1st gen power?

[florida4x4]

Hey all, I just bought a 93 w250 in great shape and only 123k on the odometer. The PO said it wouldn't pull so he put 4.10's in it. Even with the gears it pulls worse than my 90 burb with a 350 / 700r4 and 4.10 gears does. I want to turn it up a little so I've been reading this forum. I guess I'm dense because I'm still not sure what I need to do! lol. I'm thinking turning up the fuel screw a couple turns is a good start. What about the star wheel and smoke screw? Am I talking about the same things here? Should I mess with the 3200 rpm spring? I think my top speed is about 85 the way it sits now. The gears aren't helping apparently. It goes without saying I want to preserve the MPG as much as possible too!

Anyways, I'd like to know how much power increase I can expect without getting a new turbo and injectors OR are they a necessity to keep up with a lowly gasoline burning suburban? Yeah, it's true, I'm not so impressed with this first gen but I do want to make it better and become a believer!!!

[1991cummins]

well, putting 3:54 or 3:73 would help the top speed and milage for sure lol. but other than that, no, your not talking about the same thing, the fuel screw is on the backside of the pump and allows you to inject more fuel overall, here is a link for a how to:
http://dodgeram.org/tech/dsl/more_power/Power_ve.htm

This is a good site for general information, at the bottom of this page is a bunch of stuff you can do for cheap performance and such:
http://www.dieseltruckresource.com/dev/ ... p?t=102027

The star wheel and "smoke screw" are found in whats called the AFC and is basicly boost compensation. as you build more boost you need more fuel to keep up. so the air pressure of you boost pushes a diaphram down which allows more fuel to inject. that is usually user preference, so you could play around with that a little to see if you can find your "happy place."
FYI, all that is located under the 4 screw cap on top of your pump.

Hope this helped, and good luck with the first gen world [/url]

[Philip]

Well for starters that 92 has a 21cm exhaust housing on the turbo. Replace it with a 16cm or 18cm if its an auto equiped truck. If your a stick shift most of the guys prefer the 12cm waste gated housing.

Now for the pump mods. If you do not have a pryometer and a boost gage get one first. You need to know at least the exhaust gas temps. Turning the pump to much can melt pistons when towing.

[1991cummins]

oh yah, as far as the 3200 gsk, they are a great investment, alot more drivability and power for 16 bucks. its just a spring that you replace in the pump, that controls the governer weights.

and you can get a great deal of power out of these, you have a 93, so i assume you have the wh1c (i dont know what size that housing is) and the small injectors if its stock. but none the less, you can still get a great deal of power out of compared to what you probably have now. i would guesstimate mid 100 hp right now, with pump mods you could 225 i would think is safe to say. you will like it loads more than your suburban, trust me

another thing i forgot to say, you will be VERY wise to get guages before modding, at least a pyrometer(egt guage). you dont want to melt a turbo or something.

[florida4x4]

'91, thanks for the links that first one is just what i've been searching for. The second one I found and then lost again! philip, I read about the housing too. I guess that and a 4" exhaust will halp keep the EGT's down when I turn up the fuel? If I know one thing about turbos it's they don't like back pressure. BTW, I have the EGT and boost gauges just waiting to be installed.

Are 4.10's too steep? Would 35's tame them enough? Who makes the best exhaust?

[florida4x4]

'91, you got a post in there before I could reply.. I don't know what turbo it has. I do know there is no wastegate which surprised me a little. I found the spring on ebay. I think I'll get that and a 16mm housing and exhaust then try the screw mod.

Thanks for the information!!! :beer:

[RumbleFish]

while the 21cm housing will make it seem pretty sluggish, you may also want to check the lift pump. the ve injection pump will suck straight thru it, but it will be down on power. im curious as to what the previous owner was trying to tow that this thing wouldnt.

[florida4x4]

He had an underground utilities business so probably a boring machine. Igot the impression it was over 10k but maybe not. I pull around 8k with my truck and trailer and it's a dog! I'll look into the lift pump.

[dpuckett]

You didnt say if it was an auto or stick- HUGE difference in power and torque transfer.

I'll agree with Rumblefish on the lift pump. I put a new piston style (not stock) lift pump on my W350 and it was like adding 40hp injectors to it. If the lift pump isnt doing its job, it wont make the power.

Add a fuel pressure gauge to your list of gauges- more important than a tach, IMO. If your pressure post fuel filter is less than 5psi at any time, replace the lift pump, and dont waste your time with a stock replacement- get a low pressure piston pump.

If you have an auto, it has a sloppy loose torque convertor. Get a better torque convertor in there, and it will also seem like you put some 40hp injectors in it.

If you have a manual, you'll be just fine with the stock clutch- they are actually better than many aftermarket options. One of the few times Dodge stock was better than aftermarket......

FOr the gears, I'd look for a set of 3.54s. 35s would normally have a more agressive tread pattern, and be wider, negating any gains you'd get in the MPG department. I think 20-22mpg is about right for your rig if all is well.

Welcome to the forum.

[1991cummins]

yah, i think if you get a 12 or 14 cm housing, put in the spring and mod the pump you will be very very happy add a good lift pump to keep everything wet and lubed and it should be a good reliable work horse, of course, injectors would help too, but that is bighting into a good sum of money... lol

I dont know if your interested, but i have an hx35 that would bolt on to your set up, they're a much better setup turbo, its whats on the 2nd gens, 12 and 24v's... i liked mine a great deal over my h1c(stock). but i have a 5 speed, i dont remember you saying what you had???

[florida4x4]

It's a 518 auto and it probably needs a rebuild. It chatters in first a little. Other than that it shifts hard and firm so it must have had some work done to it. I might be interested in the HX35. I'll definitely add a fuel pressure gauge to the list.

[1991cummins]

yah, you would be smart to get a fuel pressure guage, and like dpuckett said, if it gets below 5psi at any time, its time for an upgrade. and the low pressure piston lp is a good choice, i believe it came on alot of ag equipment and such... i am in the process of getting one right now lol

but i think first thing on your list after gauges would be pump mods and 3200gsk, and piston lp. then you will be pretty good with fuel.

and let me know on the hx35, just pm me if your interested

[Richie O]

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[Richie O]

If it was mine I would leave the 4.10's in there for pulling. It will keep the tranny a little cooler while towing and be much easyier to start off with a big load. As far as top end speed with 4.10's it is the same as the 727 3 speed auto with 3.07's. I can do 90 plus in high gear with my 89 after I adjusted the high idle screw out. If it is at stock settings then it will feel doggy till you get used to how the truck pulls. The first cummins I ever drove was numb. I had been used to a gas engine and was used to having 4 thousand rpm's to play with. With a stock cummins you only really have 1200 rpms of usable power. 1500 to like 2700. After I got used to the power band I was fine. And also in love. I think If you can bump up your high rpm's a little you will be happy. And get rid of the big exhaust housing. I had a 16 cm on mine for a while and was better.

[RumbleFish]

its also possible your auto has a sloppy converter