Guys who went to 35's . . .

[JWSchmidt3]

Originally Posted by lotus4s

As someone else suggested, contact PCM for less. They can adjust the shift tables....

Looks like I'll be doing the PCM for Less. The dealership finally stepped up, and agreed to properly set the PCM with my recommendation of the PCM for Less. I take it in next week, and pick up the loaner until it's done. Will report back the difference after I get it back.

[wpage]

Do the math on a long page. Take your time with whatever you decide. Count to ten. Take a deep breath. Then tell them all your going with the competition!

[JWSchmidt3]

Originally Posted by wpage

Do the math on a long page. Take your time with whatever you decide. Count to ten. Take a deep breath. Then tell them all your going with the competition!

I doubt the PCM is the solution anyway.

[JWSchmidt3]

Originally Posted by Steve - SanJose

I doubt the PCM is the solution anyway.

Then what is??

Based on the way GM thoroughly engineered the H3, 32" or 33" inch tires are optimal, since a gearing change is not readily available.

[JWSchmidt3]

Originally Posted by Steve - SanJose

I doubt the PCM is the solution anyway.

You would be incorrect. Just got back the H3 over the weekend, and it now drives great.

I'll do another post about it when I get a chance.

Originally Posted by JWSchmidt3

You would be incorrect. Just got back the H3 over the weekend, and it now drives great.

I'll do another post about it when I get a chance.

Good to hear it's downshifting less, which means the acceleration is that much slower than stock as engine lugs in higher gears.

[marin8703]

question for you smart people. I am in the final stage of getting 35s but have one final question. I noticed most of you that have 35s have the adventure package which has the 4:1 transfer case. I dont have that, i have the basic.

I dont know what the gearing is in the base transfer case or how it would effect anything so this is my question. Would I, with the regular transfer case, notice any difference in perforemance (decrease due to the larger tires) more than you guys have or just the same?

Thanks,
Marin

[JWSchmidt3]

Originally Posted by marin8703

this is my question. Would I, with the regular transfer case, notice any difference in perforemance (decrease due to the larger tires) more than you guys have or just the same?

Thanks,
Marin

Probably the same, but you're starting with less (in gearing) to begin with. IMHO

[marin8703]

so what does that really mean, that i am starting with less gearing? In the t-case are the hi and low gears different from the base to the adventure or only the low? Thanks!

[Sewie]

Originally Posted by marin8703

so what does that really mean, that i am starting with less gearing? In the t-case are the hi and low gears different from the base to the adventure or only the low? Thanks!

Only the low range gear ratio is different. The only gearing difference for day-to-day driving would be between a manual and an auto.

[marin8703]

Originally Posted by Sewie

Only the low range gear ratio is different. The only gearing difference for day-to-day driving would be between a manual and an auto.

does anyone know if the pcmforless thing would calibrate the truck for 35s. The reason that i wopuld like this is because of my nav, it uses the VSS, is teh differnce between 33s and 35s gona throw it off. the nav is an aftermarket pioneer avic-z1.

i know this can be done my purchaseing a speed pulse generator from pioneer but its around 250, and it would be used only for the nav. are there any other options?

thanks.

[Desert Dan]

I Agree with Steve in San Jose

"Based on the way GM thoroughly engineered the H3, 32" or 33" inch tires are optimal, since a gearing change is not readily available."

Since we have an I-5, gearing is the only way to compensate for 35" tires. Off road in 4:1 low you might not notice it too much but on the highway?

35" tires are alot bigger than 33". If you change axle gears to 4:88 or lower the teeth on the gears get thinner (smaller) which are more likely to break and with bigger tires you are putting more leverage on half shafts, u-joints and front diffs.

Without changing anything and going to 35" tires your gas mileage will go down and acceleration will suffer. No ifs ands or buts!

[Sewie]

Originally Posted by Desert Dan

Without changing anything and going to 35" tires your gas mileage will go down and acceleration will suffer. No ifs ands or buts!

That is true, but it is not as drastic as some make it out to be.

I would think the hit to acceleration via the 35's would be significant, but not the gas mileage difference.

[Jeff G]

Originally Posted by JWSchmidt3

Are you having any issues with, or does it seem your transmission shifts at much different intervals than from stock?? I had an Adv. H3, and I am currently driving a 2007 dealer loaner while my lifted H3 is at the dealer, and my suspician is confirmed. One of the issues I sent the H3 in for is the tranny shifting. It always wants to shift down to low gear way too early. Is this because of the 35's?? Is there any way to properly calibrate the bigger tires?? My truck drives like a turd compared to thos '07. BTW, I also have a CAI and exhaust installed. Any help appreciated, as the dealership has yet to give me any real hope.

I've had mine installed for less than 24 hours and I would highly recommend the PCM for less tune. Totally different beast with the 35's.

[marin8703]

another quick question. The about 7% difference in the speedo between the 32 inch stock tire and the 35 inch toyos, is that a linear diffrence or exponential? By that I mean if your speedo shows 65, then you are actually going 70, is the same true if it shows 15 the actual is 20 mph, or would it be different?

Also do you think that this difference (speedo 7% slower tahn actual) is enough to throw off an aftermarket nav (pioneer avic z1) which uses the speed pulse in doing its calculations?

also i didnt understand if the pcmfor less calibration of the pcm can calibrate the speedo for the 35s, can someone clarify that? I know they ask what tire you are ising but do they actually configure teh speedo?

thanks

[JWSchmidt3]

Originally Posted by marin8703

also i didnt understand if the pcmfor less calibration of the pcm can calibrate the speedo for the 35s, can someone clarify that? I know they ask what tire you are ising but do they actually configure teh speedo?

thanks

Yes, they fix the speedo with their tune.

[HUMMJAY]

JWS- you've had the new pcm for a couple of months now,,, how's it working?? I've had 35's on my truck for about 9months and would love to get my milage and proformance back,,,, I'm on the verge of going back to 33's