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joecycles
12-13-2004, 12:38 PM
I have a Datsun 510, uses 13 x6 wheels. I am of the understanding with the new wheel rule that I can up the size to 15" wheels. I understand the thinking of this but is there an advantage with the larger wheels? Second, I do not believe 15's will even fit under my car so I am better off converting the car to H-Prod (limited prep)!

Geo
12-13-2004, 01:09 PM
Originally posted by joecycles:
I have a Datsun 510, uses 13 x6 wheels. I am of the understanding with the new wheel rule that I can up the size to 15" wheels. I understand the thinking of this but is there an advantage with the larger wheels? Second, I do not believe 15's will even fit under my car so I am better off converting the car to H-Prod (limited prep)!

I'm not sure why any of this would be reason to move to HP.

You can fit up to a 15" wheel. You are not required to. If a 13x6 fits, why wouldn't a 15x6? You would just need to change the profile of the tire. I seriously doubt any performance advantage to a 15" wheel - especially for your car with a fair bit less power than those in higher classes.

In short, I think you're over reacting.


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George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com

racer_tim
12-13-2004, 03:03 PM
But do consider converting to LP HP. Racing on real race tires is a kick, and you can use your same 13x6 rims, and flare if you want to.

The 20x8x13 slick does need some extra room on a 510, but you could still use your DOT tires at first. There is nothing in the production rules that state that you can't run a DOT tire.

Come on over to the dark side.



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Tim Linerud
San Francisco Region SCCA
#95 GP Wabbit
http://linerud.myvnc.com/racing/index.html

rbt510
12-16-2004, 03:06 PM
Originally posted by joecycles:
I have a Datsun 510, uses 13 x6 wheels. I am of the understanding with the new wheel rule that I can up the size to 15" wheels. I understand the thinking of this but is there an advantage with the larger wheels? Second, I do not believe 15's will even fit under my car so I am better off converting the car to H-Prod (limited prep)!

I run a ITC 510, with 205-60 x 13 Kuhmo's, and have started to look at this rule. I know many people run 14 or 15 inch rims on 510's, but for street use, so fitting them is possible. Tire options is a big reason to consider this. A 205-50 X 15 Hoosier is an inch taller than a 185-60 x 13. Also, not all 205-60 13 tires are created equal, and some cause clearance problems.
For example, Hoosier's or Yokes in this (205) size won't fit, and you have to drop to 185's, but Khumo's or Goodyear or Toyo's will.
Is is going to worth the effort to buy more wheels and tryout all the variations?? Not sure yet, but I know tire availability may force us to.......

Bob

Andy Bettencourt
12-16-2004, 04:30 PM
Originally posted by rbt510:

Is is going to worth the effort to buy more wheels and tryout all the variations?? Not sure yet, but I know tire availability may force us to.......

Bob



Bob,

I think you have to weigh a few factors. Width on a car of the 510 weight is in the category of a balancing act. You COULD overtire the car...with such a low weight and realativly little power, a norrower tire that 'works' better should be faster. We also love the Goodyears BTW...

The other issue is gearing. If you are limited in the gearing you have available, then going to a taller setup may be a bad thing even though you have more rubber on the road. Having said that, maybe you have enough punch out of teh corners but arelimited on the big end and you want to grab a few extra MPH...

I am betting that going to a taller setup will hurt most in overall speed.

AB

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Andy Bettencourt
New England Region, R188967
ITA project SM
www.flatout-motorsports.com

racer_tim
12-16-2004, 10:15 PM
Andy, the final drive gearing on a 510 is EASY. I know of a previous ITC 510 driver that had 3 different "pumpkins" for the 3 tracks that we run (Laguna Seca, Sears Point, Thunder Hill)

Gearing on a 510 isn't an issue.

Not like in a FWD VW.

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Tim Linerud
San Francisco Region SCCA
#95 GP Wabbit
http://linerud.myvnc.com/racing/index.html

[This message has been edited by racer_tim (edited December 16, 2004).]

rbt510
12-17-2004, 12:17 PM
Andy,
Tim is right - many gear ratio's are available for the 510, but some are harder to get than others.
I am going to try the 13 inch Goodyears next year. Just concerned about longevity, so I was leaning torwards the Toyo's.
I am not really ready to be buying more wheels, considering how much I have run the car, and other work I would like to do first.
Bob

rcr510
01-07-2005, 05:52 PM
Bob & all,
I am curious what type of Goodyear & Kuhmo DOT tire you are talking about for a 510?

I have another question as to running 205/60/13's. I have one set of Panasports which I usually run Hoosier 185/60/13's on. These barely fit and I will see a faint black line where it is rubbing on one side. Toyo's (185/60/13) on those rims have excess room. I have another set of what I believe to be Enki rims which have a mesh pattern similar to an upgraded BMW factory wheel from the mid 80's on a 3 series car. The Enki's have a slightly narrower offset. Will say the Toyo/Goodyear/Kumo fit on the Panasports as well as the Enki's?

For the record, I love the Hoosiers (excepting wear although I can get about 3+ full weekend's on them) but the 185/60/13 Toyo's I have ran fall off about half way through a session and begin to whail & completely loose grip. I gave up on them as I did not think a 205 would fit. Also, isn't a 205/60/13 taller? I have been running a 4:37 gear ratio which seems a tad low and the 205 may help that.

Matt
ITC 13 - Kansas Region

Bill Miller
01-07-2005, 06:13 PM
Matt,

One of the things you'll find is that not all tires are the same size, even if they're "stamped" as such. Hoosiers tend to be wider than Kumhos, I can't speak for the Goodyears or the Toyos, as I haven't done a side-to-side on them. For a 205/55/14 on a 6" rim, the Hoosiers were 1 - 1.25" wider than the Kumhos.

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

Despr8dave
01-07-2005, 08:41 PM
I ran 205/50/13's on Pannasports on my 510 with no clearance problems at all, but with Bridgstone Potenza's (potatoes). Also had two "pumkins", one, 410, the other 390. The ratios don't seem too far apart in numbers, but a big difference when driving, specially coming out of a turn and down the straights. Doesn't take much time to change out either, just unbolt the axles and four bolts for the rearend. And of course the drive shaft!
David
No replacement for displacement