MicroSquirt.com read only forum (Jan.15,2018)

Hey, someone out there i'm guessing has squirted a manual trans car (hopefully a V8). Would there be any pointers you could give a dumbass who needs to a few more times I guess because I just can't get it right.

Attached is a small datalog of me giving the throttle a few 'blips' in the driveway and sorry to say it just doesn't feel as crisp as I want or as it was with the carb. My holley needed the 50cc accel pump to work which may give an indicator to how much fuel this motor can and will use

Also i'm finding that the AFR is going lean between gear changes too so I'm trying to weight MAPdot a bit heavier than TPSdot which is helping but I found I had to reduce MAPdot a little bit so AE would kick in..

Am I on the right track? Should I tried making the End Pulsewidth smaller so the accel shot is a bit more aggressive or concentrate on the bins?

Your idle seems lean, did you set your idle mixture to give maximum vacuum? If so I would have expected to see it richer. It's convenient when the ideal idle mixture is on the rich side because it helps transitions. Your overall AE scheme looks like its behaving properly on the log, you could fine tune the numbers but you're getting close and I see no problems except for the lean mixture at steady state. You may even consider running your mixture richer than the what your sensor tells you at all conditions, it will probably eliminate the other stumbles and make the car more driveable, you'll still be way ahead of a carb. Your car might like the xtau AE that's in beta testing now.

My cam doesn't really allow much more than ~60kpa of vacuum at idle. I originally tuned it for that peak vacuum figure then leaned it out about 3-4% so it doesn't have the 'stink' factor. Obviously i'll experiment and richen it back up to about 13-13.5:1 if it's compromising the transition.

I was more worried that I was veering off the wrong path but after having a good sleep last night I come up with this chain of thought. Lowering the MAPdot threshold and leave TPSdot where it is and adjusting the bins will be my first start. Experimenting with the end pulse i'm still a bit vague on but i'll do some more reading later on today to try get my head around it.

Cheers for the insight
Kris

Your tpsThreshold is set very high so is only working when you really mash the throttle.

Personally I have found mapDOT too quirky to make work. A setting that works off idle dosen't work at power because of map signal noise.

You may not know, but the decel settings only work off of tpsDOT. This makes sence, because it is not unusal for mapdot to go negative at high power were you would not want lean out.

For simplicity in testing you could try 100% tpsDOT and see what settings work for that.
I also like to set the fuel cut to about 4000 rpm and set the recover rpm to maybe 2000 rpm. Then I can just mash the throtle and not worry about over speed. It makes it easyer to isolate AE richnes from throttle closing richness.

Good tip. I may try that.

A.J.

Jedrik wrote:Your tpsThreshold is set very high so is only working when you really mash the throttle.

Personally I have found mapDOT too quirky to make work. A setting that works off idle dosen't work at power because of map signal noise.

You may not know, but the decel settings only work off of tpsDOT. This makes sence, because it is not unusal for mapdot to go negative at high power were you would not want lean out.

For simplicity in testing you could try 100% tpsDOT and see what settings work for that.
I also like to set the fuel cut to about 4000 rpm and set the recover rpm to maybe 2000 rpm. Then I can just mash the throtle and not worry about over speed. It makes it easyer to isolate AE richnes from throttle closing richness.

Yeah it does work GREAT when you give it a decent stab but it's just the smooth subtle gearchanges that i'm working on at the moment. I've managed to RDP into my laptop at home from work and make the +5% changes back to the idle bins and grabbed a snapshot of the VE table...

It runs a little lean at about 3000rpm onwards (only in teh 13:1 range though) with about 1/2 throttle and pings occasionally there but I figured i'm going to be tuning 1/2 - WOT on the dyno soon anyway so i'll be able to dial it up accurately...

Great tip on the TPSdot though! thanks for that!

Hi Kris

Of all the MS-2 tuning I have found tuning the AE to be most difficult and I am still not quite satisfied with what I've got.

I have found my most successful settings to be with MAP ONLY! (slider to the left max) Especially at fairly small/moderate pedal movements. This (I think) is because a large capacity V8 is more capable of jerking around the MAP values than a small cap high revving screamer.

Here's my comments on your settings:
1) I believe your 120 MAP bin ms is too low - try 4ms
2) I realise you have a wild cam but can you reduce your MaPDOT threshold to say 45?
3) I recon your accel time of 0.2 is WAY too short. I've got mine on 0.5 -0.7 sec;
4) Ditto taper time - try 0.5 or more
5) The default setting of end pulsewidth (2ms) really stuffed me around. Set it to 0 and work from there (effectively flooded my engine towards the END of the accel period)
6) your TPSDOT threshold seems VERY high - I've got mine on 2%/s!! (see comment on TPS lag factor below) (What's the sense of having a 5%/s bin if TPS only kicks in at 20?)
7) Leave Decel fuel amount at 100% until you're happy with everything else then fiddle with this - I doubt you will ever see the effect of this value on your fuel bill even at its best.
Your cold accel mult seems very low - mine's sitting at 130%
9) Then, on your VE map, don't go too lean on low MAP bins - this is where the engine comes from just before you step on the gas. I found making the very low MAP bins (<30) richer (13.5 or so) "prepares" the engine for when the throttle gets opened suddenly.

Did you know that you can adjust your 0 - 300 MAP bar in MT?
Ditto with the 0-200 TPS bar?
Specially with TPS I found that I could hardly generate more than 50%/s UNTIL I realised that my TPS lag factor was "slowing" down my TPS response. I recon I've NOW got my TPS lag factor around 80 - 90 % I recon Map lag factor should stay around 45 - 55%.

I sat playing around with my TPS lag factors and the AE TPS bar MT settings (engine off, ignition on - obviously) until I was happy that the TPS gauge "mirrored" my foot movement and until I could "Fill" the TPS AE bar with my most aggressive stomping

Hope this helps. I believe that a much more elaborate writeup on how to set AE params is needed and once I've got mine sorted I'll have a go unless someone else has done it by then (I'm a slow learner...)

Thanks again guys! The printer is warming up to print out these hints so i can scan them into my brain for tomorrows tuning runs