spec tire size

#1

Just curious to know if any1 has run during a pracice / test and tune, the spec tire vs a toyo ra 1 225.50 tire. Would like to know how car felt in comparison. I have a car built along spec rules but mainly doing DE’s as of now. TIA

#2

Some have used this size and felt the car was faster. However, I have raced with other E30’s on 225’s and they were not much faster…but of course the tires are only one part of the package.

The Spec E30 philosophy is close and low cost racing and if everyone has the same tire (regardless of the size or brand) it won’t affect the actual racing. It will, however, affect how much we spend on tires.

Carter

#3

Carter…
thanks for the reply. I have an opportunity to get some 205’s priced well, and have been running 225’s, so I am curious if it is much of a step down…my current speed/skills may not even notice it!

#4

I did some testing in my KP car with 225 Toyos and they were slower than the 205. My car was perfectly dialed in for 205’s, but the 225’s would have worked better with a stiffer front end. Another 50-100lbs of spring rate would have done it, or more front swaybar, but I was already running full stiff so not much I could do about it that day. For SpecE30, 205 is plenty of tire for the soft suspension we run. Also, 205 is the same tire as SpecMiata runs so Toyo makes plenty of them and there’s good pricing out there as a result.

#5

I guess it’s possible that I improved by a couple of seconds due to mental imaging between race weekends at Willow Springs, but I think the gain was at least in some way related to my switching to the 225’s. Honestly, I would say it was likely partly due to the tires and partly due to the driver having more confidence that the car would hold better with the bigger tires. I’ll go with 25% tires / 75% driver.

Joel - I would say that you likely will notice a slight drop in cornering grip, but not all that much.

I also ordered 2 sets of Hoosier R3SO5’s in 225/45/15 trim, to try out in GTS this summer. They have them at ~ 33% off at www.hoosiertire.com, and I just couldn’t resist! :evil:

#6

sdais wrote:

[quote]I guess it’s possible that I improved by a couple of seconds due to mental imaging between race weekends at Willow Springs, but I think the gain was at least in some way related to my switching to the 225’s. Honestly, I would say it was likely partly due to the tires and partly due to the driver having more confidence that the car would hold better with the bigger tires. I’ll go with 25% tires / 75% driver.

Joel - I would say that you likely will notice a slight drop in cornering grip, but not all that much.

I also ordered 2 sets of Hoosier R3SO5’s in 225/45/15 trim, to try out in GTS this summer. They have them at ~ 33% off at www.hoosiertire.com, and I just couldn’t resist! :evil:[/quote]

While I completely agree, support, endorse and really like our tire spec,
you will notice some very dramatic decreases in lap times with the hoosiers. Of course you will also notice a sharp decrease in tire life, and dramatic decrease in pocket book.

I love hoosiers, but I can afford toyo’s…

#7

thresholdBen wrote:

While I completely agree, support, endorse and really like our tire spec,
you will notice some very dramatic decreases in lap times with the hoosiers. Of course you will also notice a sharp decrease in tire life, and dramatic decrease in pocket book.

I love hoosiers, but I can afford toyo’s…[/quote]

Ben - that’s what i’m hoping for (the decrease in lap times), and expecting (the decreae in tire life & pocket book). Actually, I kind of hope that I don’t like them - that way the temptation won’t be there anymore! I’m not sure what the chances of that are, though. From what I’ve heard not very good.

Steve

#8

traqrat wrote:

Rumor is that that tire is getting scarce…I will look in to what is available to see if it is really true.

#9

nasaregistrar wrote:

[quote][
Rumor is that that tire is getting scarce…I will look in to what is available to see if it is really true.[/quote]

Last time I was at Radial Tire in Silver Spring, I assisted in looking for my rain tires (mounted on 14" bottle caps) in the back and there was an overabundance of the 205 50/15 tires there.

-Steve

Post edited by: stevekappy, at: 2006/05/11 08:27

#10

I think it is the 15’s which I thin is the same as the Spec Miata’s use

#11

When on the track does the car ever feel "under tired" w/ the Spec set up?

#12

Only when you go into a corner too hot. :wink:

#13

This is off-topic, so I’ll apologize in advance, but a couple of times last summer during practice weekends I drove with the 195/65/14 Pep Boys Mud & Snow tires that come on the car when I bought it. Do this once and you’ll never think the spec tires are "under-tired"…ever!

Actually, I was pretty darn surprised that the Pep Boys tires really weren’t nearly as bad as I’d thought they would be in cornerning grip. They sucked at braking, though I was still able to pull laptimes within 6-7 seconds of the RA-1’s. Still, it was fun - and challenging - to try to get around the track on snow tires. Of course it looked like you guys out east could have used them earlier this year!

NOTE - YOU’RE TRACTION WILL BE SIGNIFICANTLY REDUCED WHILE DRIVING ON A TRACK ON SNOW TIRES, AND YOU SHOULD REDUCE SPEEDS ACCORDINGLY. THE AUTHOR OF THIS POST ASSUMES NO RESPONSIBILITY FOR ANY INJURIES OR PROPERTY DAMAGES THAT MAY RESULT SHOULD YOU FOLLOW HIS STUPID IDEAS AND TRY DRIVING ON A TRACK ON SNOW TIRES