x3
Despite shitcanning diesels in Sierras for years I've been looking into this, because I found that Acme adapters make an adapter for the VW engines to the AW-4 auto., so I could consider it. I'm currently running a G16B, AW-4 auto, 6.5 case and 5.12 diffs with 35's. My Sierra is big and heavy.
This is going to be a enormously complex and/or expensive swap to do here. As far as I can tell, we didn't ever get the mechanical pump motors here. That means using the whole TDI loom/instrument cluster/immobiliser key etc, or you can swap a TDI motor to a mechanical pump, but they're USD$1200. Ouch. This pump will allow more HP (and easier tuning), which is cool, but more HP means more turbo, more intercooling, and more torque to kill driveline with.
The exhaust is on the driver's side for us. That might create turbo/steering shaft interference in a RHD application. Not sure.
Now the gearing. This gets really problematic.
You're going to want tall (stock) gearing and tall tyres (31" at least) to pull highway revs down. A Stock sierra runs about 3500 rpm @ 100km/h. You're going to want to take that way down with a diesel. Once you get off road, the torque of the diesel will cope with a tall gears, but so long as you're happy going fast. if you really want to crawl, you're still going to want some sort of reduction gearing, and that's going to push your highway revs back up. It might be the one time where swapping to a hilux transfer case with it's direct high range is a win.
In principle, I can see the appeal, but only if you can sort the gearing and only if the motor has plenty of tune in it. Have a good look at that acme adapters site. They list HP and torque for all the VW variants. What they don't list is power/torque for a G16B. Even the most powerful VW variants are only close on HP to a G16B.
But the torque! Surely the torque will dig you out of any HP hole!
Hmmmaybe.
Consider this. Cruising in a sierra with a VW diesel, it's going to be way above it's torque peak. The higher you go above the torque peak, the softer throttle response gets, and the more torque falls away. Whilst the car will be economical and will pull up hills well, it might not have all that much throttle response if you're already at 3500rpm when you're cruising. I've owned quite a few diesels, and I currently run a X3 3.0 diesel as a commuter, and it's very quick and economical, but it has an 8 speed auto (yes, 8, not a misprint) and cruises at about 1500rpm at 100km/h. At 3500 rpm it's pretty soft, even with 190KW and 550Nm. A Sierra doesn't have that sort of gearing.
all up, it's an interesting idea, but I don't think it makes sense economically, or really from a performance standpoint compared to a G16B, and that's the important bit - Acme don't compare their conversion to a G16B, only the carby/TBI motors.
Just some thoughts. I don't have direct experience with the conversion, and I do understand it's appeal, but I just don't think it makes sense.
Steve.
|
