CAI indicator lights

While good looking, these indicator lights are designed for maximum air flow to the air filter on a track days.
They are direct bolt on, as they integrate turn signal indicator, to plug in to the car stock connector.

Will be available as silver brushed steel and black.

Sun visor replacement cap with interior light

 Sun visors in a cabrio do the job ... sometimes.

Many of us are removing them because ...
- cabrioing a lot and simply not taking advantage of them
- being Big Boy and not seing because trough them.
- badly needing some kind of interior light, as the bottom ones are not doing it really

Or maybe all 3 of them.
If you have done it and facing the naked paint every time or want interior light, this is a direct replacement.


This sun visor cap is made of anodized aluminium and is avialable as black, silver, yellow-green and red.
It is direct fit to cover the hole and to hold the A-pillar trims tight together.

A version with strongest 14500mcd LED is available. It lights on with the interior lights and is bright enough to lit the interior of the car and the road, when the door is opened. It is discrete light and does not blind the driver.
Bith are coming  with instalation manual and cable divider clamps.

Rev limit crystal

As the MX5 ECU is not fully readable and changable yet, a common mod to raise the rev limiter is to increase the working frequence. The ECUs differ depending of generation and region, so to buy the proper crystal, you will need to inspect and see which one you already have.
My 1.8 NA had the 8Mhz crystal /German, '94/.
To raise the limiter safely I went for 8.5Mhz crystal and ~7800/min limit.
No problems after many miles, even with some aggresive ignition values and lots of track driving.
Even teoretically, after studying the air/fuel tables, there should not be problems, as tables are preset very rich.


As the 1.8L engine is not very rev happy, to fully utilize the new rev limit, best is to combine it with some intake/exaust mods.

Designing custom leather door pull for MX5 NA

Getting into MX5 and trying to close the door leaves you with a strange feeling, something is ... not really right. I guess if you are taller than average there is more than average chance to feel it hitting your leg.

First thing is to remove the door pull, second - to put some stripe there. I believe everybody has done this so far:).

Well, for track dedicated car a "stripe" mod could do, but I wanted to daily drive it and trip across Europe and ... started this project.

The requirements list (Die Anforderungsliste;)):

• Material - thick and genuine leather to match rest interior, all black with exact cut.
• Ensuring functionality - the original door pull holds the door trim to the door.
• Offset from door trim (easy pull catch,  no trim scratches)
• Tight fit
• Wear-resistant
• Universal for both sides
• Better feel than original
• Better look than original

The door package was simulated in 3D program. The design options converged with the technical solutions and after the obligatory comparison matrix for all the options, a design was nominated to continue.

Water proof and not stretchable leather was found for the purpose (convertible gets wet). It is 5mm black leather.

First draft was with laser engraving:

One first draft:

The actual design implements embeded "Roadster" writing to the leather. Elegant design element, presented in a decent way, that will match every interior.

The holes for the screws are secured with special rust resistant eyelets. 

The screw heads (original ones should be reused) are hidden with supplied black head caps.

This is very succesful end product, that expands the drivers leg room enorm, but also perfectly integrates in to the car leather interior and gives decent and fresh touch to it.

The door pulls can be also purchased, contact me at  automotiveconvepts.eu (at) gmail.com.

Creating the Mazda MX5 "Roomster" edition

The write up "Creating the Mazda MX5 "Roomster" edition" can be found and is currently updated at this address:

jassperformance.com

Designing fully functional rear towing hook for MX5/Miata MK1 NA.

The original NA MX5 towing bracket is ... well mine at least, already rusty. It is heavy and it is not alowing me to use any aftermarket rear spoiler, as it is not adjustable. As I do racing with the MX5, nice to have option is to comply with the FIA requirements for tow hooks.

On the other side, the original towing bracket is quite well engineered and dimensioned piece of mild steel. It is designed to withstand very high loads. And it is the guiding light in terms of strenght, dimensioning the new one.
Defining towing strenght, even for a small and light car like the MX5 is impossible. Towing it on a tarmac road doesn't require much strenght, but pulling the car from mud could be even impossible.
I desided to dimension my tow hook to withstand the strenght of a standard 1500kg rope. The rope has to tear before the hook breakes or bends, basicaly asuring the towing hook is reusable.
Broken hook can be a deadly weapon, as the rope accumulates very high energy, that accelerates the hook, when torn.

Lets collect the requirements so far:

1. Strenght: it has to at withstand more than 15000N (1500kg) pull.
2. Weight: lighter than original
3. Rust-resistant
4. Adjustable in the height

This below are animatated GIFs you can see on clicking on them.
1. I-shaped 4mm steel. Almost afordable stress levels for highest position.

2. As we want adjustable bracket, we test this also in the lowest position. This is already too much stress for the thin steel.

3. Next is to stiffen the steel design, by bending a wall and screwing the hook one more time at the back. Stress levels are affordable. The stress levels even in the lowest position are acceptable.
Downside on this design is the weight which is 522 grams. Still it is a good option, offering 3 point connection.

4. Next step is to change material - we took strongest airspace 2024 T3 (approx. 1,4 stronger than 6061-T6) duraluminum instead of steel. The calculation is with 10mm thickness and in already lowest position.

With a weight of only 300 grams, fully adjustable and covering the requirements this is another option to concentrate on.

The 10mm billet 2024-T3 duraluminium ready for real life test:

Designing lightweight MX5 frame rails

The frame rails have to stiffen the weak body of the MX5 and provide protection against incidently hitting speed bumps.

The requirements to consider:

• Stiffening more that common market designs
• Lightweight
• Rustproof
• Max road clearence
• Minimal effort to install

Light and strong at the same time can be achieved by only optimising shapes and profile.