Syvecs Forums

Nice one
Would manifold re-wetting after traction control fuel cut be a good idea?

Does this also include the Launch enabled via speed option?

Jez,

the traction control fuel cut is a randomised cut which is progressive with slip, rather than a simple on/off type cut like overrun fuel cut, it is therefore unlikely that any given cylinder will be un-fuelled for any appreciable length of time; the idea is to keep the whole engine producing torque. The manifold is therefore less likely to dry out in such few cycles but the point is taken, swapping between fuelling a cylinder and not will cause AFR transitions as the residual fuel level clinging to the manifold and intake ports is constantly changing. If we can think of a sensible way of trying to reduce this variation then by all means we'll try to implement it, but it's nowhere near as straight forward as the overrun fuel cut reinstate manifold re-wetting.

Wez,

That particular change didn't make it into 1.5.1. This release contains some important changes that we wanted to get "out there", so rather than delay until ALL the changes we wanted had been implemented, 1.5.1 was released to address immediate needs. The launch control without launch switch feature will be in the next release... it is near the top of the ToDo list

Hope this helps,

Pat.

pat wrote:Wez,

That particular change didn't make it into 1.5.1. This release contains some important changes that we wanted to get "out there", so rather than delay until ALL the changes we wanted had been implemented, 1.5.1 was released to address immediate needs. The launch control without launch switch feature will be in the next release... it is near the top of the ToDo list

Top stuff, Thanks

pat wrote:Jez,

the traction control fuel cut is a randomised cut which is progressive with slip, rather than a simple on/off type cut like overrun fuel cut, it is therefore unlikely that any given cylinder will be un-fuelled for any appreciable length of time; the idea is to keep the whole engine producing torque. The manifold is therefore less likely to dry out in such few cycles but the point is taken, swapping between fuelling a cylinder and not will cause AFR transitions as the residual fuel level clinging to the manifold and intake ports is constantly changing. If we can think of a sensible way of trying to reduce this variation then by all means we'll try to implement it, but it's nowhere near as straight forward as the overrun fuel cut reinstate manifold re-wetting.

Cheers Pat - just wondered because I can detect knock when using purely fuel cut traction control on my engine - I'm pretty close to the knock limit. To get round this I'm using ign retard with fuel cut - works fine. I expect that I'm getting knock due to lean conditions after fuel cut - although I can't be sure as you can't measure it.

Did you get my email with the Integrale trigger info and my L2H2 WBLS findings?

Hiya Jez!

Some engines are very fussy with regard to AFR, so yes, when an injector doesn't inject, you will get at least one cycle which is very lean rather than dry, and when it starts again you'll get at least one cycle where it's leaner than desired due to having to re-wet, but this happens so frequently that it should just average out, but if you're running the ignition close to the limit then it may well take you over. Applying the retard to take you away from knock is a sensible precaution, at least that way the leaner-than-desired cycles won't knock I'll have a think about whether there's a sensible way of re-wetting after torque reduction cut, but it's certainly going to be dependant on a number of factors, some of which may be highly non-trivial, may require a fundamental change to the control code or even FPGA.

I did get some info regarding the Integrale trigger, but I have no specific recollection of the L2H2 findings. As you may have noticed, 1.5.1 added support for dual-edge triggering, which was certainly necessary to support the 4G63 pattern, but because the 4G63 and the Integrale share a common theme, direct support for both patterns will most likely happen simultaneously....

Cheers,

Pat.

OK cool - it'd be good to see the Integrale and Evo on the supported list

When I used the L2H2 lambda sensor and Solaris the logs were almost identical to the readings I got using my TechEdge WBLS. Seemed to work fine.

Just a quick update....

In the Launch Control setup the options are to enable off the Launch or the Pit Limit switch, but not off the Cal switch. In the Calibration Switch, however, one can program a virtual Launch Switch, and set its position as a function of Calibration. In the past I'de had ECUs refuse to boot when Launch was configured but no Launch Switch was assigned in the I/O config, while others had reported that although the ECU would boot under those circumstances it still wouldn't arm. Today I had an opportunity to configure Launch without a Launch Switch, the particular application only had enough inputs for a Cal switch but no Launch Switch. I am happy to report that it does what it says on the tin; the Cal switch presents a virtual Launch Switch to the Launch strategy and it can be enabled and disabled as a function of Calibration. Note that it may be necessary to re-flash the ECU before such changes actually happen, and there may be other oddities (EGT disable due to a default EGT reading higher than the EGT disable on the Launch strategy, for example)... but fundamentally it does work, it may simply be a case of dotting all the 'i's and crossing all the 't's.

Hope this helps,

Pat.

Thanks Pat

Is definatly a 1.5.1 update though as tried it on a car yesterday which wouldn't work before on 1.4.1 and it now works sweet with 1.5.1

Good firmware update this one

This product just keeps getting better and better

Ryan

What was it that wouldn't work Ryan?