…..it's close enough to being done for me not to want to take it to another shop.


The one thing stopping it running at the moment related to the immobiliser. The immobiliser unit apparently has one wire that tells the ECU that the immobiliser is there. I'm not using the immobiliser. Therefore, problem. Without knowing the VIN of the original S2000, Honda do not want to touch it, let alone reprogram it. Currently, one of Quent's friends at Honda is sending the shop a reprogramming unit that gets around the lack of VIN, lack of bypassability, and all the other problems that I've forgotten about which make this wire such a little bitch.

Aside from that, I'm pretty happy with how it's worked out so far.
The clutch pedal felt very strange for the first part of it's travel, then suddenly felt normal after this point. After some chin scratching, this turned out to be caused by something easily fixable…
Quent examined everything clutch-related, and eventually, with me pushing the pedal and him watching the master cylinder, discovered that the weird-feeling initial travel was caused by the firewall flexing. As soon as the firewall had flexed to it's full extent, the pedal suddenly became normal. We're talking 40% of the pedal travel feeling strange as a result of this, so the flex is significant… but easily fixable. Phew.
Other niggles to sort? Well, the driver's seat still needs to go down a bit. Also, the interior obviously needs trimming and pretty-ing. And, the dampers need work. At minimal spring preload, the front helper springs work almost perfectly, but the front ride height needs dropping 20mm, so one of the 25mm spacers will be removed. The rear is a different story - the dampers are on the bump stops at static ride height. Hmmph. May be changing to a higher rate spring. Not sure yet.


https://www.miataturbo.net/attachmen...ine=1345479469

https://www.miataturbo.net/attachmen...ine=1345479469

https://www.miataturbo.net/attachmen...ine=1345479469

https://www.miataturbo.net/attachmen...ine=1345479469

https://www.miataturbo.net/attachmen...ine=1345479469
Wires will be tidied. Note that one of the cam cover breather hoses is yet to be plumbed in.

https://www.miataturbo.net/attachmen...ine=1345479469

https://www.miataturbo.net/attachmen...ine=1345479469

https://www.miataturbo.net/attachmen...ine=1345479469
Water in the intake? Possibly… hydrolock preachers on s2ki.com would hate this. Tempted to ask the shop to put an ali sheet directly in front of the filter.

https://www.miataturbo.net/attachmen...ine=1345479469
Panel bashing required to fit XL passenger seat.

https://www.miataturbo.net/attachmen...ine=1345479469
Driver's seat touches the door, just.

https://www.miataturbo.net/attachmen...ine=1345479469
A rather flexibly-mounted clutch master cylinder.

https://www.miataturbo.net/attachmen...ine=1345479469
Investigating the dampers. Something to keep the springs located will probably be made, as the rears try to fall inwards at the top when minimal preload is used.

https://www.miataturbo.net/attachmen...ine=1345479469
Should have got a better shot of the exhaust and PPF brace, the latter of which has been modified a bit.

https://www.miataturbo.net/attachmen...ine=1345479469
More damper investigation.

Quent called today. The car is running, driving, and MOT'd...


:D

Driving it later. Haahaaaaaaa :D

John Barker (Evo car mag road tester/Jaguar test driver) has been driving it and providing feedback to the shop about what to tweak over the weekend. Apparently there's a slight dead spot in the steering right on initial turn in which the shop are currently working on. And the speedo doesn't work. I'll 'snag' the car over the next week or so, hopefully with John's help if he's available, and start getting everything ironed out.

Does that mean you're getting a feature in EVO?

(EVO subscriber signing in).

I drove it yesterday. I'm extremely happy. I can genuinely say that a year of fiscal and mental pain has been worth it.

