MrJon

It's time for me to start documenting he story of my slow build.

Almost 2 years ago I bought a 93 miata with about 275k miles on it, from a very slightly shady used car dealer outside Atlanta. The paint was/is very dull and faded, it has some scratches, but it's straight, and rust free and it runs and drives and has a radio and AC, except just today it seems to be not blowing cold, irritating after I spent a bunch of money last spring having virtually the whole ac system replaced.

I even did a track weekend at Sebring with it last April.
Sebring April 2016
For that event I installed a Hard Dog 6 point roll bar, I lost the pictures from when I did that. :( I also installed an Evo4 datalogger that I picked up used.

Along the way I have been slowly improving the car in little ways, things like a new speedo cable, wheel bearings/hubs, adjusting the drivers door for the slight sag it had, lubing the window regulator, replacing the window bushing that was gone, fixing some oil leaks, delrin door blocks etc.

So for this xmas I decided to treat myself, and I decided to replace the completely worn out suspension. I went right for the good stuff
my new xidas waiting for installation
The drivers front shock appear slightly bent when I removed. Anyway, it's actually the full big grip kit with all the bells and whistles. 700/400 springs.

Let me back up a step, I live in Panama City Beach, Florida, and I grew up on a farm in northeast Iowa. So for xmas every year I go home, and for the last several years I've driven because of so many bad airline experiences. It's about 1100+ miles and takes about 17 hours, I do it all in one day, I really kind of enjoy it. Anyway, it's the second year in a row I've driven Chicane back home for the holidays.

Dad farms, and a few years ago build a pretty huge new shed, insulated and heated, it was in the teens and twenties outside and 55 to 60 inside, which really is just about perfect for actually working.


I was trying to gather some before and after data with the data logger, just to see if I could see a difference in things, I haven't had time to really look through that data yet.
The install was going pretty well until I twisted off the passenger side sway bar mounting bolts, I twisted off the first one and chalked it up to rust despite my experience with this car that none of the bolts are rusted tight, and proceeded to twist off the second with the impact wrench. I was really irritated so I decided to work on something else for a bit to get my mind off that annoyance, when dad walks up and looks at the impact and say "why is the gun on tighten?" Somehow it had gotten switched when I switched sides of the car and I didn't notice.

Anyway, that cost us hours, and ultimately we had to shear off the captive nut and just use a regular nut on it.

Got the coilovers on and the swaybars without too much trouble other than that. When I got to the highway on the first test drive after getting them install I was absolutely shocked at how much more quickly the car wanted to change directions. I have no prior experience with modifying suspension that way so that difference was actually pretty unexpected.

I didn't install the control arm bushings because I am waiting for the sadfab bearings to put in them first. I don't have a desire to do the job twice right in a row.

I plan to come back and post up some of the data and maybe a video of a test drive.

Here's a gratuitous picture of my cat.

sixshooter

iTrader: (12)

Welcome to the forum. That's quite a "shed", haha!

Next time you plan to go to Sebring or Daytona or something, let me know.

Good luck.

Efini~FC3S

iTrader: (4)

Where exactly in NE Iowa is the farm? I grew up in Cedar Rapids and my grandparents have a small farm outside of Dyersville.

MrJon

Near Lamont. Fun fact, my grandpa had a collection of antique tractors, and Ertl came out and measured several of them to make toys.

MrJon

I went with Chin motorsports, I'm hoping to go again in March or April, I have some snowbird family that have a house in Sebring so I have free room and board when I go to Sebring . At some point I'd love to do Daytona, just to tell people I did it, but it seems kinda pointless given my current total lack of horsepower, because their second question is going to be "how fast did you go?"... 97... lol. Also it seems like Daytona track days are really expensive compared to other tracks.

sixshooter

iTrader: (12)

Chin is really expensive compared to a few of the others. See Performance Driving Group, Hooked on Driving, or NASA.

MrJon

I looked at those, Chin is roughly in line price wise, it depends on if you need an instructor, which I do, so that's a minus. What I like about Chin is that they are very clear on their website about providing instructors, PDG and HoD, don't make it absolutely clear what the situation is on the instructors they provide. The other thing is that Chin usually runs both Saturday and Sunday, which since I'm driving 6 hours to get there gives me better bang for my buck, as opposed to just a 1 day event.

sixshooter

iTrader: (12)

I've instructed with all three. NASA provides the best classroom instruction between on track sessions. The others give a little more track time each day. Most of the regular instructors are very good at NASA. Some of the same guys instruct with Chin and with PDG and HOD from my experience. I see the same familiar faces at the tracks.

