|I've seen several charts showing power bands but what would be optimal? The westy is heavy and bad uphill.|
Good question. First you have to define "optimal". It will be subjective. For many on this board, optimal will simply mean "most" which is literally self-destructive and very costly to embrace as a philosophy.
My answer would be: You should shoot for as little torque as you can stand to drive with if your top priority is to use/travel with the van and keep costs/maintenance time as low as possible. If you are a local only driver, have more than one car, go to lot's of shows, really enjoy having the most baddass thing out there as a top priority, then that comment doesn't apply and go for the gusto but don't exceed 220 Ft/lbs of torque.
It is really important to understand the entire system as well. The vanagon actually *isn't* very heavy at all for a light truck. The issue is that they have so much room, they can be loaded and made VERY heavy.
VW designed the vanagon chassis and the entire powertrain to be very lightweight, and use gearing over a large torquey powerplant. Hence the 96 HP 2.1 liter and final drive ratios *starting* at 4.86 The final drives are the real clincher of this point. Even 4 cylinder wranglers are at 4.10. If you talk to any American truck guys, they will be shocked to hear that our final drives regularly go to 6.17 to accommodate 31" tires.
If you look at the components of a vanagon transmission compared to other light trucks or even passenger cars, it's obvious that they built for light weight and gearing not torque and low revs. This is the reason why when you try to do something like a 5 cylinder TDi, or go to 31" tires you start breaking things, and will continue to break things until you concede and go back. Many people will also "upgrade" parts like move to 930 CVs to reinforce perceived weak parts of the driveline. While the individual portion of the driveline is strengthened, the rest won't be, and has very low limits so the end result is really just moving failure points around. You're only as strong as your weakest link, and in this case you're quite lucky to be able to *choose* that link ahead of time, so you know where it is going to fail before it does so you can be prepared for it, and manage the risk/outcome.
In the case of 930s you move it from an external easy to get at part (the CV) to the flange/internal break, which my good buddy John just found out the hard way, and almost took Daryl with him at Syncrofest!
So while there are many ways to approach an answer to that question, I *strongly* urge most people to be boring when building their rigs. As most people are in it to use the rig, and then start to get caught up in the hobby of modding their vans. If you transition from using your van to modding as your primary motivator, the outcome will reflect that, and your use of the van will go down. You cannot have two top priorities unfortunately. Yes it is less glamorous, yes it won't get you as much credit at a show, but if your primary objective is to travel and camp in your van, then keep a laser focus on your decision making and put it there.
So the answer for what is optimal will be subjective, however I restate it: You should shoot for as little torque as you can stand to drive with if your top priority is to use/travel with the van and keep costs/maintenance time as low as possible. If you are a local only driver, have more than one car, go to lot's of shows, really enjoy having the most baddass thing out there as a top priority, then that comment doesn't apply and go for the gusto but don't exceed 220 Ft/lbs of torque.
The needier you get, the more problems you're going to have. I'll gladly stand up as the voice of boring let's-not-push-it because I've been in the auto aftermarket for a long time, and I've seen how badly so many projects can go for people when they lose their focus and fall into the "need more" cycle or the "while I'm in there" feature creep. It's possible to work on a car until it's totaled, and there is literally *nothing* to show for the money and time. Seen it too many times.
The whole point of a vanagon really is to "need less" and if you try to flip the script, you'll pay. The people that can do with less are the ones telling me how happy they are with their rigs and sending pictures of where they are travelling to. Laying rubber is fun, but if you find you really enjoy that, get another car to satisfy the need for speed... or do like Benny, Brady, and myself do and get a fast motorcycle to offset that need. Don't try to squeeze blood from a stone, you're only going to hurt your own hands.
It's foolish (but cool) to hotrod a vanagon for 99% of the people here. Because most of the folks with them weren't gearheads to begin with... don't get sucked in!! Keep your eye on the independence, mobility, and self-reliance that you got into it for, and don't get corrupted by the more, more, more. You'll be happier being who you are.
Folks may disagree with me, that's ok. My voice comes from managing and supporting more vanagon powerplant swaps than any other individual in vanagonland far as I know. Let me tell you, the bludgeonings of reality have certainly dulled my sense of adventure when it comes to build ups... but I see consistent results too, which is worth it's weight in gold. So learn from my experience, even though I also realize that more people will actually need to find out for themselves before they believe in this rather boring philosophy. What you decide to do sitting front of a computer will eventually be related to how you feel out in the world using your creation, and what gets you excited here, won't often translate well. Know your purpose. Set your goals. Execution is everything.
Hope that helps or at least offers contrary opinion,