# Wheel size related speedo problems



## Randomshane (Jan 24, 2004)

I am aware that if I change my rims to a set of 15's that it can possibly mess with the speedo and odo's readings. What are my avail. options to fix this? If I am getting a new ecu from JWT can they fix it on thier end priar to installing the new ECU or is there some re-programing device that I can buy and do it myself? thanks


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## knock_it_off_hudson (Apr 30, 2004)

Umm, if you buy tires with the correct aspect ratio you won't screw up your speedo readings. Go look at 
http://www.sentra.net/faq/index.php?category=Suspension& 
Also try this http://www.miata.net/garage/tirecalc.html

Hope that helped


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## jerryeads (May 8, 2004)

*Tire sizes*

Easier on SE-R with 14's to go to 15's - they're 185/60-14 stock, ya just put on 195/50-15 and the rolling circumference is virtually identical. For the little-motor car with 13's, either just chat with your local tire guys and they'll match your tire diameter to stock, or go to the Tire Rack site and it'll guide you to the right size in 15.
Word to wise: the bigger the diameter (and rolling circumference) over stock, the SLOWER the car, as you're effectively decreasing the gear ratio. Another good way to slow the car down is to buy heavy rims - I suspect those little 13" rims are about 15-18 pounds (stock SE-R is 17 lbs) - If you go get fancy steel chrome-plated rims at 25 lbs or such a corner, it'll be even slower, because you have to get all that fat spinning. Takes a lot of torque to do that. While we're at it, you go to 35 or 40 aspect ratio and your ride will go to hell in a handbasket.


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## OddyseusDSM (Mar 19, 2003)

the tire diameter is almost the same on the 13s vs the 14s


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## Randomshane (Jan 24, 2004)

*So far no answer*

So far the only person who was at all helpful was hudson but I still havn't got an answer, I am going to be doing an engine swap to the sr20de so jerryeads I am not to worried about the car's ability to move, I am worried about my speedo being incorrect. I just wanted to know if I could modify something on the car to correct it... so if anyone can actually answer my q please help!


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## Blank (Aug 21, 2003)

you can get your speedo recalibrated, but its not fun... its not something you do from the computer from JWT, so they cant help you...


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## Randomshane (Jan 24, 2004)

blankgazex said:


> you can get your speedo recalibrated, but its not fun... its not something you do from the computer from JWT, so they cant help you...


Thank you, where would I go to get this done? dealership, garage, can I do it myself?


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## samo (Apr 30, 2002)

There's no reason at all to recalibrate the speedo, unless you're like me and deliberately run oversized tires.

What you want to do when you get larger wheels is run tires with a smaller aspect ratio. For instance, on a B13, if you get 15" wheels, get 205/50/15 tires. If you're going to run 17s, run 205/40/17. That way, the overall diameter remains the same (or pretty damn close) as stock, thus not altering the speedo/odo readings.

The Miata.net tire size calculator posted above will allow you to play with different tire sizes and see how much they mess with your speedo.


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## Randomshane (Jan 24, 2004)

*well*

If I want to run over size tires (I like the look better) Then where can I get my speedo calibrated?


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## Mr. Nice Guy (Jul 28, 2003)

Randomshane said:


> If I want to run over size tires (I like the look better) Then where can I get my speedo calibrated?


What size rims do you want? As long as follow the advise of the forum members, no need to re-calibrate your speedo. In the previous posts, the forum members was giving you the proper info to make a good decision. Unless you have a different agenda that you are not expressing.


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## Randomshane (Jan 24, 2004)

*It's Simple*

`I want 15" Rims with the same ammount of rubber as the stock tire has, I don't want to upsize the rim and downsize the tire... I want to upsize them both... it isn't that hard to understand I just want toi know where I can get my speedo calibrated


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## Mr. Nice Guy (Jul 28, 2003)

Randomshane said:


> `I want 15" Rims with the same ammount of rubber as the stock tire has, I don't want to upsize the rim and downsize the tire... I want to upsize them both... it isn't that hard to understand I just want toi know where I can get my speedo calibrated


So, if you go with 195/50/15 (upgrade) you will keep the same circumfance as the stock wheels 185/60/14. I have same car as you have, upgraded my wheels and tires, speedo never changed. So.... you will not need to get your speedo re-calibrated. Also, no aftermarket or dealership will re-calibrate your speedo because you changed the wheel and tire size. Duh.


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## Randomshane (Jan 24, 2004)

Mr. Nice Guy said:


> So, if you go with 195/50/15 (upgrade) you will keep the same circumfance as the stock wheels 185/60/14. I have same car as you have, upgraded my wheels and tires, speedo never changed. So.... you will not need to get your speedo re-calibrated. Also, no aftermarket or dealership will re-calibrate your speedo because you changed the wheel and tire size. Duh.


You ever heard the saying "Everyones got a price" Duh.
And in case you didn't hear me the first time... I DON'T WANT THE SAME CIRCUMFRANCE


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## Mr. Nice Guy (Jul 28, 2003)

Since you want oversized tires, how big do want to go? That might clear up some questions and give you some answers.


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## Randomshane (Jan 24, 2004)

The easiest way for me to describe it is like this: Click Here


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## samo (Apr 30, 2002)

Your car is going to sit _high_ if you keep the same profile tire with 2" larger wheels. But hey, if offroading is your thing (it certainly is mine  ), then the best advice I can give you is to invest in an Autometer speedometer. It's adjustable, so as you change tire sizes the speedo remains the same. I'd just remove the speedo and all its electronics and sink an Autometer one into the same spot. That's what I plan on doing once I get 27" tires.


