The carbon fibre time attack/superlap MX5 NB twins blog

[lightyear]

I will keep you guys updated on the build of the twins.
Here is a pic of the first one-

Just about stripped.

I haven't touched mine yet so it still looks like this-

We have a heap of stuff to sell, will post soon.

[lightyear]

I just worked it out, we took off 253 kg's not including motor/box and all accesories on motor, like a/c p/s brackets etc. I figured that the turbo gear would weigh similiar.

Seats weigh 28.5 kg's for the pair - new seat 6kg's. The softtop with all accesories weighs 22.3kg's - carbon fibre roof 6kg's. The doors weigh 23.2 kg's each without the doortrim and handle - c.f doors about 3.5 kg's with window. Dash assembly with support is 16.5kg's not inc heater, a/c and blower. The complete carpet and soundproofing is 11kg's, loom 12.5kg's, alloy bonnet 8.1kg's, exhaust cat back 18.2kg's, and we have a bucket of bolts that weighs 8.2kg's.

We will be putting roughly 70 kg's back into it by my calculations. Also cutting out about 20-30kg's of metal. Plus the cage about 50kg's. That means the cars will weigh under 900 kg's finished if the weight is 1060kg's for a factory car. Not sure but i think that's what they weigh. I am sure we will find more weight to take out before they are finished. I think the most we are going to save is about 300kg's over a standard car. I am hoping for around 800kg's or less.

my car almost finished pulling it apart.

[lightyear]

The car weighs 1026 from factory. I reworked out the numbers. It would be minimum 260kg's of stuff that has come off that won't be needed. Replacing that with about 60-65kg's of new stuff. Plus cage 40-50kg's Minus metal removed 20-30kg's. should weigh between 836kg's and 861kg's finished. We will see at the end how close i get. It is not so easy getting them under 800kg's. I will be looking into making a jig to replicate the subframes in tubular steel as well as all the suspension arms. That should save another 20+kg's.

[bruce]

I wonder if it is worth considering a different type of motor-vation?

[16bit]

duratech (mzr for mazda but its a ford motor) out of the new mx5 is all alloy i am pretty sure. and the head on that flows way better than the bp unit.

if you are going to make a new subframe you could do that at the same time and get an adapter made up to fit the stock box.

[16bit]

if you go with this bbk you will save even more weight - and the best kind, unsprung.

http://949racing.com/miatawilwoodV8R.aspx

there is about 7kgs there.

[bruce]

Yup. You're going all-out with the body, I would consider ditching the original motor.

[Okibi]

I know you can get a carbon drive shaft, what about a carbon PPF?

[lightyear]

We wanted to build the fastest mx5's we can (using our skills and a very small budget_) without changing away from the original design. Yes we are changing a bunch of things, but really all we are doing is taking what mazda made (a road car) and adding more power and less weight. We can change the motor, but we will use what we have for now. Can always upgrade in the future. Same with the brakes. The ppf weighs 4kg's, i don't think there would be a huge gain in c.f. And located down low, so would be no gains for racing. The tailshaft is 5.1kg's, i wouldn't mind looking into making one later. They are going to have stock 1.8 motors running about 10psi of boost, stock 6 speeds, stock diffs with after market l.s.d and stock brakes. Basically stock cars......... Ecxcept every panel will be c.f, lots of weight will be cut out, like the seatbelt towers, parcel shelf, boot floor, fuel tank, etc,etc. And be running some coilovers, swaybars, full cages etc.... The build should come in under $15,000 each.

[rascal]

...Basically stock cars.........

[Fatty]

...Basically stock cars.........

yeah sure , this should fit in "standard NB" class, why not ?

awesome project dave! keep us posted.

[wazman]

10 psi through stock motor is great. Mine makes 153 rwkw ...... But i have just found out that the stock coil packs are no good and the spark is getting blown out. They could just be old. But i aint risking it, gunna install haltech coil packs and igniter, then might be able to add more boost...

Just thought i'd mention the trouble i had since you are gunna run a similar setup.

Stitch weld the chassis and ditch all the braces !....... or at the least make alloy ones.....

[lightyear]

We will be running coil on plug set up. Darrens 1.8 made 180rwkw at avo, but i think there dyno is optimistic. c.f braces will be used. I am going to ring tmrow to see how much it costs to acid dip the cars, and the guy in the shop next door does sand blasting. So i will see how much he will charge, not sure if it will take off all the seam sealer with sand blasting. Looks like we are not running stock motors now too.

And i finished getting my car ready for the cage too. All the metal has been cut out that needs to be in order for them to get the cage in.

[little decks]

wow.... looking impressive so far.

You going to do your own engines?

[lightyear]

Yep. I just bought the 1.8 that was on here for sale that had been fully rebuilt, balanced etc. And it is an na8 motor, i didn't know at the time that they are different motor's to nb8 motors. The head is different, so then i was thinking of rebuilding an nb head and using that. But now we are going to do forged bottom ends. So that motor will have to go up for sale again.