so the last time I attended an SVRA event I took some aged out toyo's (RA1's) that I've owned for a few years...

they were as bad as I expected and put a taint' on the weekend
I'm used to driving on hoosiers A6/A7 and realize that I'm not going to get anywhere close to that level of grip from aged out toyo's


so I'm working on my summer schedule and planning for this year
I think I will attend another SVRA event or two
and will buy fresh tires this time around

the approved list is below:
I will shave the new set
my experience (recent) has really all been with the hoosier radials that are not allowed

I'm aware I may need to make some alignment changes with a bias ply, but ultimately I want the fastest tire so will take steps as needed.

I would love feedback from anyone that has done testing or driven multiple brands of tires on the approved list

ultimately, I'd like to buy a set of the stickiest tires I can
I noticed that many of the racers were running the RA1's and hoosier vintage tires
I assume these are probably the 2 fastest options

but would love feedback from anyone as I plan for the summer
thanks in advance

-------------------
Approved tires:
Avon: ACB10, CR6ZZ
Goodyear: Blue Streak
BFG: g- Force Sport
Hankook Ventus RS2, RS3-V2, Z213, Z207
BFG: g-Force RIVAL
Bridgstone: RE 11
Toyo: RA1, R888, R1R
Dunlop: Direza Sport Z1, Z11 or Z11-Star
Hoosier: Street TD & Speedster
Yokohama: A032, A048
Falken: RT615
Kumho : V700, ECSTA XS
Nitto: NT01 (minimum 3/32” tread depth)

Specifically Prohibited for all Group 6:
Slicks or any of the following tires: Avon Tech RA, Avon ZZR, ZZS or CR500, BFG G-Force R1, Goodyear GS/CS/RS, Hankook Z214, Hoosier DOT Radial, (A6, R6, R7 or SM7), Kumho V710, Toyo RR, or any other “street slick” type DOT tire.

My experience has been on shaved (to 4/32) RA1's and this past year on RR's.....Frankly at my level I can't tell the difference---meaning that shaved RA1's are as good as RR's.
"My level" translates as 2:18 at VIR full course, 1:47 at Road Atlanta, 1:28 at Summit Point main, 2:19 at Watkins Glen, so you can see I'm not working the tires to their limit. Never corded a tire yet.

Brant - I have experience with the V700's, NT01's, RA1's, A6, R6 and R7's. Hands down the best tires are the R6 & R7 on the list (that I have experience with)...I don't think you can run those though. I just saw the Blue Streaks - been there done that too - they suck.

Based on my experience -the NT01 stands apart from the rest (on the allowed list) and is largely used as an economical replacement to DOT slicks (even when the slicks are allowed!) - the performance gap is not too far off. If you want slightly more life the RA1 might give it to you over the NT01 but they're not in the same class performance/grip wise. JMO.

Tony

Hey Brant,
I'm 2.5 seconds faster on toyo RA1s over Falkens RT615. That was at Sebring. In the Falkens defense, they were used for a Chump race.
Those are the only tires I've tried.

Crossing Falcons off of the list
Thankyou

Tony

Wow.
Very helpful.

Were you running all of those on a 914? What weight of vehicle if other?
We're the toyos shaved? and the nt01's
What pressure are you using on each?
(Any temp reading?)
How long of a session?
Alignment tips you have for each brand?

I know nothing about the nt01. Thanks a ton!


Ps I love the a7 so far... but don't have any longevity evidence yet
wish I could run them instead...

Brant - I'll send you a PM tonight...

that would be great
sorry for all of the questions
brant

Coming back to Sears Point?

MB

I think so...
my race shop wants to do the SVRA event in june though (instead of csrg)
its a tough call... I prefer my tires allowed in csrg
but its always extremely comforting to travel with a crew and engine builder also
the support is hard to overlook

It that the Wine Country Classic? It's invite only now. I requested invitation. We'll see how that turns out. CSRG is a done deal, spring and fall.

is there a treadwear minimum you are having to meet (sounds like a 140 or so rating is what most of that list carries.

IIRC, years ago when the NTo1 was introduced, it was a "retreaded" RAI. Folks were split, Some liked the RA1, some the Nitto.

I always liked the RA1 from a dual use purpose (that being driving to a DE and then using them at a DE). Never ran the crack pipe that is hoosiers. RA1's are a great tire overall.

I ran them on my 911 (225-50-16 and 245-45-16) as well as my 914 (205-50-15). I would rate them at the top of the "streetable" ones in your list above.

What size are you needing to run?

its SVRA tire rules
they don't state a minimum treadwear, but the tires on their approved list are all leaning towards longer wear and less grip. I believe its how they are limiting speed and performance. Funny because the motors in those cars are definitely not hurting for performance (frank becks 2.5/6 was rumored to be 296hp at the wheels), yet he drives on new/shaved RA1's too....


they are even limiting how much shaving can be done with a minimum tread depth too


I run 225/50/15's at all 4 corners.
it is slightly too large of a tire for my car's weight
but I've used it to run softer compounds in the past and increase my longevity by not creating as much heat per contact patch


when you ran the RA's did you ever shave them?
and if you have seat experience in shaved vs unshaved I would love to hear your experience.


oddly I can't find any NT01's for sale with shaving.
and I don't know any local shops that do shaving

anyone have idea's about that?

An old school tire shop here does it....they call it "buffing"...to take out flat spots or cupping...$10 per tire & they'll take them down to whatever you want...even offered to put in stagger for circle track use.

I would buy my RA-1s full tread at the beginning of the year and run them all year. My cars were street legal, so I would drive to/from events as well. Sometimes they would last a full season, sometimes not (6-8 2day events, about 2500 total miles). This way, I had full treads at the rainy spring events and nice bald ones by mid-late summer (or worse case, cords showing .

Can't recall time delta's between the two (full vs shaved). Obviously full treads are squirmy, but in cold or rain, who cared...

I like the idea of limiting tire grip, especially in a "vintage" series. We all have seen period photos of the old cars just sliding/drifting everywhere due to lack of grip. Also can make putting down "too much hp" a skill too.

Heat buildup can be severe in tires with full tread if you're really loading them up on dry tracks. Shaving actually lengthens the life of the tire in hard track use....YMMV.

I've been using the Hoosier Street TD*S tires on my 2 liter 914/6 GT (2240 pounds wet without driver) for the past few years with 7 & 8 x 15" wheels and they are a pretty fast bias tire (1:48 @ Laguna) and look pretty vintage correct both in tread and sidewall. I start at 19 pounds cold typically get them up to 24-25 lbs hot. They've been quite durable but do gradually lose their stickiness after a few typical weekends.

I've also used the R6 tire (225/50-15 on 8" wheels at all 4 corners) at Sears Point and it is probably 2 seconds faster than the TD*S per lap, but has the typical radial fast break away issue and is not really period correct. Same durability as the TD*S.

In the past I used the Goodyear Blue streaks which weren't as fast as the TD*S tire and they don't have the right sizes any more.

Jon