18" MTs

[stroker]

Well finally got some answers from MT on what size 18" tires they will be offering. I dont think the 345 will fit our cars correct me if I am wrong. Last time I talked to them it was May or June now its different. Here is the email I got:

We will be offering 18, 305/35R18 and 345/35R18 should start seeing them June – July.

 

[94tbird]

305 sohuld fit with no problem

 

[Charlie Sheen]

Won't they be a little on the "short" side?

 

[cekim]

Won't they be a little on the "short" side?

305/35/18 should be 26.4 vs stock 27.1

So a little short, but nothing earth shattering...

 

[ChevyKiller]

Ditto not too bad but remember it's height that = hook and not width. I have the 305/45 nitto for my street tires and they hook fantastic for the street. I drove in another car with the same 555R's but a 305/35 and it was a big difference in hook even though it was only slightly shorter.

We put the cars side by side and it is actually a pretty big difference when side by side comparison seeing that 28" next to it.

Remember - HEIGHT is more important than width when it comes to hook. I always look for the tallest tire I can fit, not the widest.

 

[don_w]

Rear end gearing, low end torque and launch rpm are also big factors when considering tire size. On my N/A motor, with an auto trans and stock converter, I liked the short tires because it helped me launch... even with 4.10s. But, once the engine build was done, I had much higher torque numbers, plus a higher stall converter, so I switched to 28" tires (and kept the 4.10s).

Bottom line, every one needs to evaluate their specific combo to figure out what will work best for them.

 

[ChevyKiller]

Good point. I'm sure the auto and TC play a big role but on my manual on the stock motor the 28" worked better for me as well. But I was never N/A so I don't know about that...lol

 

[travelers]

Rear end gearing, low end torque and launch rpm are also big factors when considering tire size. On my N/A motor, with an auto trans and stock converter, I liked the short tires because it helped me launch... even with 4.10s. But, once the engine build was done, I had much higher torque numbers, plus a higher stall converter, so I switched to 28" tires (and kept the 4.10s).

Bottom line, every one needs to evaluate their specific combo to figure out what will work best for them.

Are you still staging deep? I was woundering how that was working out for you.

 

[don_w]

Are you still staging deep? I was woundering how that was working out for you.

Yes, I've been trying to stage a couple inches deeper, and it's helped my RTs. But I go red more, so I need to stop doing that. haha

 

[ChevyKiller]

Nah - keep doing it...




at least for a few more weeks...

 

[paco_pony]

+ 1. It's really all in the physics. Taller tire = bigger circumference= bigger linear distance through which the tire drags across the pavement. Frictive force = (weight of object)*(distance thru which it's dragged)* (coefficient of friction).

yes there are lots of other factors, of course. but all too often tire height is given short shrift vis-a-vis hooking.

Ditto not too bad but remember it's height that = hook and not width. I have the 305/45 nitto for my street tires and they hook fantastic for the street. I drove in another car with the same 555R's but a 305/35 and it was a big difference in hook even though it was only slightly shorter.

We put the cars side by side and it is actually a pretty big difference when side by side comparison seeing that 28" next to it.

Remember - HEIGHT is more important than width when it comes to hook. I always look for the tallest tire I can fit, not the widest.

 

[cekim]

+ 1. It's really all in the physics. Taller tire = bigger circumference= bigger linear distance through which the tire drags across the pavement. Frictive force = (weight of object)*(distance thru which it's dragged)* (coefficient of friction).

Well, a bigger tire (all things being equal) works against you if you don't compensate with the gear as it lowers your effective gear ratio...

That said, a lower aspect ratio will generally be stiffer than a taller one and thus flex less...

The flex is good - the flex is very good...

So, as Don said - its all about the big picture of what else you have done - no one tire size will be perfect and bigger is not always better (more flex is almost always better)...

 

[ChevyKiller]

+ 1. It's really all in the physics. Taller tire = bigger circumference= bigger linear distance through which the tire drags across the pavement. Frictive force = (weight of object)*(distance thru which it's dragged)* (coefficient of friction).

yes there are lots of other factors, of course. but all too often tire height is given short shrift vis-a-vis hooking.

My brain actually hurts after reading that....

Jesus, as if Cekim wasn't bad enough....

 

[travelers]

Yes, I've been trying to stage a couple inches deeper, and it's helped my RTs. But I go red more, so I need to stop doing that. haha

Yea I watched you posted video here and had to laugh. Good runs though.

 

[ChevyKiller]

Reading the thread starters sig, it is obvious we know what we're dealing with for this particular question and he definitely needs a taller tire than a 26" in his particular case - no debate about it.

 

[don_w]

Yea I watched you posted video here and had to laugh. Good runs though.

Keep in mind that at that track they give out a trophy for best reaction time of the night. So, on a few runs each night, I intentionally take a shot at the tree hoping to get that perfect 0.500 light (and the trophy that goes with it). I won it a two races ago with a 0.501 light.

 

[paco_pony]

yeah, Cekim is pretty bad. JK Cekim. Your an engineer. You can't help it. Geek is in your genes.

Btw and off topic, what the hell does Cekim stand for?

Btw and off topic X2, these emoticons are f'ing awesome. This one's my favorite...

My brain actually hurts after reading that....

Jesus, as if Cekim wasn't bad enough....

 

[don_w]

Reading the thread starters sig, it is obvious we know what we're dealing with for this particular question and he definitely needs a taller tire than a 26" in his particular case - no debate about it.

Did he ask about what tire he should be using? I thought he was just providing new info he got from M/T.

And if he was asking, I don't agree with you that it's quite so clear cut. There is no indication about his gear ratio, or whether or not his converter has been changed, or what boost level he's running. If his trans/converter is stock, and he's running 3.31s - 3.73s, a shorter tire may still be a better bet. But, on the other hand, if he's got a new converter and 4.10s, then I would agree with taller tires for sure.

He also doesn't mention if these are for street or strip use. For street, I say go as tall as possible. For strip use only, my above discussion holds.

 

[cekim]

Geek is in your genes.

I am not a geek, I am a nerd - and yes, its genetic - my father had and used a multitude of pocket protectors...

Btw and off topic, what the hell does Cekim stand for?

It doesn't stand for anything - but it does mean something... There are too many mikec's in the world...

 

[travelers]

Keep in mind that at that track they give out a trophy for best reaction time of the night. So, on a few runs each night, I intentionally take a shot at the tree hoping to get that perfect 0.500 light (and the trophy that goes with it). I won it a two races ago with a 0.501 light.

Nice going congrats. How does your wife do?