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Grez's 1991 Miata Roadster

Posted: 29 Jul 2008, 17:35
by Grez~Supra_RZ-S
All work carried out by myself, UKDM car bought 1 year ago stock.

Engine

1600cc Mazda NA6CE DOHC 4 cylinder N/A (EFI)

-SS Autochrome 4-2-1 exhaust manifold
-370mm silenced de-cat pipe
-Apex'i muffler
-Timing advanced to 14 degrees
-K&N drop-in filter

Chassis/Handling

Lotus Elan S1 chassis
-Tein front tower strut brace
-Carbing four point roll cage w/ harness bar
-Custom developed four wheel alignment; -1.7deg camber rear, -0.9deg front, 1/16 toe-out front, 1/32 toe-in rear
-Spax RSX (new-age) fully adjustable coil-overs (ride height/32pt damping); -35mm height, 27/32 front, 30/32 rear
-Sportmax 002 15x8J ET0 wheels/Yokohama A539 195/50/15 tyres
-EBC Greenstuff pads/ DOT5.1 fluid

Exterior

Mazda classic red/matt black hardtop & A-pillar

-Garage Vary front air-dam
-Rolled/flared arches
-Removed mudflaps
-Lightweight 'racing' tow-hook (front)

Interior

Cloth/black

-Mountney 340mm suede wheel/Momo boss
-RS shift light
-Sabelt clubman 4pt harness (drivers side)

Pics
Image

Image

Performance

Mazda official specs - 1989
-120bhp/1036kg
-0-60: 8.2 secs
-400m: 16.8 @ 80mph


Proven:
-930kg
-400m: 16.8 @ 81mph (York raceway - stock specs, several timeslips to confirm)

''Kill'' list - On track
-Subaru Impreza WRX (GD8 Prodrive pack)
-Single turbo FD Mazda RX7 (dyno'd 430bhp)
-Mitsubishi Lancer Evo 7 (FQ320 - modified)
-Lotus Exige (S2)
-Honda CBR600
-Suzuki Bandit 1300
-Yamaha R6

Its worth noting that I knew the tracks, and this is definitely down to driver inexperience on their part rather than me being God-like, or my car being a supercar slayer. Its also worth noting that in a straight line, they would all murder me.

Plans

Short term
-GReddy TD04 turbo w/ FMIC @ 7PSI
-270cc injectors
-Advan A048 tyres 215/45/15
-Nurburgring trip (4 weeks)
-NA8 brakes/LSD/under-chassis bracing

Long term
-SR20DET transplant

Re: Grez's 1991 Miata Roadster

Posted: 29 Jul 2008, 18:47
by taz947
Just astonishing.


Love it. :)

Re: Grez's 1991 Miata Roadster

Posted: 29 Jul 2008, 18:56
by xHaZxMaTx
Do want. :( I'm gonna buy an NA and any spare parts you have. :U

Re: Grez's 1991 Miata Roadster

Posted: 29 Jul 2008, 20:57
by Felixkissa
Grez~Supra_RZ-S wrote:-SR20DET transplant
Sounds interesting with a car weighing less than 1000kg. Are those transplants how common?

Re: Grez's 1991 Miata Roadster

Posted: 30 Jul 2008, 06:26
by boganbusman
Looking great as always mate :)

What are the Greenstuff pads like? I still can't decide what to get for my car.

Re: Grez's 1991 Miata Roadster

Posted: 30 Jul 2008, 10:36
by Grez~Supra_RZ-S
Thanks folks!
Sounds interesting with a car weighing less than 1000kg. Are those transplants how common?
Theyre not common, in fact theres only 3 in the world I know of and theyre in the US. But it is do-able, and thats good enough for me hah. I did toy with an F20C swap, theres only one of those even in the US, but prices of parts are ridiculous.
What are the Greenstuff pads like? I still can't decide what to get for my car.
For street-use, pretty good. Their only major downside is theyre very dusty. On track, they take a fair beating, but once they fade, theyre gone. Going for Mintexx pads next.

Re: Grez's 1991 Miata Roadster

Posted: 03 Aug 2008, 11:18
by baumaxx1
Nice! I want one! lol... Mx5s are awesome, make great track cars, and punch well above their weight with the right mods. (circuit battle, lol... one took it out against other GTRs and all... and evos and Rexs... but the GTR that dominates it was at Tsukuba or something). Nah, but you gotta love the Mx5. It's got a cool old-school shape, but still looks fantastic.

Re: Grez's 1991 Miata Roadster

Posted: 10 Sep 2008, 18:19
by Grez~Supra_RZ-S
Image

:twisted:

Car is now off the road over the winter. ALL suspension components are coming off, as are the brakes. Time to start fresh.

Re: Grez's 1991 Miata Roadster

Posted: 10 Sep 2008, 22:10
by Zero260
That is a brilliant photo. And I am extremely jealous. :(

Hope she has a nice hibernation.

Re: Grez's 1991 Miata Roadster

Posted: 26 Oct 2008, 13:27
by GLoPJe

Re: Grez's 1991 Miata Roadster

Posted: 26 Oct 2008, 23:05
by Koenigsegg_Rox
LOL!!!!

I love one model/manufacturer races, cause that's where it all comes down to skill.

Re: Grez's 1991 Miata Roadster

Posted: 01 Dec 2008, 17:35
by Grez~Supra_RZ-S
Had the car dyno'd yesterday at a Miata event in Hull, East Yorkshire. There were 30 or so cars there, ranging from an 87bhp '95 N/A 1.6L, up to a 324bhp turbo'd '92 (w/ N20) which eventually destroyed the inlet manifold.

