gear cut/shift setup H pattern using strain gage gear knob

[kielcivic]

Hi guys
Iam currently running a honda civic fwd drag car with a ppg 4 speed drag box the time iam running 9.0 @166mph and the time has come to get the strain gage working for flat shifts/full throttle shifts.
I have the gear knob type strain gage all wired in and sat at 2.5 volts in normal position then forward around 1.7v
Backwards is around 3.1v
Now it would be great if someone had some more advice on what to setup next and what to log on the strip when getting info to input the strain gage! Even some basic setting to start from
I also have it cut request coming on but only one way not both and need help with that to.
Any help would be great
Thanks very much kiel

[stevieturbo]

With an H pattern I cant see any way of making that work

The transition to low voltage indicates the blip/downshift, and the transition to high voltage will indicate an upshift cut

I'm not aware of a setting on the ecu's that will allow both signals to be recognised simply as an upshift to start the power cut. Although I'm sure some of the syvecs team can offer more info in that respect

I went for one of these, a simple microswitch knob. Not perfect but reasonably functional

With it, any fore/aft action will give the rising voltage which you can set to trigger the upshift power cut.

http://www.sqsracing.com/produkt/319:41 ... power-knob

it just takes a little setting up, and you need to ensure you dont hold the knob after a shift or else the voltage will stay high and it can trigger another cut after the mask time expires.

wire the strain gauge or shift knob to "gearcutinputV"

[kielcivic]

Thanks for that steve
Well on the website ka sensors it says suitable for h pattern and ryan told me to get this one so there must be some possible way to do this I hope!
Cheers

[TimH]

Cut/blip input thresholds can be set on a per-gear basis, so I would think that's the way to do it?

[stevieturbo]

I guess using the voltage thresholds as Tim suggests it could maybe work.

You only have the option of a rising voltage to trigger, or falling.

So for forward gears, -e 1, 3, 5 with the low voltage you'd maybe to set the trigger voltage to lower than 1.7v, eg 1.5v

These would be entries for gears 0, 2, 4 in the table as you're in that gear moving the stick forward and need it to cut at that voltage level to enable the shift. ( I know there is no 0 or flat shift to 1st )

Voltage would rise above the trigger and hit 1.7v activating it.

Only problem I see with that, is the voltage would already have been sitting at 2.5v which is higher than the trigger level so it isnt rising through the trigger threshold, it's staying above it the entire time

Definitely curious as to how it could work on an H pattern.

[kielcivic]

Thanks for that input guys
I will have a try with some of them ideas.
Anymore ideas are very welcome cheers

[POPWORTH]

Does anyone have anymore info on this thread? Has it been done before? Is anyone running gear cut with H Pattern Dog box? I'm curious as have just fitted a Dogbox myself and would really like to be able to flat shift. An help great fully recieved.

[stevieturbo]

You can easily do shift cuts on the upshift with the open loop settings.

I'm not sure if you can easily do anything for downshifts, largely with an H pattern it's harder to let the ecu know whether you're doing an upshfit or downshift.
Hence just work as every shift is an upshift requiring a cut for a pre-determined time

SQS do a gear knob with a microswitch built in that can work for this for flat throttle clutchless shifts.

Or for flat throttle shifts, but still using the clutch, you could use a clutch pedal switch or pressure sensor on the clutch line.

[POPWORTH]

Thanks for your swift reply stevie, with an open loop setup using the sqs gear knob is there a way to make the across gate shift cut (2-3) longer than the 1-2 and 3-4 or would it have to be an average time for all shifts? So the sqs gear knob supply's the same voltage in either direction making the ecu cut everytime. I drag race my car so am only worried about up shifts, I use the clutch all other times.

[stevieturbo]

Thanks for your swift reply stevie, with an open loop setup using the sqs gear knob is there a way to make the across gate shift cut (2-3) longer than the 1-2 and 3-4 or would it have to be an average time for all shifts? So the sqs gear knob supply's the same voltage in either direction making the ecu cut everytime. I drag race my car so am only worried about up shifts, I use the clutch all other times.

You can set the cut time as you wish for each shift selection.

Obviously for this, the ecu will need to know, or calculate what gear you are in. ie in the absence of a gear pot as per a sequential type box, you will need to have a reliable vehicle speed input. From this you tell it the gear ratios and it can calculate which gear you are in.

The SQS knob is simply a microswitch it will trigger on fore or aft movements of the stick. As it's an H pattern even a load cell would not know whether you're going up or down a gear as you move the stick both directions anyway.

http://www.sqsracing.com/produkt/319:41 ... power-knob

You will need to play with the settings, mask times etc for this...and also ensure you dont have a habit of holding the gearstick too hard which would leave the switch trigger active. It's easy done ! lol

But it is workable