Hoosiers on GT?

TommyC said:

Looks great.

What did you do for the brake ducting/cooling?

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been a long time since i put them on. iirc, jlt. only 2.5" but no off-the-shelf 3" kits were available when i bought them in early 2015. that said, there isn't a lot of room to maneuver the ducting in there, and i do get some rub (especially with large steering inputs), even though they're well-routed, so not sure i'd want to run 3" anyway (since this is also my daily driver).

boardkat said:

been a long time since i put them on. iirc, jlt. only 2.5" but no off-the-shelf 3" kits were available when i bought them in early 2015. that said, there isn't a lot of room to maneuver the ducting in there, and i do get some rub (especially with large steering inputs), even though they're well-routed, so not sure i'd want to run 3" anyway (since this is also my daily driver).

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Do you mind snapping some pics of the routing/attachment points? I ordered a DIY kit and am going to attempt the install this weekend. I also did 2.5"

TommyC said:

Do you mind snapping some pics of the routing/attachment points? I ordered a DIY kit and am going to attempt the install this weekend. I also did 2.5"

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won't have time this weekend, but the jlt page shows routing that (off the top of my head) looks like mine.

https://www.jlttruecoldair.com/ZenCart/index.php?main_page=product_info&products_id=701

fwiw, i have it ziptied in a few other places, mainly to keep the ducting off the steering rack, and from protruding out too far (and rubbing my really wide wheel/tire combo)

boardkat said:

call me crazy, but i don't think my 25.9" 335/30R18 square setup looks that goofy....... ;)

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Wrong angle to show the tire diameter mismatch with the wheel wells that is the issue. But those are a bit taller than the 315/30-18's that I have seen that look goofy.

What surgery have you done to get a 335 to fit up front?

Not sure I'm seeing the logic in applying conventional street-driver/car show 'tire gap' standards to a dedicated track setup.


Norm

If you prefer, short tires make the short gearing problem in a PP worse is another reason to try to get reasonably close to the stock tire diameter.

True.

It might be worth thinking about dropping the gearing back down to 3.55's or possibly even 3.31's and letting the overall gearing for the street driving part fall wherever it may. Possibly with tires a little taller than the (short) track tires but still shorter than the big-OD OE sizes.


Norm

Norm Peterson said:

True.

It might be worth thinking about dropping the gearing back down to 3.55's or possibly even 3.31's and letting the overall gearing for the street driving part fall wherever it may. Possibly with tires a little taller than the (short) track tires but still shorter than the big-OD OE sizes.


Norm

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A little off topic, but why do the OE tires look like balloons on this car? Is the wheel too narrow, so it squishes them up and out? They seriously look like all season SUV tires.

TommyC said:

A little off topic, but why do the OE tires look like balloons on this car? Is the wheel too narrow, so it squishes them up and out? They seriously look like all season SUV tires.

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Which wheels/tires are you picturing here? GT? GT/PP?

The short answer is that mfrs tend to stick pretty close to "measuring width" wheels for the more mainstream trims whose typical customers are presumed to be somewhat more interested in a "softer" ride/handling compromise point than what people like you or me would look for. There's also the matter of providing scuff protection for the wheels.


Lots of people don't like the appearance of a mildly 'stretched' tire for that reason alone. Tires always used to bulge out a bit from the wheel flanges (especially in the original "muscle cars"), and once the OE tires are replaced with something wider the bulge gets bigger . . . how many threads are there about 'what's the widest tire I can fit on my OE wheels? Bottom line, the bulge shape itself becomes an expected part of the appearance.


Norm

GT350 & R have a pretty ideal wheel to tire fitment.

Yeah. Take a look at the sidewall on my R vs GT:

I saw the comment made about putting PP rears on the front. I have not done this personally, but from my research it's totally doable...you just have to run a 20-25mm spacer up front.

H@mmer said:

I saw the comment made about putting PP rears on the front. I have not done this personally, but from my research it's totally doable...you just have to run a 20-25mm spacer up front.

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Except the PP wheels weigh 33lbs each... the last thing you want is excess unsprung weight. Dropping down to 18s should drop about 15lbs per wheel, which will be hugely noticeable (it will feel like about a 150lb sprung weight reduction).

TommyC said:

Except the PP wheels weigh 33lbs each... the last thing you want is excess unsprung weight. Dropping down to 18s should drop about 15lbs per wheel, which will be hugely noticeable (it will feel like about a 150lb sprung weight reduction).

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I wasn't commenting at all about that.
I was simply adding information about PP rears on the front.

TommyC said:

Yeah. Take a look at the sidewall on my R vs GT:

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Yeah the PP summer PZeros looked like balloons.

Good images to demonstrate. So, you know the R comes with different tires and wheels so some (most?) of what you're seeing is the stiffer sidewall on the R tire, but the tire tread to wheel width "stretch" is also at play.

PZeros, Contisport, MPSS, etc all buldge like that at bit. Street tires are like that. Competition focused tires can have a straigher, stiffer sidewall in the same sizes, but you'll get some extra harshness on the road and maybe more noise and weight. FWIW, as the sidewall ratio goes up, stretching a tire becomes less useful.