Engine/Transmission (1994 - 1998) DTT 89% v. 91% - I prefer the 91%

[Ben Rumson]

I began my upgraded aftermarket transmission with a 91% TC from DTT. I have the power and the use for one - and I LOVED IT!



A while back we had problems with it and Bill graciously sent me a rebuild, new TC at 89%, Valve Body, etc at no charge. Thanks Bill! I also purchased several OEM upgrades that are now available that were not when I bought the original 91%.



I was talked into getting an 89H torque converter due to our altitude... but ever since it's been in (several months now) I have been very disappointed with it.



It launches of the line a bit faster because spool-up is quicker, and it is slightly less smoky under heavy throttle, but that's where it ends.



I would gladly give up these minor improvements in exchange for the 91% in a heart beat. I loved the way it pulled the engine down a bit more, and once a slight bit of boost was registering, I REALLY miss the way it hooked up and laid the power to the rear wheels.



In comparison to the 91%, I now feel like I'm making lots of noise and heat and not really going anywhere - more similar to the original stock transmission.



I hope the 91% is still available in the future. I'm confident that I'll be going back to it after the 89h needs replacing.



Just my observations and personal opinions...



- Ben

 

[Cooker]

Thanks for posting this info.



Currently I have a 91% TC and am strongly considering going to an 89H when I pull the transmission out for upgrades that were not available a couple years ago when I originally had the transmission rebuilt.



I'm thinking of going to the 89H for slightly better spoolup around town particullarly when I have the trailer in tow. I am running 33" tires with 3. 55 gears which certainly doesn't help the spoolup. However I really do enjoy the way the 91 drives and feels and I don't want to give much of that up. I did not think there would be such a significant difference between the two.



I wonder how the standard 89 would drive in your situation as compared to the 89H (at least I think there are still a couple different flavors of the 89 available)?



What size tires are you running?

 

[KB0OU]

I am in favor of the 91, that is what I have. Ya punch it and it goes!!!

I don't mind the smoke.....

 

[Rhondasway]

Wish I could do a heads-up comparison between the two... Bill swears the 89 is the only way to go for racing, but I've heard other opinions. I love mine, just wish I could compare (without having to pay, of course! ).

 

[dezrat]

I vote for the 91 also.

I have 50,000 miles on mine and never once have I wanted the 89. Sure it smokes a little more at 5000 feet but I am happy.

 

[Fred Swanson]

Having installed and owned all of them, I really liked my 93% in my old 2000. With the DD cam and HX-40, it was capable of anything.



I started out with the 91 in it, then the 93, and when I sold it, it had the 89%. I gotta admit, the 89% setup was super fast off of the line. Again, the cam made alot of that happen.



If the truck is not crazy on power, I'd have to agree with Bill, the 89% is the way to go for all around performance.

 

[Jim Fulmer]

Bill swears the 89 is the only way to go for racing



If I raced more I'd probably go back to an 89, the way my power is right now I have to lock the converter switch in first so it would lockup after I made the 1-2 shift because its' just too much power to try to flip a switch when trying to shift gears also, the 89 will allow you to spool the chargers a little easier and flash the R's more when you leave the line. When I updated to the Billet input I swapped to a 91 and love it but doing locked shifts all the time would be annoying.



Jim

 

[CATCRACKER]

ATS

 

[Jim Fulmer]

I'd rather have one that would handle my power, and one that would move the truck in fluid coupling..... this was a DTT question.



Jim

 

[propuller]

Originally posted by CATCRACKER

ATS

read the guidelines on transmission threads.



Kurt

 

[TxDieselKid]

Originally posted by CATCRACKER

ATS

One size does not fit all, now moderator, could you please spank this post.





I L-O-V-E my 91, and wouldn't trade it for the world. I have driven trucks with the 89, and they were nice, just not what I prefer.



91% TC's all the way baby!!





Andrew

 

[Bob Wagner]

Originally posted by TxDieselKid

One size does not fit all, now moderator, could you please spank this post.





I L-O-V-E my 91, and wouldn't trade it for the world. I have driven trucks with the 89, and they were nice, just not what I prefer.



91% TC's all the way baby!!





Andrew

DITTO #ad

 

[jjohn]

Re: DTT 89% v. 91% - I prefer the 89H%

Originally posted by Ben Rumson



In comparison to the 91%, I now feel like I'm making lots of noise and heat and not really going anywhere - more similar to the original stock transmission.

- Ben

Hey Ben,

I drove a 91TC before choosing the 89H. I know what you are saying.

The 89H may be more like stock... . "BUT" It's no where near close to it!!!

I love my set up! Hot weather high altitude smoke control is important to me. I do a great deal of city driving, It was the right choice for me.

JJ

 

[MD500E]

40,000 miles on my 89tc and I was loving it until I spent some time in my friends truck that has a dd cam and a 93 converter. Well I sort of fell in love with the 93. The 93 feels like a manual transmission that just happens to be able to shift itself! I clean his clock from a stop light but his 93% makes my 89 feel like I have a stock transmission again:{ Well, not quite that bad but when I get to do it again I think i would go with the middle of the road 91.

 

[Fred Swanson]

Yeah, the 93% with the DD cam is a real pleasure to drive, especially hard. It gave the closest impression of driving a manual.

 

[nbr1trucker]

Hey bob,not to get off the subject, but where did you get that little shifting icon at the bottem,, thats awesome Ian

 

[Bob Wagner]

Ian, I borrowed it off the www.nwbombers.com site



it fit the bill

 

[Jim Fulmer]

I love my set up! Hot weather high altitude smoke control is important to me. I do a great deal of city driving, It was the right choice for me.



Me too, smoke oh yea, tonight I was going to the store and on the on ramp I lit the girl off at 80 psi flying on to the freeway shifting gears/walking all over the road and thinking am I going to run over the guy in the right lane... ... yee haw, dog was on a hunt... ... ... ... . oops sorry, reality check. I do like my 91 just like AndrewOo.



Jim

 

[Bob Wagner]

Originally posted by Jim Fulmer

I love my set up! Hot weather high altitude smoke control is important to me. I do a great deal of city driving, It was the right choice for me.



Me too, smoke oh yea, tonight I was going to the store and on the on ramp I lit the girl off at 80 psi flying on to the freeway shifting gears/walking all over the road and thinking am I going to run over the guy in the right lane... ... yee haw, dog was on a hunt... ... ... ... . oops sorry, reality check. I do like my 91 just like AndrewOo.



Jim

#ad

 

[Rhondasway]

You people are making me really depressed... I love the way my truck performs, but now ya'll are making me feel like it could be even better... knock it off!