mitch_f1's mariner NA6

[Nemo]

Dear Mitch,
Please slow down and let me catch up.
Cheers,
Nemo

[Guran]

Nice one Mitch! Excellent times at Wakefield on Saturday.

re. "really really nice road about 30mins out of Nowra"
That'll be the recently upgraded Main Road 92 which links Nowra and Nerriga. The pass at Bulee Gap (shown in your photo) between Nerriga and Sassafras is a cracker. Hopefully the unsealed section from Nerriga to Braidwood (20km) and Oallen to Windellama (4km) will be sealed soon. Then we'll have an awesome drive from Goulburn to Nowra via Nerriga OR Canberra to Nowra via Nerriga.

[mitch_f1]

Thanks for the comments. Nemo, not a chance!

Guran, it sure is! I was silly enough to think that I could take that unsealed section of road in the mx5. I didn't go faster than about 15km/h for that whole unsealed section

[mitch_f1]

So I've been a l've been a little bit busy the last couple of weekends putting in the set of Tein Flex that I got ages ago, but didn't have the time to install.

I started on the rears, being the easiest. There is a shot of Koni v Tein


Installed


Last weekend I woke up pretty late (was my birthday, so I wanted a sleep in), and was tired, so I left the fronts for another weekend. I did manage to clean the remnants of gaffa tape off of the inside of my boot, and in doing so uncovered a "Mazda R Dot" sticker hidden under some body coloured sticky tape (which I was very impressed at, because it was an exact match for the colour. At this point I got really excited thinking I had some limited edition boot lid or something A quick google search turned out that it was a OEM replacement panel. Great. So at one point the boot has been replaced on my car.
From this:

To this:



So I decided to pull the boot carpet out to see for any evidence of a big rear ender, and there was none. I did, however, find a peculiar looking hose near the battery, which had an exit near the tail pipe on the outside of the car, but which the ends joined nothing??

The exit is in the center of the photo here:


Until next time mr car.

Fast foward to this weekend, and I got the fronts in.



While under the car I noticed that the bush for the sway bar is all manged up, no idea how???


I also took the opportunity to investigate the front brake pad situation (from Wakefield they just weren't holding up), and they were a bit crumbly in the middle, but no cracks like the previous pads. While I was working on the brakes I decided to chuck a little bit of slider pin lube on as well.


I took it for a really slow drive around the block (I get the fronts in I removed the camber bolts from the lower control arm - the only possible way of removal of the strut, and I torqued them with no weight on them, so the bushes (I assume) will be all twisted in them, so I am going to wait for my wheel alignment when they will be loosened and torqued with weight on them), and the ride is managable; a bit harsher than the Koni's, but not jarring. I did notice though that there appears to be next to no travel in the shock. I set it up to Tein's specifications (like exactly, one of the measurements on the rear was like 2mm off, but I made it so it was the same on each side, I just couldn't get this one to the Tein specs), and put a cable tie on the rod of the shock, and after a drive around the block the cable tie is right up the top. Now I am not sure if this is because of the dust boot which is sliding it up, or the bump stop (which is just under the dust boot), but I am concerned. Has anyone with Flex encountered the need to extend the shock travel from the Tein specs?


I am also concerned about the clearance between the end link and the shock. With no weight there is about a pinky fingers width separating the two, with weight on the wheel there is less than that. There is evidence of the sway bar moving laterally in the bush, is there anyway to prevent this?

[Jeo]

Nice. Hopefully you'll see a difference in your times.

The tube near the battery is a battery ventilation tube.

[NitroDann]

RE: lateral swaybar movement. Use hoseclamps next to the bushes. 4 in total.

Dann

[mitch_f1]

How about the shape of the bush itself, is that an issue do you think Dann? Also, would the hose clamps themselves not slide around?

Thanks Jeo. What purpose does the tube serve do you know?

[NitroDann]

Re: battery tube.

Because in an mx5 the battery is inside the car your not supposed to use a regular battery. Regular batteries just vent out the top, poinonous gases. The tube is for a proper sealed battery like they cam with from factory, the tube vents outside of the car properly.

Sway bars:
T-bolt hose clamps wont budge. I mean proper clamps not $2 supercheap worm drive ones.

Dann

[mitch_f1]

So I have spent my last few days off setting up the cars suspension. As I think I said before, when I put the flex in I set it up to exactly what the tein instructions says it should be set up to, thinking that this would provide me with a good starting point from which to work from. I was really disappointed with the result; it was riding literally on the bump stops and was really jarring and skittish. Basically not nice.

I have spent countless hours combing over setup guides and discussions on Flex in MX5s (this was by far the stand out thread from which I gathered most of my information: http://forum.miata.net/vb/showthread.php?t=266038 as Emilio from 949Racing was supporting and clarifying a lot of the advice given, which was a pretty good assurance that this wasn't just some enthusiasts blowing wind out their ass; this was a proper discussion from engineers and educated peoples!!). From these hours I concluded several main things:
-full droop difference needs to be <1.75" in the rear (this is the difference between the hub center and wheel arch at full droop and at normal ride height). If there is more than 1.75" then you are to increase the preload
-less droop=more bump travel
-a 0.25 to 0.5" rake is suggested in the fender gap height
-measuring the droop on the front to estimate bump travel isn't as accurate as the rear. Instead, there should be 90% of the rear exposed shaft on the front exposed shaft (if the rear has 10mm exposed shaft then the front has 9mm exposed shaft)
-ride height (between hub center and fender arch) should be around 12-13"
-on the track the shock stiffness is suggested to be at 1-8 clicks on front, and 2-4 clicks on rear.

