Anti lag

Hello experts,

I have a manual transmission, turbocharged car running a MoTeC GPR package. The car does not have any gear detection available and can only rely on a clutch switch to indicate that a gear change is about to take place.

I noticed during my races that I'm losing far too much speed and time during gear switches, and I'm looking for a way to improve it.

this is because during gear shifts im losing from 0.5-0.7s just to get back to my boost levels.

Can someone guide me as to what is the best way to implement the anti-lag function to retain some boost during gear changes? or to have some sort of gear change ignition retard to occur as i change gears?

Thanks alot.

If you engine isn't equipped with proper antilag system the only way to keep turbo spinning is to retard ignition timing and add much more fuel in those areas of ignition timing and fuel tables where your engine falls during deceleration. It's pretty much the same thing as for making pops and bangs sound on NA engines

so that would be having the clutch switch activate the secondary fuel aim and ignition table, where ignition retard and extra fueling is added to the areas that fall under shifting event?

It depends on what kind of racing you do and what ECU you're using... If it's rally it's just enough to change ignition timing and fuel tables. If it's drag racing you would need to think of some way of activation antilag initiated by that switch but that would require some advanced ECU to make it happened.

As Shota said, but don't go too far with the enrichment, it still needs oxygen to burn and you want the burn in the exhaust manifold to keep the turbine spinning - basically a "two step" setting.

There may be some benefit looking at the switch position, too, so the clutch is already at the point of release when it activates and engagement when it de-activates, to minimise the time the engine isn't actually producing power.

Im using M150 ECU with GPR package and the car is used for drag racing, i was trying to think of a less intrusive way to apply the ignition retard and extra fueling other than manipulating the main fuel and timing tables.

Given the correct setup, can the antilag option in the GPR firmware provide this function? Or would activating auxiliary time with the clutch switch and applying fuel and timing trim work also?

Appreciate your input guys,

Do you have a Wheel Speed input into the M1? If so, you can use this the Gear Estimate to workout the gear position.

Unallocate the resource from Clutch Switch to one of the Driver Switches, then allocate the Driver Switch as the Gear Lever Up Switch. This then allows for the Gear Change system to work, rather than trying to get anti Lag to work in a way that it is not designed to.

Thats great, Thanks Stephen

So I would use my clutch pedal as an input to the gear shift system, and from there I would apply the ignition retard.

I have a wheel speed input into my M1, Better start working on the gear detection to see if it's reading correctly then.

Would you be able to guide me as to what goes into setting the shifting part of this system?

I read in an old post of yours where MoTeC only considers upshifts for Manual H-patterns (which I assume is upshift power on?). However, here I see the throttle aim workbook (does it relate to speed matching only?), gear shift timing, and gear shift ignition cut (I assume it will allow for easier gear engagement?). and finally what im looking for is the gear shift ignition retard.

Would I have to set all those parameters up to ensure the ignition retard system is working?

Again thanks for taking the time to reply and would appreciate if you can guide me through that

Read the firmware help for "Gear Shift State" -- that explains what can happen with the gear shift system, and how/when you can retard the ignition on various Gear Shift Types.

Thanks for the help guys, i got the gears properly reading and the gear shift working.

The issue now is that i still can not get that anti-lag sort of ignition retard. i used 10% ignition cut to ease things on transmission and up to 70 degrees of timing retard with no effect. Have also played with increasing the shift timing so that ignition timing can get that low but with no effect. only thing i noticed is the car would experience an engine braking kind of phenomena from the sudden timing drop during gear changes. i have not played with the gear shift engine speed limit as i dont fully understand how it can help me in this situation.

I'll datalog the system in operation and post it later so my situations makes more sense.

I really like to use Gear Shift Engine Speed Match. This basically sets the Gear Shift Engine Speed limit to the proper revs for the next gear, allowing the gear box drop into gear, and not over slow the engine.

i dont know what magic happened there but i added more ignition retard and played around with the engine speed match and it worked.

Thanks a million, guys,

One last thing haha, it seems that my clutch pedal switch is based on some sort of contacts that trigger with the lightest of touch ( even vibrations trigger it).

Are there other ways i could wire a signal from the clutch pedal?

Thanks

This is the setup i have

I would adjust the switch position somehow -- remove a washer, modify the mounting -- yours looks like it uses the clutch switch as the stop. Perhaps a different switch that allows some some pedal throw before it activates.