Wheel/tire packages for track

[lbp]

I will definitely not miss the Porsche-priced visits to the dealer for routine maintenance!

No doubt. ;D I think the Boss is going to deliver a lot of the fun/rewards of a GT3 at a fraction of the price. I look forward to reading your impressions after you track the Boss.

Cant' wait for sure ;D

Can you make it to Limerock on 5/31? There's a bunch of other Bosses coming out that day

I don't know my schedule that far in advance, but I will definitely put it on my calendar & try for it.
Which group is running? - NASA/PCA? (I think that's Joe Casella's date).
Do you know if it is a half or full day?
Cool...

...I think the Bosses will most likely give something up to the Porsches at LR ...

 

[lbp]

I think your link references the same info contained in the pdf link.
I've sent an email to Jeff Speer at Hoosier for some recommendations on the B302 which I will post when received.
My inquiry with him is specifically in regard to running 315x30x18 all around (requires suspension mods), so his reply may not be 100% relevant to the staggered setup most will be running.

Here is his email: [email protected].

Jeff is a very responsive guy and will be sure to answer any questions you ask...

The PDF shows lower pressures than I referenced. See page 3 of the PDF. For example, on cars 3,000+ lbs, it says 23-29 psi cold and 34-39+ hot.....


Funny, I emailed him on Friday about recommendations on a staggered set of slicks on my Enkeis. What suspension mods are you planning to run those tires?

Here is Jeff's (Hoosier Rep) response to this question:

Sent: Saturday, February 04, 2012 8:12 PM
To: Jeff Speer
Subject: RE: Hoosier Tire - R6

Hi Jeff,
I’m getting close to finalizing the tires specs for the Boss 302 Mustang & have found a setup that can accommodate Hoosier slicks, 315x30x18 all around.
- Do you have any setup recommendations to start from, i.e., Cold/Hot pressure & temp; also alignment suggestions?
Jeff, many thanks, as always.
Lee.

Lee Palmiter
Alpine Motorsports Club
Launch Team - Technology

www.alpinesignature.com

Lee,
The R6 likes to run at 36 – 38 psi HOT which your cold starting pressures should be 6 – 8 psi lower(28 – 30 psi).

Camber settings should be between -2.0 to -3.0. I like your front end settings closer to -3.0 degrees if possible.

Tire Care Tips: http://www.hoosiertire.com/pdfs/tctR6_A6.pdf
(you might have to click twice on this link to get it to open)

Let me know if you need a contact to purchase the tires.

Glad to help.

Jeff Speer, HRT

...I also replied to Jeff with this question (much to the point in this thread):

PPS –
Jeff,
I also notice that the starting cold pressures in the pdf are quite a bit lower than what you mention in your email.
Is there any reason for this?
Thanks,
Lee.

 

[cloud9]

Thanks for posting that Lee. I also got a response from Jeff this morning on running slicks on a staggered set of Enkei PF01s. Below is my question and his response:

Hi Jeff,

I am looking for a recommendation on your road race slicks. I’ve been running your R6 in a 295/30/18 and 275/35/18 on 18 x 10.5 and 18 x 9.5 rims. I’m trying to maintain a stagger of approx 1” to 1.5” front to rear based on my suspension setup. I ran these previously on a Mustang GT and last season on a 2012 Boss 302 Mustang with -2.7 degrees of front camber. I also have run several sets of Nitto 555RII in 305/35/18 (26.3” tall) and 285/35/18 (25.9” tall) which give me a little wider tread than the R6s albeit with less grip.

Looking at your size chart, it looks like the widest setup that fit these wheels would be:

43855 285/645R18 10.9" 25.5" 80.0" 10-12" 11" 11.7" R80, R100
43835 265/645R18 10.1" 25.5" 80.0" 9-10" 10" 10.9" R80, R100

Alternatively it looks like this may work, but my front tire would be .4” taller and I’m not sure how that will affect handling and aero if at all:

43857 295/680R18 11.7" 26.5" 83.3" 10-12" 11" 12.3" R100
43840 280/680R18 CUP 10.0" 26.9" 84.6" 9-11" 10" 11.3" R100

Any suggestions would be appreciated.

Thanks,
Gary

His response:
Gary,
Thank you for writing and I appreciate all of the details to what you are currently running. With your current rim widths, I agree to what you suggested below.

Front - Item 43835 – 265/645R-18($423.00 ea)

Rear - Item 43855 – 285/645R-18($451.00 ea)

You could go as wide as our 43865 – 305/645R-18($468.00 ea) which has a 11.8” tread width using your 18 x 10.5” wheel. I would not go any wider. Of course this depends on your wheel well clearance.

I do not see any issue with having similar diameter tires front to rear. Should be fine there.

Let me know if you need a contact to purchase these tires and do include the state you live in.

I do not think Option 2 is best. Stay with the above setup. The CUP is specifically made for Porshe Cup race cars and is rarely used on any other vehicle.


Jeffrey A. Speer
Product Manager

 

[OLOABoss]

I have run Hoosier R100's on the 996 GT2 and would not do it again. They are very finicky for camber, tend to cord the edges, and need a stiff suspension to really work. Also if you are running a track like Daytona they have real issues with blowing on the banking. IMHO YMMV If you want a hero tire for a couple of laps better to run the Hoosier A6.

