Engine/Transmission (1994 - 1998) WOW is right-Just got DTT and everyone is right.

[jtwcummins]

Very good group of people and had them put in DD2 inj, 3k GSK and set timing plus do some tweaks in addition to complete trans. The way the truck runs is totally night and day. It hauls *****. Going back to the motel got on it the way I use to getting on the hiway to get up to speed and it just goes, no sluggish getting to speed, was going way fast when I looked at speedo. The throttle response is going to take some getting use to, kinda like driving a big block gasser when taking off.



You read posts all the time about how you have to learn how to drive all over again, like a different truck. Well I am here to say that is no BS. I have been driving my truck since Jan 1997 and it has just got a major personality change, and it's GREAT! :-laf

 

[Jesselee]

man i envy you i wish i could get the money to put one in my truck im sure it worth it. its just alot of money :{

 

[RJPotts]

I don't know if you have the ability... but I set up a "truck fund" account. Its just a regular savings account that gets a certain amount a week through direct deposit. It works great and keeps me from spending too much money on my truck.

-R. J.

 

[bluthndr]

I don't know if you have the ability... but I set up a "truck fund" account. Its just a regular savings account that gets a certain amount a week through direct deposit. It works great and keeps me from spending too much money on my truck.

-R. J.

How much is too much?

 

[HoleshotHolset]

You read posts all the time about how you have to learn how to drive all over again, like a different truck.

Told ya so!!



Matt

 

[RJPotts]

I don't know how much is too much. That's why I set this account up. So I wouldn't find out the hard way. :-laf

jtwcummins, what kinda EGT are you seeing with the injectors?

-R. J.

 

[jtwcummins]

Before doing the injectors EGT maxed just under 1100*, now I can get it to about 1200-1250, same as when completely stock, hard on the pedal up a 7% grade. Haven't had a chance to check under load towing but wouldn't be surprised if I had to back off from the throttle a little, but the added power and the DTT trans makes me feel this won't be a problem since so much pedal won't be needed. The 'feel' you get used to at diffent speeds has to be reaquired. I drive in town with OD off and the first day back went to the store and what felt like 35 was really 50 mph.



I have only had the injectors and GSK for a week since they were installed at DTT with the trans. I can say I pulled out to pass a row of big rigs going up a 6% grade on Hiway 5 coming home and with the pedal I was use to before, when I pulled back over after the pass I was doing 90 MPH and the EGT never went over 1100*. That was the first time I was able to go much over 80, that was with a tail wind on level ground, since I have had the truck.



The trans with billet input was around $5k USD. Everything I had done was about $6500 and well worth it. I am going to retire this summer and, as much as I like the new trucks, didn't want to go for big payments when the only area of concern on my 97 was the trans. So I did the mod and plan on keeping the truck for a long time. The total cost was less than a down payment on a new one and the 97 has been a great vehicle.

 

[tgrfan2]

That sounds great! I have been patiently waiting for my DTT upgrade for several weeks. I hope to get my 98 out of the shop Friday and do a weekend test run to the mountains. My transmission shop doesn't do the GSK and timing so I have a chance to see how the truck responds before and after to those mods too.

Looks like fuel economy is another reason to stick with the "old". I just towed with my 06 work truck this week for the first time. Grossing 21K and averaging 80mph into the foothills I only got 8. 3 mpg. I hope it limbers up for more power and economy soon.

 

[jtwcummins]

that weight and speed you will never get good mileage unless you were say 80 KPH

 

[tgrfan2]

I am comparing it to the 98 12V that gets 11 - 11. 5 running the same route at the same speed and pulling the fiver which should be at an aero disadvantage to an equipment trailer and skid steer. Or you can compare both unloaded with the 06 getting 13 and the 98 getting 19 on same road and same conditions. I hope the 06 will eventually compare closely to the 00 SO it replaced by getting 10. 5 and 16 under these conditions with more pulling power.

 

[tgrfan2]

Dtt

Very good group of people and had them put in DD2 inj, 3k GSK and set timing plus do some tweaks in addition to complete trans. The way the truck runs is totally night and day. It hauls *****. Going back to the motel got on it the way I use to getting on the hiway to get up to speed and it just goes, no sluggish getting to speed, was going way fast when I looked at speedo. The throttle response is going to take some getting use to, kinda like driving a big block gasser when taking off.