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## Randomshane (Jan 24, 2004)

samo said:


> Your car is going to sit _high_ if you keep the same profile tire with 2" larger wheels. But hey, if offroading is your thing (it certainly is mine  ), then the best advice I can give you is to invest in an Autometer speedometer. It's adjustable, so as you change tire sizes the speedo remains the same. I'd just remove the speedo and all its electronics and sink an Autometer one into the same spot. That's what I plan on doing once I get 27" tires.


Thanks, I just might do that... And I plan on lowering it so it will sit stock hight, then with the drift kit it will look a little bit lower and un-like all the morons up here with the honda's I won't have to dodge every last pot hole :thumbup: But if I do go with an aftermarket speedo what should/ can I do with the odo which is sitting in my speedo?


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## samo (Apr 30, 2002)

Ahh, another childish Honda hater, great  ...

Anyway, some aftermarket speedos come with an odometer, some don't. Find one that has an odometer.


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## Randomshane (Jan 24, 2004)

Thanks... and it's not that I'm a honda hater... I just don't like fallowers who claim to be leaders... honda's arn't bad cars... it's just that when everyone in the state who is into car modifying owns a honda, well it doesn't seem to original to me, yet the say the are and thier car is differant when it's not... so like I said, It's not the car I have a problem with... it's the people.


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## samo (Apr 30, 2002)

People are welcome to modify whatever they choose. It's certainly possible to be different and own a Honda - there's a ton of very unique Hondas just in the Seattle area. And anyway, who says you should _have_ to do something unique with your car? Shouldn't the owner be allowed to do whatever they choose?

Anyway, there's also plenty of "morons" with Nissans that have to dodge potholes - I was one of them.

I just think it's stupid to even bring up the Honda hate in a thread about tires.


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## Randomshane (Jan 24, 2004)

samo said:
 

> People are welcome to modify whatever they choose. It's certainly possible to be different and own a Honda - there's a ton of very unique Hondas just in the Seattle area. And anyway, who says you should _have_ to do something unique with your car? Shouldn't the owner be allowed to do whatever they choose?
> 
> Anyway, there's also plenty of "morons" with Nissans that have to dodge potholes - I was one of them.
> 
> I just think it's stupid to even bring up the Honda hate in a thread about tires.


If you were from new hampshire you would understand, and as I said, it is the person claiming to be original when they are not... In new hampshire that is easily summed up as a honda


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## samo (Apr 30, 2002)

Obviously NH is a totally different world than here, then. Here, we have nice-ass Hondas that are nothing to complain about.

Modifying a Sentra isn't all that original either, anymore. Maybe a little more original than a '93 Civic, but given a choice between a B13 or an EG Civic hatch, I'd take the EG.


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## Randomshane (Jan 24, 2004)

I have been to many places in the USA and I like none of them as much as san diego, you are right about it being two differant worlds, I am modifying a sentra cause that is what I have, My choice would be a cavalier w/ a corvette engine, but thats just me. I have seen the honda's that come out of the west coast and you are right, they are nothing to complain about. But in new hampshire little 16yr old rich kids buy a brand new honda slap a bodykit on it (Always see them driving around primed never painted) and a shift knob and a set of pedals and all of the suddon they think they are racers. first off this is very dangerous and 2nd my personal opinion is a car modded for looks is a show car not a race car and a car modded for speed is a race car not a show car, it takes a special car/person to combian the two and that is where I think the cream of the crop come from... where the original ideas and new parts come from. like I said I don't hate honda's I dislike the people here with thier roaring exhausts, primed body kits and few interior mods that ruin it for the rest of us. Because of these people new hampshire now has a decibal test on the exhaust to pass inspecion. so as you can see, there is some justification to my feelings. And that is all they are... My opinions.


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## samo (Apr 30, 2002)

And Honda owners mod what they have, just like you mod a Sentra because it's what you have.

There's plenty of rich kids who do crappy work on a car here too - don't forget that Seattle is the home of the Microsoft and Starbucks empires - there's plenty of money, and plenty of riced-out cars. But so what? It's not your car. I don't see how it ruins anything for anybody. They're not hurting you in any way.

And I know of a lot of Nissans with primered kits and loud exhausts, among other questionable things. Percentage-wise, I see a far higher percentage of tastefully modded Hondas to riced out Hondas than I see nice Nissans.

There's a decibel test here too, and it's not solely because of loud imports. The domestic guys who run straight pipes and the loud trucks don't help either. Anyway, the dB level they require you to be under is pretty damn loud - I can't imagine why anyone would want their car louder than 93dB.


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## Randomshane (Jan 24, 2004)

As before stated, two compleatly differant worlds


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## 92sentra (Dec 31, 2003)

Randomshane said:


> The easiest way for me to describe it is like this: Click Here


IMHO, it seems like an awful lot of trouble to have your speedo recalibrated for a few MPH difference going to larger tires. Are you worried about getting pulled over by 5-0? I'm cheap,so if you are concerned about that, have a friend drive next to you and have him tell you what speed he is at, and adjust it in your head accordingly. "Ok, I'm showing 55, but i'm actually going 60". I've done this, and it works pretty well. Good luck, whatever you decide to do.


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## fatboypup (Oct 3, 2003)

hondas are like tampons, every pussys got one


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