Modifying a MK1 MX5

[charlesdavis84]

Hi all,

I have acquired an mx5 (1999 P reg, 1.6, red) which has mostly been sat in a garage for the past decade.
It was my dad's before he died about a decade ago, my mum's just been sat on it, not wanting to get rid of it while also not really enjoying it.

It has now come to me and it's in need of some love attention, restoration and modification.

Things this car has going for it, it's been kept garaged for most of its life and doesn't have an inch of rust or rot on it. It's been driven occasionally during the summer months and has never missed a beat when starting back up after 6 months of storage. It's been well looked after but just routine maintenance.

Things which aren't so good, it's done 130k miles, my dad faffed about with the suspension and it handles like a wobbly jelly.

I am hoping to turbo or supercharge the engine, have the engine rebuit/restored but I'm not really sure what would be needed to support the forced induction, and I want to sort out the suspension and probably best put some bigger brakes on, as well as putting a roll cage in as it will mostly.be for track use.

Questions...

Turbo Vs supercharger, I'm leaning toward SC to keep the more na feel.
Which kits are any good? On top of the kits will I need different cams or other subsidiary bits?

Big brake up grades, worth it or are there good pads and discs to upgrade the standard calipers with?

Coil over springs, good options and any suspension specialists around the south west to help align it all once fitted?

I'm.excited to be giving this car a new lease of life, but very much feel at the beginning of a big learning curve.

Any advice welcomed.

[howardb66]

Sounds like a great place to start.

When was the cam belt last changed? I’d check that out. Along with the brake fluid. Check the date of the tyres too.

My MX5 was supercharged & is now turbocharged, you do get a lot more power from the turbo & in my experience more reliable too.

BC Racing or MeisterR coilovers are the most popular upgrade brands.

If you want somewhere that sells pretty much everything, take a look at Bofi.

bofiracing.co.uk/

There are plenty of people on Mighty5 that have gone down this route…🙂

[scottydugg]

Look forward to seeing how you get on, like Howard says preventative maintenance would be a good start.

I was going supercharged until a last minute change to turbo, I think I can partially blame Howard and others on here for the last minute change over. Less stress on engine, smaller turbo will offer the power delivery you want but not always be on (like a S/C), easier to upgrade in the future, more readily available second hand parts might be beneficial depending on budget.

Don't go cheap on the suspension, probably the biggest improvement I've made to mine is switching to a set of MeisterR.

Any questions, they're a helpful bunch round here!

[charlesdavis84]

Hi Howard and Scotty,

Thanks for the helpful replies, I might do some more research and maybe look at turbos, I don't want to over stress the engine, I just find it quite under powered at present.

I'll be sure to get some pictures up next time I'm in the garage.

The suspension will be the first thing to look at as well as new or poly bushes throughout.
The handling is very under whelming at the moment.

So other than cambelt, and other routine type maintenance I don't need to strip the engine right back and have it skimmed or anything before bolting a turbo on?

[batou]

Oct 19, 2022 8:34:11 GMT charlesdavis84 said:

Hi Howard and Scotty,

Thanks for the helpful replies, I might do some more research and maybe look at turbos, I don't want to over stress the engine, I just find it quite under powered at present.

I'll be sure to get some pictures up next time I'm in the garage.

The suspension will be the first thing to look at as well as new or poly bushes throughout.
The handling is very under whelming at the moment.

So other than cambelt, and other routine type maintenance I don't need to strip the engine right back and have it skimmed or anything before bolting a turbo on?

Welcome, mechanicals on these is nothing to worry about, mines done 215k km and I'm adding more engine mods (it will get overhauled in time), so if the body is in good condition underneath the body panels (rust will only show on wings/arches when the inside of the sill has rusted through (they rot inside out).

It sounds like a late UK market 1.6 so you'll also probably have an open diff and the 1.6 is a small ring gear, so if you are going turbo then factor in the cost of a 1.8 rear diff conversion as its likely you'd pop that soonish, maybe a 4.1 torsen if you can get one for a reasonable price condition or open and aftermarket LSD (ie. Kaaz/Cusco). You'll need the driveshafts and prop from the 1.8 from memory. 

Lots of resource on here, have a look through this thread in regards to bushings: mighty5s.com/thread/3302/na-suspension-bushings-sprint-hillclimb

I'm in the process of overhauling the front suspension (already have coilovers fitted) and the bushes are proper tired...



I've gone with firmer rubber bushes as they are maintenance free unlike poly, but if I was going the poly route I would use either Superpro or Supermiata with the bronze inserts and drill the arms to add zerk fittings to re-lubricate when they start to make noise/bind.

[charlesdavis84]

Hi Batou,

Just wondering where did you get the stiffer rubber bushes from?

[wannabe]

Welcome!

A rust free MX5 is a rare thing lol

I think first priority would be to get it fully rustproofed!

