tire pyramid discussion?

[Jad]

It is raining, another race weekend is about to be cancelled, and I was getting ready to order tires for Fontana and was thinking through my options. I thought this might be interesting to some and wondered if anyone disagreed with my thoughts or had something to add? I will base this info on a typical ~90 second Q track driven properly (no power on oversteer, or overdriving and scrubbing the front tires causing excessive wear).

The fastest tire would be a full racing slick, they last about 1 track day, and cost $1k+ per set.

About 1 second slower, are the Hoosier tires, they last 2-3 days and cost about $1K.

Another second slower would be the Victorracers, they last 5-6 days and cost about $700.

The Toyo RA-1's are next. They seem to be a couple tenths slower when new, but catch up to the Victorracers as they were out. They last 8-10 days and cost about $750.

Another second+ slower would be the Azenis, they last 12-14 days and cost about $650. (limited sizes available for Porsches)

Next I would say all the 'ultimate' performance name brand tires are about 1 second slower. I haven't really noticed much difference in times among the tires. The expensive tires in this category tend to ride smoother and quieter, but not necessarily improve times. There are a LOT of variables here, so I may be missing some tire, but basically nothing has stood out in the last few years, though some tend to chunk and fall apart after 1-2 days if you are not very gentle with them. These tires range in price from $600-1,300 and last from 10-20 track days.

I am basing the above on my experience in a Boxster S, 996 and 944 turbo.

Anyone disagree or have something to add?

[ajackson]

Only thing to add is something that some people miss when looking at prices:

Slick: $1k/day (0 sec)
Hoosier: $300-$500/day (+1 sec)
Victoracers: $120-$140/day (+2 sec)
RA-1: $75-$95/day (+2.x sec)
Azenis: $45-$55/day (+3.x sec)


These are all roughly based on what you posted. Puts things into perspective when comparing various tires.

[Greg Phillips]

I will base this info on a typical ~90 second Q track driven properly (no power on oversteer, or overdriving and scrubbing the front tires causing excessive wear).

Anyone disagree or have something to add?

But who drives like that ?

Good assessment, probably as fast (maybe faster) as the Falken's are the BFG TA KD. But they are also more like $900-1k per set.
Would be nice to have a few larger size Falkens for the 928.

Falken or Toyo spec tires??
Although another issue to consider is several people are using used slicks at significantly lower cost, but with variable grip.

Greg

[Pete Millikin]

But who drives like that ?

Yes Mr. Power oversteer your milage may vary


Good point on the used slicks and Hoosiers. I believe Mr. Tweed has some experience here.

How about setup complications? For example, I know the Victor racers and Hoosier radials like lots (approx 3 deg) of negative camber. I'm not sure about true slicks like the camber due to sidewall stiffness and tread softness, so optimally you don't run them lots (timed runs only??) unless you change your setup.

[Jad]

Only thing to add is something that some people miss when looking at prices:

Slick: $1k/day (0 sec)
Hoosier: $300-$500/day (+1 sec)
Victoracers: $120-$140/day (+2 sec)
RA-1: $75-$95/day (+2.x sec)
Azenis: $45-$55/day (+3.x sec)


These are all roughly based on what you posted. Puts things into perspective when comparing various tires.

Well put. I have heard time costs money, but if we figure a 12 lap AX, saving 1 second per lap on slicks vs hoosiers, at a cost of $500. 12 seconds for $500 is $2,500 per minute or $150,000 per hour . Hmmm, maybe this wasn't a good thread.

[kary]

I have to say I used to run hoosiers and now run slicks and I do not use 1 set per day, not even close.

I get between 4 and 6 track days on average for a Pirelli slick. The average is because the rears on my car go faster than the fronts (3 to 1). The effective performance of these tires is good for the the first of the life and then deteriorates after that, which is mostly the same for all tires.

Hoosiers on the other had, I was getting 5 to 8 track days per set. same usage from front to back.

So I am not quite buying into the scale you presented. Though I have not sepnt a great mount of time calculating, just provinding my expereince.

Another factor is it all depends upon your driving. Whe I drove with cort Wagner in my car betweent he two of us I used up 1 new nset of hoosiers in 3/4 of day. We drove for 2.5 hours of track time. He definietly drove hard because those hoosier were screaming!

[ttweed]

Good point on the used slicks and Hoosiers. I believe Mr. Tweed has some experience here.

Used slicks can be had for $80/ea., plus shipping, so they can be quite economical. Depending on your driving style, the compound, and the weight of the car, they can last a short time or a very short time (20-60 laps) before performance falls off so much that you might as well be on DOT-Rs. The first laps are always the fastest, and you start losing a tenth or two each lap from there. Some of the used slicks I have bought have looked almost new, perhaps only used for a qualifying session and then resold. Choices in size can be limited by availability in the used market, though. Right after the SCCA runoffs in Sept. is a good time to buy them.

How about setup complications? For example, I know the Victor racers and Hoosier radials like lots (approx 3 deg) of negative camber. I'm not sure about true slicks like the camber

There are both radial and bias ply construction slicks. The radials like a lot of camber, the bias plys don't. The ones I have used have all been bias ply, so I have to run a compromise setup on my 911 when switching back and forth to DOT-Rs, but Steve G. runs a Goodyear radial slick on his 914 that can use the same setup as the Hoosier DOT-Rs. Brand new, his slicks would be almost $400/ea. Used, they are a bargain at $80.

