333pg333

I've done a bit of reading and searching in here but I can't quite find what I'm after. I have been tossing up between going for a DOT Hoosier / R-1 type tire or just going for full slicks. From what I gather, except for the top of the line Michelins et al, you can get into Dunlops or Kumho level slicks for a good price. Granted they are not meant to last as long as any DOT or R spec, but if I'm contemplating entering the Open class against GT3/2s with slicks then there's not much point giving up the advantage totally to them. Our 'racing' is either time trial sprints over 6 laps where you can overtake or be overtaken (It is a competition), or even racing in pairs. I have a modified 951 which probably weighs around 2850lbs plus another 220lbs with me and fuel. It is about to have a motor that will be generating over 450whp. I can't afford the uber F1 type tires or the ones that last 1 day. Is there something between these and the DOT that will give me a good compromise of speed vs durability?

btw how do you get more specific on the search function? If I just type in Slicks in Advanced it comes up with a million threads. Is there a better way of doing searches?

Thanks

Bob Rouleau

Racing slicks are faster then Hoosiers. On the other hand your suspension has to be set up to work with them. Race slicks usually require stiffer springs/shocks and a lot of negative camber. Moreso than Hoosiers. A race shop can advise you if your set up is appropriate or, post your setup here.

Best,

brucegre

As Bob said, slicks are considerably faster than R-compounds. To quantify, at Calabogie, my best lap in three years on R-compounds was a 2:17 flat. I bolted on a set of Pirelli's last year that were already starting to heat cycle out and did a 2:14.6, with no changes to the car (a street 2004 GT3 with a track setup).

However, they are pretty expensive - in Canadian pesos, Michelins are about $1700 a set, Pirellis $1500, Dunlops $1900. Preferred tires are the Michelins, you can push all of them to about 10 heat cycles but performance starts to fall off after the first few heat cycles. They do seem to go off a second or two a lap and then hold there until the end of their life, so I'll run them 10-12 heat cycles and then treat myself to a new set.

The real problem, cost wise, is that 6 laps is going to be a heat cycle and that could be pretty expensive. Hoosier R6, BFG R1, Michelin Pilot Sport Cup - all will last considerably longer then the slicks, but none will touch the slick performance - welcome to competition!

dmwhite

slicks typically take longer to come up to operating temp than dot's - this might be something to consider it you are doing sprints...

i'm also not convinced that all slicks are that much faster than hoosiers/hankooks/bfg's...i'd say that some of the best slicks (very expensive if available) are a good bit faster but not all of them...

333pg333

Hmm, the cost factor is a definite concern. Almost sounds like having the R spec on in the morning and going out on the slicks in the afternoon could be a decent way of extending the life of them.
The car has a custom KW '2 way' race setup. Springs are 616lb/in f and 708 lb/in rear effective so it's not stock.
Are there not cheaper sets than $1500 - $2k? Not that I want bargain basement stuff but I thought there were sort of an elite class and then the 2nd level underneath these?

mark kibort

We have a lot of data out west for that comparison. even lousy slicks (meaning cheaper versions, but not heat cycled out) are much faster than new hoosiers. Times are in the 2 second a lap faster time at Laguna Seca, Sears Point or Thunderhill. The BMW guys have proved this pretty conclusively. Most rules add a substantial amount of performance weight on a slick, regardless of the manufacturer.

Set up is important as was mentioned, but often, a simple bolt on will amaze the driver. Just because someone doesnt take advantage of the increased adheasion, doesnt mean its not there. Anderson for example in his monster 928, runs 1:30.7 on slicks and hasnt run much faster than a 1:34 on DOTs at Laguna. He was doing such a test this past year to save wear on the slicks and saw this kind of spread. Brand new hoosiers, (under 4 heat cycles old) and the (A) series version of hoosiers, might narrow the gap a bit.

mk

333pg333

Thanks Mark. I'll see what sort of money slicks cost out here. Generally everything automotive is more expensive, sometimes double!
It's very tempting to go for slicks but the cost / life factor will come into it.
btw, what sort of protection for oiling issues are the race 928s taking?

DanR

if you are only doing 6 laps per session and you will get t best 10 HC, that is only 60 laps per set or $32 per lap. Now that is expensive tire use!!! As you said, cost is an issue and to me it seems that it will cost double as slick HC faster than a Dot R.

I suppose the question is that extra second or so worth the cost

333pg333

Yeah that pretty much sums it up. Hmmm again.....

cgfen

when you do an advanced search, search by KEYWORD, choose the forum of interest, and select the SEARCH TITLES ONLY option, instead of SEARCH ENTIRE POST option.

cheers

Craig

SG_M3

I tend to agree, as long as they are similar compounds. The slick is probably a little more stable through a race, but not sure if its out right faster.

Care to share this data? An valid data please, not 3 years ago i ran xx.xx on DOT's now i run xx.xx on slicks.

Same day, same car, same driver, same track, only tire change being the difference. Then see, how much fasterit is setup for sliclks. That would be valid data, not heresay

333pg333

Just got quoted on some Dunlops (4 x 280/18) $2600au....told you we pay over the odds.

va122

isn't that like 1900 USD?? That's normal

333pg333

Yes I s'pose so, but it's also relative. If you and I get paid eg $900 per week it's going to take me longer to pay for my slicks than you.
Are Dunlops considered one of the better brands?

mark kibort

Over 300 race days, on 3 different platforms, one of which has more races on it than any 928 in existance, and no oiling protection, EXCEPT..........Amsoil.

mk