Newbie! Need Some Advice Quickly!

[JMcDon1007]

Hi All,

I have a unique situation, so I hope someone on here can point me in the right direction.....

BACKGROUND:
I live in Cornelius, NC, but had my C6 Corvette Grand Sport shipped to Indiana last September and had Lingenfelter do their 670 HP Supercharger Package on the car. They used EFI Live to tune the car. After 7,000 glorious miles, my GY Runcrap Supercar Gen One tires are shot. I picked up a set of Michelin Super Sports but got them a little bigger (285/35/18 Front and 345/30/19 Rear) so I can hopefully improve my grip. I was told by LPE that I could change the tire diameter parameters in the software to compensate for the speedo.

DILEMMA:
A local guy said he would do it for me with his HP Tuner software, but he wants to charge me $250 to do it!!!!!! He says he has to buy "credits" from HP Tuners in order to make the change. That just seems to be a TON of money to go in and change 4 parameters!!

QUESTIONS:

Does anyone know if these parameters can even be changed with HP Tuners' software?

If so, would anyone know how many of their "credits" it would take to make the changes for the tires?

Does anyone know how much each credit is?

If I download the Trial Software from EFI Live, could I make this change with the trial version? I just sunk $1,800 into 4 tires and they're not even on the car yet. I'm just trying to find the easiest and least expensive way to make these 4 small changes.

Does anyone have any suggestions?

Any help or assistance anyone can provide would be greatly appreciated.

[GMPX]

You probably need to be asking on HPTuners forum about their pricing :nixweiss:
With EFILive if someone doesn't have the E38 stream then it will cost them $125 for the VIN license, so that is your minimum cost.
The 'software' as such is only half the puzzle, you need the V2 hardware as well to be able to flash the ECM in your Vette.
You could always get in contact with LPE again and maybe organise to ship your ECM to them to have them change it for you?

Cheers,
Ross

[joecar]

JMcD,

Your new tires are 285/35/18 Front and 345/30/19 Rear...

what were your old tires...?

[isak81]

i dont think it will cost him more than 100. Find a tuner that uses EFILive or call Lingenfelter.
It will only be a 1.12% difference if my calculations are correct. About 3/4 MPH at 70

[JMcDon1007]

Hey Joecar!

The OEM tires are 275/35/18 front and 325/30/19 rear. Is there a table somewhere that would tell me what parameters I would need to input into these fields?


JMcD,

Your new tires are 285/35/18 Front and 345/30/19 Rear...

what were your old tires...?

[JMcDon1007]

Isak81..... Yes, that sounds about right. When I first started investigating, I calculated about 4 MPH at 70 MPH.


i dont think it will cost him more than 100. Find a tuner that uses EFILive or call Lingenfelter.
It will only be a 1.12% difference if my calculations are correct. About 3/4 MPH at 70

[JMcDon1007]

GMPX,

Thanks for the reply. Do you happen to know what hardware I would need for my 2011 Corvette and how much the hardware costs? By "hardware", I am assuming you mean the handheld device? Thank you!

-John


You probably need to be asking on HPTuners forum about their pricing :nixweiss:
With EFILive if someone doesn't have the E38 stream then it will cost them $125 for the VIN license, so that is your minimum cost.
The 'software' as such is only half the puzzle, you need the V2 hardware as well to be able to flash the ECM in your Vette.
You could always get in contact with LPE again and maybe organise to ship your ECM to them to have them change it for you?

Cheers,
Ross

[joecar]

No, Isak81 means it will be only 0.75 mph off at 70 mph... :)

[JMcDon1007]

Aaahhhh... Really? If someone could confirm that, then I may just leave it alone. I thought I heard the tuner say it would be 4 MPH at 70. What about at 90? That's my usual cruising speed!! :cucumber:

[joecar]

70*1.12% = 0.78 mph
90*1.12% = 1.00 mph

[JMcDon1007]

Ok, thank you. How do you get to the 1.12% number?


70*1.12% = 0.78 mph
90*1.12% = 1.00 mph

[joecar]

1.12% is what Isak calculated.

I calculate a slightly different error %...

old rear tire diameter: 325*.30*2/25.4+19 = 26.68"
new rear tire diameter: 345*.30*2/25.4+19 = 27.15"
difference: 27.15" - 26.68" = 0.47"
percent diff: 0.47/26.68*100% = 1.76%


at 70 mph: 70*1.76/100 = 1.2 mph
at 90 mph: 90*1.76/100 = 1.5 mph

those are still fairly close to what Isak calculated.

