[DFiorelli]

525 miles on my QC. Initial impressions: Weak bottom end compared to potential - I expect we'll find the same low end lean condition as in the RC. Can't wait to get Roktman's VEC2 report.

Early upshifts in normal driving - I suspect this, like the low end lean condition, is emissions related though the warranty/clutch theory for the low end lean condition has merit as well.

Early WOT 1-2 shift at about 5400 RPM. I'll refine the "about" as I've only done it twice due to low miles on truck. Feels like the engine management system has the engine fall flat just before the upshift (the automatic tranny manifestation of detuning for reliability?). We may need to take a cue from the hot rod diesel guys and beef up the 48re - ATS looks like one to call. I'll report what they tell me.

I will post some g-tech runs to give a rough reference point for 0-60 and 1/4 ET if it ever quits raining here in Texas.

As an owner of a 1996 Viper - now in SCCA T-1 trim and previous owner of 3 Lightnings and a VCA Edition Ram SRT-10 I'm a bit amused by the comparisons - especially the "which one is the best truck" variety. They are different. The best one depends on what you want to accomplish.

 

[Joeykunz]

Early WOT 1-2 shift at about 5400 RPM. I'll refine the "about" as I've only done it twice due to low miles on truck. Feels like the engine management system has the engine fall flat just before the upshift (the automatic tranny manifestation of detuning for reliability?

Hey Buddy, got your PM. Wow I can't believe it. It sounds like torque management to me. On the 2003 Hemi Ram there is sensor that runs to the tranny back to the ECM. 2003 Ram owners could find that wire and cut it/disable it. On the 2004's dodge caught wind of this mod and changed the design of the computer so it was all integrated together (no wire to cut).

So far the only people that have been able to disable this (its called Torque management request) have 2003 Rams. Also the superchip programmer also disables it without cutting any wires. But the programmer is only available for 2003 hemi as well. Superchips plans on releasing one for the 04 that also disables it, but it’s not out yet.

As far as the Ram srt-10 viper tranny, who knows.. The term in 2003 hemi engine/computer manuals was "torque management request" which is what people picked up on after a while. Some one tried cutting it and bam no more torque management.

on the Hemi's its good for at least a half second in 1/4 ET!! Its called the "TMR mod". Ram forums have tons of info about it (dodgetalk, dodge truck world).

 

[nothnbutrouble]

Great advise Joey...had the Hemi Q cab also 2003...torque management was a real drag with these trucks. I did not do the TMR mod though.... PCM held the truck back also...
Superchips had a slight impact with that.
The lag associated with the drive by wire got old.


I had a feeling that these 48re automatics put out by D/C might be "soft"... We shall see.

It will be interesting what the "guys" will be coming up with......LOL Always improving....Bill will have one in the 11's probably....snicker...

 

[mauiSRT/10]

Fricken torque mgmt......sucks!!!!!!!!! Had a 03 qc hemi as well, hated the lag in power when the tranny shifted....one of the big reasons I bought the srt10, I wanna shift and control the power.

patrick

 

[DFiorelli]

Yeah - I really liked my RC and the 6 speed. But I have to have the towing capability of the QC.

Further update on peformance: my QC shifts from 2nd to 3rd at 5,300 RPM when at full throttle. With the trans in "1" on the gear selector the dive in power beginning about 5,300 - 5,400 prevents reaching anywhere near redline.

I sent a detailed e-mail to ATS (Cummins 48re transmission upgrade specialists) and will share their response when I get it.

I should get a chance to do G-tech 1/4 mile test Friday and will post that as well.

 

[toohighpsi]

About the torque management on the SRT10's:

The 48RE used in the QC vehicles has several beefed up componenets for improved durability over the base 48RE, mostly due to the higher speeds & engine RPMs that it sees in this application. There is torque management but only while the shift is occuring. As soon as the ECU senses a shift is occuring, there is a momentary cut in spark (very short, a few tenths of a second) and does not affect the performance numbers on the vehicle... trust me So, any lag in the low end on the quad cab is a function of increased mass of the vehicle and the fact that there is a torque converter in the system that reduces its efficiency - not of any other type of torque management going on.

Any 'harsh' shifting on the part throttle shifts is a direct result of making the WOT shifts firm and crisp for good performance and transmission durability... as you guys could imagine, having 500HP and 525ft-lb can wreak havoc on band life if shifts are not made promptly. Unfortunately, the 48RE is a rather old trans and is not easily tunable for different part throttle and WOT shift curves... but it's the only one in the DCX aresenal that could handle the power output of your engine.

The WOT shift speed on the SRT10 48RE is somewhere between 5400 - 5500 RPM depending on conditions at the time... you'll also find that the ultimate engine redline on the QC application has been set at 5500 RPM due to the transmission's rotational limitations. All the prior uses of the 48RE have been at lower speeds (i.e. diesel applications) or applications where there have been lower ultimate power and torque levels.

Although it could wreak havoc with ultimate transmission durability, theoretically you can play with your kickdown cable adjustment at the throttle cable bracket on top of the engine to change the feel of the transmission... put more pre-tension on the cable and it will shift later in the RPM band, put more slack in the cable and it will shift earlier.

So... cutting any wires on the SRT10 won't get you anywhere but into potential trouble...

 

[DFiorelli]

Great post - thanks for the info. Any comment on the very high A/F ratios in the Regular Cab (I suspect we'll see the same on the QC)? Is it emissions related (my expectation) rather than durability?

 

[Joeykunz]

Hmm interesting, so it does indeed exist. I guess the next question is to get some real world 1/4 mile et's to see just how much its being limited. As DFiorelli said earlier he can feel it, so I dont quite believe the whole "It doesnt effect performance" thing. If trucking mag ran a 15+ sec 1/4 mile, I would tend to think that it does effect it quite a bit. I hope not.

 

[slbelt]

Picked up my QC on Tues and the momentary "hesitation" during 1-2 shifts was one of the first things I noticed. BTW, it happens not only at WOT but at any throttle. Very noticeable and I can't imagine how that doesn't affect performance, but I can tell by the post detail that TooHighPSI knows way more about this than I ever will...