New to this forum. Just bought a 98 Cummins quad cab 4x4, auto, long bed. 190K miles on motor/truck, 20K on rebuilt trans. Cream puff, fully loaded, never had a fifth wheel, never towed anything big, one owner, dealer maintained, bought it from the dealer (Guy traded it in on a new truck when Chrysler had their fire sale) as a trade in - the dealer is one of the small family-owned dealerships that got canned when Chrysler tanked. Really a sad story for them but a bonus price for me. Right now it runs great, just a little slooowww.

I've been hot rodding stuff for 35 years - everything from outlaw GTOs to my current frankenproject - a SBC in a 5 series BMW sedan with a 700 R4 and a procharger. However, this is my first diesel. I bought this year specifically because it's the last year for a Cummins without a computer. I work in IT as a day job but I don't want a computer in my car, if I can help it. That's why my current other project uses a blow-thru carb with the procharger.

I've been using the search tool to find out what I can do to up the power moderately without hurting mileage and reliability. The truck will be used as an off-and-on daily driver for light work/pleasure. It will rarely carry more than people and haul boats less than 3,000 lbs 100 miles or less only a couple of times per year. Nothing heavier than that. In short I'd like it to be a lot quicker on the street but still economical and reliable. No sled pulling, no drag racing.

I'd like to get as much power as I can out of it with simple, mods without having to go too far inside the transmission.

From what I've been able to gather from the search engine, I should:

1. Install pyro, boost and fuel pressure gauges (maybe trans temp, too.)
2. Get a fuel/cam plate.
3. Get some way to adjust the boost.
4. Get a BHAF
5. Open up exhaust.

Assuming I'm on track, I have some beginner questions I'd like to ask the more experienced folks here:

Fuel Plates - Every manufacturer seems to have a different numbering scheme for their plates. A #5 plate from one shop might equal a #10 from another. Is there any rhyme or reason to the plate numbers?

Installing a plate - It seems that the farther forward the plate is moved, the more fuel you get and you use a combination of your butt dyno, smoke and the EGTs to tell when the motor is happy. Have I got it right? BTW, the last thing I need in my residential community is black smoke so the cleaner I can get it to run, the better.

Stock vs. aftermarket - I've read that you can get nearly the same effect as an aftermarket plate by moving a stock plate as far forward as possible. But here's the question - won't that make it run over-rich at low speeds and low boost? With boosted gas motors, you only need enrichment when you're both on boost and at fairly open throttle settings. The rest of the time you can run fairly lean for economy. Are the aftermarket plates designed like this - to run a little lean at part-throttle, low boost conditions and richen up fast under high load/high boost? If so, aren't they superior to a stock plate thats's been moved forward?

Given my goals, any opions on the best plate to use?

Adjusting the boost - I've read a couple of posts about boost elbows and boost controllers, but the pictures don't seem to be in the links anymore. Seems like a mechanical bleed device to change the reference pressure going to the wastegate. I saw a post about how to build a boost controller from hardware store supplies, and reference to a way to mount some sort of control **** inside. In the event I am towing something big, or just plain hitting it up on the highway, I'd like to be able to turn down the boost a bit if the EGTs start to climb. If possible, I think that would be pretty cool to do and a nice smack back at the computer diesel guys with the fancy computers on their A-pillars. Any advice on how to make a rig like this?

Exhaust - The Chrysler dealer I bought the truck from just put in a brand new shiny stock exhaust 5 miles ago. Seems a shame to junk it but if it will be choking the engine, so be it. Couple of questions:

1. If I take the motor to 250 to 300 hp, how large a pipe will I need not to restrict it?
2. Is it the pipe that will be restricting the motor or the muffler?
3. If the mufler is the problem and a straight stock pipe will work for me, how loud will it be running with a straight stock pipe?

Transmission - Lots of references in the posts to the automatic transmissions running out of steam with only modest engine mods. I've done trans work so I'm not afraid ot getting inside. Here are some questions:

1. If I run a temp gauge will this be sufficient as a warning indicator of problems to come?

2. What are the weak points? Torque converter? Valve body? Clutch packs? Plenatary gears? Some? All? Does anyone make upgrade kits for these transmissions that make them more reliable? Are these kits affordable?

Just from my searches, it seems there is a ton of knowledge here and I look forward to learning. I like the idea that working on these motors seems a little like distributor and carb gas motors - you don't need a laptop to burn a chip to make it go.

Thanks...Steve.

 

first of all throw everything you know about a gas burner out the window!!!there is no rich or lean.there is no air/fuel mixture.when you buy a different profile plate,that just controls when and where you get the fuel.when you increase the fuel you will see an increase in boost,it takes fuel to light your turbo or give you boost.i have a #100 plate all the way foreward in mine and i get 22mpg's.it all depends on how you drive.a #100 is like a stock plate at the bottom,but as the arm rides up it slopes down to the #0 plate profile which is the hardest fueling.and as far as the boost controller,and turning the boost down to lower EGT's,that is exactly backwards.you increase boost to cool it off.it is not like a gas burner,when you add air it burns hotter,you add air and it cools off.ant the weak points in your tranny are convertor and valvebody.

 

Don't know much about the 12 valve engines yet, but have been trying to get up to speed for my '96. The 12 valves are the best in my book. Good luck on your project.

 

i would get you a conservative plate if i were you. I got mine for 29 dollars ive tried 3 of them, a 100 first then 11 then a 10, i went back to the 11 and love it. not as powerfull as the 10 or the 100 but deffinatly a lot smoother. i dont know much about how it would run in an auto truck. But for about a couple hundred dollars you could have a sweet runnin truck that still gets over 20mpg. i would just put a turbo back 4" exaust. you can get them for about 300 or a little less. and the rest is you tuning and the fuel plate. I am happy with mine i dont know how much hp im runnin but its plenty to play around with.

 

The weak points in the trans are the converter and VB...and depending on your use the input shaft. But since you have no issues digging in there when you pull it just go through the whole thing with a good rebuild kit from some place like Suncaost or Garmon. Then put a good converter, VB and a one piece billet input shaft and you'll be good to go. I ran a #8 plate with my stock trans and a shift kit for a LONG time. The 100 plate and my heavy foot is what killed the trans but I had 225K miles on that stock trans.

 

you can get a complete performance rebuild kit with clutches,plates,bands,ect.for a little over $500.that would be your best bet if you can do the work yourself.sucoast is the best
http://www.suncoastconverters.com/do..._products.html

 

this thread has been most informative thanks guys for the information. now I know where to start with mine

 

Judging from my searches and replies, a 100 plate would work well for me. I'm not into drag racing but I'd like the truck to scoot along and passing/merging power is key for me. A plate that only fuels up at higher revs/open throttle situation would seem to be a good economy compromise when highway cruising.

I see 100 plates advertised on ebay for $30. I also see plates from Hi Po vendors from $200 to $300. Is this a case of "you get what you pay for" or are the $30 plates of acceptable quality?

Any reliable vendors of inexpeisive plates?

If not, whose got the most affordable acceptable quality 100 plate?

Any plans for "harware store" boost controllers?

Thanks...Steve.

 

I ground my stock one....I would assume that is all the $30 eBay plates are as well.

 

I also ground my stock plate. Then you can have money for other mods. I 3gsk really helped my motor wake up. And even if you dont rev it up to 3k all the time it helps it the lower end or at least it did for me.