[Dynamical]

Hey guys! I have an LT1 with 245 40 20 tire. Tire diameter is 27.7. I want to put SS wheels on the back. Tire is 275 35 20. Tire diameter is 27.56. Does this change need to be recalibrated? How much of a change in wheel/tire size does there need to be to have to recalibrate? Thanks!

[joekd]

Actually the 275 35 20 should be a diameter of 27.6 which means under 1% difference which will be fine

Not sure where you are i new england but if you ever want to try a set on I have 2 sets of rear ss wheels with mounted tires in the 275 size therefore one set is always sitting in my garage here in northern CT

[Dynamical]

Wow no kidding! I’m in New London county.
I wanted some drag radials for my LT1 wheels but nobody makes them. Figured SS wheels for the rear would be good, nitto makes some for the SS size.
I looked on the Goodyear website and tires for stock lt1 range from 27.7-27.72 and SS 27.56-27.6
The NITTO DR is a 27.56 according to their specs.
Do you know at what point a recalibration would be in order for size change?

[arpad_m]

It's up to you, really. As long as you keep the aggregate front-to-back percentage difference within 3% relative to your original OEM delta, no systems will fail or shout at you, the only snag is the inconvenience of a slightly off speedometer.

Then again, the stock speedo calibration displays a slightly higher than true speed, so you may actually fix the calibration by changing tires (in the future, not with this swap, because this one makes it a touch worse).

Here is a useful site to check the broad impact of any wheel/tire size changes you may be considering: https://tiresize.com/comparison

[joekd]

Originally Posted by Dynamical

Wow no kidding! I’m in New London county.

Do you know at what point a recalibration would be in order for size change?

I'm right on the MA/CT line

Never seen an official % of difference but have read before that the front/rear tires need to be about 1" difference to start throwing codes

[lt4camaro]

Originally Posted by joekd

I'm right on the MA/CT line

Never seen an official % of difference but have read before that the front/rear tires need to be about 1" difference to start throwing codes

Have read a few times from different sources that if you stay at or below 3% there are no issues.

[lt4camaro]

Originally Posted by Dynamical

Hey guys! I have an LT1 with 245 40 20 tire. Tire diameter is 27.7. I want to put SS wheels on the back. Tire is 275 35 20. Tire diameter is 27.56. Does this change need to be recalibrated? How much of a change in wheel/tire size does there need to be to have to recalibrate? Thanks!

You would be using the SS front and rear size which is not a problem.

[Dynamical]

Originally Posted by arpad_m

It's up to you, really. As long as you keep the aggregate front-to-back percentage difference within 3% relative to your original OEM delta, no systems will fail or shout at you, the only snag is the inconvenience of a slightly off speedometer.

Then again, the stock speedo calibration displays a slightly higher than true speed, so you may actually fix the calibration by changing tires (in the future, not with this swap, because this one makes it a touch worse).

Here is a useful site to check the broad impact of any wheel/tire size changes you may be considering: https://tiresize.com/comparison

Now THAT is a very cool tool! I'll be checking that out more. Thank you sir

Originally Posted by joekd

I'm right on the MA/CT line

Never seen an official % of difference but have read before that the front/rear tires need to be about 1" difference to start throwing codes

Good info thanks

Originally Posted by lt4camaro

You would be using the SS front and rear size which is not a problem.

Thanks lt4

[wintertopdown]

I am wanting to do the same. I have been driving on the 245’s for a long time and find myself loosing traction now with the v8 but I do like my square setup for rotations.

[BatMobileLT1]

Originally Posted by wintertopdown

I am wanting to do the same. I have been driving on the 245’s for a long time and find myself loosing traction now with the v8 but I do like my square setup for rotations.

I went through exactly the same desire to get wider tires on my LT1 and also would have preferred to stay with a square setup for tire rotations.

However, when I did some google research it seems there are some pretty good reasons why it makes sense to have wider tires in the rear on the V8 Camaros (hence why all SS and above models are staggered) to:
1) Rear tires need wider to have more grip to put the power down on launch as you noted
2) There are some advantages in steering,.. to not make front's wider than needed
3) Having the fronts narrower biases car for some understeer - easier to control than oversteer

So with that and figuring that going w/TireRack and Chevy Camaro recommended sizes was a good thing, I decided can't go wrong with upgrading to go with the SS front & rear wheel and staggered tire sizes (245/40/20 + 275/35/20) and just deal with the cost of more rear tire replacements. I've been very happy with this upgrade so far - feels great to know you have that extra width on the rear tires especially for 1st gear launches. And it also saved me some money to only have to get wider rear wheels.

I later even saw a post on another camaro6 thread that Camaro engineering said that they tested various tire size combinations and found staggered was the fastest around a race track before they selected it. So it was nice to know the staggered OEM sizes may not just be to dumb it down to keep it safer at the limit...
Hope that is helpful input whichever way you decide to go!

[Dynamical]

Thanks for the info fellas.
On my old LS1 Camaro SS I ran the stock ZR1 wheels. 275 40 17 all around. Front tires were street tire but rears were Mickey Thompson ET Street drag radials. I was never one to have a drag pack with skinnies or anything like that. I like the simpler/cheaper route if possible so I can run the same setup on the street and then show up to the track without having to change wheels if I want.
I figured swapping my stock LT1 rear wheels with some stock SS wheels on the rear would fit my style. Nitto makes the drag radial that fits the size needed which is a 275/35R20 27.56 diameter. My car is stock right now so hopefully that will do the job. Mods are coming though

[lt4camaro]

Originally Posted by Dynamical

Thanks for the info fellas.
On my old LS1 Camaro SS I ran the stock ZR1 wheels. 275 40 17 all around. Front tires were street tire but rears were Mickey Thompson ET Street drag radials. I was never one to have a drag pack with skinnies or anything like that. I like the simpler/cheaper route if possible so I can run the same setup on the street and then show up to the track without having to change wheels if I want.
I figured swapping my stock LT1 rear wheels with some stock SS wheels on the rear would fit my style. Nitto makes the drag radial that fits the size needed which is a 275/35R20 27.56 diameter. My car is stock right now so hopefully that will do the job. Mods are coming though

Let us know what your 60 ft times are and the 330/660 times with the nitto's.

[wintertopdown]

I have a very similar hot red LT1 with the black 20 inch 8.5 wheels. Can I get away with just swapping the rears to the stock 9.5s? As I drive in the winter, I will probably stick with all season. I found some on eBay https://www.ebay.com/itm/275842213603

[Dynamical]

Originally Posted by lt4camaro

Let us know what your 60 ft times are and the 330/660 times with the nitto's.

Do you think they will be enough?

Originally Posted by wintertopdown

I have a very similar hot red LT1 with the black 20 inch 8.5 wheels. Can I get away with just swapping the rears to the stock 9.5s? As I drive in the winter, I will probably stick with all season. I found some on eBay https://www.ebay.com/itm/275842213603

Yes