[howardb66]

Oct 19, 2022 11:36:29 GMT charlesdavis84 said:

Hi Batou,

Just wondering where did you get the stiffer rubber bushes from?

IL Motorsport supply stiffer rubber bushes. 

Look on MX5parts.Co.uk 

[batou]

Oct 19, 2022 11:36:29 GMT charlesdavis84 said:

Hi Batou,

Just wondering where did you get the stiffer rubber bushes from?

MX5Parts, they are made by IL motorsport and whilst they are tried and tested by the Max5 Racing series they are apparently still just as compliant as OE rubber on the road and certainly less NVH than poly.

[boggissimo]

Oct 18, 2022 23:10:43 GMT charlesdavis84 said:

Any advice welcomed.

Welcome Charles! A good bunch of folks here, I've had a lot of help since I first got my Mk1 in late 2019. First things first, I'd get it up in the air and see if it really *is* rust free, as that would be pretty rare for a UK car that has done 130K miles, even if it was well looked after and always garaged. Check that the drain holes that come out under the car are fully clear, otherwise any rain will have sat inside and started rusting it from the inside out. If you can get an umbilical camera inside the sills that would be very helpful.

When I first got my car it already had a half roll cage fitted (all behind the seat), and it would be a good idea to look into getting one fitted "just in case" for road use. For the track if it's just trackdays then at least a half cage would be even more sensible, and a full cage (over the top and across the doors) if you're going to do anything more serious like race or rally.

Then I'd be looking at brake and suspension upgrades long before thinking about going turbo or supercharging. You can have a lot of fun in a well set up NA car as long as it stops and turns. I've fitted the bigger calipers and discs from the Mk2.5 Sport model, with braided hoses and a brake bias valve, and it works a lot better than the small standard Mk1 brakes, especially if you don't have ABS.

[dickie]

Hi and Welcome to the fold.

If you have the budget look at Rotrex Superchargers its a a belt driven turbocharger


Rotrex – Superior Centrifugal Superchargers

www.rotrex.com

I run BBR ITBs on my Mk1 though.

[charlesdavis84]

Oct 19, 2022 15:19:05 GMT boggissimo said:

Oct 18, 2022 23:10:43 GMT charlesdavis84 said:

Any advice welcomed.

Welcome Charles! A good bunch of folks here, I've had a lot of help since I first got my Mk1 in late 2019. First things first, I'd get it up in the air and see if it really *is* rust free, as that would be pretty rare for a UK car that has done 130K miles, even if it was well looked after and always garaged. Check that the drain holes that come out under the car are fully clear, otherwise any rain will have sat inside and started rusting it from the inside out. If you can get an umbilical camera inside the sills that would be very helpful.

When I first got my car it already had a half roll cage fitted (all behind the seat), and it would be a good idea to look into getting one fitted "just in case" for road use. For the track if it's just trackdays then at least a half cage would be even more sensible, and a full cage (over the top and across the doors) if you're going to do anything more serious like race or rally.

Then I'd be looking at brake and suspension upgrades long before thinking about going turbo or supercharging. You can have a lot of fun in a well set up NA car as long as it stops and turns. I've fitted the bigger calipers and discs from the Mk2.5 Sport model, with braided hoses and a brake bias valve, and it works a lot better than the small standard Mk1 brakes, especially if you don't have ABS.

Hi boggissimo,

Yes I'm not going to jump down forced induction straight away, I want to get it running well first, which mostly means investigating what suspension it has on it and why it's so aweful! I have a feeling my dad probably put some cheap coilovers on, so first job is to see what's on there.

Thanks for the tips on where to look for rust/rot.

I'm heading up to have a look this weekend and to take some pictures to start forming a before/after thread.

My order of work will be suspension, bushes, bodywork, routine maintenance items.

Drive it for a while and track it, then think about brakes, induction kits, exhaust and forced induction.

[charlesdavis84]

Oct 19, 2022 16:36:29 GMT dickie said:

Hi and Welcome to the fold.

If you have the budget look at Rotrex Superchargers its a a belt driven turbocharger


Rotrex – Superior Centrifugal Superchargers

www.rotrex.com

I run BBR ITBs on my Mk1 though.

Hi Dickie,

Thanks for this information I didn't even realise you could get belt driven turbos, this is very interesting, just looking at the kits and although expensive they aren't much more than a supercharger kit and potentially more reliable 👍

Cheers

[dickie]

Hi,
I used to have a supercharged Mx 5 it was lots of fun but prone to destroying drive belts as my set up ran the stock four rib belt.
It upped 130 BHP to just over 200 BHP.
Current 1800cc car has around 160 BHP on ITBs

[thruxton]

Don’t forget the Zed delete kit.
Worth its weight in gold.

Regards.
Rich.

Ps.
Too harsh?
I kid because I love.