Quote Originally Posted by Yoinkers View Post
any sprintex updates? mainly...is it worth the pricetag? If you could have your truck back as it was before, without all the work to turn it back AND you could have the money back......

would you do it?
I think it's worth the money, but I'm still not completely satisfied. In my initial review I said the tune was about 95%, but that was probably generous (honeymoon stage). Since I've been driving for a few weeks I've noticed a few annoying things. The first, which we can all acknowledge is not the fault of Sprintex, is the shifting. With the TCM being locked tighter than Ft. Knox, there's not much anyone can do about that. The next thing is that there is slight hesitation sometimes (rare, but present) and there is sometimes surging under light acceleration at around 2k rpm. The last thing is that the throttle does not feel linear. It is kind of notchy, or lumpy feeling. Some of this could be due to the extreme cold we've been experiencing in Kansas City, or maybe the bypass valve vacuum actuator, or just the tune -- I'm not sure. However, this is still my first tune and I just recently contacted Gary and he seems eager to help. Here is his response to my message:

Jay is working on some cold tuning in China right now. I should have something over the weekend.

Dialing that linearity in the throttle is indeed difficult. We can work with the scaling inside the tunes and that has been part of the challenge. I keep comparing it to this, an F1 car playing the Star Spangled Banner.

https://www.youtube.com/watch?v=gZIUGreqrCY

Scaling in the map and “playing scales” are not entirely different meanings of the same word.

https://www.youtube.com/watch?v=RqVzi36AlNA

I don’t know if you are into music or not, but it feels like the motor is “playing scales”, like it’s practicing music. I noticed it in earlier testing. It feels like the motor is revving one note at a time.

You can scale the throttle, all 4 cams, and the spark timing in the mapping. That’s the challenge in mapping current PCMs.

We’d definitely appreciate a log if you can send one, please. This explanation/translation may seem a little weird.

Kind Regards,
Gary Turner
USA Coordinator
www.SprintexUSA.com

I'm hoping I can get some log files this weekend and get to work on the tune. On a positive note, there is plenty of power now and it seems as though there is boost at lower RPM, because I can stay up-to-speed at cruising RPM (1800-3000 RPM). I am extremely happy about that. Also, at WOT it is ridiculously quick for a Jeep! If the drivability becomes smoother with future tunes, I will be incredibly happy. And once someone unlocks that damn transmission, this thing will be GREAT!

Now to the hardest question of whether I wish I had the money back or not... Well, I kind of wish I would have saved it towards a LS conversion from Motech this summer. If the tuning is straightened out, I may move from this position. For now, I have two reasons for saying that. The first is the fact you can go with something that has been factory tuned (optimized for a wide variety of conditions). No need to worry about special cold weather tuning or other factors. The second is the transmission. Another gear, plus it is easily adjusted. If we can't get the tune much better for the Sprintex, well.... I'll get that LS transplant in the next couple years anyway. Sorry for the long diatribe, but I hope it helps.

Randy