Peter

 

[lbp]

Thanks for posting that Lee. I also got a response from Jeff this morning on running slicks on a staggered set of Enkei PF01s. Below is my question and his response:

Hi Jeff,

I am looking for a recommendation on your road race slicks. I’ve been running your R6 in a 295/30/18 and 275/35/18 on 18 x 10.5 and 18 x 9.5 rims. I’m trying to maintain a stagger of approx 1” to 1.5” front to rear based on my suspension setup. I ran these previously on a Mustang GT and last season on a 2012 Boss 302 Mustang with -2.7 degrees of front camber. I also have run several sets of Nitto 555RII in 305/35/18 (26.3” tall) and 285/35/18 (25.9” tall) which give me a little wider tread than the R6s albeit with less grip.

Looking at your size chart, it looks like the widest setup that fit these wheels would be:

43855 285/645R18 10.9" 25.5" 80.0" 10-12" 11" 11.7" R80, R100
43835 265/645R18 10.1" 25.5" 80.0" 9-10" 10" 10.9" R80, R100

Alternatively it looks like this may work, but my front tire would be .4” taller and I’m not sure how that will affect handling and aero if at all:

43857 295/680R18 11.7" 26.5" 83.3" 10-12" 11" 12.3" R100
43840 280/680R18 CUP 10.0" 26.9" 84.6" 9-11" 10" 11.3" R100

Any suggestions would be appreciated.

Thanks,
Gary

His response:
Gary,
Thank you for writing and I appreciate all of the details to what you are currently running. With your current rim widths, I agree to what you suggested below.

Front - Item 43835 – 265/645R-18($423.00 ea)

Rear - Item 43855 – 285/645R-18($451.00 ea)

You could go as wide as our 43865 – 305/645R-18($468.00 ea) which has a 11.8” tread width using your 18 x 10.5” wheel. I would not go any wider. Of course this depends on your wheel well clearance.

I do not see any issue with having similar diameter tires front to rear. Should be fine there.

Let me know if you need a contact to purchase these tires and do include the state you live in.

I do not think Option 2 is best. Stay with the above setup. The CUP is specifically made for Porshe Cup race cars and is rarely used on any other vehicle.


Jeffrey A. Speer
Product Manager

Gary,
Here is Jeff's response to the delta in pressure recommendations:



Sent: Monday, February 06, 2012 4:02 PM
To:
Subject: RE: Hoosier Tire - Air Pressure

Lee,
Good question. If your car setup(camber, springs, shocks, toe) are just perfect for the Hoosier R100 or Hoosier R6, you can run lower air pressure to get optimum performance and tread wear. Not knowing each customer’s car setup(expect the worse – close to factory setup), I always recommend high so the competitor can lower pressures as he continued to use the product.

I would not want the first impressions of a new R6 customer to be bad – cord a set of tires in a weekend.

I have also seen a good car setup using the higher pressures and finding faster lap times as well. There are mixed reviews about using high / low air pressures in our tires . . could be driver preference as well.

Hope this helps.

Jeff Speer, HRT

PS – Thanks for posting my responses. Hopes it helps other people.

 

[cloud9]

Thanks Lee. I also was told by Jeff that I can run the 285 on my 9.5 fronts even though it's listed for a 10-12 rim. That's some wicked rubber with a slick having a 285 front and 305 rear. I currently run the 305 rear and 285 front in the Nitto but their 285 is 11.22 overall width versus 11.7 on the R100. I have the room for a 1/4 on each side. I can only imagine the roller coaster ride on slicks this wide. I'm going to give them a shot and see how they hold up. Can't be any worse than I'm getting on r-comps and hopefully will last longer and be faster.

 

[lbp]

I have run Hoosier R100's on the 996 GT2 and would not do it again. They are very finicky for camber, tend to cord the edges, and need a stiff suspension to really work. Also if you are running a track like Daytona they have real issues with blowing on the banking. IMHO YMMV If you want a hero tire for a couple of laps better to run the Hoosier A6.

Peter

For some years (since 2004) I've run A6, R6 & R100 Hoosiers on a 2146 lb car with a 1:4 hp/weight ratio and had excellent results. That car (still got it) is light and highly prepared, so for sure it benefits tremendously from big Hoosiers (335x30x18/rear & 305x30x18/front, A6, and 335x30x18/rear & 305x30x18/front, R6; and also 320x30x18/rear 305x30x18/front, R100) and those tires have all been a perfect setup.
- Years ago I ran an Audi S4 with 245x40x16 (I think) all around and had equally excellent results, although tire wear (yes cording) & heat were both issues on that 3841 lb car.
Although I've never rolled a tire, I think that a heavy car with radial slicks does need to be watched closely for all of the reasons mentioned by Jeff & in this post above, in particular, too low of pressure.
I've heard other reports from time to time (and seen some disastrous results (Michelin)) of rolling a slick off the rim.

