Author Topic: Rev counter & shift light outputs  (Read 16816 times)

Offline lugnuts

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Re: Rev counter & shift light outputs
« Reply #15 on: June 25, 2007, 04:03:32 pm »
Wow I really need to go to sleep before 6 am and not post, I made myself look stupid haha.

I was intending on using a 12v supply for the tach, but I somehow lumped that thought in with wondering if the 5v supply can be used for more than one other pullup input channel at a time.

Can you recommend a resistor setup for using the launch control and the shift cut with the 5v supply?

Thanks,
Kevin

Offline rob@vems.co.uk

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Re: Rev counter & shift light outputs
« Reply #16 on: June 25, 2007, 05:33:26 pm »
Here you go:


The configuration details are found in the Using Spare Analog Inputs section of the User Guide:
http://www.vems.hu/wiki/index.php?page=MembersPage%2FPhatBob%2FUserGuide

Offline lugnuts

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Re: Rev counter & shift light outputs
« Reply #17 on: June 25, 2007, 07:41:01 pm »
I did see that and I will say here thanks for the User Guide, it is a life saver!

I was wondering if the Launch Control and the Shift Cut can both be poweed by the Pin 28 +5v supply, and what resistor(s) would be needed. Come to think of it the Launch and Shift would not ever be used at the same time, so that seems a non issue.

Can Launch and ALS both select one channel as an Input? (I think I will be fine with launch only)

For those interested, my Launch and Shift setup would be as follows, I have 2 possible setups:

Setup 1:
Launch Control and Shift Cut on a clutch switch, use the handbrake handle switch to disable Shift Cut while using Launch Control. FWD drag guys use the handbrake to hold the car still at the starting line and to allow pre-loading the clutch to reduce breakage.   
- possible issue, driver could release the handbrake first, which would cause the shift cut to enable and shut the engine down. Two possible solutions:
1) A diode(?) on the Launch Control Relay to hold it open for a fraction of a second, in case of early handbrake release (can this be done?, like how OEM ecus hold open injectors after engine shutdown)
2) Use a Misc. Output to allow the shift cut to only occur at high rpm (~1000 short of redline) which would be higher than the startline RPM to avoid conflict.

Setup 2:
Use ALS for Shift Cut, more flexable on/off with better turbo respool using retarded timing and spark cutting. Need to read up on the ALS.

Offline rob@vems.co.uk

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Re: Rev counter & shift light outputs
« Reply #18 on: June 25, 2007, 08:54:28 pm »
Yes you will need seperate 2k7 resistors to limit the current draw so that you can connect up multiple switches to the various inputs.
You will need two seperate inputs for the Launch control and ALS functions.

I have never used the Launch control, Shift cut or anti-lag as I tend to do NA stuff and those with turbos are not keen on using these due to turbo life expectancy, gearbox issues and what have you.