Clutch tech

[Mike Lawless]

Who knows Mexx. You may find it'll be quicker at the 60 with a slightly heavier rotating mass.

[MeXX]

Hi

This is my new clutch setup for the Race:
more base pressure and 8 short & 4 long counterweights

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Engine ready to race


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Clutch closeup


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Short and long counterweights close up


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Engine in the car

MeXX

[Frallan]

Love it all!  Good luck!
Also thanks for sharing with such detail.

[Airspeed]

Hi Mexx,

Why such tall manifolds and tall stacks?
I thought hi-rpm motors were more efficient with short everything?

[modnrod]

Why such tall manifolds and tall stacks?

I'm guessing at total intake length being about 16" (400mm), which would focus tuning around 7500-9000rpm.

[BeetleBug]

I thought hi-rpm motors were more efficient with short everything?

But then again you have the nitrous that does its job best at lower rpms, increasing the cylinder pressure drastically and giving one hell of a kick in the butt.

[Jon]

50 cm is 4100 rpm and 25 cm is 8200 rpm, from what I can remember.

[MeXX]

Hi Mexx,

Why such tall manifolds and tall stacks?
I thought hi-rpm motors were more efficient with short everything?

Hi

If you want to calculate the manifold length seriously you have to know the cam timing.
In my example it is for FK 47
length : 530mm
Power loss at 5166 RPM and 8611 RPM
Power gain at 6458 RPM

So the usefull power range is 5500-7800 RPM

But I think we should do a separate threat on this.

MeXX

[richie]

Hi Mexx

your ability to get things done,and so quickly is really impressive,some real inovative thoughts going on here hope version 2 works ok,with my own tests the heat caused by excessive slipping of the clutch distorts parts real quick,I found it needs to be real thick material to survive,but then I am using much more basic materials than you,hope you have success at the next race

cheers Richie

[MeXX]

Hi Mexx

your ability to get things done,and so quickly is really impressive,some real inovative thoughts going on here hope version 2 works ok,with my own tests the heat caused by excessive slipping of the clutch distorts parts real quick,I found it needs to be real thick material to survive,but then I am using much more basic materials than you,hope you have success at the next race

cheers Richie

Dear Richi

THX for the kind words.

BTW here is my success:
We were out for racing in Kiskunlachaza (HU) this weekend.
The track was prepped very well but a little bit slippy at the beginning that gave us the time to make clutch and wheelibar adjustments on the naturally aspirated engine,
but how it turned out traction was perfect later in the afternoon which gave me the chance to run still no bottle in the car, at 16:16

9.968 @ 220.64 km/h  

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Later on my long time friend and racer buddy Fredy did a run with my car:

9.767 @223.34 km/h  

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WoW    

MeXX

[MeXX]

Just for demonstration:

 my poor driving skills

<a href="http://www.youtube.com/v/RWbNojWgFyo" target="_blank">http://www.youtube.com/v/RWbNojWgFyo</a>

Fredy's second run with my car and a clutch how it should work:

<a href="http://www.youtube.com/v/RcCFV3wy8gA" target="_blank">http://www.youtube.com/v/RcCFV3wy8gA</a>

MeXX

[richie]

That is why i never let anyone drive my car


On Fredy's pass it looks like he launches,then puts the clutch back in again,it kind of hops forward,then settles down and goes,your launch looks much smoother? or is that how the clutch is set up?

It would be nice to see a video of it from behind from the burnout onwards to see how the suspension & wheelie bars etc are working

9.7 without the bottle is very good time though,maybe you need to tune the car and have Fredy drive

cheers Richie

[Jyrki]

Impressive stuff!!!!! Is this the first naturally aspirated 9 in Europe (aircooled flat 4, two doors etc)? CONGRATULATIONS!!!!
Jyrki


[/quote]

Dear Richi

THX for the kind words.

BTW here is my success:
We were out for racing in Kiskunlachaza (HU) this weekend.
The track was prepped very well but a little bit slippy at the beginning that gave us the time to make clutch and wheelibar adjustments on the naturally aspirated engine,
but how it turned out reaction was perfect later in the afternoon which gave me the chance to run still no bottle in the car, at 16:16

9.968 @ 220.64 km/h 


Later on my long time friend and racer buddy Fredy did a run with my car:

9.767 @223.34 km/h 


WoW   

MeXX


[/quote]

[Jon]

Congratulations Mexx!!

