planned miata project

[minispeed]

Got the new tires installed today. 185 70 14 front and 195 70 14 rear. It has dropped about 500-600 rpm at 100km/hr. The speedo now reads 100 when I am going 102-103 instead of reading 100 and going 95 as it was before. The odo was pretty dead on before and now puts 14km on for every 15km I drive.

I had searched and heard that 185 70 14 fits on the front with minor right hand turn rubbing, however I found it was pretty annoying and had people turning heads when I entered the gas station. I trimmed back part of the wheel lining and then after a quick test drive it was only minor rubbing. If I had to do it again I would have went with 175 70 14 fronts.

Here is a picture with just the passenger side changed to show the ride height difference.



Here is a picture from the side.



I can tell it's much higher when I'm getting in and out, about 2 in over all diameter so 1 in higher. It actually makes it more comfortable to get in and out of. Because of this height I will be concentrating more on the under air flow and playing around with air dams. I went to Home Depot but couldn't find the appropriate edging that I have seen used before.

Now I'm at 45psi all around, I never did a full coast down test before but on one main slight downhill from my house I made it past a stop light that I was usually starting back up before. It feels like it coasts smoother and when trying to shift at 1800rpm first gear feels like it should instead of an instant shift to second.

The next big project will not be fuel economy related. Painting the hard top flat black. However it will allow me to do a tank or two with the soft top up/down and compare the MPG from having the hard top installed.

[Frank Lee]

You'll have to change the name to Bigfoot or Sasquatch.

Ex GF used to think she had big feet so I'd call her Sasquatch. Hmmmmm....

[minispeed]

Oh also forgot to add that I thought I may have needed to re connect the power steering but these turn as easily, maybe even better than the 155 80 13 did.

[minispeed]

I was excited as I was approaching the half tank mark since I had done way more km than I usually get. I usually hit 200km either just before or just after the half way mark, hitting it before was a good indication that I was going to have a good tank. So when I left work at 244km and not at half way yet I was really excited to see how many km I'd hit half way at. Well I got home just a hair under half way at 288km so the new tires really are working.

After several longer tests the odo is off by a factor of 1.088. and all the kms I have are corrected. The old odo was never off by more than .1km after 20k tests so it was pretty accurate.

I'm very excited to start work on an air dam but I really want to do a whole tank with the tires being the only change first.

[minispeed]

5.43 L/100 km
43.31 mpg (US)

[minispeed]

It's been fun.... but the miata is dead. Took it in to get it certified to switch from my dads name to mine and it was found to have a leaking gas tank. The mechanic said "that's a major safety issue" and it's bad but my first thought was.... that means I was actually getting better millage than it read since some of it was just leaking out!

So now it's time to look for a new car. I'm thinking to leaning towards a cruze eco 6spd or hyundai accent 6spd. I love the hatch back and larger back seat of the hyundai but the cruze is just a much nicer car for the front seat occupants and the triple over drive will be nice for the work highway drive.

[baldlobo]

or you could just buy a new or used gas tank, phone around to some junk yards.

[minispeed]

Originally Posted by baldlobo

or you could just buy a new or used gas tank, phone around to some junk yards.

The problem is the gas tank is under the rear subframe. Fixing/replacing it involves dropping the whole rear axle and removing a lot of bolts that are very rusted on. I thought about it but with the labour involved in just getting it out to maybe find that it won't bolt back up together was too much of a risk.

[minispeed]

Replaced with 2012 Kia Optima 6sp manual.

[ChopsQube]

What a waste.

Getting rid of a perfectly good Miata just because the fuel tank needed to be replaced. A competent Miata owner (in a local club) could have had it switched out for you within a day for the cost of lunch or something...