205/50/15 >>> GTU transmission >>> GTUs speedo gear = accurate speedo?
 

The difference between 205/60/15 and 205/50/15 (the only size close in high-performance tires) is like 7%, and the difference between the GTU (standard NA) and the GTUs is about 5...

Will using a GTUs' speedo gear get you within a 2% change (and within OEM specs)?

use a 225/50/15 its a little bigger

I don't want tires bulging on my tiny 6" wheels.

It would be different if I had turbo rims...

why not a 215/50/15

that would make it a .5% difference...

if not.. thats only a 1.5% difference with 205/50/15...

so thats what... 1.5 mph difference traveling at 100?

You apparently don't know WTF you're talking about

Go try to find a set of Falken Azenis or any other ultra high perormance tire in that size.

You're lucky if they even have 205/50/15, a far more common size, to begin with.

my friend has 225/50r15 on 6" wide rims and it doesnt look bulged.

The only 15" Falken Azenis is 205/50/15

http://www.edgeracing.com/tire/1532/

Exactly, hence why I'm asking about it.

A lot of competition tires don't even come in that size (especially Advans).

The stock speedo is optimistic to start with, so it should be pretty accurate.

Ask the Honda guys

alright mister alabama, too much moonshine or not enough time with your sister? you are not making sense... at all... and a 1.5% difference is 1.5mph @ 100mph.

your na would have a fun time getting up there anyways... and the link for the set of falken azenis in the 205/50/15 size like you asked is here. http://www.edgeracing.com/tire/1532/ - posted again.

No crap it's 1.5 MPH at 100 MPH.

But NO ONE makes any tires I want in 215/50/15.

And NO CRAP the Azenis comes in 205/50/15. That's what I was planning on getting anyway. I was simply saying that we're lucky they even make them in that size, and not JUST in 16s and 17s.

My question was about whether using a GTUs speedometer drive gear will correct for the 7% difference, which is 5 MPH at 70, which isn't within OEM accuracy specs.

OR, would it go in the opposite direction and make it 5% worse.

Also, for the record whenever I pass a radar gun display on the highway, it shows me that I'm going pretty darn close to what my speedometer is telling me. If you guys think it's all that inaccurate, perhaps you need to check your tire pressure...

(all mechanical speedos are inaccurate at over 100 though, I'm talking about normal speeds)

???
um NA's have no trouble blowing past a 100 mph?

BTW 205/50/15's also stack nice and neatly behind the seats, making a tire trailer unecessary :D

it will say u are going faster than u are but not by much or u could always get it calibrated

It will make it more accurate.

The GTUs speedo gear compromises for the 4.3 GTUs diff.

Say that now you have a 4.1 NA diff, with a smaller rear tire. That, in effect, spins your axles faster, just like having a higher final drive. Gear ratio is gear ratio at the end of the day.

Why are mechanical speedos inaccurate over 100? Isn't the amount of tire rolling on the ground the same per mph at 20 as it is at 100?

The speedo is inaccurate at any speed, it just gets worse (in # of mph) as you get faster because it'll be a % out. Check the FSM, there's a pretty loose tolerance there.

I know that, I was just asking to make sure.

well i know these are not racing tires but they are f'n awsome tires none the less! i had them on my 87 gxl when i first bought it and was dumbfounded at how well they stuck to the road, rain, dry, snow, ice, what ever it was these tires just stuck to the road!


http://www.tirerack.com/tires/tires....eed_rating=(Y)

I'm looking for summer tires, and specifically something with a 200 tire wear rating.

200, it's either the Azenis or the Ecsta MX.

The 180 Advan Neova isn't really worth the money, but it's the best street tire.

The 180 Potenza RE-01R isn't a bad tire in terms of longevity. I've had one year from May to December of normal street use before I switched to snow tires. From March of the next year, I've used them for street use, and from April to now I've used them for street, autox and track use. They've finally let go.

I've seen that the Azenis and the MX are far inferior to the Potenza and the Advan in inclement weather racing, as well as track use. On the track, they seem to get greasier faster as their best laps are typically early on. In a wet weather autocross, the Azenis and the MX's finished much lower than the other two that I've mentioned.

Except that Falken and Kumho's cost half as much as Bridgestones, and WAY less than Advans...

You can deal with the greasiness by spraying water on the Azenis to keep them from overheating.

You'd be surprised how fast they get greasy again....they really start to let go once they let go. There's a reason why the Bridgestones are kicking so much ass in Street Touring.

Anyway, the Potenza's in 195/50/15 are just about the same price as the Azenis in 205/50/15. They seem to be just as wide, if not wider and shorter. Seems like a win for me.

Maybe it's not an issue of winning, but more an issue of just getting some good street tires. MX's don't suffer the overheating issues that the Azenis do, but they're slightly slower.

Acesanugal runs Azenis in that size...
I run Ziex's on it...

...you can get Ziex in the stock size... That's what my car came with before I got set of BFG G-Force sports, which are excellent for the price, but they didn't wear evenly (probably due to air pressure) since there is much more tread left on the sides than in the middle.

Hence why I need new tires...

If I had a huge wad of cash I'd just buy some new wheels so I could get a better size of tire...

Did you over-inflate those tires? How is the outside tread compared to the center and the inside?

My bridgestones lost one side completely, due to not having enough camber through the turns. I had to un-mount them and remount them to the other side, but they still worked all the way till now.

Tires in that size shouldn't cost more than $100-$110. Did you ever check out the head-to-head comparison between the Bridgestone and the Falken? I believe it was Grassroots Motorsports who performed the test.

The Azenis are great tires, especially for the price. They give up very little in performance to the Bridgestones yet are much cheaper. Just because something outperformed them by a slight margin doesn't suddenly make them bad tires. It's not always about getting the absolute ultimate performance. I don't think you're going to convince him given his stated budgetary problems.

How much are Azenis? Last I checked on discount tire, they were $105. My point is that they're the same price these days.

not bad, $74 per tire's pretty good.

Yeah, I'd say I had them overinflated slightly, especially during autocross.

I generally had them at 35 instead of 32, and they'd go up to about 40 when hot... now they're back to 32, and I'm going to remember to reduce the pressure when they're hot (I learned this at my last autocross...finally. It made it handle much better).

The outer tread has maybe 30% more tread left than the centers, which are probably close to minimum thread...

and how many times do i need to answer your question

your speedo will read within 1.5mph of 100mph when traveling at 100mph with 205/50/15 and gtus speedo gear. it is better than running a 4.1 rear speedo sensor.

obviously you dont know enough, otherwise, why would you be asking?

That wasn't even my question.