Tires

[roketman]

Yup,no doubt about it .Drugs are cheaper !
But I do thing our drug is a better option!
I so can’t wait to get my car !
I am living precariously though Cloud Nines Laguna antics!
Tell me what track you went to!

 

[cloud9]

Oh yea a much better option indeed ;D

Mid America Motorplex in Pacific Junction, Iowa

Next outing is at MPH in May located in Hastings, NE

Then in June Road America Elkhart Lake, WI

Then BIR in Brainerd, MN in July

 

[Dean#4AI]

Oh yea a much better option indeed ;D

Mid America Motorplex in Pacific Junction, Iowa

Next outing is at MPH in May located in Hastings, NE

Then in June Road America Elkhart Lake, WI

Then BIR in Brainerd, MN in July

What event at Road America? I have many many laps there and would love to bust the LS cherry there.

 

[cloud9]

GT track days the 13/14th. Will be my first time to RA. Bunch of Vette guys going from here.

 

[roketman]

Great track schedule ! I can attest to Road America.AWESOME! fast ,technical and gutsy!
I get back to you on what Hoosier recommends for tire sizing.Sounds like you know what size you need anyway.

 

[cloud9]

Thanks for checking on the sizes. I'm just waffling back and forth on the NT01s vs the R6s. Reason for considering the NT01s this early in the Boss game is if I want to know whether I like the square or staggered setup better, it's better to run the same tire on both sets of wheels. If I run R6s on the staggered wheels, it won't be a good comparison. Also, since I'm still learning the Boss I'm not likely to record my fastest lap times right now anyway so better to get more laps on a little slower tire than burning up the best tires before I've got a good feel for the car.

Can you tell I'm conflicted!? ???

 

[cloud9]

Either rear tire option (r6 295/30/18 or NT01 315/30/18) is 25.3" tall. I am wondering how the speed limiter calculates and electronically limits the car. I would hit the 155 mph limit at BIR and RA. I just hope I wouldn't get limited to 145 mph with a smaller rear tire.

Calculations in 5th gear:

7500 RPM on 27.1" stock tire = 162 mph
7200 RPM on 27.1" stock tire = 155 mph (factory speed limiter)
7500 RPM on 25.3" track tire = 151 mph
7200 RPM on 25.3" track tire = 145 mph

 

[Dean#4AI]

Either rear tire option (r6 295/30/18 or NT01 315/30/18) is 25.3" tall. I am wondering how the speed limiter calculates and electronically limits the car. I would hit the 155 mph limit at BIR and RA. I just hope I wouldn't get limited to 145 mph with a smaller rear tire.

Calculations in 5th gear:

7500 RPM on 27.1" stock tire = 162 mph
7200 RPM on 27.1" stock tire = 155 mph (factory speed limiter)
7500 RPM on 25.3" track tire = 151 mph
7200 RPM on 25.3" track tire = 145 mph

Are clubs still using the full course at BIR? I thought they put in a slower, tighter course in because of the high speed turn 1?

Also, I'm not sure you will hit those speeds at RA. There are 3 separate straights that are high speed but not sure a stock Boss will hit the rev limiter on any of them. It will be close though. :-\
Although on a short tire, I think it might be possible. It's hard to know since my race car had lower RWHP but it was around 500 lbs lighter.

So at 7200rpm on the short tire, the speedo will read 155 even though you will only be going 145mph, correct?

 

[cloud9]

Are clubs still using the full course at BIR? I thought they put in a slower, tighter course in because of the high speed turn 1?

Also, I'm not sure you will hit those speeds at RA. There are 3 separate straights that are high speed but not sure a stock Boss will hit the rev limiter on any of them. It will be close though. :-\
Although on a short tire, I think it might be possible. It's hard to know since my race car had lower RWHP but it was around 500 lbs lighter.

So at 7200rpm on the short tire, the speedo will read 155 even though you will only be going 145mph, correct?

I've been running with the PCA up there because they do get the full track and turn 1 rocks! Turn 2's a little bit of a gut check though The last event in the fall we ran the short course (2.5 miles) on Friday, and the big course Sat/Sun. The short track is o.k., but will be more fun with the Boss than the GT500. I was hitting 160 about 2/3 of the way down the front straight at BIR in the GT500 and could have gone higher if I wasn't afraid of sailing over the embankment on Turn 1 into the woods. I'd lift and coast through 1 at 145.

Good to know about RA. I haven't been there yet, but thought the main straight was around 1 mile like BIR. Does the elevation (uphill) keep you from hitting that high of a speed?

I was using an RPM to MPH calculator to come up with that Dean. I think I was doing it correctly, but I'm not sure how the PCM calculates speed. Unfortunately I don't have a handheld programmer for the Boss yet to change tire sizes. I wish TracKey gave you the option of buying it on a handheld programmer versus a dealer reflash. Even just the Pro-Cal from Ford Racing. Will need to look into that further.

http://www.wallaceracing.com/calcmph.php

 

[PJWANNABE]

GT track days the 13/14th. Will be my first time to RA. Bunch of Vette guys going from here.

Road America and Mid-Ohio are on my to-do list. When you mentioned RA I thought you were talking about Road Atlanta- that is one you should put on your list if you haven't driven it.

 

[roketman]

Here is what available from Hoosier
fronts 265 35-19 OD 26.2
Pirelli Corsa 255-40-19 OD 27
REARS
Hoosiers 295-30-19 OD 26.1
Pirelli Corsa 285-40-19 OD 26.8
So as we can see slightly larger tire.
I will look in to the application for the Laguna’ s.

 

[Dean#4AI]

Good to know about RA. I haven't been there yet, but thought the main straight was around 1 mile like BIR. Does the elevation (uphill) keep you from hitting that high of a speed?

Yes, there is a long gradual hill that limits speed on the front stretch. You're still moving pretty good but the hill does limit you. Turn 1 is much faster than it initially looks. It's one of those corners that you can brake too early and hard and not carry as much speed as you should.

You have another long stretch that ends up going downhill into turn 5 which is a brake killer but it's a great place to pass.

Then after the carousel is the infamous kink that looks pretty innocent but if you screw up, you can write off your car in blink of an eye. How you get through the kink will determine how fast you are going into Canada Corner. You will be humping it pretty good through there and it's another great braking zone that you can make some passes.


Helluva track, you're going to love it!

 

[ArizonaBOSS]

I wish I had a car that was worth taking to Road America, when I lived in Milwaukee.

 

[BossJockey]

Well I'm struggling. I ran the square NT01s 275/40/18 and the grip was good and I showed almost no wear running for a half a day. I wasn't crazy about the feel, but can't tell if it was the square setup or the 40 profile. I've never run either, I've always had staggered 30 or 35 profile tires. I liked the square shape of the R888s and lower profile better, but I only got 1.5 days out of the fronts! I had been getting 2-4 days out of R888 fronts and 4-8 days out of the rears. My lap times were about a second faster on the R888s, but I also had more seat time at that point in the day.

It looks like the NT01s hold up good and provide decent, but not great grip. I could go with a 315/30/18 NT01 with a 275/35/18 front. Nitto recommends a 10.5-11.5 rim so they must run a little narrower than the R6s. They are only about $20 less than the 295/30/18 R6s, so it would only make sense if they would last a lot longer than the Hoosiers. I don't have enough experience with the NT01s to know.

I guess I'm struggling since we don't have enough data out there yet on the Boss for tire performance, but need to make a decision before the next track event in 3 weeks.

Catching up on some old posts. Why do you need two sets of tires mounted on rims? Couldn't you get two more 275/40/18s for the 9.5" rims and use them as spares? What didn't you like about the square setup?