Curious if anyone has used a variable vane turbo in a LS turbo build? Is there any aftermarket ones readily available? Don't really see any used other than OEM diesels.

Been debating between twins or a single turbo and got to thinking it would be cool to get a big single variable vane turbo setup. Spool quick yet flow great on the top end, and much more simple to package then twins.

 

I've always wondered the same thing. I work a lot with ford 6.0 diesels and thought that the stock Vgt turbo would be cool on a LS build. Never went far with it since the turbo sits on a pedestal for oiling purposes but would be cool to see still.

 

A diesel turbo wouldnt really work well as they would be way too small. Reason being is displacement is the same but diesels only rev to 3000 rpm then are out of steam, so need much larger turbo for ls engine

 

The vane control is difficult on the ford type unit. They use oil pressure and a computer that reads the turbo speed and make constant adjustments to the blade pitch.

The holset stuff is much easier to control (can use a simple spring or WG actuator). Many have used these on 4 and 6 cyl applications with great results. Twin Holset He351 turbos would work well on a basic build. They are a high flow 60mm turbo.

 

The 6.0's didn't have the VVT's; I believe they started on the 6.4's. Isn't that correct? Also, aren't the VVT very quiet?

 

Both the 6.0 and 6.4 have a VGT turbo(s)

 

6.0 is vgt it is controlled by oil pressure from a spool valve in the turbo, it monitors exhaust back pressure and manifold gauge pressure to sselect vane position, the 6.4 is twin turbo and 1 of them being vgt and being controlled by a motor with similar monitors also both have oddball flanges

 

The main issue is EGT's on a diesel are much cooler so it's easier to make the vane mechs live.

But some people have used them on petrol applications. Would it be worth the hassle on such a large V8 ? I cant see it

 

I thought Porsche had VTG on their new turbo cars?

 

They do, and I'm sure their units will have a much higher price tag than cheap diesel offerings

 

To me, the Holset “vanes” look like a lot sturdier design than the Ford style. When the variable HE351ve’s first came out the vanes would gum up with the diesel soot and seize. Most of these were still under warranty and replaced instead of repaired. So there were dirt cheap “failed” warranty units on Ebay for years. ($150-$300) Guys were just taking them apart, cleaning the soot and running them with great success. The gas engines didn’t “gum up” the vanes and seemed to work well. Only read about a few using these in a performance application. (Supras and DSM's mainly) There’s a build thread on theturboforums with a thunderbird running an HE351ve on a 5.0. Never heard of a failure in a gas application.

These are basically an HX-40 variable turbos and would perform very well in a twin LS setup IMO. A friend used some clay and calculated the max an min available AR sizes. His rough measurements suggested you had a range of 6cm to 22cm . I’d think this could provide crazy fast initial “spool” and provide very little back pressure in the upper rev range.

The controls setup I got to work with was really simple. Used a spring and adjustable stop. With vanes fully closed you could hear the turbo accelerate/whine/whistle like crazy. Wouldn’t make positive manifold pressure, but sure sounded cool! We set the idle to 2400 (typical cruise rpm) and adjusted the stop until we could just hear it start to whine. Spring had enough tension to hold the vane position on the stop at idle/cruise. And was light enough that drive pressure alone would allow the vanes to fully open by redline. Unfortunately it still needed a wastegate to keep boost in check.

Worst case scenario you have dual hx40’s that you could set at your desired AR/CM size and lock in place. Best case you get one of the coolest sounding setups around, fast initial spool, and low peak back pressures.

I could see space being a big issue. Would make for a cool remote mount twin setup assuming you could find a pair cheap these days.

http://www.ebay.com/itm/He351ve-Cummins-Turbo-/221661346972?pt=Motors_Car_Truck_Parts_Accessories&hash=item339c0bbc9c&vxp=mtr

 

I don't know much about turbos, yet, but my 6.7L diesel's turbo spins to 80k rpm at 1800rpm engine speed. It's a single VGT.

 

turbo speed has nothing to do with it. Essentially a turbo from a diesel would not be a good match on a LS motor. The diesel turbo's are much smaller and the compressor and turbine maps would be no where near what an LS engine need.

Anyway in my research a few companies do make variable geometry turbo's but they are not very common. Plus everything is aimed at diesel engines. Looks like Holset does make several different models, but they don't give any specs as far as inducer and exducer sizes.

Being able to control the vanes based on vacuum/boost pressures would be fun to fine tune a turbo characteristics to suit your driving style.

 

General rule is double the liters for a turbo that would suit gas needs. Some of the 10-14 liter diesel stuff could work well on 5-7 liter gas setups as a a single IMO.

Same goes for twins...


HT60 looks like a good choice. Surprised we don't' see more of them.



http://www.ebay.com/itm/161401021175?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

Compared to what? I see/seen massively high EGT numbers from Diesel engines.

 

I used one kind of as a dare form a friend. It was a huge large frame t6 billet wheel, ball bearing variable vane Garret unit. He basically gave it to me as a joke and said if my stock bottom end 5.3 would spool it, I could have it. It actually worked surprisingly well, considering it was advertised as having a 1.72 a/r hotside! It was responsive, came on smooth and pulled very hard. Only downfall was the added mass and weight. It was nice not needing a wastegate though. I later swapped to an ebay gt45, and it was not nearly as responsive or pulled as hard at the same psi as the bigger VV unit. I still have it, considering putting it on my SBE 6.0 build now and seeing what it will really do when turned up.

 

Show us some pictures and videos! What model was it? How did you control it?

 

Lolz. Yeah those s400 based units don't work worth a ****

 

Hell I ran a 12.9 with a 300series Borg on my 7.3! bitch was still on 35's too

 

Generally EGT's as high as gasoline will be borderline on destruction in a diesel, and any with enough fuel to get that high would be belching smoke like ****.

No OEM setup should ever be anywhere near that, hence their VNT turbos would never need to sustain such temperatures.