Hi! First post of mine here, sorry if i'm in the wrong place...

Just bought an '85 SJ410 body mounted on an '86 frame/axles/t-case etc.
It has a mid-80's 1.6 VW turbodiesel, SOA lift, 34x10.5" super swampers, skid plates, bumpers, custom molded sliders that follow the lines of the original rockers, toyota power steering, 6.5:1 tcase gears, locker and 26-spline up front, spool in the back with standard diff gearing, rear sammy springs in the front, YJ springs in the back with missing links, leather seats, sandblasted and repainted body...
Its 90% of what i would've done to the project sammy i was looking at last month, already done for me. wheee!
Can't wait to go wheeling! Already took it out on a class 6 trail near my buddy's place and it is a beast off-road

trouble 1: on-the-road performance is garbage, and i don't want a trailer queen. i'm probably going to step down to 33x10.5 BFG MTs, and i'm trying to figure out something to do to the t-case.
Someone on one of the forums said a guy in oregon had put stock high range gears and 4.9:1 low range gears together to get stock high range and approx 3.5:1 low... that sounds pretty great to me, this motor has torque coming out its ears and not a lot of high end.... anyone have more details? better ideas? already has the 3.72 axle gearing, and last i checked there wasn't anything higher.

trouble 2: the EGT redlines when going up even modest hills on the street, and will probably be a bit worse once i put the standard exhaust back in (he had it set up with a hood stack, which is cool / fun for about 5 minutes, then just loud and smelly). should i start by detuning the motor? Add an intercooler? add water cooling behind the turbo? put in a bigger turbo that won't cook so much?

Welcome and congratulations on a solid purchase. My experience with the VW diesel as been similar to yours. If you want to put on logging roads and do trails it's fine but on the highway it's absolutely crap. You could fiddle with the gearing and tire size but I really think the problem is HP. Yes, the engine has torque but when you want to go down the highway or heaven forbid the freeway, there just isn't enough guts there to do it. It may be worth taking some tricks from diesel bombers and add propane, bigger injectors, crank up the injection pump, intercooler, etc... That may shorten the life of the engine but who cares if it goes from 300,000 miles down to 30,000? Not me.

If you're having EGT problems, it is possible your injection timing is off.

Good luck and post up a picture!

-Eric.

There is no easy answer.........as you already know. You will need to make some compromises if you want better road manners, one way or the other.

I suggest asking over here, as there are many diesel / zuk guys here that may be able to help / come up with ideas.

http://bbs.zuwharrie.com/content/board,48.0.html