anyone ever considered a variable vane holset?

[ZimbutheMonkey]

So after looking into the possibility of using a holset HY35 for a BAT build, I came upon this little gem of a thread http://www.turbotalk.org/bb/viewtopic.php?f=25&t=4 A few guys have been successfully running the HE351VE turbos on gasoline engines.

First off, I realize that variable vane and gasoline engines may not mix well on account of EGT's. However, I see no reason why a good water/meth setup couldn't be used to keep things in check. I know on my GTRS, I never saw much more than 1500F under full boost conditions, which is in the range (albeit the high end) of diesel EGT's.

Looks what these guys were doing were just hooking a wastegate actuator to the VGT actuator in lieu of the electronic controller and using a 38mm external wastegate to limit boost. Apparently it worked quite well. By the looks of it, the VGT can go from 5cm2 to 20cm2 so you could get some wicked fast spool and good top end to boot.

I'd like to see some longer term testing on these to see how long they'd last before degrading. However they look to be about $250-600 to replace, so even if you got a year or two out of one it'd still be worth it IMO. I'm thinking that on a small displacement engine like a 1.8l they may be a good match, any thoughts?

[walky_talky20]

Wow, that is some interesting stuff.

I just went to an EVO/DSM vs. WRX shootout at a drag strip the other day. Sooo many turbos, 1 for each car...but none of these variable type that I saw.

[badseed]

A guy on here by the name of SpeedWorksAuto has a thread in the builds section and he uses a VGT Holset on his 1.8 stroked to 2.1.

[ZimbutheMonkey]

Yeah, I saw the speedworks link in the B6 thread. But with these turbos being so retardedly cheap, I think you could make one of these cars into a friggin monster with a well setup VGT Holset. (oh yeah, Bullseye also has an upgraded compressor for it too)

Walky_talky, other than the VGT turbos being a bit of an unknown I think what keeps a lot of guys from using them is that they would be a bitch to fit on a transverse engine due to the turbine housing size.

[auh]

Is this the type of turbo Porsche has been using on the 997? If so I'd love to see how they work on a B5 platform!

[ZimbutheMonkey]

No, those are a different type. On the holset the vanes are fixed on a sliding collar which slides in and out of the turbine housing. On the Porsche, the vanes are fixed in the turbine housing and rotate in unison to vary flow.

As far as I know, that's what the problem was in using the fixed vane type on gas engines. The vanes were constantly exposed to the exhaust flow. Since gas engines run much hotter than their Diesel counterparts, a fixed vane wouldn't hold up until now. In the case of the holsets though, the vanes can be withdrawn during WOT and during cruise. So they're not constantly being heated.

Finally, I don't know if you could run the Porsche type without their electronics. That and since they're a twin design, each turbo only needs to support 25-30 lb/min of airflow. So you'd probably be better off running a 28RS power wise. However the VGT Porsche one would sure spool like a MF.

[Sales@RAI]

Both storx and speedwoksauto have these on 1.8Ts and liked them very much

[JEmm]

I looked up pictures of the turbo that guy used... that is a massive piece.

[onemoremile]

It is a bad ass build but appears to have a voodoo hex on it. Hopefully it can shake the bad juju and show it's real potential.

http://www.audizine.com/forum/showth...1-95.5mm-build

[ZimbutheMonkey]

Agreed, I'd love to be able to run something like that successfully. That's the problem with pioneering though, you learn a hell of a lot, but you also blow things up and blow through money like crazy. (That's where I run into issues being a student for another 3 years) Props to those trying it out though. I figure if the DSM guys can run it there's no reason we can't.

I think these Holsets in general have an enormous amount of potential though. It's nice to have an option for a BAT setup that isn't a $1300 Garrett or Bullseye turbo.