Controlling back pressure with Elite turbos

[White_monster]

Well as most of you know I have a set of max powers to go with my build. Also most ppl that read my thread before I removed it figured out that I try to be through. So I'm asking how I can control back pressure with big nozzles. Reason I ask is I've asked around and the few ppl with experience with similar setups can't keep from over speeding the big turbo, even with Elites dual gate setup. I've spoke with Tadd and he's confident it can be done but if it can be done why are there so many issues? I'd mention names but that's not important. I'll enclose some pics of my setup during fabrication at Elite. My question is should I put a 3rd gate from between the 2 turbos to the down pipe to keep the big turbo from over speeding? I'm open to suggestions on this. Right after I do my turbos a good buddy has the same set of turbos and he's concerned with this as well.

Also maybe someone from Elite can get Precision Turbo to disclose a compressor map for the PT8285 turbo.

Thanks heres some pics. I'd like to put the gate from the s bend pipe to the down pipe, space is tight and might require some hammering on the firewall. Anyways here's some pics of what has been tried on different trucks, results have varied. Thanks to Boostfed for the pics of the race truck and of how the upper gate plumbs in from elite. Thanks to Jd from Elite for the pics of my parts.

 

[Dzchey21]

Gate both manifolds don't gate between stages

 

[White_monster]

Both are gated. I have one gate from the passenger up pipe to between the turbos and the drivers side to the down pipe just like Shone. Dustin I'm sure your aware of the issues.

 

[Dzchey21]

And im willing to bet that on most set ups aren't over speeding other that rudys drag truck.

30 psi of boost isn't that high of a pressure ratio.
3.05 isn't that bad most turbos show a decent map all the way to 4.5

 

[White_monster]

So why does the big turbo keep dieing on other trucks. Rudys not the only one that has had a turbo failure. I want to avoid the failures from happening and make these work for me.

 

[Dzchey21]

Both are gated. I have one gate from the passenger up pipe to between the turbos and the drivers side to the down pipe just like Shone. Dustin I'm sure your aware of the issues.

Don't run the gate between turbos. Cap it off and run that gate to atmosphere or to the down pipe.

Trust me we've tested it and its what works best. The turbines are so well matched for the set there is no need for a gate between stages

 

[Dzchey21]

So why does the big turbo keep dieing on other trucks. Rudys not the only one that has had a turbo failure. I want to avoid the failures from happening and make these work for me.

I don't know on every failure what was the cause. Over speed usually breaks the wheels bends the shafts or wears the thrust bearings early.

You can tell over speed from other failures. You just gotta get all the facts. Ball bearing center sections usually take alot higher speeds because the roller bearings take alot of thrust load.

 

[White_monster]

Huh. So why is that kind of info not disclosed. Tadd never mentioned it to me, and it's never been mentioned on the forum till now. Whos actually done this? Also if we have 50psi ebp going into the high pressure what's the ebp on the big turbo? I'm not the only one interested in this info.

 

[White_monster]

Dumping to atmosphere makes sense. Just it sounds messy.

 

[Dzchey21]

This is the product of hours... and hours.... and hours of dyno time and gate tuning, as far as i know tadd might not even know.

the one thing that we have never checked is back pressure between stages because its really hard to check with the cast elbow, what a guy should do is either put a place for a sensor in the wastegate cap or in the elbow it self but im willing to bet that its really close to boost pressure.

The other thing is im sure whatever air filter you run you gotta make sure that the air filter is clean. I dont think alot of the guys running max powers run a restriction gauge, i feel that is imparative that one is used, if you take away supply air pressure you have effectively raised the pressure ratio

Think of a vacuum cleaner...

You put your hand over the hose and what does the motor do.... speeds up... alot

Same thing with a dirty air filter. Not pointing fingers but i have put some thought into it

Mal burnside has had one of the first set of max powers, running about 60psi of boost for about a year now, no problems regular maintenance

 

[Dzchey21]

Dumping to atmosphere makes sense. Just it sounds messy.

Its not bad, they only need gated just passed like 3300 rpms or something so the gate is only open on a WOT shift and just for a second, turbos have spooled so there is very little smoke, just alot of heat

 

[White_monster]

You make a good point Dustin. Is Mal's setup gated to the down pipe on both gates? Putting a gauge between stages is easy enough to do and might be a wise idea. You've got the first hand knowledge of Mal's setup and it is lasting so that's promising.

The air filter idea makes sense for sure. I'm not gonna run the restriction gauge but I will be changing filters every couple weeks just to make sure. Anyone else want to chime in please do. This info applies to high powers and most likely to Tow power x's too.

 

[White_monster]

Its not bad, they only need gated just passed like 3300 rpms or something so the gate is only open on a WOT shift and just for a second, turbos have spooled so there is very little smoke, just alot of heat

Ya. The heats an issue since that's what drives the turbos and creates the pressure.

 

[Dzchey21]

You make a good point Dustin. Is Mal's setup gated to the down pipe on both gates? Putting a gauge between stages is easy enough to do and might be a wise idea. You've got the first hand knowledge of Mal's setup and it is lasting so that's promising.

The air filter idea makes sense for sure. I'm not gonna run the restriction gauge but I will be changing filters every couple weeks just to make sure. Anyone else want to chime in please do. This info applies to high powers and most likely to Tow power x's too.

Ya. The heats an issue since that's what drives the turbos and creates the pressure.

I was just saying that you need to make sure that everything is clear so it wont melt anything, its dumping pressure and heat thats just how it has to be.

in an ideal world you would want to gate everything into the low pressure but there just isnt enough room in the valley for a bigger turbine, or turbine housing so thats part of the problem with needing to gate between stages, but honestly only having to gate 3-500 rpm of run isnt that big of a loss

You only really need one gate with 110s two gates might be overkill

 

[Dzchey21]

and tow powerx turbos need a gate between stages because the turbine on the high pressure isnt bigger like the 63/66's in the high/max powers

 

[Dzchey21]

Shane, you also might look into getting a 1.32 or 1.44 exhaust housing for the big turbo, it will take some grinding to make it fit i think, but thats another option. You would prob need to gate between stages then

 

[White_monster]

Well I'm running 150's so 2 gates might be needed. I get what your saying Dustin. I'm not building a race truck either. My truck and my buddies trucks are street trucks that get used almost daily. Overkill is my build.

So by gating both up pipes to the down pipe you have seen things to be good? What do you think when 150's are used in this setup? Hopefully Haller will post up some more.

 

[White_monster]

Shane, you also might look into getting a 1.32 or 1.44 exhaust housing for the big turbo, it will take some grinding to make it fit i think, but thats another option. You would prob need to gate between stages then

Ya. I might need to hack my manifold up a bit to make things fit with that bigger housing. That'll come once I have a long block thou.

 

[forcefed6.4ford]

I think a looser housing is the way to go Shane.

 

[White_monster]

I agree Chris. This kind of info in this thread has needed to be posted for months. Many ppl have invested a lot of money in Elites big vgt turbos and they want them to work, even if it requires some modifications to do so. If we get all our minds together on this we should be able to make things work and progress our trucks to work better.