Ninja2042

Just recently purchased a 2003 Miata LS with Auto ( wife will not drive a stick ). Silver with black top and cockpit. I have owned a couple of others, a 2003 that we traded for a 2007 but then her back started acting up and couldn't get in comfortably so we sold it. Her back problems are better and we found this 2003 and are starting again. All stock so far with some plans for the future (Intake, Exhaust, Wheels & Tires - want to go to 17s with 225/45-17 tires). Any help with info on what works and what doesn't would be appreciated.
I am trying to get info on the car and was trying to get a VIN decode when I found the forum. Any help in that direction would be very helpful.
I have 2 problems with the car... 1. The AC works but not well. Seems to blow cold air after hitting the freeway but have to keep it going full blast all the time to maintain temp. Driving around town is warm at best. 2. The car seems to be down on power and that is the main reason for doing the VIN search to find out what output the engine is supposed to have and trans ratios along with rear gear ratio that went in at the factory.
I did take it to Raleigh Nc (I am from Wilson Nc) and got a pull on a Dyno which resulted in 104hp and 98 ft/lb torque. Rpm ran up to 6350 on the Dyno sheet. I also noted that the Air/Fuel ratio started at 15:1 and ended at just over 13:1. With the Auto trans, I thought that was about right but all info that I have been able to get of the net says that the engine should pull 142hp @ 7000.
Well guys I have rambled.
Thank you in advance for any help.
Walter

Captain Bwana

Welcome Aboard! Running the bigger tires will tend to bog things down even more. There are articles on baselining your car. Basically it is a comprehensive service to get all your systems up to speed. I don't have any experience with the NA/NB auto trans, but from what I read they are not high performance vehicles. The NC with auto is another story, mostly due to the MRZ engine.

sixshooter

Your car will ride poorly and be much slower to accelerate and stop with 17 inch wheels. You can achieve the same width with 225/45 R15 tires at a great weigh savings. Any wheel over 13lbs is a boat anchor with our cars. I have several different wheels and can feel a big difference in ride quality and acceleration with a 3lb difference per corner.

Try Miata Wheels and Tires - Wheels - Mazda Performance Parts for lightweight choices that will also be in the correct offset for the Miata (zero offset wheels will ruin a Miata's handling).

GoodWin Racing also has some of the exhaust parts and other things you might be looking for to enhance your ownership experience.

Ninja2042

Thank you guys for your input.
My wife has, shall we say, her inputs for the car and she wants the wheel wells filled up without lowering the car. So that is the main reason for the 17" wheels. Also I don't want to lower the car at the present time because I don't want to agrivate her back again and neither of us is getting any younger (me 72).
That said, I have found a wheel that weighs 14.1 lbs (stock weighs 15.6) and a BF Goodrich g-Force Rival tire in 215/45-17 that weighs 21 lbs. Tires on it now are Nexen N3000 in a 205/45-16 that weighs 20 or 21 lbs (just a guest, couldn't get an exact weight).
I have visited the Good-Win Racing site along with Flying Miata site and a few others. Almost all sites recommend 15" wheels and tires. I know that low weight at the corners is a big factor in handling etc. but the wife is more concerned with how it looks.
Thanks again,

Captain Bwana

I understand your priority. You and your wife want a cool looking ride that is pleasant to drive. You are certainly not alone. Enjoy the ride!

BTW - keep us posted on your car. Even if you are not interested in a street rocket, we still want to know how things are working out for you.