When you programed your truck did you enter the "stock" rear end ratio or did you enter your axle ratio ex. 3.73 ?

 

Hey LX4rickDe,

On my initial install, I made the mistake of entering "3.73" instead of "stock" and in another moment of genius, I manually entered the tire height instead of going with "stock". The result was not good. My truck would not shift out of first gear and after a few minutes I got a whiff of what smelled like roasting tranny. Immediately after that, the truck went into fail safe mode and I pulled over, reloaded the stock setting and then reloaded the hi-performance program properly. Since then, no problems. I guess I was in too much of a hurry to load the damn thing and didn't take the time to fully read the manual. Duh...

 

If the rear gear ratio you entered is correct, and the tire size you enter is correct, what went wrong? I would think it should all be the same as long as the correct info was put in. I don’t have a tuner (yet) and I’m just curious, if you know.

 

I had to change the tire size when I programed my truck. Just wanted to make sure that the rear axle option (stock) was correct. 285-70-17 Toyo Open County tires

 

jpdadeo,

I'm not sure what went wrong. I just know it went wrong. Apparently, something in the programing is changed when you choose your own tire size and ratio. The Superchips manual does say to leave the settings for gear ratio and tire size "stock" if they are indead still stock. My bad on that one, but when configuring your tune you are given options and it seemed appropriate to choose the ones that applied to me. Lesson learned. Read the whole book first........

Other than that brain fart on my part, I'm happy with the results I'm getting. A good indication of the gains I've seen are this:

Before the tune, If I power braked it just long enough to get the tires spinning and then let off the brake and mashed it, I would get maybe 5-10 of tire spin before hooking up, depending on the road surface.

After the hi-perf tune, I did the same power brake deal the other day. Temperature , 90 degrees - humidity, way high. I came to a stop and clicked off the A/C. I then footed the brake, got the tires spinning for 2-3 seconds and then let off the brake. The truck fishtailed left and then right, engine near 5000 rpms and tires ablaze! It was awesome!! Posi marks were more than 50' long. I hope the guy behind me wasn't in a hurry as he had to wait a few seconds for the smoke to clear. I don't do this kind of stuff very often, but every time I think about it I grin!

My only complaint is that I sometimes get very harsh upshifts at low speeds and during kick downs. Full throttle 1-2 shifts @ 5300 rpms are a blast and so much more fun than the wimpy 4800 rpm shifts that get before. That alone is almost worth the price of admission!

 

If you enter stock, how does the tuner know know if your stock is 3:55 or 3:73? Maybe it can tell from the stock program when you download it? I have changed the tire size on my truck so I will have to enter that info. I am waiting for my tuner to be shipped but now I am curious as to what, if any problems anyone has had with this. Thanks.

 

GB150,

Perhaps it extracts that info from your stock program. The problem I had may or may not be related to how I loaded the new tune, but manually entering my tires size and gear ratio is the only thing I did differently. I have changed my tune nearly a dozen times (trying to get it just the way I want it) and haven't had any trouble when leaving those settings at stock. Since the instructions indicate that those settings are not to be changed (unless you have made changes), I was left to assume that it was my mistake. But, you know what they say about assumptions!