Basic V-6 Tech Specs, etc.

[Force Fed Mopar]

You guys are really making me want to mod my '91 AWD Caravan...and that is really not what I need to be doing at the moment

[Ondonti]

Chris got his first view of AWD parts today. His main comment was "Those are really big, much bigger then a DSM.

[Vigo]

Factory DSM makes LESS torque than stock 3.8 and the van's GCVW is probably twice as much.

[Reaper1]

Both VERY true! Seeing the parts in person, and having seen the DSM and 3Si "equivalents" really puts things into perspective.

Knowing what I do now, it really makes me wonder why I "followed the pack" on the old thinking that the AWD van parts aren't capable of handling any power back in the old days. LOL

There are a few weak spots, but the only one that is of any real major concern to me is the PTU shaft that engages the diff in the transmission. That part to me (Brent pointed it out and I agreed) looks like it would end up being the real fuse in the whole thing. Everything else either looks like it would do just fine, or it could be beefed up with just a little effort and it would never be an issue again.

I was also pleasantly surprised at how relatively light the parts are! I honestly believe there is merit to putting the AWD system behind some good power and letting it rock!

[Vigo]

You're talking about the hollow shaft that splines onto the side of the diff carrier? I guess you are thinking the splines themselves are the weak point?

[Reaper1]

Yeah, just like the CV axles. The stress riser at the end of the splines would be my concern. Of course there is more contact area, and the torque will be shared, so overall the splines will probably see less stress than a FWD car with a posi, big power, and a hard launch.

Only way to know is to try it, really!

[Vigo]

I would look and see how Kreel was launching his AWD/5spd van. IMO the hardest part of an AWD launch as far as parts strength is when you put the momentum of the motor@ high rpm through it at launch. I personally doubt that power levels have much effect on that initial load unless you are building boost at the line. If Kreel was launching his full-weight grand van from near redline with the 3.0, i would bet that it can take truly goofy power levels under normal acceleration.

[Reaper1]

I agree...hard launching, like dumping the clutch at high revs and/or with boost built up will be the hardest thing the system has to deal with, which is what I think most people worry about that race AWD cars. That is unless you are in a condition where high torque is hammered on the system like in special stage rally racing.

In general you can apply high power to most drivetrains if they are already in motion. The hard parts more than likely will live for a while. There are always exceptions, however.

[Rrider]

Zin, graft a 1967 volvo wagon body on to a 3.0 awd minivan. Retain the pre-smog vin from the volvo.. kiss smog nazis goodbye.

Like this except minivan: http://losangeles.craigslist.org/wst...770376729.html :P

[zin]

Nice!

[Ondonti]

You're talking about the hollow shaft that splines onto the side of the diff carrier? I guess you are thinking the splines themselves are the weak point?

I wonder if it would help at all to polish down the sharp edges of the splines near where they convert to normal shaft. The shaft also necks smaller after the splines so it is thinner then even the edge would lead you to believe. What one person said about the shaft was hoping that the large diameter would be able to deal with something that a smaller solid shaft would not. I know my large hallow shaft axles never broke in those large hallow areas. The input shaft of the PTU would really only see about 200 of 400hp or 400 of 800 hp. Those shockloads though, I don't know what kind of clutch Kreel was launching with or how violent it hooks up. I think a carbon carbon clutch would help if we did find failures. Something that slips at the hit and then locks up. Its hard to always be perfect with your clutch on launch (especially with nerves).

[Vigo]

Definitely. Personally, i kind of want to try a very stiff disc with extended clutch lever and a stock disc material. I know there is one guy on TM who ran low 11s on a stiff plate and stock disc, but it was a <3000 lb car. I would think that would have friendly engagement. We already know that a super stiff disc and solid 3 puck is overkill on torque handling but probably suffers in drivability and durability for a heavy van as you'd need to slip it a lot to get rolling. I think a super stiff pressure plate and stock disc might be nicer for that kind of setup. Or one of TU's purple plates with a stock-style disc.

Ive put a 4 puck in a <2500lb car and it drove fine once you get used to using it. But, ive also driven 6puck in a full-weight short wheelbase caravan and imo the amount you have to slip it to get rolling nicely with that weight makes it a bad fit. I just dont think a ceramic puck clutch is going to be the best disc choice for a heavy van. My .02

[Reaper1]

To give you an idea, my Z weighs 3115# race weight. (ok...did LOL) Anyway, I'm running the TU purple plate and 6-puck set-up and it drove around town beautifully.

I had a dual diaphragm PP with a 6-puck clutch and that thing was TERRIBLE. Brent says his clutch is stiff in his Duster, but when I pressed on it it was MUCH easier than what I had...even with an extended clutch arm. Not only was it a pain to push the pedal down, but feeling engagement was pretty much non existent. It was darn near impossible to take off smoothly with that clutch set-up.

I've driven a stock weight Spirit with a 4-puck and a TIII PP and that was easy as well.

From my experiences I'd still suggest the TU set-up. It simply works, and works very well. Also, it is pretty much mandatory to keep a steel flywheel if using a pucked clutch. From my own experience and from what others have also posted about, the aluminum flywheels simply don't work as well as they should with pucked clutches. Also, for the heavier vehicle (and AWD), having that extra mass spinning so the momentum can help things to get going is probably beneficial, even though you may be sacrificing some transient response of the engine.

[Ondonti]

Part of the trouble with driving my daily is the aluminum flywheel not getting along with my solid 4 puck. My 3 puck has a steel flywheel. It engages much much better then my 4 puck but can still be violent. My aluminum flywheel likes to cause the clutch to shudder, my 3 puck just locks the heck up if I accidentally let it out a little too much. . I also wonder if the plate is bit weaker since I bought it in 2007.

Stock type disc with strong plate is not a bad idea for the cheap way of doing things. Just need to make sure you order something that will still handle your goals. Not sure what those custom setups Cindy and others have run cost.

[Reaper1]

All I can say is I tried doing it on the cheap....it ended up being more expensive than if I had just done it right the first time.

[Vigo]

Well I never drove the duster or even pushed the clutch but if that clutch effort was livable than that's sort of the cheap option i was looking at: a DD plate, extended clutch arm, and a stock disc. If you can reuse your stock disc and fab the clutch arm you are looking at $200 and change.