Sometimes the 2 day events can drag on a little late on Sunday for people who have a long way to drive home and work on Monday. I've done Road Atlanta a few times and leaving the track at 5 or 6pm for an 8 or 9 hour drive plus unpacking when I get home is a little tough. Especially when you have already had a big day. Not everyone can drift into work at noon on Monday with no issues. It's a trade off.

Plus, sometimes your car breaks on Saturday and you need to stay the whole rest of the weekend just to meet your instructing obligations. It happens on occasion.

x_25

Heck, that is no excuse. I managed to hit 105 at Pocono. I am sure you can manage at least that at Daytona.

How is the ride on the 700/400? I am debating what spring rates I want to get when I buy my Xidas and I am a pansy that does about 8k a year on the road with my car.

Ryan_G

iTrader: (8)

Daytona is expensive because the track is very expensive to rent. I've been twice and to be honest I think it's overrated. Maybe going once is worth it but I feel like it's just not super fun after you get over the novelty of the high banks. Sebring, on the other hand, is an absolute blast every time. I want to do a weekend with performance driving as I've only been with NASA. I like that performance driving gives me a little more track time in one day than NASA gives me in 2. Saves me money on the hotel and gives me most of my Sunday back.

emilio700

iTrader: (3)

Perfect for a lighter Miata (<2250) on 205's. Heavier car and or 225's, we prefer 800/500. Ride doesn't change much either way, just better suited to available grip.

Mark my words, you will be surprised at how well your Big Grip Kit, full race suspension, rides on the street and will wonder if you should have gotten 800/500.

MrJon

Have you seen the movie Rush?


I'm the opposite of Lauda, my mind is excellent, my *** not so much, also I'm apparently weirdly able to drive forever with no issues, I drive the 1100+ miles back to Iowa in 1 day and don't have any problems. So take my opinion with a big block of salt, but compared to what I had, which was completely worn out stock springs and shocks, I think it rides slightly better, but in some ways differently. On the gravel roads around my parents house I think it was maybe slightly "busier", just now thinking about that I suspect that has to do with the billet coaxial upper mounts I also got. I definitely think it rounds off larger bumps better.

Maybe a better data point is when I got home, I gave ol' what's her name (that's a bit of an inside joke about the girl I'm seeing) a ride, she knew I had worked on the car, but I'm not sure she even knew that it was suspension parts I put on, regardless, she's not into cars except she does like to hear me talk about what I'm doing. Anyway, I did sort of prompt her to give me her thoughts about if she could tell any differences in the car. Before we got out of the parking lot she mentioned that she thought it rode better. eventually she also mention that it rolled less, and I wasn't even driving all that aggressively. This is with the dampers set about 3 clicks from full soft, in the last couple of weeks of dailying the car there have been a few times when I thought it could stand a bit more damping.

Also, at this point I don't have the poly bushings installed yet, waiting on the sadfab bearings.

I have some data that I took with my datalogger that I haven't really gone through in detail yet, I ramped up the z-axis sampling rate and did some before and after driving, I'm curious if I'll be able to tell anything in the data. When I get that sorted out I'll post it up here.

One other comment I'll make is that you need to keep in mind, is that the actual forces the spring is putting on the car don't change nearly as much as the change in spring rate would suggest. At rest both the stock 160ish lb springs and the 700lb springs are putting something like 700 or 800 pounds of force on the body of the car, and if you hit a large bump that compresses the spring an inch, the forces become something like 860lbs, and 1400 lbs, which is a significant difference, but it's not even close to being over 4 times as much like you might expect just comparing the spring rates.

MrJon

Got around to looking at the data comparing my old stock suspension to my new xidas. You'll have to excuse my totally amateur noobness with the data analysis. Also I somehow lost the data for one drive I did where I switched it from full hard to full soft and drove that same loop back to back.

This first screen shot is the complete test loop. the pink line is the old worn out suspension, black is the first drive with the xidas, they were set right in the middle. The test loop starts at the gas station in Lamont, I made a loop through town, and then headed out, there is about a 4 mile stretch of smooth hiway, then I turn onto a rougher hiway and drive about 3 miles before making a u-turn, 3 miles back, and then back onto the smoother road for a couple miles, and then a few miles of gravel road.



Here I zoomed in on the first 3 miles of the rougher hiway.


And here I've zoomed way in on the big bump



This is a zoom of the big bump after I made the u-turn