I'm in the process of ordering the SCT II with Bamachips tune (for my JLT II CAI) from Doug and wanted to ask about the tire size that he requires us to submit with the order.....while my tires are still the stock size 235/50 ZR18's - I'm planning on upgrading to a 255/45 18 size soon and was wondering if the SCT II will allow you to input a different tire size on the fly OR would I have to go back to Doug for a "Tune update"?

THANKS!!

 

No doug locks all of those features so you will need to get a "tune update". Not a big deal though since he can email you a new tune.

 

What Leo said...

 

If you're staying with 18s no adjustments will be required. Only when changing diameter, i.e., to 19 or 20s are adjustments to the tune required sine it will throw off the speedo. But you can change this youself on the XcalII.

Or am I getting this mixed up with the tire rotation adjustment on the XcalII?

 

Adjustments would be required for tire circumference changes, not necessarily wheel diameter changes.

 

With the SCT, you can change custom parms when you flash, I had doug make mine default to 4.10 gears. Yet I still have the stock gears so I go into custom parms when flashing and change it to 3.55. I'm assuming the wheel diameter is the same.

 

Maybe I'm getting my terminology mixed up, so let me say it in plain English. I went from stock 18" BFGs to 255/45 in front and 285/40 out back. Wheels went from Fanblades to Konig 18x8.5 (front) and 18x9.5 (rear). No adjustment to my tunes required.

 

What other parameters can you change? I got mine from Doug and under custom parms the only thing I can change is the spark timing or something like that. Other than that I can't change anything else.

 

You just need to scroll through the spark timing and the list will keep going. A/F at WOT, fan speeds, idle at neutral, idle driving, etc.

 

Hmmmm...I'll have to go check that out BRB.

 

I can't believe I never figured thought before.

 

Nevermind my previous post you can adjust it yourself.

 

Im also about to order one of these. So heres my question, if I switch between the stock rims/tires for the winter, and then my 255/45/18's for the spring/summer, what tire size should I put in the ordering sheet?

 

Which ever ones your running now. Then when you switch out the tires you can make the adjustment yourself.

 

Well that was a quick asnwer! Thanks! I didnt know you could do that, would I need to email Doug to get the new info, or can I do it by myself? Sorry but Im new to all this car stuff.

 

You can do it yourself or you can call Doug and he can do it free of charge.

 

Very cool! Thanks again!

 

Thanks guys for all the quick responses....gotta dig this forum Since the overall tire/rim diameter is very close between the 235/50's and the 255/45's I'll probably be Ok either way - but think I will go ahead and list the 255/45 - since that's where I'm going to be soon enough anyway. Good to confirm that the SCT II has adjustable parameters - sounds a lot like the Edge Performance products "Evolution" tuner I have on my F-150.

 

When you talk to Doug all you have to do is ask him to put the features you want into the user adjustable menu. There are quite a number of user items that can be added.

When Doug custom tuned my GT I stood there and watched him put a bunch of user adjustable items in my SCT. He left out a few for my own protection.......good thing too!

 

The end user adjustability should allow you to change gear ratio, tire sizes, and small fuel and spark adjustments. That's enough adjustability to be able to do a little bit of modding without having to buy a whole new custom tune.

CR
Tillman Speed