Street tires - 19" vs 18"

[bradynel]

Hi all,

I'm a new member who just signed up for the solosprint 2010 series. I will be driving my 350z. I say driving as opposed to racing due to the fact I have very little experience on a track. I'm enrolled for the two day drivers training which I hope will help but it's hard to teach an old dog new driving techniques...

Anyway the purpose of my post is to evaluate the benefits/compromise of running 19" wheels vs. 18" wheels. I want to run street tires for safety reasons (maintain slower speeds) but still be competitive. I am on 19" rims now which I think are a little on the heavy side (21lbs) and was curious if I should consider changing to 18"s? These wheels will be for track days only. I'll be doing the wheel swaps at home. Also any input as to what type if street tires to run would be GREATLY appreciated.

Thanks in advance,
Brady

[Cap'n Pete]

Brady,

IMO, 21 lbs is pretty good for a 19" wheel! Even the 17" Corvette wheels I have are around that weight!

I would tend to think that the larger diameter wheel would be better, as you would then run a tire with shorter sidewall to fit. Less sidewall = stiffer, less give = better steering response ........... again, all IMO ;).

The popular, sticky street tires these days seem to be:

- Kumho Ecsta XS
- Nitto NT-05
- Bridgestone RE11
- Toyo R1R

... and maybe a couple others.

Look for treadwear ratings of 140 - 200 UTQG, where 140 is the lowest you can run in "street" class. Below that is considered an R-comp.

For your first season, it doesn't really matter WHAT you run under the car, as long as they're round and rubber and have enough tread depth to survive the day ;).

[jonweir]

For a novice to solosprint/track I'd recommend going with a budget solution at first. You will have a much better idea of what you want to spend on after a couple events.
So, my recommendation is to get good street tires for your existing wheels, and run the season on them. Then, later on, you can decide on track wheels and tires. You will be more interested in the widths of wheels and tires you can fit, rather than the diameter. The diameter will generally only add a bit of rotating weight and increase the cost of tires.

My personal fave street tire is the Yokohama Advan Neova AD08. I just finished off a set of them, they lasted a whole summer with 6-8 lapping days and competition events on them. They are also arguably one of the fastest street tires on the market. This tire and the ones mentioned by Pete are all in the same performance category, you won't be disappointed with any of them.

[bradynel]

Thanks Pete, and it was nice to meet you at the open house.


Brady,

IMO, 21 lbs is pretty good for a 19" wheel! Even the 17" Corvette wheels I have are around that weight!

I would tend to think that the larger diameter wheel would be better, as you would then run a tire with shorter sidewall to fit. Less sidewall = stiffer, less give = better steering response ........... again, all IMO ;).

The popular, sticky street tires these days seem to be:

- Kumho Ecsta XS
- Nitto NT-05
- Bridgestone RE11
- Toyo R1R

... and maybe a couple others.

Look for treadwear ratings of 140 - 200 UTQG, where 140 is the lowest you can run in "street" class. Below that is considered an R-comp.

For your first season, it doesn't really matter WHAT you run under the car, as long as they're round and rubber and have enough tread depth to survive the day ;).

[bradynel]

Good points. Thanks Jon. I have some time to mull it over and see how I feel after the first few events.

Look forward to meeting you all!



For a novice to solosprint/track I'd recommend going with a budget solution at first. You will have a much better idea of what you want to spend on after a couple events.
So, my recommendation is to get good street tires for your existing wheels, and run the season on them. Then, later on, you can decide on track wheels and tires. You will be more interested in the widths of wheels and tires you can fit, rather than the diameter. The diameter will generally only add a bit of rotating weight and increase the cost of tires.

My personal fave street tire is the Yokohama Advan Neova AD08. I just finished off a set of them, they lasted a whole summer with 6-8 lapping days and competition events on them. They are also arguably one of the fastest street tires on the market. This tire and the ones mentioned by Pete are all in the same performance category, you won't be disappointed with any of them.

[Todd #65]

Something else to consider is that the wheels you use on the track often end up with some minor scratches on them. It's not too bad but if your street wheels are pristine and you want to keep them that way, it's something to think about.

[Cap'n Pete]

^ ^ ..... and on rare occasions, they become the basis of a grow-op ;).

[Dave Barker]

21 lb is a really light weight 19" rim.:eek:

OTOH I don't agree with Pete on sizes.

You are a novice and the taller side wall of an 18 " tire (assuming same overall tire diameter as the 19" combo) will be more forgiving. If 17s fit over your brakes, I would use those.

Definitely pristine street wheels may not look so good after a couple of spins so if you have access to cheap 18"s I would suggest those. 18" tires tend to be a bit cheaper as well.