There are tweaks that need to be made. The sump guard is currently 80mm from the road, and it's too low. The front end feels 'spongey' - slightly unreactive, heavy and heavily damped, which I hope can be sorted with geometry and damper adjustments as I do not want to use a thicker anti roll bar. I'm hitting the bump stops at the rear. And there are a couple of fault codes (one of them air pump related) that Quent had to keep erasing as I drove it in order for the engine to behave itself.
I'm pretty confident that all of this can be fixed. My only concern is that the Xidas 'might' not have enough travel for UK back roads. I'll see once it's all been tweaked.



Richy, I really hope so. However, I can't remember the last time they featured an individual's heavily modified project car.

With the ~50mm spacers you added, no. When installed as shipped with NB mounts, the tires will bottom against the chassis before the dampers run out of bump travel. No lack of droop or bump travel as designed.

Forgive me for not reading the entire thread but what is the reason for the huge spacers?

I drove it yesterday with no spacers at the front, and only 10mm spacing at the rear. The original idea of the spacers was to lift the car to a point where the lowered front subframe would clear speedbumps/road bumps, without winding the dampers higher than you've suggested previously when you've referred to max pinch weld ride heights suitable for these dampers.

For the record, the car's setup is not completed yet, so I'm reserving any definite damper judgement until that point. I have a feeling raising the car 20mm and gaining bump travel at the expense of droop travel might do the trick. That's what it feels like from the driver's seat, anyway.

Your spacers do the opposite in effect. Less bump travel, more droop travel. Same stroke, just more ground clearance.

I think what you meant to say is the Xidas allow the car to run so low that the engine can scrape with your particular engine hanging lower than a stock Miata engine. For that reason you have raised the whole car up to near OEM height and required spacers to do it.

I only chime in to clarify that the issues you are having are unique to your particular build and requirements, not a short coming of the Xidas. When installed in a Miata with a Miata engine, they're perfect ;)

You're right, yes. My car's an odd case - probably a heavier than standard rear end (substantial half cage, next to no weight saving measures rear of the seats) and a lighter than standard front. The car still undeniably bottoms out at the rear, with 10mm spacer and lower than standard (not sure of figures) ride height. I believe the shop are ditching the helper springs (so much for our determination to get them working perfectly!) and ordering longer springs. One way or another, it will be sorted.

The rear dampers have 103mm stroke. Plenty for a Miata. If you are bottoming too soon, you simply don't have enough spring preload and/or spring length. Simple.

It's alive!
Ugly foglight will be replaced by a rainlight mounted in the bumper.

Interior still needs trimming.

Weight distribution without driver:

Before: 52.5% front, with around 23kg/50lbs of fuel;

After: 51.4% front, with no fuel.


I've got the car back, now in prototype numero deux form, to put some miles on it.
First main issue is related to the suspension. Second main issue is that yes, the exhaust does clonk a bit every so often. Third semi-issue is that the 2nd gear synchro in the Honda 'box is possibly a bit ropey. Hmm. Aside from that it's all good. Just hope these problems can be sorted.

I'm still unconvinced that these dampers are the right ones for my needs. What I've realised I'm looking for are near-rally-spec dampers designed from the outset to run at standard ride height.
Roads are extremely bumpy around here, and when 'pressing on', the rear bottoms out (feels like hitting the bumpstops, not the tyre hitting the chassis) perhaps three or four times in a ten minute drive, when running slightly lower than standard ride height. With the same settings, the rear hops around under braking. Edit: this is with a 7" spring and 10mm top hat spacer.

I can't seem to make the problem go away by tweaking the damping. On smoother roads the secondary ride is fantastic, and I'm still convinced that these are probably the best track and anything-smoother-than-a-rally-stage road dampers available for these cars.

If they had a similar or longer stroke and body length as other dampers, I would concede that the travel problem I'm experiencing - if that's what it is - is inherent to the notoriously short-travel MX-5. However, the OEM Bilsteins, as skittish as they were, still somehow managed to keep the wheels on the ground much more of the time.* What adds to my theory is that the dampers I originally wanted for this car, that were developed on UK roads, featured a longer damper body and an extra 15mm stroke at the rear.

