A customer/friend of mine bought a 91 1ton that had a cab fire. So all we got is the chassi. Its a 727/np205 set up. The plan is to build a wheeler, trail rig, rock crawler. I know these motors really come alive when the boost comes on, problem is, slow crawling isnt too much fun at 1800rpm. The basic plan for the rig is to run the 727 with a 203/205 T-case doubler, Unimog 406 axles (6.17 gears), 52" michelin xl's. I know a lot more about the 24v(cuz I own one) but not the early 12's. steer me in the right direction for off idle POWER.

Thanks!

 

umm... thats all mine has is low end power.... its a diesel it will make way more low end grunt than a gasser. stock mine has peak torque around 1600... any lower it is idling. i think the earlier 12 valves may peak torque lower than the 02 you drive. correct me if i am wrong but the later engines had a wider power band.


wayne

 

Put an HY35 turbo off an 01-02 automatic truck on it, and keep the BOMBs light...then you'll have near off idle spool up. From what I've seen, those huge turbine housings on the early engines is the reason they're so sluggish...it's not that they don't have the fuel!

Chris

 

A smaller exhaust housing is what you really need - 12cm would be best.

 

Normally on a street driven truck yes, but on a crawling rig I agree with signature600 about the HY-35 turbo and its 9cm housing for the quick spoolup.

 

Not to totally disagree, but do keep in mind that a transfer case doubler will provide incredibly low gearing (I have one in my Toyota - 100:1 gearing) and he will see RPMs rise so fast it'll make your head spin!

 

Thats what I'm talking about! thanks guys. I know they make low end grunt, more so than the 24v's but we want off idle power. let the clutch out and have 400ft lbs without touching the skinny pedal. Is that possible? A buddy runs a caddy 500 in his rig and the torque is amaizing. looking for similar results...

 

I would go with the HY35 as well, that little 9cm housing will spool fast.

Be carfull (I'm sure you will be) that engine with those low gears and 52" tires...

Hit skinny peddle just for a sec and jam a tire and "SNAP" goes lots of expensive parts.

Sounds cool though, would love to see it when your done and durring construction as well.

dan

 

At idle, it doesn't matter what turbo you have, there will be zero boost. You will have to give it some throttle to build boost...no fuel = no boost - the nature of turbo diesels, but if that's what you're going for, the other guys are right, go for the smallest exhaust housing.

 

Put a supercharger on it...and gear it up so you have about 5psi at 1000 RPM

Chris

BTW, I still think the HY35 is the best option for what you're doing...unless you can find an HX30 off a B3.9T

 

Its an auto and the gearing isnt that deep. about 67 to 1 in low with the converter locked. The 406 mog axles are the toughest without going to U1300. 406=2 ton truck, u1300=5 ton truck. We could have used rockwells but we really wanted the clearance of the mogs.

I'll keep my eye open for the smaller turbos.

I'll start a thread here when construction starts, if its allowed. Here's what we're starting with

and here's what we're thinking
http://www.pirate4x4.com/forum/attac...1&d=1153254753
For some reason I cant get the last pic to post. Sorry.

 

Boy you have a long way to go but I reconize the engine caus I have one just like it.