You might also consider the Dunlop Direzza star specs. Good in the dry and very good in the wet, especially if you are using them to get to the track.

[bradynel]

Something else to consider is that the wheels you use on the track often end up with some minor scratches on them. It's not too bad but if your street wheels are pristine and you want to keep them that way, it's something to think about.

Never thought too much about that but I don't want to scratch these up.

http://i21.photobucket.com/albums/b272/bradynel/volks2.jpg

I'll get a dedicated track rims/tires.

Thanks for the heads up!

[Kart14]

Brady

As you know I'm running 17x9.5 RPF1s with 38 offset and 255/40 RS3 on the z. As you've probably seen from the my350z.com formus there's lots of options. I decided on the 17s because the wheel and tire combinations are a lot cheaper and lighter. Extra fender gap with the shorter combination cuts down on street cred:); but it is a track setup.

I need a 3mm-5mm spacer in the front and there's tons of room in back. I don't have the Brembos so can run higher offsets. I believe you can still fit 17" RPF1s with the Brembo provided you run a lower offset like 18 (I can't be sure, check the forums if you go that route) and then you might run into fender problems.

A second set of wheels is nice if it's in the budget and it does save dog earring your street tires. But it is a big commitment you may want to defer until you've got the disease.

Good luck,
Matt

[bradynel]

Hi Matt!!!

I am selling the Volks and using the money for rotors/pads/brake fluid/18" rims/tires. Even though this is my first year I hope to post some ok times...

Thanks for ALL the advice, it is greatly appreciated.

Cheers,
Brady

[RRRex]

Brady

As you know I'm running 17x9.5 RPF1s with 38 offset and 255/40 RS3 on the z. As you've probably seen from the my350z.com formus there's lots of options. I decided on the 17s because the wheel and tire combinations are a lot cheaper and lighter. Extra fender gap with the shorter combination cuts down on street cred:); but it is a track setup.

I need a 3mm-5mm spacer in the front and there's tons of room in back. I don't have the Brembos so can run higher offsets. I believe you can still fit 17" RPF1s with the Brembo provided you run a lower offset like 18 (I can't be sure, check the forums if you go that route) and then you might run into fender problems.

A second set of wheels is nice if it's in the budget and it does save dog earring your street tires. But it is a big commitment you may want to defer until you've got the disease.

Good luck,
Matt

^^ If you can fit 17s, then that's the way to go. Hell, if you can fit 16's I'd say get those. I find decreasing the overall wheel/tire size with the smallest rim that will cover your brakes and the lowest sidewall tires you can find will improve gearing and makes the car feel more torquey. It's annoying on the street because your speedo is off and you're changing gears a lot more, but on the track it's heaven. You hit the gas and she goes. It does look a little goofy though, but when your times start falling, no one will be laughing. :D

[gearhead]

Interesting article on the affects of different size wheels & tires.

http://www.caranddriver.com/features/10q1/effects_of_upsized_wheels_and_tires_tested-tech_dept

My car came with a forged 19" setup that is lighter than the factory 18" cast setup.I run 10x 18' s that weigh 20 lbs on track mainly because of the wider availability of 18" track tires that are much cheaper than the 19" stuff.

[ADAM]

kinda stupid test when all the tire widths are different..why wouldnt they test the same tire widths?


IMO go with the absolute smallest diameter rim with the widest tire that you can fit over your brakes

they will be cheaper tires, and less weight overall

[h.diep]

Off topic, but is your exhaust running a single exhaust out the driver side? I think I might have seen you today on the 401 but I could be mistaken.

[bradynel]

Off topic, but is your exhaust running a single exhaust out the driver side? I think I might have seen you today on the 401 but I could be mistaken.

I was indeed on the 401 this morning. Yes it is a titanium single coffee can off the drivers side. Were you in the Acura?

[h.diep]

I was indeed on the 401 this morning. Yes it is a titanium single coffee can off the drivers side. Were you in the Acura?

I was actually in the red honda going eastbound, this was in the afternoon during rush hour.

I can tell you like to downshift haha, sweet ride though, hope to see it out some more this summer

[bradynel]

I was actually in the red honda going eastbound, this was in the afternoon during rush hour.

I can tell you like to downshift haha, sweet ride though, hope to see it out some more this summer

Yeah, trying to get in some rev matching, blip, shift, blip, shift. Kind of hard in rush hour... You have NO idea how annoying that exhaust is early in the morning!! I was going to switch it out for some other exhaust but I'll leave it on for a few events and take the other car to work.

Eyes out for a purple charger.