[JMcDon1007]

Ok, thanks for the explanation! Although I could live with that, I ultimately would like to get it right! I'm wondering if I could get the handheld and a license for under the $250 the tuner wants to charge me for doing the change?


1.12% is what Isak calculated.

I calculate a slightly different error %...

old rear tire diameter: 325*.30*2/25.4+19 = 26.68"
new rear tire diameter: 345*.30*2/25.4+19 = 27.15"
difference: 27.15" - 26.68" = 0.47"
percent diff: 0.47/26.68*100% = 1.76%


at 70 mph: 70*1.76/100 = 1.2 mph
at 90 mph: 90*1.76/100 = 1.5 mph

those are still fairly close to what Isak calculated.

[ScarabEpic22]

Well a FlashScan V2 with 2 VIN licenses (tune any 2 sets of ECM/TCMs, so 2 complete cars) is $899+shipping. An AutoCal from a tuner is probably a much better idea, you buy an AC unit from a tuner, then ship it to you, you read your tunes out and email them. Tuner adjusts the tunes, emails them back, you flash in. Different tuners have different costs for AC units, I think usually they're around $299 + whatever the tuner charges for tune changes.

You might be better off finding someone locally (fill out your profile info in your User CP) who'd do it for the license cost ($125 for EFILive) plus some beer or something. I dont know if you just need to adjust the TCM, if so Id do it for like $50 as Ive got lots of TCM licenses that arent doing me any good.

If you can find a local shop, if they tune enough cars and have stream licenses then they can do it a lot cheaper because they wont have to pay $125 to tune your car.

[JMcDon1007]

Hey Erik,

Thanks for the reply. Yes, all I have to do is the tires, which is why I was shocked when the tuner said $250....but it looks like that's the route I'm going to have to take.

Thanks for the offer; however, I live in Cornelius, NC which is about 20 miles north of Charlotte, NC. Since this is a daily driver for me, shipping the ECU is not a feasible alternative for me, however I do appreciate your willingness to help.

Take care,

-John


Well a FlashScan V2 with 2 VIN licenses (tune any 2 sets of ECM/TCMs, so 2 complete cars) is $899+shipping. An AutoCal from a tuner is probably a much better idea, you buy an AC unit from a tuner, then ship it to you, you read your tunes out and email them. Tuner adjusts the tunes, emails them back, you flash in. Different tuners have different costs for AC units, I think usually they're around $299 + whatever the tuner charges for tune changes.

You might be better off finding someone locally (fill out your profile info in your User CP) who'd do it for the license cost ($125 for EFILive) plus some beer or something. I dont know if you just need to adjust the TCM, if so Id do it for like $50 as Ive got lots of TCM licenses that arent doing me any good.

If you can find a local shop, if they tune enough cars and have stream licenses then they can do it a lot cheaper because they wont have to pay $125 to tune your car.

[minytrker]

Autocal's are atleast $549 and up with a tune from myself and the others I know selling them. Your best bet is to find someone with efi live, they would probably change that for $150-$200 of which $125 is the license cost.

[ScarabEpic22]

No problem John, might be easier to just put the tires on and ignore it, put that $250 towards an Escort 8500 or Valentine 1 instead! :D

[isak81]

1.12% is what Isak calculated.

I calculate a slightly different error %...

old rear tire diameter: 325*.30*2/25.4+19 = 26.68"
new rear tire diameter: 345*.30*2/25.4+19 = 27.15"
difference: 27.15" - 26.68" = 0.47"
percent diff: 0.47/26.68*100% = 1.76%


at 70 mph: 70*1.76/100 = 1.2 mph
at 90 mph: 90*1.76/100 = 1.5 mph

those are still fairly close to what Isak calculated.
Well I just calculated it with a common tire size for a Corvette. I would just live with that little difference.

[Gordy M]

When you look at the big picture you spedo is more than likely 1.0+ mph off at 70 mph. I have put on numerous TDS rallyes using GPS equipment and my Corvette is doing 68.95 when my spedo says 70 mph and that is with new tires at 36 psi (cold). More than likely your vette is really doing about 70 mph when the spedo is saying 71. With the new tires you bought, they are probably close to being on the money at 70. HTH