Diesel Conversion

[Maugan_VX]

Joe,

Thanks for enlightening us (me).

At ~$1000 and "plug and play" functionality, whats the downside? Does that price include the ECU? Will it behave with TOD and the 4L30E like the 6VE1? What are the changes needed to the fuel delivery system? Exhaust? Are there any resources online that you'd recommend concerning diesel conversions in general?

what kind of emissions regulatory implications are there?

Curiosity is killing me.

[Joe_Black]

Joe,

Thanks for enlightening us (me).

Well, I first got interested in doing this prior to getting a VX when I wanted to build an '89 Trooper RS into the ultimate road and trail rig. I had been reading a lot about the then-new 4BD2TC as used in the NPR medium duty trucks and that a few HD Troopers came with the same engine. So I got really interested in fitting an intercooled turbo-diesel powerhouse into an RS, complete with the big ole hood scoop.

At ~$1000 and "plug and play" functionality, whats the downside? Does that price include the ECU?

From what I've learned only the very latest engine is (4JX1 IIRC) electronic with common-rail fuel delivery. All previous models are fully mechanical.

Will it behave with TOD and the 4L30E like the 6VE1?

I'm pretty certain you'd have to baby it if retaining the 4L30E, but it may just survive normal driving as it's not that bad of a tranny. Just not well-suited for high-torque offroad use. I still haven't fully deciphered the connection between the TOD computer and the ECU, but know only minor changes were made to the rally VX's which had 5-speed manual transmissions. My hope is to confirm soon that the TOD transfer case will mate with the diesel auto and manual trannies.

What are the changes needed to the fuel delivery system?

Diesels use a non-pressurized system with a vent and a return line. Our system is already plumbed and you'd need to just change the tank-mounted fuel pump.

Exhaust?

A new exhaust would be needed from the manifold to the cat since it's an inline 4-cylinder and diesels use a different cat/particulate filter set-up. Everything after the cat would work fine as diesels are pretty flexible with exhaust and not as sensitive as gas engines.

Are there any resources online that you'd recommend concerning diesel conversions in general?

I've found a lot of folk converting a variety of vehicles to diesel or US spec vehicles to domestic diesel spec, but nothing specific comes to mind. I'd just Yahoo! or Google "diesel conversion" and browse. There was a '98 Trooper on eBay twice recently that had a well done Mercedes OM617 conversion, and that is a potential back-up in the event Isuzu diesels proved too difficult to obtain.

what kind of emissions regulatory implications are there?

That I'm not 100% sure of as Florida is pretty lax in that department and I haven't really looked at other states requirements. It shouldn't be too difficult to poke around your particular state's DMV or DOT web pages to glean any local emissions regulations.

Curiosity is killing me.

Yeah, it's been getting me for years as I keep generating about 2 more questions for each answer I get. LOL!

[blacksambo]

While you can go on forever on the statistacal benefits of a diesel the sad fact remains that they can only "react" to the load they carry. In otherwords, "react" (and we all know reaction means time) versus a gas unit that responds purely to throttle input and in so doing provides more than instant torque, it almost anticipates the vehicles needs. And torque is the name of the game when it comes to cornering ability. Without instant torque you don't the power neccessary to preload the suspension and corner hard and decisively. Think about it for a minute... can you come up with the name of one racing organization, in a non-spec racing series, that perfers diesel technology over gas and wins? It's never going to happen race fans. The only race a diesel will ever win is one of load reaction and fuel efficiency. What do you want your VX to do, haul or handle? The choice is most certainly yours but its original designers, coming from a wealth of diesel-technology experience definitely chose the magic of instant throttle response and handling-optimizing torque versus load-sensitive reaction power.

[Joe_Black]

Think about it for a minute... can you come up with the name of one racing organization, in a non-spec racing series, that perfers diesel technology over gas and wins?

You bet! Check out some racing diesels...

Paris-Dakar Rally

CAT Rally Power!

SCCA Rally BioDiesel VW Golf TDI

British Truck Racing Association

FIA European Truck Racing Cup

Diesel Hot Rod Association

BMW X5 Bi-Turbo Diesel Rally Truck

Banks D-Max Road Racing Truck

First Diesel Indy Car

And the list goes on! The proof of diesel performance is out there, and has been for almost a century in our desire to succeed and win where others have failed. And as far as diesels being "reactionary" you really should get some more hands-on experience. That kind of thinking and a run-away (diesel no-load) will get you into trouble.

[ameetw]

Hi, I am also interested in the diesel conversion. I have another diesel truck a land cruiser using a 4.2 TD engine. There is a slight lag initially but catches up with the Vx and overtakes it. The truck is still tuned for soft driving, ie. no boosting nor playing with the fuel pump.
The plus side in Malaysia is that diesel is about 1.35 USD / Gallon. I'm currently discussing this conversion with a friend so far it seems promising. Trooper in Malaysia is the "Government Choice" vehicle. So Isuzu diesel engines are easy to find.

Ameet

[MZ-N10]

You bet! Check out some racing diesels...

Paris-Dakar Rally

CAT Rally Power!

SCCA Rally BioDiesel VW Golf TDI

British Truck Racing Association

FIA European Truck Racing Cup

Diesel Hot Rod Association

BMW X5 Bi-Turbo Diesel Rally Truck

Banks D-Max Road Racing Truck

First Diesel Indy Car

And the list goes on! The proof of diesel performance is out there, and has been for almost a century in our desire to succeed and win where others have failed. And as far as diesels being "reactionary" you really should get some more hands-on experience. That kind of thinking and a run-away (diesel no-load) will get you into trouble.

i didnt realize how many competition cars acutally use desiels....but i noticed tat none of those are road courses. other then 1930s indy car and the trucks.

but wat i think blacksambo was getting at was theres no desiel cars racing on tracks. atleast not desiel vs gasoline.

[blacksambo]

You've got that right! Where pure speed and high performance handling is concerned gas is the undisputed king. Remember VX fans, the raison d'etre for the VX was "torque on demand", not torque after it reacts to the load! Load handling driving is typically not concerned with performance cornering ability... there is no such spec at Caterpillar, its purely load reaction engineering for diesel success. Where diesels race its just a novelty, they are not setting any speed records on road courses. Believe me, if diesel was a viable road course option they would have tried in Formula 1 the pinnacle in motor sport a long time ago. Not even the Safety Car in Formula 1 is diesel, it would be deemed too dangerous to use such a load reaction vehicle in high speed pace work. Also, remember that the VX came equipped, stock, with license plate holders. In other words, it was designed first and foremost for highway or road course type use...off-road driving was secondary in the original designers' minds. It's a street machine that adapts (sports car first,truck second), not vice versa.

[Joe_Black]

:laughg: