Well im learning the ropes over here in NZ. Every car has to have a warrant of fitness in which they inspect the entire vehicle to a certain standard. Trying to get things in order so I can drag race this weekend. I had to get a new warrant of fitness not only to be street worthy but in order to drag race these vehicle inspections have to be in order as well.

Today I find out both of my rear tires will have to be replaced in order to pass inspection. Unaware of the condition and being on a low budget I had to scramble around and find some new tires.

I ended up with some Hankook K106. Many times we only consider the weight of our wheels/rims but some of these tires will put a hurting on you as well being quite heavy.

Here is a comparison of the Toyo Proxes T1-S versus the Hankook K106:
(225/50/16)

Toyo Proxes T1-S : 21 lbs.
Hankook K106 : 27 lbs.

Thats a whole 6 lbs heavier per tire. Now I dont claim to know that much about unsprung weight, but the two Hankook K106 added 12 extra pounds of unsprung weight to the car. Which according to some theory I see floating around is like adding 100-120 lbs to the chasis.

So keep an eye out on tire weight as well. I plan on passing WOF with these and then swapping the Toyo Proxes T1-S back on just for the race this weekend.

Overall wheel and tire combo were as follows:

SSR Competition/Toyo Proxes T1-S: 32 lbs.
SSR Competition/Hankook K106: 38 lbs.

I got 26,683 miles out of the Toyo Proxes T1-S, and the front tires (toyos) passed warrent of fitness today and still have tread left. I will be planning on swaping those soon for daily driving. The roads here are much tougher on tires than the USA.

Other notes:
Toyo Proxes T1-S : Treadwear 280, Traction AA
Hankook K106: Treadwear 340, Traction A

 

You're not going to see a difference changing the back tires, don't bother.

The issue with acceleration is for weight that is being actively rotated by the engine, i.e. only the front wheels on our cars. The rear wheels are dead weight just being pulled along. Reducing 12lbs off the rear wheels/tires of the car is just reducing 12lbs of static weight which is nothing. Of course every little bit helps, but you won't notice a difference in your timeslips. If it were the fronts you would though.

 

Reducing the diameter also helps as it gives you more agressive gearing AND lower weight. But a tire with too little sidewall will suck for traction.

 

neal i was hoping for some replys, it could be in my head that the car feels like it is pulling a trailor along now, lol ! i had to sit and scratch my head, should i put these heavier tires on the front for possibly better traction, but adding the extra weight to the front might counter against any gained traction.

Neal i think ive heard you say it 1,000 times that tire brands dont matter, and maybe condition too like ( new versus some old worn out trash tires).

the toyos on the front are old, and seem almost dried out..but i bet i keep them on there for race day versus putting the hankooks upfront. The toyos are rated AA traction and the Hankooks A. Again i dont really know enough about tires to know if that really means one is sticker than than the other, but the toyo sure are lighter.

Neal what would you do, leave the old toyos on with 26,683 miles on them, lol , or put the heavy new tires up front ? you know i should just put the new ones up front tommorow and go through the gears good and see if they stick. the toyos break loose pretty easy, could be the road or could be the tires age and wear, not sure.

So extra weight versus traction ? what to do ?

And very good points about the rear wheels just reducing static weight.

 

If the toyos are dry rotting, i.e. the rubber getting hard and crumbly and cracking then I'd considery putting the new tires up front. If the toyos are just worn down alot, but the rubber is still normal then you should leave them in the front.

 

here is a photo of 1 of the 2 toyos that are still on the car. both are in the same condition. Is there any good 60 foot times left in these, lol ?

 

I don't quite understand why Toyo T1-S are a good tire for drag racing, seeing as how the sidewall is quite stiff. Good tires for drag usually have mushy soft sidewalls.

 

I think the T1-S is popular mostly because of the weight which is an advantage over nearly any other street tire. And since they're affordable many people run em and make em work. I'm mostly in agreement with Neal's statement about rear weight and the testing Mike did a couple years ago.

In racing besides drag though that unsprung weight does make a huge differerence in performance handling though. I run the Hankook H405's on my rear; 205/50/16 are only 17lbs with 3/32" tread.

 

The K106's are heavy. My freind has them on his turbo G20. With his ALT Lite Speeds and a 205/50/16 he added 4 or 5 lbs per wheel. I was very surprised at the weight of these tires.

I miss my 34 lbs beater wheels.

 

whoa what happened to the inner tread?

and I am very suprised you squeezed 26k miles out of these tires....and still have tread left...jeez I had AVS ES100 rated at 280 treadware...drove normally with ocassional trips to the track...man they were gone at 17k

 

My G-Force T/A Drag Radials 225/45 R17 weigh 23lbs
http://www.tirerack.com/tires/Spec.j...omCompare1=yes
http://www.bfgoodrichtires.com/asset...rag_radial.pdf

 

well my tire woes have come to an exciting end. got four new Toyo Proxes T1R's which is now superceeding the T1-S. I went out for some test runs, they are just as light and have more traction than the old T1-S's up front. but to make a long story short i just got sponsorship from Team Toyo NZ, so this is great news. they also make a Toyo Proxes R888 I will be testing out soon. only 2 days until the drags !

on another note went for a ride in a 460 hp Nissan Pulsar, what a rush, he will be racing also this weekend, i bet its going to be a blast !

anyone one need some k106's ? ha !