Next inovation? Dual mass flywheel... Spinn up both disks before the start and release the second disk when the start is done. Have the cake and eat it too... ;-)

[dangerous]

Well done Mexx!
nearly 139mph!
Do you know what it weighs?

[MeXX]

Well done Mexx!
nearly 139mph!
Do you know what it weighs?

Hi Dave

Yes I Do

MeXX

[Andy Sykes]

Awesome well done

[dangerous]

Well done Mexx!
nearly 139mph!
Do you know what it weighs?

Hi Dave

Yes I Do

MeXX

 
 

Just trying to make some apples with apples comparisons,
but that is OK, I know you can't share everything.
I am glad that you DO share so much, thanks for your posts!

[58vw]

awesome work!! nice run

[Shag55]

Very nice Mexx! Keep it up.

[MeXX]

Hi

Here are some further reports from my clutch testing:

After about 20 runs I have to say that it works like expected, it hooks up softly and can hold the power easily,
the only down side I had to accept is that if you put in a too soft spring and too heavy counterweigths (which would be perfect for soft launch and high horsepower) you are not able to open the clutch enough at high RPM. This is definitely killing the sycro hubs and gearboxes.

This happend at last race, were I had a fresh gearbox and at the 4. run (semi finale):

The nitrous set up was at 185HP 30% start 2,5s to 100%;
I had a pretty good launch and there was enough traction for this nitrous level.
  60 ft        1.455s was OK
  1/8          5.799s @ 201,73km/h (personal best)

but as mentioned before the clutch didn't open enough an so I broke the 4. gear syncro hub.
ending up with a sill amazing.

  1/4         9.584s @ 177.86km/h

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As we couldn't fix up the broken sycro hub I had to to the final run without a 4.gear:

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Without the forth gear I had to stay in the third gear and in the rev limiter from half to finish line.
But I was still able to win.

MeXX

[richie]

Nice ET for a wounded car   and congrats on the win 

Any idea why the 660 ET and mph were much slower on the second ticket with a better 60ft?

cheers Richie

[MeXX]

Nice ET for a wounded car   and congrats on the win 

Any idea why the 660 ET and mph were much slower on the second ticket with a better 60ft?

cheers Richie

Dear Richie

As I didn't want to kill the gearbox completely, I shifted much earlier at 7000 to 7200 instead of 7800 to 8000, and engaged the nitrous is the 2nd gear instead of the 1st.

MeXX

[Shag55]

Nice Mexx, so next Tim you will try a med spring and lighter CWs?

[dangerous]

What sort of gearbox do you use MeXX?
Perhaps an 'ignition cut' will get you better shift quality with those heavy clutch discs?

[MeXX]

Nice Mexx, so next Tim you will try a med spring and lighter CWs?

Right Shag

I'm goin' back to 12 light CWs and stage two base pressure.
Although because of the stage two spring it will not launch so smooth but it should handle the trq easily.

MeXX

[MeXX]

What sort of gearbox do you use MeXX?
Perhaps an 'ignition cut' will get you better shift quality with those heavy clutch discs?

Dear Dave

I'm runnin' a modified Porsche 901 gearbox:
4 gear vertical gate
aluminum spool
swing axle with 1350 spicers.

I'm runnin' Mega squirt MS II with ignition cut.

Yes my next setup will have lighter clutch discs.

So long

MeXX

[MeXX]

Hi

I'm very proud that one of the world leading companies in clutch friction technology is supporting me (and my insanity )
www.miba.com

Big big THX

Here is the next level of my clutch development:

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Delivered parts from Miba


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small box: clutch discs 5135 compound                                          big box: bronze floaters


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aluminium flywheel


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bronze floater installed

MeXX

[MeXX]

The next step in development:

A used Raypesto 5135 (aka Black Magic) was cut into pieces to find the best friction partner for this material.
You can see the cutted disc on the top of the small box.

As the right compound was found the floater plates, which were made from a special 2mm thick stainless steel that won't wrap under excessive heat, were sintered with a 1,5mm thick layer.

As now both floaters and the clutch disc will wear, it was possible to make the clutch disc slightly thinner (7mm) to help quicker shifts and make it easier for the sycro hubs.

The idea was to get better heat dissipation from the clutch disc and thus a more constant and easier to maintain clutch setup.

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Disc installed

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2nd floater installed

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pressure plate installed

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bronze floater Back Magic bronze floater sandwich

Just have to assemble

Friday T&T in Bechyne (CZ)
Saturday Championship race in Trencine (SK)

So keep on clutchin'

MeXX

[dangerous]

Bring on the first N2O 8's!!!