The carbon fibre time attack/superlap MX5 NB twins blog

lightyear · Postby **lightyear** » Sat Jun 28, 2014 6:43 pm

Tyrone had the engine on the dyno. And he had to fiddle around with oil pressure for a bit. Then he started doing the tune up to 4000rpm. But the turbo, intercooler and bits are so efficient he couldn't get the boost low enough. At 4000rpm 60% of exhaust has to go out the waste gate. It was making about 450hp at 4000rpm. He is tuning the motor to keep the gearbox alive. So to keep the boost down, he had to machine the exhaust manifold and make a place to mount an external waste gate. As well, he cut out the down pipe between the exhaust and waste gate. As it had a divorced waste gate pipe. So now the down pipe is a massive funnel flowing smoothly into the 3" system. Last I spoke it is all working well, and he got the power down to around the 220-230rwkw at 7000rpm. The 6 speed, even though it is an SE box will not take more than around that mark. It will have different torque and power in each gear. As he knows the weaker gears won't like even that much power.
One day when I get a decent gearbox, he can up the power. But 220rwkw in a sub 800kg car will still go o.k.

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16bit · Postby **16bit** » Sat Jun 28, 2014 6:45 pm

so you think this is a 550hp engine running as it pleases?

lightyear · Postby **lightyear** » Sat Jun 28, 2014 7:38 pm

It could make 550hp I would think. Not much point in making power and blowing gearboxes.

He used to race a 1.8 turbo MX5 with a small restrictor. So it wouldn't rev past 5000rpm. He had enough torque to embarrass most V8's. But broke gearboxes on a daily basis.

Postby **Okibi** » Sat Jun 28, 2014 9:03 pm

lightyear wrote:Tyrone had the engine on the dyno..

So happy to hear Tyrone is still playing with MX-5s, id LOVE to have him working on my car.

Sean · Postby **Sean** » Sat Jun 28, 2014 9:43 pm

He's the KING!

16bit · Postby **16bit** » Sat Jun 28, 2014 11:58 pm

lightyear wrote:It could make 550hp I would think. Not much point in making power and blowing gearboxes.

He used to race a 1.8 turbo MX5 with a small restrictor. So it wouldn't rev past 5000rpm. He had enough torque to embarrass most V8's. But broke gearboxes on a daily basis.

aint that the truth.

an old v8 supercar 6 speed h pattern could take it!!!

lightyear · Postby **lightyear** » Thu Jul 03, 2014 4:45 pm

So the tune is finished, and it has 374hp (279kw) at 6000rpm. 380lbft (512nm) of torque at 5700. Rev limit is 7000rpm as the injection tors are maxed. Could go bigger, but I am happy to leave it as is, and chase more power once I upgrade the box.

So basically the same power as a 6.0l SS commodore, but 1100 kg less weight to lug around.

16bit · Postby **16bit** » Thu Jul 03, 2014 5:34 pm

that sounds mean.

do you intend to compete at wtac?

CM sport · Postby **CM sport** » Thu Jul 03, 2014 5:49 pm

Wow is all I can say really

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Timmeh · Postby **Timmeh** » Thu Jul 03, 2014 8:29 pm

Just out of interest what would be the next viable option in gearbox to keep the 450hp?

lightyear · Postby **lightyear** » Thu Jul 03, 2014 10:30 pm

I can get a gear set for the 6 speed. But it costs thousands. There are a few options, but at this point I am not looking to make more hp. And hopefully the car will be reliable as is.

I don't intend to enter WTAC. Not this year at least

lightyear · Postby **lightyear** » Thu Sep 04, 2014 11:37 pm

Picked up the motor and bits today. Went to install the motor, but due to not having the engine mounts that I bought for it. Been borrowed...
And the ones I have here don't fit. Left one doesn't bolt up.

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Postby **beavis** » Fri Sep 05, 2014 4:21 am

Asif you were ever going to get your motor..... it's been 3.5 years in the making.
You probably Photoshopped that motor in the pictures.

plohl · Postby **plohl** » Fri Sep 05, 2014 7:46 am

It's actually an elaborate birthday cake...

So when if it going to be running?

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lightyear · Postby **lightyear** » Fri Sep 05, 2014 5:56 pm

It has been running and dynoed. But if you mean the car, well early next year. I need to buy a few key elements. Like a diff. But have most of the gear. The wiring loom is so tiny.