Hemi fever tune problems...

[Jdperry]

When I first installed the custom 93 tune I didn't have any problems. Now that I switched to a bigger tire 35x12.5 I changed the tire size on the programmer and now it's showing a constants 3-4mph off and I know it's affecting my actual miles as well. Has anyone else had this same problem. I would really like to find a solution to get it back right. I emailed Sean with no response yet. Thanks in advance

 

[Dubstep Shep]

When you say it's showing a constant 3-4mph off, how are you figuring this up? GPS I'm guessing? And at what speed is it that much off? Usually it will be off a percentage of your current speed, not an absolute difference.

Have you tried using different tire sizes in the tuner?
Have you actually measured the tires that you have on there? Don't just blindly trust the markings on the tire, different brands WILL be different sizes.

 

[Jdperry]

When you say it's showing a constant 3-4mph off, how are you figuring this up? GPS I'm guessing? And at what speed is it that much off? Usually it will be off a percentage of your current speed, not an absolute difference.

Have you tried using different tire sizes in the tuner?
Have you actually measured the tires that you have on there? Don't just blindly trust the markings on the tire, different brands WILL be different sizes.

Yes checked by GPS. I modified the tire size again and went with the metric size of a 35x12.50x20 (325/60/20) and I think it's working now. It's showing a lot closer from the little I drove. I will test more after I'm off for the day. But to answer your question it was off starting at 20.

 

[iam_canadian22]

Yes checked by GPS. I modified the tire size again and went with the metric size of a 35x12.50x20 (325/60/20) and I think it's working now. It's showing a lot closer from the little I drove. I will test more after I'm off for the day. But to answer your question it was off starting at 20.

Ya itll be by percentage if its off by 10 at 100 it will only be off by 5 at 50, basically the faster you go the more it'll be off

 

[N1ck]

This has nothing to do with a Hemifever tune or any tune for that matter. You changed the tire size, they don't always run true to their size and most people have to alter the tire size in the tuner a few times before it is bang on.

 

[charonblk07]

This has nothing to do with a Hemifever tune or any tune for that matter. You changed the tire size, they don't always run true to their size and most people have to alter the tire size in the tuner a few times before it is bang on.

Very true. It should also be noted that even though a tire is listed as a certain size on the side wall the actual dimensions of the tire can be different depending on what wheel width it's mounted on, inflated pressure, etc.

 

[Jdperry]

This has nothing to do with a Hemifever tune or any tune for that matter. You changed the tire size, they don't always run true to their size and most people have to alter the tire size in the tuner a few times before it is bang on.

That's what I'm doing. I went with the other size and I think it's working out now

 

[coleflo]

I bet Matt will log on tonight and see this thread title and think oh great.

Jay will logon and .