 

i loved my t1-s tires, never took them to the track tho but they gripped awsome on the street

A friend just bought t1-r's for his spev v, said they are amazing.

 

Actually, in theory at least, that's not true. The motor still has to rotationally accelerate the rear tires too, it just uses the "ground" as part of the drivetrain (hence the feeling of towing a trailer). Rotational inertia should matter just as much as the driven wheels (except if you're talking about wheelspin and its effects, but that is a short period of time).

 

Congrats Ceasar! That's great news!

How did the sponsorship deal come about? What did you have to do to get it?

 

well, i chased down an SUV about a week ago that had toyo decals all over it. the guy was a toyo rep, and talk about my interest in it. he gave us a contact person and a tire shop that just started Team Toyo NZ. They just started looking for cars and have a Honda Integra Type R I believe they said it runs a 13.6, the Nissan Pulsar I mentioned above which must run 12's or 11's. And then a Nissan Maxima, lol ! So at present they have 3 cars running in 3 different classes. Im C3 All Motor.

Since the car looks different ,will be out at the drags, and just lucky timing, I believe thats how it all came about. im real happy about it.

its another example of it never hurts to ask, all a person can say is no. its still funny though a nissan maxima ? I also obtained another sponsor street legal performance cars, which the owner is a good friend of mine now. They throw in cash for gas on race day to get to the event and to get home, in exchange for a banner. ha, excellent !! i never had it this good in mississippi, lol !

edit:
they require me to put toyo decals on the car windshield etc, and use toyo tires

 

No, I've done extensive testing on it. It acts as dead weight. You can clearly see the difference in my timeslips when I swap the front (drive) wheels out for lighter or heavier units. The same cannot be said for the rear wheels, swapping of the rear wheels made absolutely no discernable difference in acceleration as measured by the track equipment. I've got more than 300 1/4 mile passes to back up my data on this.

 

BTW the T1-R is slightly heavier than the T1-S, according to Toyo's website. The website is not responding right now, but I remember looking at the weights for my particular tire size was 21lbs for the T1-S and 24lbs for the T1-R.

 

I respect your experience and expertise, but I maintain that the rotational inertia of the rear wheels matters, beyond their static weight. At the end of the 1/4, the rear wheels are traveling forward and rotating at the same linear and rotational velocity as the fronts. it takes work/energy to do accelerate them linearly as well as rotationally. the energy comes from the engine. But what do I know, i only run 15.1

 

Hey Tom I agree with the theory and I had doubts as well but after going from stock rears to 4x16" RX7 alloy space save spares with Metzler front Motorcycle tires at a total weight of less than 20 lbs ea it made no measurable difference in the 1/4 mile.

Its really difficult to measure small differences either at the 1/4 or on the dyno so thats not to say it doesn't help it just that its difficult to prove with the yardsticks we have.

 

Still, all the pro FWD cars have skinnies in the rear, less surface to the ground = less drag.

 

I agree that logically there is some benefit to reducing the weight in the back, however my data (and the data posted by other members) shows that the difference is so small as to not be detectable in our 1/4 mile times. For all intents and purposes appears to act as static weight. I know that if you were to calculate the force needed to drag a lighter tire as opposed to a heavier tire it's inevitable that the heavier tire requires more effort, but it's my contention that the calculations for dragging the rear tires are not the same as those for rotating the front tires, and that the effects of reducing an equal amount of weight on each are not the same when it comes to accelerating the car down the 1/4 mile.

 

neal, put the toyo proxes T1R's on momma's bathroom scales and it tipped the scales at 33 lbs (wheel/tire combo). so thats 1 lb more according to my crap weight measuring setup. but used the same scale for both. last time i checked toyos site said t1-s in my size was 22.7 but it never weighed that for me when weighing it at home, and toyos website said the T1R was 21 lbs. but from my findings the T1-S is 1 lb lighter.

silently i sorta disagreed with neal on the real wheels, but after thinking about it and reading around, i agree with it, the front wheels on our car matter more. what i could have been feeling with those K106's was just a different, heavier, new tire, compared to the old lighter tires in the front. who knows, i could possibly be the worlds worst "seat of the pants" dyno judge.

chariot feels good, but i tell you riding in that pulsar yesterday makes me feel like im racing our 91hp civic.

on another note, maxima/cefiro (the 4th gens) are not popular for performance here. the older cefiro drift cars are huge, but i told the guys about jime, marty, and neal and they could hardly believe the maxima was capable of these feats.

 

That's part of the fun of having a sleeper and suprising the heck out of everyone... hehe

 

Sorry dumb ? it's just dead weight.