How to make your P5 faster in 30 minutes....
- Thread starter sethro_GT
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oaklandopen
Member
Nitrogen is a ripoff like paying for a 36 point inspection at the dealer, or anywhere else for that matter
And since my tires are 10mm wider with the same series I guess my tires rotate less per mile, so my speedo would be reading slower than actual speed
And since my tires are 10mm wider with the same series I guess my tires rotate less per mile, so my speedo would be reading slower than actual speed
I read that article too. Very informative.
And I got a JDM KLZE so it's OBD1. You may be thinking of the USDM KLG4 which is OBD2 from the 626.
justanothermp5
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Wait how does that make sense? How wide your tire is has no impact on how many times it has to turn around for your car to be going a certain speed the only thing that would do is make it heavier. The concept is while it is harder to turn bigger rims its also harder to turn small heavy tires. Basicly if you wana make it faster small lightweight rims is about the only way or fill them with the nitrogen stuff. If you want to make it faster with big rims invest in a nitrous kitmy 2 cent (I got a jar of change if anyone else wants to chime in)
most people forget that the second number is a ratio, its not a set size
what he said
tweety2300
Member
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- 2001 mazda protege mp3
Well guess I learned somethin today sorry for my ignorance.
justanothermp5
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no problemo
oaklandopen
Member
Yea there's a lot of info directly imprinted on a tire. You can find out when it was made, too
What 16" tire weighs 15lbs??? I'm gonna call BS on that one... and will eat my words if you prove me wrong.
General Exclaim UHP 195/50ZR16 have an advertised weight of 15.6lbs and 205/45R16 15.7lbs http://www.generaltire.com/tires/T1/Exclaim-UHP
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justanothermp5
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there is actually a 205 tire from...(ah s***, cant remember the company, federal i think) that has an 8" accepted wheel width
if that makes sense, pretty much they say its ok to run it on a 8", and thats the 205/40, the 205/45 should be fine,
but most people who run fd's run drag-sized tires anyways, like 255's or some dumb s*** like that
if that makes sense, pretty much they say its ok to run it on a 8", and thats the 205/40, the 205/45 should be fine,
but most people who run fd's run drag-sized tires anyways, like 255's or some dumb s*** like that
The physics of it is this:
Mass moment of inertia depends a lot on how far from the axis of rotation the bulk of the mass is. Also metal is WAY heavier than rubber and air. What am I getting at you say?
Well. Say you have a 14" wheel with 85 side wall. The bulk of the outer mass is just air and rubber with the heavy metal tucked in close to the axis of rotation. This means the wheel will not resist angular acceleration very much and the engine can spin it easily.
Now you slap an 18" wheel with super thick side walls and dense sticky compound tread (not to mention wider) on the car. You notice that your acceleration and braking have gone to hell. WTF you say?
Well think about how far away from the axis of rotation all that heavy metal and rubber is now. Not only farther but more of it. This is SUICIDE if your car is already underpowered.
Perhaps someday I'll do some calculations to see exactly how much the difference is. If you consider the wheel as a thin ring (way approximated I know) the mass moment of inertial is I = m * r^2. You can see that as radius increased (think of the heavy metal ring the tire mounts to) the inertia increases exponentially.
Plus its just more unsprung weight which is bad in of itself.
Mass moment of inertia depends a lot on how far from the axis of rotation the bulk of the mass is. Also metal is WAY heavier than rubber and air. What am I getting at you say?
Well. Say you have a 14" wheel with 85 side wall. The bulk of the outer mass is just air and rubber with the heavy metal tucked in close to the axis of rotation. This means the wheel will not resist angular acceleration very much and the engine can spin it easily.
Now you slap an 18" wheel with super thick side walls and dense sticky compound tread (not to mention wider) on the car. You notice that your acceleration and braking have gone to hell. WTF you say?
Well think about how far away from the axis of rotation all that heavy metal and rubber is now. Not only farther but more of it. This is SUICIDE if your car is already underpowered.
Perhaps someday I'll do some calculations to see exactly how much the difference is. If you consider the wheel as a thin ring (way approximated I know) the mass moment of inertial is I = m * r^2. You can see that as radius increased (think of the heavy metal ring the tire mounts to) the inertia increases exponentially.
Plus its just more unsprung weight which is bad in of itself.
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georgecastaneda
Member
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- 2000 Mazda Protege ES 1.8L
forget about 17'' wheels for my ES
georgecastaneda
Member
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- 2000 Mazda Protege ES 1.8L
Question. 195 55 15 (stock), is that ok if i put 205 55 15 on my ES
BoostedPR5
Member
All this talk about the mass of the wheel/tire combination changing acceleration/braking etc. but no one mentioned rolling resistance being changed by this??
I use a flux capacitor.
ha ha, I gotta get me one of those.
I would think resistance would have little to no effect. Since it doesn't make it harder for the engine to turn the wheel, just harder to maintain speed (probably some sort of kinetic energy loss due to dampening properties of the rubber). However, if the tires were actually sticky they would resist rotation, but otherwise they just roll.
BoostedPR5
Member
A tire with less rolling resistance gets better gas mileage, gives me the idea that it takes less energy to spin since it takes less fuel. Just throwing it into the topic since it seems relevant since when you change to a bigger wheel/lower profile and wider tire you change the footprint a lot.
Well stated.
