Join Date: May 2005
Thanked 4 Times in 4 Posts
First thing would be to make sure that the car is running as it should. Make sure the valves are adjusted, timing is set correctly, get the injectors pop and pattern tested. If you really want to make sure all is right, you might want to pull the IP and have it tested and adjusted to spec. A 23 year old IP is probably in need of some work.
Next thing would be a Pyro and a boost gauge. Check to make sure your boost is at about 10 PSI. If you have done all of the above the car should be good for about 100WHP and a 0 to 60 time of 13.5 seconds or so assuming you have the 3.46 rear end. They did have a 2.88 avaialble back then too. If you have to switch rearend ratios, you'll need a matching speedometer.
Don't waste your time with a 4 speed manual swap, unless you are doing it for MPG. As far as performance will go an auto will out perform the manual.
An 84 turbo has an MW pump. There are a couple things that can be done with that. One is to turn up the full load screw and the other is to remove the rack limiter.
Once you've done that you will need to up the boost by adjusting the wastegate or adding a mechincal boost fooler. 15 PSI is about it for the factory T-3 which is a 45 trim I believe. You can get a 50 or 55 trim T-3 from a 300SD or an SVO Mustang to get a little more air flow. 20 PSI is about the limit without upgrading the head bolts to head studs. You'll also want to work on getting an intercooler in there.
After you've upped the fuel, added the intercooler, and added boost you MIGHT see 130WHP. More realistic would be about 120HP.
Power adders? Water/Meth was tested on a couple Turbo 300D's and it netted 1 to 2 hp. Propane, risky but doable. Nitrous, but what's the old saying about lipstick and a pig?
There is talk about injector internals from later model diesels in the OM617 engine. That may add some power, but as of yet I don't know if anyone has tried it.
You can order a Myna M-Pump from a company in the Netherlands, but that will set you back about $2K. I have seen the benefit from that. There is a guy with Myna pumped om617 and he put down 150HP with an otherwise stock 300D with his boost turned up to 17psi. He now needs more turbo and an intercooler and I believe he could be up around 200WHP.
Much over 150WHP and you have to start thinking about transmission failure. But the trick will be to get to 150WHP first.