Sic!

You sticking that on top of the 55?

There gonna feel you blowing in Iowa!

 

Negative, that will be force feeding the GT3782R, which will go on the 12v.

The GT55 will be feeding my 64/71 that is currently on the 12v. I don't subscribe to the idea that a 75mm secondary is needed, it definitely takes away any of the streetability that the smaller turbos provide.

 

That makes much more sense now.

 

The impeller design of the GTX is different that what I expected. Typically higher flow impellers will have less blades and a good sized anti-stall guide. Doing this you lose more of the top map, as high flows impeller typically don't have the high pressure capacity. The compressor housing part numbers are the same. I looked abit closer after I posted? How much different is the turbine disk design from the typical GT42. Nice piece buddy, I saw that garrett now has a GTX3582 that flows around 74lbs/min, vs mine 60-65lbs.

 

Turbines are identical (although this one isn't missing bits). Comparing the maps, there is really no downside to this compressor. Higher pressure capability, higher efficiency (77% for the GT, 78% for the GTX), and its sweet spot is 20 lbs/min higher.

The case numbers are the same, but they are machined different. The GTX is 1.1mm large in diameter (I misspoke in the other thread when I said two). Any how, here is the comparison from the GT to GTX wheel.

 

Should be a very good turbo, the turbo should perform the same except with abit more air as the GT4202 did. You planning on running an external gate or going with the internal gate on the GT37? The real trick is to get that GTX to load-up decently.

 

Sticking with the internal, everything is setup for it that way, so I'll leave it like that. I have my second boost gauge for the GTX, so I can see what kind of boost its pushing, and can tune it a bit more than that quick adjust we did when it was on the dually.

 

Tate, if things wernt already set up for the internal would you still go that way or would you go external if you were starting from scratch?

 

I started from scratch, and actually had 2 external gates at my disposal. But I didn't have the flange for adapting it between the manifold and turbo, nor the ability to weld it to the manifold, so I just used what I could. For what I'm doing with this twin set, I think the internal gate will be fine. I only plan on 600hp from this truck, and the GTX is overkill for that even.

On my S300/GT55 set, there will be a large external gate, but I'll run the internal gate as well. That one will have a lot more volume to move though.

 

I think he means if you were starting over from scratch knowing what you know now.

I agree with Tate, and well I am a huge proponent of the external gate, for 600hp with those turbo's it won't make much difference.

 

I don't think it would be that hard for you to throw on an external gate on your existing set-up. Could always just spray some water/methanol or NOS stuff... but thats different debate.

 

I'd have to redo my hot pipe, and possibly my cold pipe to get the turbos to mate up. If the stuff wasn't ceramic coated, I'd be more likely to consider it, but I don't want to do that again. But you never know, this may get too hot for even my 12v and might have to consider changes. But that'll be a bridge I cross later.

As for sprays

 

A grinder can easily remove enough coating so you can apply get a decent weld. The spray stuff just add a couple nozzles into the air horn, push a button. I've must been spraying water/methanol for years now...

 

Not questioning anyones judgement, tryin to learn... probably a better way to put would be if I was starting from scratch, what would be a better way to pursue, internal or external.

Those turbos should be capable of way way way way...... way more than 600 so my thought would be an external to start builds in the growth potential at the start. Sounds like up to 600 ish the internal is fine, but I wonder if there is any downside to starting with an external to start with.

There was a comment a bit back about the BB's not liking heat. Wouldn't a big external help with that? Of course with those turbos heat shouldn't be a problem if you can get them to spin. At 600HP I would think they should live in the sweet spots.

 

Tate twins set-up has more than 600rwhp of air available, the trick is getting it to work. At some point you're not going to flow enough exhaust thru the internal gate and will start to restrict how much power you can make. Its all based on how much exhaust flow and how much the secondary turbo restricts the primary to spool-up (turbine housing and turbine disk size is important).

I'm just bugging Tate, he has a rock solid set-up as is. What tends to occur is the secondary does most of the work and the primary isn't spooling up as well as it could. He will have no issues pegging the 80psi with that set-up.