So I finally dropped the dough on the pcm exchange/tuner and got it installed in the truck a few days ago. Just a quick tip for those that swap out the pcm. Remove the 3 bolts holding the pcm in FIRST, and then once you have room, use a flathead screwdriver and push down the plastic sliders that hold the connecters to the pcm. If you try to use the cheesy latches, there's a very good chance that they will be stuck and trying to use just those is very, very irritating.
Updating the i3 was a breeze, I got the updates thru wifi connection automatically. That feature is awesome! The inital stages of uploading the tune onto the truck with the i3 took about 20 minutes from start to finish. Here's my takeaway of the driving characteristics of the tune after about 3 average days of driving to and from work/running errands etc.
The first thing that I noticed was how remarkably unchanged it felt from stock at light throttle positions. I was under the impression that the throttle would be more sensitive and it would feel "tuned". It feels exactly like stock during light throttle.
After letting the truck get to operating temp, I matted the throttle at about 20 in second gear (A8 with 3.92 gears) and the truck STARTED TO LOOSE TRACTION! It didn't light the tires up but without a doubt it was having difficulty maintaining traction. Never in the 2 years of DD'ing the truck has it spun the tires in second gear. So right off the bat, I could tell undoubtedly that the truck has more power. This alone made the purchase worth it in my opinion.
Now let's talk about the TCM tune, which I'm not too happy with.
First things first: The diablo TCM tune is a much, much better trans tune than the factory one. The downshifts are much faster and the upshifts are firmer*. Unfortunately, there are quite a few areas where I feel that it fell short.
1. The shift points are not raised from the factory ones. They're faster and firmer* but not any higher.
2. The 1-2 and 2-3 shift, as with the factory trans tune on these trucks, leaves a **** LOAD on the table and is still extremely irritating. The 1-2 shift when launched in 4x4 exhibits a 'slip' during the gearchange that is really annoying. It sounds exactly like a manual transmission that has a slipping clutch and someone is trying to bang the gears if you know what I mean. The rev's don't drop as much as they should.
3. The (*) in the above sentences are there because the 1-2 and 2-3 ***** do not work right. In fact, the first time it did the shift at WOT, I thought that there was something wrong. It's almost as if someone quickly taps the brakes during the shift. The 2-3 is especially bad, the engine audibly knocks and for this reason I'm going the custom tune route. I would like to add, I've heard this same knocking sound on the stock tune before, but only when I went from part throttle at a low RPM to WOT really fast.
Overall the power gains were noticeable and the downshifting faster is awesome, but the upshifting and knocking leaves me wondering if I could recommend this to someone who has no plans for a custom tune.
Cheers!
-Jimmy
Updating the i3 was a breeze, I got the updates thru wifi connection automatically. That feature is awesome! The inital stages of uploading the tune onto the truck with the i3 took about 20 minutes from start to finish. Here's my takeaway of the driving characteristics of the tune after about 3 average days of driving to and from work/running errands etc.
The first thing that I noticed was how remarkably unchanged it felt from stock at light throttle positions. I was under the impression that the throttle would be more sensitive and it would feel "tuned". It feels exactly like stock during light throttle.
After letting the truck get to operating temp, I matted the throttle at about 20 in second gear (A8 with 3.92 gears) and the truck STARTED TO LOOSE TRACTION! It didn't light the tires up but without a doubt it was having difficulty maintaining traction. Never in the 2 years of DD'ing the truck has it spun the tires in second gear. So right off the bat, I could tell undoubtedly that the truck has more power. This alone made the purchase worth it in my opinion.
Now let's talk about the TCM tune, which I'm not too happy with.
First things first: The diablo TCM tune is a much, much better trans tune than the factory one. The downshifts are much faster and the upshifts are firmer*. Unfortunately, there are quite a few areas where I feel that it fell short.
1. The shift points are not raised from the factory ones. They're faster and firmer* but not any higher.
2. The 1-2 and 2-3 shift, as with the factory trans tune on these trucks, leaves a **** LOAD on the table and is still extremely irritating. The 1-2 shift when launched in 4x4 exhibits a 'slip' during the gearchange that is really annoying. It sounds exactly like a manual transmission that has a slipping clutch and someone is trying to bang the gears if you know what I mean. The rev's don't drop as much as they should.
3. The (*) in the above sentences are there because the 1-2 and 2-3 ***** do not work right. In fact, the first time it did the shift at WOT, I thought that there was something wrong. It's almost as if someone quickly taps the brakes during the shift. The 2-3 is especially bad, the engine audibly knocks and for this reason I'm going the custom tune route. I would like to add, I've heard this same knocking sound on the stock tune before, but only when I went from part throttle at a low RPM to WOT really fast.
Overall the power gains were noticeable and the downshifting faster is awesome, but the upshifting and knocking leaves me wondering if I could recommend this to someone who has no plans for a custom tune.
Cheers!
-Jimmy