 

[lbp]

Thanks Lee. I also was told by Jeff that I can run the 285 on my 9.5 fronts even though it's listed for a 10-12 rim. That's some wicked rubber with a slick having a 285 front and 305 rear. I currently run the 305 rear and 285 front in the Nitto but their 285 is 11.22 overall width versus 11.7 on the R100. I have the room for a 1/4 on each side. I can only imagine the roller coaster ride on slicks this wide. I'm going to give them a shot and see how they hold up. Can't be any worse than I'm getting on r-comps and hopefully will last longer and be faster.

Watch the tire temps for sure (inner/outer/mid section), to tell if you are on the right path.
...Sometimes too much rubber is, "too much rubber," since (as you most likely know) the slick will not work properly unless it operates within the right (hot) temp range but I don't think this will be a problem on these heavy cars. I think the real challenge will be getting the setup correct for slicks (now I'm a bit happier about the solid rear axle). ;D

Of course we could always try bias slicks like they run on the SU (Super Unlimited) cars ;D ;D ;D

 

[oldbossman]

OK, based on input from this forum and others I went to discount tire to inquire about the Enkei 18 X 10.5 wheels (PF01) for the rear of my Boss. He called up his distributor and talked to him and the concern was that a 38 mm offset might cause fender rub issues. I know that several of you have run this size wheel with no problem. However, the dealer asked why I didn't go with the 45 mm offset. Does anyone have any information with using a 45 mm offset for this size wheel. Would not a 45 mm offset provide better fender clearance? Any negatives with a 45 mm offset? I will be running 295/35R18 rear and 275/40R18 front with 18 X 9.5's in front. I have already signed up for a track event in April. Thanks !

 

[cloud9]

OK, based on input from this forum and others I went to discount tire to inquire about the Enkei 18 X 10.5 wheels (PF01) for the rear of my Boss. He called up his distributor and talked to him and the concern was that a 38 mm offset might cause fender rub issues. I know that several of you have run this size wheel with no problem. However, the dealer asked why I didn't go with the 45 mm offset. Does anyone have any information with using a 45 mm offset for this size wheel. Would not a 45 mm offset provide better fender clearance? Any negatives with a 45 mm offset? I will be running 295/35R18 rear and 275/40R18 front with 18 X 9.5's in front. I have already signed up for a track event in April. Thanks !

That must be a new size for them. I wish I would have known that before I just ordered another set a month ago lol. I've run the 38mm offset for four years now on two different Mustangs using a 305 rear tire in Nitto and Toyo and a 295 in Hoosier with no issues at all rubbing and if they were going to rub, trust me I'd have found out by now The tires do sit outside the fender just a shade, but won't rub, even on my GT500 with coilovers slammed almost 2" from factory height. As long as you have your factory bumpstops you can't get them to rub. If you have shortened your factory bumpstops, I couldn't say for sure.

With a 45mm offset you should be fine to the inside with that tire. Last time I checked I think I still had almost an inch to the bumpstop bracket on the inside with a 305 on there. You're only talking a 1/4" so should have plenty of room to spare. Someone thought that the rear sway bar was the closest point on the Boss, but I thought it would be the bumpstop bracket or shock.

 

[VoodooBoss]

More offset would be nice but I just checked and I don't see 45 in the 10.5 width.

http://enkei.com/pf01.html#

 

[cloud9]

More offset would be nice but I just checked and I don't see 45 in the 10.5 width.

http://enkei.com/pf01.html#

Yep that's the size chart I've worked from as well. I know that last year they didn't offer the 10.5 in matte black and now they do, so it's possible they've added another size and not published it either. We would need to see somewhere that you could actually order it to prove it.

 

[oldbossman]

yes you guys are correct. That is why I was going to go with the 38 mm offset. I will recheck with them tomorrow but IF this offset is available, what would be your recommendation?

 

[cloud9]

If it's available, I would probably go for the 45mm offset. Here are few pics of the 38mm offsets on both cars:

By cloud91965 at 2012-01-08

By cloud91965 at 2011-10-19

By cloud91965 at 2011-05-01

By cloud91965 at 2011-05-01

 

[oldbossman]

OK Thanks. I will let you know what I find out. I suspect the dealer is incorrect. Also, aren't the rear brakes standard GT brakes?

 

[cloud9]

Also, aren't the rear brakes standard GT brakes?

Correct.

 

[06mach1]

Also, aren't the rear brakes standard GT brakes?

Correct.

Aren't they standard GT brakes with Boss specific pads??

 

[cloud9]

Also, aren't the rear brakes standard GT brakes?

Correct.

Aren't they standard GT brakes with Boss specific pads??

Yes, I guess I assumed he was referring to the calipers.

 

[CaliMR]

If the 38s don't rub, what would be the advantage in the 45 other than looks? Wider track of the 38s isn't better?

 

[cloud9]

If the 38s don't rub, what would be the advantage in the 45 other than looks? Wider track of the 38s isn't better?

You are correct. Part of the reason I love this setup so much is it widens both the front and rear track and gives the car a much more stable stance. It just seems a lot of people get hung up on the look. Same thing with the fronts, the 35mm offset gives me a wider track than the 45s, but some guys like them tucked more.

*edited from smart phone autocorrect*