I would also add that my Falken Azenis cost $275 for all four, mounted and balanced, and they are into their second season with plenty of meat left. The smaller sizes are much cheaper than $600. I haven't found anything with more bang for the buck for autox, but I hear they get greasy when overheated in continuous lapping. Maybe not the best Time Trial tire in the heat of the summer.

TT

[jgunn]

The new Kumho V710 is definitely worth a look. There are lots of tires waiting to be unloaded from containers in Long Beach that fit most Porsches. Come to the March Tech session at Discount Tire to talk to Rick Brennan from Kumho.

I ran these back to back with the Hoosier on the GT2 and the 710s are worth 1 second on a 60 second course....

Also, they wear really well and don't fall off until right near the cords. They work great for track days and autox. Ask Bill Dawson what he thinks about them. I talked him into trying them last year and ever since he is a firm believer.

I know Hoosier is working on a tire to try and catch up with Kumho. It will be called the _3s05, but from the testing I have seen it will not be any faster than the 710.

[bryanearll]

If the insight is on driving rather than modifications there is still plenty of room in the STREET STOCK classes without the additional expense, wear or BToD.

And, if your expectations are BRI indexed against your relative class then 'who cares' if he GT2 kicks serious BUTT with a 1' 17" at he last Q dialog.

OK, that was pretty damn fast and I'm reasonably assured that Gunn or Dente could drive the heck out of my ole 996.

MORE TO THE POINT, that's why I liked the 944 SPEC challenge. Sure, I'd rather kick *** in my car but "all things being equal", I'd rather kick *** in YOUR CAR.... Smile

Now if Gunn would just pony up for the GT2 Challenge... (BECAUSE, we should ALL be able to drive that car don't you think?....)
Just me and my 200k? Say do you think that $100 is reasonable to drive the GT2 for 3 laps at the Q?
Bryan
b

[ttweed]

Say do you think that $100 is reasonable to drive the GT2 for 3 laps at the Q?

Not if it was my GT-2, otherwise, YES! C'mon, Harry, hook us up, bruddah! I promise I'll drive your car slower than JGW!

JGW- the Kumho 710 is a tire I would definitely like to try. If Kary's deal on the Toyos doesn't work out, I will order a set of those in 205/50-15s instead. Tire rack shows them at $143/ea., though. OUCH! I have bought tires from Vilven too-- I just called them and they are the same price there. Any chance of your Kumho connections getting us a discount on the 710s?

TT

[jgunn]

Vilven's price includes shipping though...

The 710s seem to be wearing very well -- 100 + runs and given the amount of time they are worth....

[MVZ944T]

Jad,

As someone who has just switched from Hoosiers to slicks, I might as well add my two cents worth on this discussion. On the the streets track I picked up a full 3 seconds over my previous run using Hoosiers. That was using used slicks vs a new set of Hoosiers! On the big track at Willows, I can go around turn 2 a good 10 mph faster than previous, plus I can go into 2 without braking or lifting pretty much full throttle in 4th. I never ever had the confidence with Hoosiers that I could do that. Turns 3-4-5 the car just screams. My last run there two weeks ago with NASA I turned a 1:32 in traffic. Best time with Hoosiers was 1:33 on a clear track. Would I go back to Hoosiers? Not a chance!

Maybe it is my car as it has a good deal of power and one of the main problems I had was being able to get on the throttle hard out of a corner. With ths slicks, that problem has been diminished greatly. Breaking is immensly improved. Front lock up was a problem with the Hoosiers, with the Goodyears I have not locked up a brake once.

As far as wear goes, my rears are holding up well, fronts I have been taking off the outside corners to the cord fairly quickly. Having said that, WSIR is hard on tires. Increasing pressure has helped and Jae Lee just tweaked the suspension with more camber so that should help. If that works I should pretty much make the weekend on one set, that would be $360 plus mounting. Not bad for my car.

[ttweed]

As far as wear goes, my rears are holding up well, fronts I have been taking off the outside corners to the cord fairly quickly.

I take it you are using the radial Goodyear G19 slicks, Mike, not the bias ply ones? What compound? How much camber were you running and what pressures?

Your comments about handling (and especially braking) were right on, in my experience. 3 seconds is exactly what I picked up when I changed from Azenis to slicks at the "Other Car" autocross in my Lotus clone, but it was a shorter and tighter track than Willow, and the R45 slicks I was using don't even come up to temperature at an autox, doing one lap at a time.

Thx,
TT

[MVZ944T]

Tom,

I am using radials, 370 compound in the rear, 470 in the front, at least for now. I may switch to 470's in the rear when it warms up. I am using 25.5x11.5x18 all the way around, so a lot of rubber up front. Mark Anderson made the suggestion and I am glad he did. Now I can swap fronts and rears if I need to as I have the same backset / offset front and rear. I am starting at around 24 lbs cold, shooting for 31-32 hot so far. Initially the car was right at 2 degrees camber on the front, which was good for the Hoosiers, but not enough for the Goodyears. Jae put in 3.1 degrees on the front and I have not run it yet, Fontana will be the next run.

Mike