Tuning Transients

Give input on tuning as well as any tips and tricks you may have. Also feel free to share base mapping files for various engine types.
Jon K
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Re: Tuning Transients

Post by Jon K »

Has anyone messed with throttle transience when dealing with large injectors such as 1000cc per cylinder on a 2800 cc engine? My cold transience is a pain. Warm is "ok". I think its too fat still, but it works ok.
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stevieturbo
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Re: Tuning Transients

Post by stevieturbo »

Jon K wrote:Has anyone messed with throttle transience when dealing with large injectors such as 1000cc per cylinder on a 2800 cc engine? My cold transience is a pain. Warm is "ok". I think its too fat still, but it works ok.
It's easy to get into the notion that you need more more more.

Often too much fuel is what is causing the bogging down rather than too little.

My cold transients arent much different from warm. So mirror them as a starting point. But dont forget you are already running richer during warm up, so more may not always be what is needed.

Just start low and work up. Whether that be a small brief squirt, or a small long squirt. Only trial and error will let you know what works.
Jon K
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Re: Tuning Transients

Post by Jon K »

stevieturbo wrote:
Jon K wrote:Has anyone messed with throttle transience when dealing with large injectors such as 1000cc per cylinder on a 2800 cc engine? My cold transience is a pain. Warm is "ok". I think its too fat still, but it works ok.
It's easy to get into the notion that you need more more more.

Often too much fuel is what is causing the bogging down rather than too little.

My cold transients arent much different from warm. So mirror them as a starting point. But dont forget you are already running richer during warm up, so more may not always be what is needed.

Just start low and work up. Whether that be a small brief squirt, or a small long squirt. Only trial and error will let you know what works.
Yeah I feel like maybe my cold accels are too fat. My warm is ok. But honestly, I think if I let the car get to like 190 coolant temp and turn off transients it almost works just as well.

I need to re-read the other settings. I don't really get the ms and % stuff, have to refresh myself.
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stevieturbo
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Re: Tuning Transients

Post by stevieturbo »

Pedal speed is simply the sensitivity. 1% = very sensitive, 100% not very.

Increase in fuel is simply a percentage of current quantity of fuel added.

Duration is simply the number of engine turns that fuel is injected over.

Pedal time is the length of time the ecu looks at pedal movement before it does anything. So again a low time will make the setup far more sensitive to pedal movements than a long time.
FrankCorrado
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Re: Tuning Transients

Post by FrankCorrado »

Well I'll forget any of this for a while, cuz I have a major reliability problem that showed up without warning. My FCM is all screwed and I can hardly run sequential anymore. So I guess I will restart from scratch next Spring (can't use car during winter here).
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Jon K
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Re: Tuning Transients

Post by Jon K »

FCM?
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FrankCorrado
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Re: Tuning Transients

Post by FrankCorrado »

Fuel Correction Map
Frank
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stevieturbo
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Re: Tuning Transients

Post by stevieturbo »

FCM could only ever get screwed up if you are running stupid numbers with your closed loop setup.

CL is ONLY for making very small corrections to a known good base map. Although that's a difficult message to get through sometimes.
FrankCorrado
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Re: Tuning Transients

Post by FrankCorrado »

Exactly.
It's applying the wrong small corrections cuz my map is NOT for batch. Therefore it screwses up what I had already accumulated.
Frank
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