Any thoughts? Holset HE351VGT

[cdkilla]

Seeing as I'm a tech at a Chevrolet/Chrysler dealership, we get alot of warranty parts and whatnot. I was talking with the parts guy the other day and much to my surprise, alot of these large ticket items have been getting sent to the scrap yard for scrap price. Items like injectors on diesels get rebuilt, but apparantly Dodge doesn't care to fix there turbos they just scrap them. They have issues with soot screwing up the vane operation on the earlier ones which I believe has been resolved. I say all this because I am now in possesion of a Holset HE351VGT for free. I was wondering if anyone in the nissan world has messed with anything like this? I've seen some people rig up a choke cable to manually control the vane operation as well as some DSM'rs using a wastegate actuator to control the vanes and then externally wastegating the turbo. I'd be really pumped to make this turbo work, but haven't found too much on info. I know you've got some input on this boost_boy!

[boost_boy]

Here's my take on that turbo: Clean that puppy up and sell it, You don't need the headaches that you're going to experience. Anything is possible, but for what you're going to get out of the holset, the experience is not worth the gain. The VGT is too tricky and the exhaust housing is too big for the CA. Again, make it nice and sell it. There are a few individuals that are willing to put-up with the extra work associated with installing this blower on a small 4 cylinder engine.

[float_6969]

VGT (or VNT) has been tried multiple times on gasoline engines without success until recently with Porsche, but it required some VERY expensive materials to make it work.

The main problem seem to be that due to the greater efficiency of the diesel engine, the EGT's are lower, and so this technology will work OK with these motors. The higher EGT's on a gasoline engine seem to cause the vane mechanism to foul up pretty regularly when used with gasoline. It seems that they can be dis-assembled, cleaned, and re-assembled and they work again, but it becomes a pain.

Will it work? Yes. Will it work for long? Probably not, but if it's a free/cheap turbo, and you've got the ability to fabricate a manifold and down-pipe, I say it's worth a try.

[blownhemi]

The VGT is too tricky and the exhaust housing is too big for the CA.

It's variable, from about 8 cm2 to 34 cm2. I don't know what exact values that translates to in the "A/R" world, but it would be from "very small" to "very big". Or do you mean, too big by dimensions to fit inside the engine bay? This has been mounted front-low in a DSM, I think our bays could accomodate it.

You will need patience and some fabricating skills. I'd also say electronics know-how, because I can't see this working efficiently in any other way, than mapping the VNT position onto a 2D axis, one axis being manifold pressure, the other throttle position. This, and you'll need to want big boost, like 22++ psi, anything less, and it's not worth it, smaller turbos will have the same response and efficiency for the same power, without all the complication.

The main problem seem to be that due to the greater efficiency of the diesel engine, the EGT's are lower, and so this technology will work OK with these motors. The higher EGT's on a gasoline engine seem to cause the vane mechanism to foul up pretty regularly when used with gasoline. It seems that they can be dis-assembled, cleaned, and re-assembled and they work again, but it becomes a pain.

Does this apply to Holsets as well, or only the Garrett VNTs? (which, most of the turbo rebuild shops wouldn't touch with a stick) By fouling up, do you mean filling up with carbon/soot, or getting stuck by thermal expansion?

[cdkilla]

I've done some more research, and it does seem that the vgt has issues with gasoline engines. But what i'm thinking is fab up a manifold and try it out, worst case scenario the vanes get stuck, and if it gets annoying ditch it. After all, it is a free turbo. It seems the algirithom that Dodge used to control the vane operation is something no one can figure out, so electronically controlling the vane's is out of the question until someone cracks the case.

[roast]

Some guys argue on tdiclub.com that VNT's can be used in petrol applications, someone posted a dynochart with a VNT turbo on an ATV for ice racing... Another guy said the old Shelbey Turbo had VNT unit slapped on it from the factory. It's really up to you and if you want a challenge or headache... =D

I read a bit further in and someone with an Audi 2.2 TT was running a VNT turbo and someone else with an older legacy ran VNT...

[float_6969]

The shelbe's had the VNT, and ended up discontinuing their use due to carbon fouling.

Don't get me wrong here, it's GREAT idea, and I honestly think that once the materials require to make it work reliably on gasoline become more cost effective, it's going to become commonplace, but as it stands now, it has limited success in gasoline applications.

I would be curious to try it on an engine burning E85, as it seems to burn cleaner and cause less carbon buildup.

As for the actuator, shelby simply had it boost based. The actuator had 2 ports on it, and the unit "failed safe" meaning that w/o any boost input, the vanes would go full "open" and create little to no boost. Then the ECU simply controlled the duty cycle on a 3 port solenoid (1 inlet port, 1 NO port, 1 NC port) based on air flow vs. RPM (AKA boost) and that controlled the angle of the vanes, thereby controlling boost levels. This is exactly how almost all external wastegates work that have 2 ports on them.

[cdkilla]

The shelbe's had the VNT, and ended up discontinuing their use due to carbon fouling.

Don't get me wrong here, it's GREAT idea, and I honestly think that once the materials require to make it work reliably on gasoline become more cost effective, it's going to become commonplace, but as it stands now, it has limited success in gasoline applications.

I would be curious to try it on an engine burning E85, as it seems to burn cleaner and cause less carbon buildup.

As for the actuator, shelby simply had it boost based. The actuator had 2 ports on it, and the unit "failed safe" meaning that w/o any boost input, the vanes would go full "open" and create little to no boost. Then the ECU simply controlled the duty cycle on a 3 port solenoid (1 inlet port, 1 NO port, 1 NC port) based on air flow vs. RPM (AKA boost) and that controlled the angle of the vanes, thereby controlling boost levels. This is exactly how almost all external wastegates work that have 2 ports on them.

Yeah, I was thinking that with the E85, and if this idea does make it's way into my engine bay, it will DEF be running on E85.

[float_6969]

I might look into this a little more as I'm already burning E85 and I already have a T4 flanged manifold.

[roast]

I might look into this a little more as I'm already burning E85 and I already have a T4 flanged manifold.

Aren't you going S/C w/water to air IC?

[cdkilla]

I might look into this a little more as I'm already burning E85 and I already have a T4 flanged manifold.

Really? What engine management are you running? SDS?

[cdkilla]

Spent the last couple hours reading up on methods to control the VGT and found a guy who listed instructions on how to build a controller. Think I might go this route, maybe.

As for the build up from gasoline engines, there is a fellow on dsmtuners who put around 3k hard miles (lots of dyno time) on his talon with this turbo installed and took it apart and found it was as clean as the day he put it in.

[float_6969]

I might look into this a little more as I'm already burning E85 and I already have a T4 flanged manifold.

Aren't you going S/C w/water to air IC?

I had to give up on the supercharger. There wasn't enough room unless I ditched the a/c and i've given it up enough times I swore to myself (and my wife and kid) that I would't do that with this car. I am still going to run a water/air intercooler though. i actually just got it mounted up a couple of days ago so I can order intercooler piping.

I might look into this a little more as I'm already burning E85 and I already have a T4 flanged manifold.

Really? What engine management are you running? SDS?

Yup. SDS EM4-F.

[cdkilla]

SR t25 beside the holset.

That sure is alot of turbo!