High HP with 1991 Cummins
 

Hey guys,

I'm looking at buying a second truck, it's a 1991 D250 4x4. I was curious is it feasible to have a 400-500hp streetable First Gen? If so how difficult is it to achieve that kinda HP. Or is the cost rediculous since there's not really any electronics. (Smarty alone on a 3rd gen is almost 500HP).

Also is there anything imparticular I should look out for when looking the truck over??

thanks for the info..

from what i have herd on here our trucks are capable of the horse power with the right goodies, they will fill you in on that, for looking at a first gen, look at the roof to see if it's rusty, there may be a rusty spot beside the gas tank where the frame may have rusted through on the bottom( easy fix), if roofs rusty dont bother, look to see if they turned up some screws on the injector pump, and if they did find out how much they did turn them up. usually these truck are pritty good there tough, so there isent much to really look for, mabe look at how the cab floor is, i had to cut out spots in my floor and reweld new ones in, not a big job really.

Depends on your smoke tolerance. I consider mine streetable, but in many areas the smoke would get too much negative attention.

Remember that the 1st gens are a lot lighter than the 3rd gens, so they feel pretty peppy with "only" 300 RWHP.

smoke is not a problem for me, I run around with my smarty on 9 which yields quite a bit of the black stuff when you want it.

The truck i'm looking at is a 91 D250 single cab SRW 4x4...with 400-500hp it should be pretty quick, i would think.

I just wasn't sure how difficult it was with the 1st gen motors...

My truck feels about like my buddys 05 by the seat of the pants. My mods get me close to 300, while he had qc sb 4wd 05 with banks 6 gun and intake. So like wannadiesel said, less power is needed to get the same feel.

quick question, my brotherinlaw now has a 93 5 spdhes wants to make it Run. He has a super b from his 02 to put on it along with some 40hp inj. i got the # for the 3200 gov. springs i think somewhere written down, but what about this ol smoky pin thing i read about where can we get this pin rather than trying to grind our own. i would appreciate the 3200 spring part number and the # for the pin as well. Any 1st gen guys ever tryed this turbo is it to much, its already intended for a hot 24 valve. thanks ryan

stock600 I don't know about the turbo but Old Smokey himself as a banner ad on the top of the fourum page I'm not sure which page but its there. Here is the spring info 3200 RPM Gov Spring 1-464-650-366. I believe that this is a bosch #

Thanks for the spring number well be going and getting this right away, ill look for the ad you mentained, anyone else know this info and opinion on the turbo, i do know its a full 4" open and required a hx 40 downpipe that im sure we will have to mod to fit in this 93. As for the inj. he has some new 40hp he bought but ive talked him into seeing if they will let him trade in for larger ones, any suggestions there also, im only famil. with the 3rd gen stuff, thanks guys

As far as the down pipe I'm pretty sure Rip Rook will sell you the adapter for what ever turbo outlet you need if you buy there dp of course. Other manufactures might do the same.

does the 3200 spring just let it turn 500-600 more rpm or does it change the whole fuel curve and pull better on the bottom and have the additional rpm?

The truck feels stronger because you have more direct control over the fueling, but the only real performance gain is the extra 600 RPM.

oh i see, thanks. You dont have the smokey pin that ive heard about? Is there another option besides grinding your own?

There's also a 4200 spring... ;)
Next year is going to be interesting for 1st gens... [guitar] Going to be a busy winter...
Bryan

Wow will anything else work up to 4200. Like valve springs, harm. balancer, I think ive heard cummins had these engines in lots of mining equip. that ran high rpm all day- is HIGH 3200+ surly not over 3500 anyone know?

I've heard they don't like over 4200 on the stock bottom end, and you'd have to have heavier valve springs to run over about 3400.