650rwhp VGT Turbo

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Boogaloons

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Mar 26, 2012
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Been searching and reading threads for weeks now, time for some input from you guys.

Truck is an 03 NV4500, stock fueling minus an AD165 lift pump, UDC tuned, basic intake / exhaust mods. Looking for everyday all day 650rwhp and towing up to 14k.

Supporting mods on order list are DD clutch, BBi Stage 1 injectors, ii 85% cp3, and a 2nd gen 24v aftermarket manifold (plus the t4i adapter if needed).

Really want to have an exhaust brake for towing and have quick spool on my 5.9, lots of info on stock 6.7 spooling, power, etc... Fleece controller to control vanes / exhaust brake is what I'm thinking.

Turbos I have been considering / trying to find specs on:
modified he351ve (largest exhaust wheel squeezed in one??)
he400vg (66 comp/67 turbine / 29cm)
he451ve (64 comp / 67 turbine / 29cm)
he551 (not sure on specs, have found various sizes)
fleece performance 63mm he351 (63/68/25?)

Any advice on how these would spool, drive like with and w/o a load, or other turbo suggestions would be appreciated. :bow:
 
The 351 is definitely too restrictive. After running one with a Fleece controller my opinion is VGTs are a compromise turbo...good spooling and gives you a little better breathing but they're not as efficient across the map as a quality aftermarket turbo. The GT37R Stage 3 ball bearing turbo I run now far surpasses the 351 I ran for awhile.
 
650 hp single turbo that spools really well and can tow is a tough recipe. A 451 would definitely be the one to look at but I am not sure if it can get you to 650
 
Spools well, tows well, 650 horsepower? Sounds like a recipe for compounds...
 
twins

I know twins would easily get my goal accomplished, but I really want/need the exhaust brake function. And with a pac-brake close to $1000, I was considering alternative measures.

I'm looking at a 66/67 vgt, just trying to justify install with piping, manifold, and controller expenses versus he341/475 twins and exhaust brake
 
I ran a 66/67 vgt for 2k mile before it ate itself from not being rebuilt properly.

I didn't have it long enough to have it tuned in right and I was short on fueling. It was a long build and I just needed to get it on the road for a trip to Bonneville.

I was able to use boost and DP to control it using a double action air cylinder, and had it setup for 3 modes:

- Normal driving/ quick spool; this had DP force vanes open and boost counteracts it closed so it was biased toward faster spool.
- MPG/Highway; dp forced turbo open and boost side of actuator opened to air. This cut boost in half.
- Ebrake; this caused DP to close the vanes, so as dp increased it only pushed harder closed. Never saw over 65 psi dp. It worked great though.


As stated I had some issues yet to be worked out such as tuning and some fuel leaks (BioDiesel & all new fuel system) and only had 5x.011 and 036 (?) DV's. It spooled slow and made 45 psi boost max. I think with tuning and more fuel I couldve had it spooling full boost by 15-1700 rpm.

Is it capable of 650hp? I'm not so sure about that, my goal was only 550 and I beleive its capable of that.

In hindsight with as much time and money as I had into the VGT I wish I would've went compounds from the start. (unless anyone has a good cheap core he431ve ;))
 
twins

So should I quit going around the obvious and do twins?

Kinda jacking my own thread, but I do have a he341.....

pros and cons of twins vs big vgts? On stock sticks for now as well
 
Boogaloons said:
So should I quit going around the obvious and do twins?

Kinda jacking my own thread, but I do have a he341.....

pros and cons of twins vs big vgts? On stock sticks for now as well
Click to expand...

Just thinking out loud here, can you not run compounds using a VGT turbo as a secondary and still have the exhaust brake function of the VGT? Does that not work?
 
Red Sleeper said:
Just thinking out loud here, can you not run compounds using a VGT turbo as a secondary and still have the exhaust brake function of the VGT? Does that not work?
Click to expand...

I imagine that since a vgt already is known to have some drive pressure issues that in a compound configuration it would be a major issue but that is just me thinking out loud. No proof of that statement.
 
HE551V was good for 551/1083 on my 12v with a mechanical control and very little tuning. I sold it to 97crewcab, and I think he pushed it to around 640hp on his 12v.

With a CR, a good electronic controller, and towing with stock size tires, I can see it working quite nicely. I had it spooling at 1800rpm on my 12v Auto with 3.55's, and never got to dyno it like that. I dynoed it spooling at 2300RPM, and she did 551/1083.

Hardly no one has tried them.
Chris
 
I had a 431 with the 67mm exhaust wheel and had fleece put there 63 on the front it spooled great but if pushing it hard I'd external gate it that was our next step until we jumped into an s400 instead for pulling
 
zfaylor said:
I imagine that since a vgt already is known to have some drive pressure issues that in a compound configuration it would be a major issue but that is just me thinking out loud. No proof of that statement.
Click to expand...

Don't they have drive pressure issues because stock they won't open fast enough for the flow?
 
moparmcg said:
I had a 431 with the 67mm exhaust wheel and had fleece put there 63 on the front it spooled great but if pushing it hard I'd external gate it that was our next step until we jumped into an s400 instead for pulling
Click to expand...

Pushing hard being? I'm not expecting more than 50psi, just better flow at all rpms with the vgt versus a similar sized fixed variable compressor
 
We were running about 45-50psi pulling last year @4k Rpms carrying 3500 down the track. We went to 5ks this year and were going to gate it before we switched chargers
 
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