So with all this in mind, I set out. I calculated my rear droop and attempted to set it up. This is where I hit my first hurdle. I increased my preload to get the increased suspension travel, but I was not able to increase it enough to obtain the <1.75" suggested, as I ran out of threads. A lot of people in the discussions had the same issue, as the 150mm 6kg spring from Tein is just too short. A common fix is to go for a 175mm or 200mm rear spring to allow more adjustment. So I set it up to the maximum that I could, which was 1.8" of droop. This raised the car up, so I dropped it back down again, and made a similar adjustment on the front.

I sat on this for a week or so and was quite content with the setup. The only issue I had was that at the bottom of my street there is a large dip, with a compression, in which I was getting some scrub on my wheel arch liners. So apparently I was too low. The way to fix this would be to remove the springs, jack up the LCA and work out where the wheel sits in the fender at full compression and adjust from there. I was hesitant to do this due to all the messing around it involved (it also involved a new wheel alignment, as I would have to remove the LCA alignment bolts to remove the shock unit).

Last week I bit the bullet; I ordered a 200mm spring from King Springs, and started the process of removing shocks and springs. I did this only on the one side, as I would be able to replicate the dimensions of the shock unit on the opposite side once it is adjusted. The rear is easy (no steering), so I started with that. Removed the shock unit, used a rattle gun to remove the top nut (impossible, or just bloody difficult without one) while holding the shaft with rubber and multigrips to stop it spinning. Put shock back into rear sans spring, and started jacking it up.









The above pics are with my street wheels at full compression, and as you can see there is just enough clearance at the guard, with plenty above the wheel. I then put on my track wheels to work out how much lower the car can go with them on (much higher offset, so more room near guard). I worked out that I can turn the shock unit down 2 more turns and still have enough clearance (2 turns was the limit of the adjustment as well)



Then on to the front (which really pissed me off, and took a few attempts to get right). The first attempt I wasn't thinking and cause i'm an idiot I jacked up the LCA to full compression and checked clearance lock to lock, made my adjustments, dropped car back down, and I had like 4 fingers clearance between wheel and fender, and a ride height of almost 15cm at the sill (DOH!!). So I put my brain back in my head and repeated with 1/2 turn of lock, which I think is a reasonable position in the turning circle where I would achieve full compression (is equivalent to going around a 90deg bend and hitting a large bump). Made my adjustments, and they turned out to be MUCH more reasonable





Token shots of front bumpstops compressed




I then repeated this with the race wheels and worked out I can go 3 turns lower with them.

It took me a long while to figure out how to put the top nut back on the shaft safely. This is because you can’t rattle gun it as it would spin the shaft super fast, damaging the o-ring, and then compress the pillow ball, thus damaging it. I tried all manner of things to hold the shaft in place (started with the same method I used to remove it – rubber strap and multi-grips, but the rubber just kept slipping, allowing the shaft to turn). So I hopped on the trusty internet and did a google search. From this I found out (because I’m silly) that you can use vice grips on the flat half of the threaded section at the top of the shaft and then a 17mm spanner on the nut. I was told by wholesale suspension that I should be getting the nut finger tight and then turn it ¼ turn more, but I could barely get 1/8th of a turn out of it, so I am going to fire off an email to wholesale and tein about it, see what they say.



Here you can see the distance between the 2 black marks is the amount that I tightened it



I also took the opportunity while the car was up to do a couple more things. The first (as some might have seen in my other thread) is to install the holdfasts for the rear sway bar. I was unable to install them next to the bushes because they just didn’t fit (I worked out that if I were to shave it down so that it would fit, that there would be only a few mm of metal left, which would most likely break. So I have decided to brace them against a part of the sub-frame, which you can see here:





The other thing was to replace the front LCA alignment bolts, as one of the bolts I had in there was pretty broken, so I took the opportunity to replace them with NB items which allow for more accurate and easier adjustment

Broken NA on bottom (has flat spot for the alignment disc). The NB is on top, it has two grooves for the alignment disc


This guy should be fixed to the alignment bolt....


So I hope at least some of you read that, to make my writing it worth while. I am still going in the setup of it all; I just have to get the ride heights a bit more even. I think that a corner weighting might be on the cards somewhere down the track as well, but will see.

[Hjt]

Great write up Mitch, next time I run into you I have a few queries as I'm about to rebuild my coilovers and limit it as you have!

[mitch_f1]

Yeh man, nw. I will probably be at MB on Wed

[Hjt]

I just had a laugh to myself if you brought the mx5 and those cops defect your teins

Oh hahhaha whatever is this study doing to me, I have no idea! Chat soon!

[mitch_f1]

Forgot to mention. I am curious as to whether I am getting coil bind at the rear (due to previously mentioned maxxed out preload), so I have put some masking tape on the coils, which should distort/rip if coil bind is occuring. The photo is of the front, but you can imagine this at the rear as well.

[mitch_f1]

Oh if I get defected now because of you.....

I've been pretty lucky so far.

[hks_kansei]

probably way too late to mention, but when you remove the shocks at the front why not undo the upper control arm? (long bolt method)

works jsut as easily, and means your alignment doesn't get ruined.