopefully for one reason to keep the heads from cracking around the exhaust valves again.

I think as it stands now im going to get atleast a torque converter in it in a month or so and then start getting things together to throw a 64mm garrett ball bearing and 83mm bullseye (to keep the set up somewhat cheaper)

 

[CamTom12]

Yes the vgt set ups do work awesome and are great for driveability. But itd be nice to have lower (closer to 1:1) exhaust pressure all the time, hopefully for one reason to keep the heads from cracking around the exhaust valves again.

I think as it stands now im going to get atleast a torque converter in it in a month or so and then start getting things together to throw a 64mm garrett ball bearing and 83mm bullseye (to keep the set up somewhat cheaper)

You're not going to run into any head cracking issues from a higher bp at part throttle.

Just not going to happen.

And 1:1 at part throttle will drive very sluggish and laggy compared to a higher bp to mp ratio. Especially with a lower stall, lower STR, higher efficiency converter.