Sayajin

Okay, So I am hoping you guys can give me your input. Long story short, I own a Champion Built 997.1TT and run Time Trials with NASA and DE4 with other groups.

I am at the point where I need to make the change from Z rated tires to full road racing slicks in order to remain as competitive as I need to be. Well I have read serval posts of guys saying the stock 997.1 TT rim makes a great inexpensive track rim, however the only issue is that they are 19in and not 18in. Well through an odd situation, I currently have 3 of 4 TT rims sitting in my garage (FedEx lost one, long story, no its not replaced).

So the situation I have is, do I spend $450-550 and buy one rear OEM TT rim and try to find someone who makes 19in slicks? (Which I would appreciate some advice on if there is someone who makes those as I have had trouble finding them). Do I break down and buy a set of OZ Rims in 18in and run Toyo RA1s on them, or do I try out these Forgestars that I have heard people talking about, get them in 18s and still run the RA1s?

To my knowledge, the stock 997.1TT rims are extremely strong and relatively lightweight, the problem is I cant seem to find slicks (brand and model) that i can run on those rims. I would rather not have to buy an entire new set of wheels as these are just for the track, but I may not have a choice.

So with that said, who if anyone makes 19in slicks that I can run on 997.1 TT rims and what model? Or should I go with the OZ or Forgestars instead?

Thanks for the input! I have a few weeks before the next race and I need to make a decision.


-Sayajin

eurotom

You can run hohos with your 19's but they're not cheap and knowing your set up will last you a dozen heat cycles.

Go with an 18" wheel and run nittos

Sayajin

Are the Nittos that much superior a tire over the Hoosiers and/or Toyos? I very rarely hear of a guy running Nitto slicks.

-Sayajin

Steamboat

Most of the DE guys in our instructor/expert group who trailer their cars run Nittos and save their Hoosiers for time trials, etc. They are a bit slower than Hoosiers but last approx. twice as long. Hoosiers, as EuroTom points out, heat cycle out in 10-12 sessions. At ~$1500 per set, that's ~$150 for tires for each DE session. It starts to get real spendy....

Can't help you with the Toyo's as I don't know anyone who runs on them.....

PS You should be running at least 3' negative camber with slicks and you'll need aftermarket suspension components to get there.

Sayajin

Thanks for the advice. Now the Nittos make sense, I have been talking to TT guys about what they are running. 2x the life definitely makes the Nitto an attractive tire.

As an aside, the alignment thing was going to be one of my next questions. I currently run an aggressive track/street alignment but I realize with a full track setup I will want to be even more aggressive. I currently have a full tarrett/bilstein suspension so the car supports more, I just don't know what the correct settings to dial in are. Any suggestions on a track alignment with slicks would be greatly appreciated!

-Sayajin

Steamboat

A couple of other things: Nitto's do not come in 19" sizing so you would need 18" wheels to accommodate them. Hoosier's come in 19" but not in 305/30/19 so you'll have to go up to 315/30/19. Most of the guys I run with have cars which are RWD and they have much greater flexibility with regard to which tire size they can run. Inasmuch as the 997 TT has an electronic differential, I have been reluctant to use none-oem sizing for fear of damaging the unit. The 996 TT utilizes a viscous differential which is completely different. Apparently, according to others on other forums, you can successfully run 18's on the 997 or slightly wider 19's but the circumference needs to be withing about 3% of oem spec. But, I have also been discouraged from making these changes by others I consider to be knowledgeable in this arena so I instead run Toyo R888's in oem sizing which are somewhat better than streets and, of course, somewhat slower than slicks. I can also drive them to the track (225 miles each way) when the weather is forecast to be good and can be reasonably assured that I will make it home as well if it starts to rain.

With regard to suspension, you need to decide if this car will be strictly for the track and trailered too or a DD too. More than 3' negative camber will quickly eat your tires on the street and I know guys with Cup cars that run negative 5' on the track. However, when the tires heat cycle out in less than a dozen sessions anyway and the car rides home on a trailer, that's not such a big deal although it's an expensive one. My general advice would be to find a good tuning/race shop that does a lot of Porsche work and get their recommendations for both suspension setup and tire selection. When I had mine set up at Evolution MS, they chose to install RSS lower control arms front and rear rather than the Tarett camber plates I provided. I don't know if that was a preference thing or if the RSS components did things the Tarett could not do. You might also want to see what the track guys think on the DE/Race forum here. Best,

Sayajin

Thanks for the info. I think I am going to go ahead and get the Forgestar 18s however I have also heard about the circumference issue so I will be sure to try and keep those specs in line.

My car is a mix of both track attack and street attack. I trailer the car down to events when I am tracking it, (allowing for much more aggressive camber as well as the use of slicks) then when I get home from the event I change the alignment back to my street setup and swap wheels out. I went with just about every suspension component fully adjustable to allow me to enjoy both tracking it and driving it on the street.

I will however pop into the track section of the forum once I decide on wheels and tires to get alignment recommendations. Thanks!

-Sayajin


-Sayajin

philstireservice

The other thing is don't confuse DOT track tires with true racing (non DOT) slicks. There is a big difference.