Clutch to handle 300BHP, and cam profile choice for turbo?

Rasputin · Postby **Rasputin** » Wed Oct 02, 2013 6:07 pm

Hello again!

(I drive an 1998 NB8A)

Am looking at getting my clutch changed next Tuesday as the throw-out bearing is just about to destroy my whole clutch assembly and put me on the side of the road. (The rattling has stopped, I think it has jammed up in there somewhere)

I will be turbocharging my car soon, so I do not wish to do things twice.

The purchase and installation will be done at MX5Mania.

Can I have some advice on what clutch assembly to request, and if you have experience with purchase/installation, what is an average price on parts/labour?

Secondly, I would like to install some aftermarket camshafts at some point prior to the installation of turbo to ease the breathing of the whole setup when it all gets bolted up and tuned.

What is the maximum profile one can go, without having a large amount of valve overlap? I'd also like a bridgeport-like idle, but would not like to go so big; that the car is a pain in the backside to drive in traffic.

Would love to hear the MX5 idle like a bridgeport!

If Turbo orientated cams are installed on this naturally aspirated motor, can one expect negative performance? I believe i'd be after a larger exhaust cam, while retaining the stock intake cam (if not go a little bigger). I am aware that massive valve overlap on such a small motor with a big turbo would see full boost coming on in the late 5K rpm range, if not more - and so i'd like to have the profiles matched up so there is a fine line between overlap and none.

I am also aware that forced induction from my GT2876R alone will produce more than enough power for the stock motor on a low boost setup. The cams are more for personal satisfaction and something nice for people to see and hear.

I apologize if this post is incredibly dyslexic and unstructured - my brain is fried from a long day at work in the heat!

Thankyou for reading, look forward to the replies.

Dan.

Postby **NitroDann** » Wed Oct 02, 2013 6:15 pm

Id go with something around the 9mm/275 advertised duration side, and ask for it to be tuned to retain some lope.

This will be acceptable in terms of driveability no problem.

As for the clutch, I would have mania choose it, then it's on them if it isn't suitable to your needs.

Same goes for any shop if you are paying them for the complete job.

Dann

Rasputin · Postby **Rasputin** » Wed Oct 02, 2013 6:20 pm

NitroDann wrote:Id go with something around the 9mm/275 advertised duration side, and ask for it to be tuned to retain some lope.

This will be acceptable in terms of driveability no problem.

As for the clutch, I would have mania choose it, then it's on them if it isn't suitable to your needs.

Same goes for any shop if you are paying them for the complete job.

Dann

9mm/275 duration on both Intake and Exhaust?

Adjustable Camgears are obviously a necessity too, correct?

Postby **NitroDann** » Wed Oct 02, 2013 6:52 pm

Yeah with some camgears, it's likely that the cam set you buy wont be identical side to side but something in that region will suit you.

Dann

Hjt · Postby **Hjt** » Wed Oct 02, 2013 7:26 pm

Silvia

Rasputin · Postby **Rasputin** » Wed Oct 02, 2013 8:59 pm

Hjt wrote:Silvia

Camry...

I don't get it.

Hellmun · Postby **Hellmun** » Wed Oct 02, 2013 10:02 pm

I wouldn't bother with Cams or headwork immediately unless you have some massive hp goal in mind. My car runs a stock NB8A head , stock NB8A cams and made 220rwkw(280 ish hp?) on the standard SP GT25/60R. That's with the turbo dropping full boost past 6500rpm.... on 205/50/15 KU31's it'll spin both rear wheels in 3rd gear when it hits 4000rpm just rolling along. In 2nd it'll spin out anytime it crawls on boost. High boost actually spins the 225/50/15 V70A's race tyres for all of 2nd too but 3rd will hook up. So unless you've got money to burn I think you'd be happy just getting the snail on and driving it :mrgreen:

I went for an exedy HDB on an ACT flywheel which is handling the power fine but is a bit grabby for street use. It's fun on a mountain road but I hope your not spending much time in start/stop traffic.

Hjt · Postby **Hjt** » Thu Oct 03, 2013 2:08 am

Camry...

I don't get it.

You will one day.

Listen to the above advice, recently Niko went through his gearbox pushing high figures.

The car doesn't need 300hp and you are over thinking it.

Simple works

If you don't like my comment, sit on it and give it a few years.