Avon Replacement

[KnifeySpoony]

Tell me about the sizes on the R7s and slicks

[sf4018]

18 hours ago, KnifeySpoony said:

Tell me about the sizes on the R7s and slicks

Type	Manufacturer	Model	Comp.	Front Wheel Size	Front Part #	Rear Wheel Size	Rear Part Number
DOT	Avon	ZZR	A64	13x6	185/55R13	13x8	215/55R13 ZZR
DOT	Hoosier	R7	R7	13x6	P185/60ZR13	13x8	P225/45ZR13
Slick	Hoosier	F2000	R35B	13x6	20.5x7.0R13	13x8	22.5x8.0R13

 

Some notes on suspension...

The f/r ride height is currently tuned for the ZZRs. If I put on the F2000 I'll have to raise the front by 9mm to maintain the rake, which would not be too hard to do at the track. For the R7s though it's a real problem, I'd have to lower the front by 30mm, I'm not even sure that's possible at this point I haven't tried, but that's a huge change. Changing the rear ride height at the track would be a major pain. I already have the tires and wheels for the R7 so I'm committed for now to running them, but a better combination will be 13x6 fronts (same R7 tire) but the taller wheel size on the rear (15x8). This combo will minimize suspension setup change to the ZZR. I had a short look around to see if there are wheel sizes of the same style for 13x6 and 15x8 that would fit but I couldn't find any. I'll dig deeper later this year.

[KnifeySpoony]

Thank you. Yeah the ride height/gearing consequences are a concern for me as well. Geometry wise, I'm ok raising my front (currently, my front is quite low, with LCA parallel to ground). Raising the rear is ok too but that would mean a smaller tire and shorter gearing. I'm right at the top of 4th on the longest straights on my 2 home tracks so I'd really prefer not to have to go to 5th (nitpicking I know). Why is rear ride height change an issue for you? Seems just as easy as the front. I'm as low as I can go on my spring perches on rear (actually I've removed the locking perch in able to go as low as I am currently), so any larger diameter tire in rear will require raising the front. 

 

I have also considered going to a 15" setup to run A7s in 205/225 but the diameters are quite a bit off. Would require new wingstays and front wings as well. Also I drive my car to the track, so driving on slicks is kinda sketchy. I'm severely grieving the loss of the ZZR in our sizes...

[sf4018]

2 hours ago, KnifeySpoony said:

Thank you. Yeah the ride height/gearing consequences are a concern for me as well. Geometry wise, I'm ok raising my front (currently, my front is quite low, with LCA parallel to ground). Raising the rear is ok too but that would mean a smaller tire and shorter gearing. I'm right at the top of 4th on the longest straights on my 2 home tracks so I'd really prefer not to have to go to 5th (nitpicking I know). Why is rear ride height change an issue for you? Seems just as easy as the front. I'm as low as I can go on my spring perches on rear (actually I've removed the locking perch in able to go as low as I am currently), so any larger diameter tire in rear will require raising the front. 

 

I have also considered going to a 15" setup to run A7s in 205/225 but the diameters are quite a bit off. Would require new wingstays and front wings as well. Also I drive my car to the track, so driving on slicks is kinda sketchy. I'm severely grieving the loss of the ZZR in our sizes...

The front suspension is easy access, just jack up one side, make the adjustment and repeat for the other side. The rear suspension can only be accessed from underneath. I don't have the trailer space to put in a hydraulic lift so putting it on jack stands is the only option, which is time consuming, especially if I have to repeat a few times. Maybe at the end of the day but then I'm eating into beer time