You read posts all the time about how you have to learn how to drive all over again, like a different truck. Well I am here to say that is no BS. I have been driving my truck since Jan 1997 and it has just got a major personality change, and it's GREAT! :-laf

I got the chance to go camping in the foothills above Greenville, SC this weekend and the transmission did great. I ran 90 miles of interstate at 70-75mph and then 35 miles of through Greenville rush hour and into the foothills stop and go type driving. The transmission is everything I hoped it would be and then some.

As luck would have it my easy break in run turned out a little different. We went to a small older campground that had been renovated and had a new owner. It was designed more for motorhomes than trailers. I had to pull in the exit which was much steeper just to be able to back into my site. The owner helped me get in, but since it was raining we didn't get to chat.

This morning as I was hooking up he and another camper came over to visit. The owner remarked about how I had just "idled" up the slope. He has a gas Ford automatic and he said pulling that kind of load up that slope he had to shift his transfer case into low and it was still a pretty hard pull. I told him I was breaking in a DTT, but really hadn't wanted to do it quite that quickly. He laughed and introduced the other camper as a transmission shop owner out of Asheville, NC. I thought it was a bit strange the shop owner never asked anything about the DTT upgrade, but as we pulled out and up the remaining slope my wife said the guy was intently watching us make the grade.

 

[Kawi600]

What Im real curious about is whether the DTT trans and torque convertor couples well at lower speeds unlike the stock one on my '95 and if so whats the fuel economy benefit? Im also real close to having a local DTT installer build up my transmission. The billet input sounds like a must with the mods you got.

 

[jtwcummins]

As far as the lower speeds go, before the transmission upgrade the TC lockup was when the sluggishness of the stock trans was gone. Really would pull hard when the TC locked. Now it is more of the rpm drop noticed when lockup happens and not much else. I filled up last week before going to work so I can see what change, if any, occur in mpg in town. Generally get 13-14 and if this increases will be the first mod causing any noticeable increase in fuel economy. My commute is in town 13 miles 1 way. I always run with OD off in town.

 

[Kawi600]

Yeah, the stock setup is sluggish below ~2K. once it gets spinning it isnt as bad but getting there makes the truck work harder. I notice it pulls really well after lockup at 40, unless you stomp it and it unlocks.

Did your DTT installer recommend a billet intermediate shaft? I heard that was an option and I forget where in the drivetrain that was and when/why it was necessary.

I know the input is recommended, and the stock output is fairly strong.

I read a post someplace where the poster suspected the OE torque convertor was setup to couple poorly at low speeds to keep the transmission alive through the warranty period. doesnt sound so far-fetched!

Keep us posted on the fuel economy change!

 

[jtwcummins]

Had mine done in Abbotsford, BC at DTT and only billet input was recommended for towing. Did my break in on 1000 mile trip home. Stock TC is basically for gasser, not good coupling at lower RPM. Will let you know about mpg, I am curious to see if trans makes any difference around town. The way it performs my feeeling is it should, maybe 1-3 mpg.

 

[ProMac1K]

Well, if you're curious about low speed operation with a DTT, it's nothing to be concerned about. I can just about hit third gear idling on a level road, and can hit it going down a very small decline. Now that is some efficiency!



I'm running it with exactly the same combo as you Kawi (6 plate/18*/3KGSK/BHAF), but I have 370's, and I ran my pump on the test bench and did some test/tune work to it.

 

[Katmandu]

I don't know if you have the ability... but I set up a "truck fund" account. Its just a regular savings account that gets a certain amount a week through direct deposit. It works great and keeps me from spending too much money on my truck.
-R. J.

Do the 3K GSK as the 2nd Mod (1st being a EGT Guage). I bought my 3K GSK from www.CityDiesel.com for $95.

HUGE Bang-for-the-Buck MOD!!! MUST DO MOD!!!

.

 

[Stefan Kondolay]

the site is citydiesel.net