I'll keep trying to find a compromise, but I have a feeling I've just bought the wrong tool for the job.

*NB - If someone can find info on the '95 OEM Bilsteins that show they have a similar body length and stroke to Xidas please let me know, because that would tell me that I'm talking rubbish and should be trying harder to make the Xidas work.

How much bump and droop travel do you have at the rear at your ride height?
It still sounds like you have too little preload because you have lengthened the assembly with those custom spacers. We roll over 10" high race track kerbs at 100+mph and the Xida soaks it up. If you are bottoming at 60-80mph on smaller bumps, you need more preload and possibly higher spring rates.

We took the large spacers out, probably for good, last week. The comments I made above were using no spacing on the front, and 10mm spacing at the back. 9" springs on the front, 7" on the back, lots of preload. I will measure the bump and droop travel this weekend :)

\
7" springs with lots of preload should never bottom unless you jump it. I'm baffled as your experiences don't match anything we have encountered here yet.

Will await bump/droop numbers.

Uk roads= the suck :-(

By jove I think Quent's done it.


Quent wound both front and rear up 10mm, and backed off the adjuster three clicks, and suddenly, the car feels a lot better. It still takes off, and occasionally bottoms, but it's a controlled take off and bottom instead of a pant-meltingly terrifying take off and bottom.

So, I'm essentially still running out of travel, but it's controlled, so I'm happy.


The steering feels miles better too. Lighter with even more feel. John described it as 'more linear' when I was in the passenger seat. I didn't know what he meant until I drove it. I can now confidently describe the steering of this car, in tech-speek, as "rather bloody good". Only thing it lacks, to me, is a little positivity around centre, but I'm picking hairs. When I have a go in my friend's Mk1 Elise tomorrow I'm sure it will cast a harsh light on the steering of my car, but with no benchmark to compare it to, I love it. Apparently, Quent has added a little more toe in and reduced the negative camber of the front end. Contrary to what I'd have thought, this has done wonders for the steering.

John had two gripes with the car. The first was that the rear end is a little too planted. I drove it after John, and I actually quite like the way it is - it's not twitch-of-toe oversteer-adjustable mid corner unless you're over 7000rpm, but on the plus side, it's safe, and adjustable when you are determined for it to be adjustable. To clarify, the car still adjusts its attitude extremely well mid-corner depending on throttle and steering input, but it will not produce much oversteer on the exit of the corner unless you're really trying. Which is fine by me.

The second gripe he had is a little more subtle, to me - he felt the front end rose up a little too much between the braking and turn in phases of a corner, which unweighted it a fraction more than he'd like. He suggested adding more compression damping to the rear dampers, and a little more rebound damping to the fronts. Unfortunately, with single adjustable dampers, I'm unable to do this. Perhaps there's another way to achieve this effect.

The car is spectacularly un-slammed now, by the way. And yes, the front is a fair bit higher than the rear. It really works, though, which is considerably more important than any aesthetic considerations. Hella functional, yo.

Here's some pics of John and I.

https://www.miataturbo.net/attachmen...ine=1347656292

https://www.miataturbo.net/attachmen...ine=1347655131

https://www.miataturbo.net/attachmen...ine=1347655131




Finally, I thought the car felt a little under-powered on the drive home. Quent told me I'm probably just getting used to it, which I think is likely. I recorded a 60 to 100mph acceleration figure three times, and the average is about what I had predicted. On the same stretch of flat-looking road, I recorded 6.3 in one direction, and 6.8 in the other. The latter included accidentally brushing the rev limiter for a couple of blaps between third and fourth gear. The third time, on a different stretch of road, I got 6.53.
I checked the speedo calibration against the sat nav just to make sure it was about right. Quent calibrated it with marker posts, so it's probably more accurate than said 'nav. Also, all were conservatively timed - for example, I didn't hit 'stop' until I had definitely reached 100mph. All in all, the drivetrain has worked out exactly as predicted. Gearing is spot on too. Happy :D