I was aiming for somewhere around the 115bhp mark, the stock power figure from 18 years ago, and almost 110'000 miles ago when the car was new. I was hoping my exhaust system would've made up any horses I'd lost down to wear during the cars life-span.

However, due to money constraints at the moment I haven't even serviced the car in around 10k miles (I usually do it every 3k), so there is a mis-fire low down in the rev-range, and I'm also experiencing a vacuum problem which causes the car to stutter at idle. So, I set my sights a little lower and decided I'd be happy with anything over 100bhp.

After initial problems actually getting the car on the rollers, I was sent into the car park with a trolley jack and some C-spanners to raise the ride-height so we could actually do a power-run.
Image

It's the first time I've really heard the car from the outside, and I can't deny I had a huge grin on my face as Mike (the garages owner and also the owner of the turbo'd/nitrous'd Miata) gunned it through the power-band before hitting the limiter. Here's a quick vid taken from a friends phone:

Video

A few minutes later, Mike came over laughing with a sheet in his hand:
Image

She made 118.8bhp @ 6436rpm, and peak torque of 105.3lb-ft @ 5410rpm, which turned out to be the most powerful N/A 1600cc car of the day! He was most impressed by the torque curve, though, which is likely the result of the 4-2-1 manifold.

Another friend who I drove down with has an N/A 1.6L, with only 57k miles and a JR exhaust, same de-cat, but with a 4-1 manifold. He made 113.3bhp and 97.2lb-ft of torque so I was quietly impressed by my chart. I'll try and dig out some more pics/footage from other cars on the day too.

Unfortunately, there's no DSLR pics of my own. The camera has somehow broken, so hopefully I can get it fixed soon. :(

Re: Grez's 1991 Miata Roadster

Posted: 02 Dec 2008, 01:34
by RedCarDriver
What the...? The video is of some guy washing a cat in a sink... wrong video or something?

Re: Grez's 1991 Miata Roadster

Posted: 02 Dec 2008, 01:43
by xHaZxMaTx
Can I have some of whatever it is you're smoking?

Re: Grez's 1991 Miata Roadster

Posted: 02 Dec 2008, 01:50
by t3ice
RedCarDriver wrote:What the...? The video is of some guy washing a cat in a sink... wrong video or something?
:? NO..it works perfectly for me.. :-k

Re: Grez's 1991 Miata Roadster

Posted: 02 Dec 2008, 20:56
by korge
That miata has one mean lookin stance. 8)

Re: Grez's 1991 Miata Roadster

Posted: 04 Dec 2008, 05:34
by RedCarDriver
xHaZxMaTx wrote:Can I have some of whatever it is you're smoking?
:roll:

I think your image host is screwed up for me or something. It's probably my browser or something.

EDIT: Nevermind, tried again and it worked. Last time, when it didn't work, it showed the correct preview image but when I hit play apparently it somehow played "the next video in the folder" or something.

Re: Grez's 1991 Miata Roadster

Posted: 20 Dec 2008, 19:04
by Grez~Supra_RZ-S
I now have some Pit Crew Racing carbon fibre interior goodies (instrument cowl, centre console, gear knob). OK, so they're not exactly performance-enhancing, but they look so cool. :D Pics will follow soon...Two poor ones from my phone:

Image

Image

Re: Grez's 1991 Miata Roadster

Posted: 20 Dec 2008, 20:06
by viper16
Have you ever considered an all out N/A build before the SR swap. Toda Racing has a few parts for this car.

Re: Grez's 1991 Miata Roadster

Posted: 21 Dec 2008, 01:10
by boganbusman
Man I'm so jealous that you can run those crazy offsets. It looks amazing.
Can't see anything in that interior pic though :lol:

Re: Grez's 1991 Miata Roadster

Posted: 21 Dec 2008, 13:24
by Grez~Supra_RZ-S
I've only just realised that I hadn't posted it up in here, but I abandoned the idea of an SR swap a while ago now. At the moment, the car is set up perfectly for me, and on the exit of turns I have just the right amount of grip and balance to punch well above the cars' weight. I just couldn't justify ruining it with double the power. My brother has offered me the TD04 from his Impreza, so I've been looking into low-psi set-ups (~160bhp), but still working out whether it's worth it or not. I'm extremely happy with the throttle response of the current N/A set-up, so for at least the next 12 months, I won't change. If I decide to upgrade after that, then it'll be a toss-up between the TD04, some bike-carbs and ECU work, or a Honda S2000. :mrgreen:

Cheers Bogan, glad you like the look. I've just nipped out (with my phone again...) to grab some (hopefully) clearer ones. You'll have to excuse the state of the interior, it's in dire need of sorting out. :oops:

Image

Image

Image

Re: Grez's 1991 Miata Roadster

Posted: 12 Jan 2009, 05:48
by Countach
Should drop an LS1 in this instead of the SR20DET. Less to spend to further achieve more horsepower. Stock they come with like 350. But, that's just my $0.02.

Re: Grez's 1991 Miata Roadster

Posted: 12 Jan 2009, 09:52
by steelsnake00
What do you mean less to spend? Do you have any idea how difficult it would be to get it to fit, let alone to run?

Re: Grez's 1991 Miata Roadster

Posted: 12 Jan 2009, 22:00
by Countach
These guys make it so simple. http://www.racingconcepts.net/index.html

Re: Grez's 1991 Miata Roadster

Posted: 13 Jan 2009, 01:28
by RedCarDriver
Simple, but with lots of work required still... :?

I think you should keep it the way it is. If anything, throw on a small turbo and add some non-internal mods like (as you said) better exhaust and ECU tuning.

It looks great so far, by the way.