Please help, some problems!

[lander]

Hallo
I have Suzuki Swift Kit Car for hillclimbing and I installed on my 1,3 liters engine ITB and MS-2. I am using code version 2.684.

Yesterday during test I had problem with VR, not able to get over 5000rpm. I find here on forum that I need tu tune VR pots R52, R56. I tur ned few times both to the right and now I am able to get to around 8600 but need to go to over 9000. Dont know if problem is only in that VRpots.

I have also problem with rev limiter. My ignition timing in high revs is 24 degree. I use spark retad, lover limit 8500, uper limit 8600, 12 degree retard. But the result in timing is 24 minus 12 to 12 degree as you can see in dataloging . Is it OK? I also get another strange timing spikes up to 17000 rpm. Where is problem? rev limit? Not well tuned VR pots? Lag factor of RPM? next pulse tolerance? Anything else????

I have also problem with vBATT spikes? Any idea how to solve? Or is it OK?

I think that I have now relative good VE table for WOT from 5000 - 8500 rpm. What you think?

When I solve problem with VR and rev limit I need to tune acceleration enrichments. Any tips for racing engine with ITB ?

Here is my dataloging http://lander.tuning.cz/23.xls

And here my MSQ http://lander.tuning.cz/msq.msq

Thank you soo much for any help

Lander

[lander]

Another dataloging with spikes

http://lander.tuning.cz/22.xls

Lander

[mops]

well yeah, this indicates tach spikes.

you *might* be able to tune it out with pots, but if interference is too high then that wont work. Keep turning bottom pot clockwise until the problme goes away. you might find that once problem is fixed your car wont start any more....

second thing to try is in megatune->settings->ignition->next pulse tolerance. try changing normaal running value +-10% see whether it has any effect. again, you might notice that if you fix the problem your car might not start....

THE proper way to fix the problem is to run proper shielded cable from vr sensor all the way to MS' db37 connector (all the way shielded), avoid proximity of any other wires.

let us know how r u doing.

[lander]

Thank you for your answer
I will try to look on that pot and on setting of next pulse tolerance.

What you think about rev limiter? Does it work?

And what you think about vBATT spikes?

Filip

[mops]

yes, rev limiter definitely kicks in. 12 degrees might not be enough to limit a raging motor.... first play with fuel cut rev limiter, just to make sure you wont overrev.

yes, just noticed battery log. it looks rellay bad. it might be creating your issues. make sure all ms sensors are grounded to MS and MS ground is separately wired straight to battery's (-) if that wont help then I dunno... but that wonky voltage will defeinitely create problems.

[PSIG]

...now I am able to get to around 8600 but need to go to over 9000. ... I use spark retad, lover limit 8500, uper limit 8600

You only get 8600rpm but your upper rev limit is 8600. You can' t get over 9000 with an 8600 rev limit. Do I misunderstand?

[lander]

yes, rev limiter definitely kicks in. 12 degrees might not be enough to limit a raging motor.... first play with fuel cut rev limiter, just to make sure you wont overrev.

yes, just noticed battery log. it looks rellay bad. it might be creating your issues. make sure all ms sensors are grounded to MS and MS ground is separately wired straight to battery's (-) if that wont help then I dunno... but that wonky voltage will defeinitely create problems.

I was thinking that rev limit will add taht 12 degree so result will be from 24 to 36 degree as is timing in low kpa.... Is possible to find somewhere some teoretical instruction how timing work what happend if it is 12 degree or for example 36 degree?

All sensor are grounded to MS. And all that grounds are wired in engine bay wall. Batery is in cocpit and grounded to body.
That vBatt spikes is in another time than rpm problems. I dissable Dwell corection from battery voltage to get stable Dwell.

Lander

[lander]

...now I am able to get to around 8600 but need to go to over 9000. ... I use spark retad, lover limit 8500, uper limit 8600

You only get 8600rpm but your upper rev limit is 8600. You can' t get over 9000 with an 8600 rev limit. Do I misunderstand?

No no, in datalog 23.xls you can find that i get in one try without any problems to 8998 when spart timing went from 24 degree to 12 degree. After that 8998 I get "jump" to over 1700 rpm!!! So rev limiter is not working is that jump to 12 degree correct? I was thinking that I need to change timing from 24 degree to 36 degree... I think that it is two problems together, rev limiter and VR signal. In today test I try tu turn clockwise botton VR pot. Probably I am still getting high voltage during high rpm.

Lander

[lander]

And what about to use fuel cut rev limiter? Is it OK on racing engine?

Lander

[PSIG]

Actually, I prefer fuel-cut on both street and race IF I am using 1 squirt or 2 squirts alternating. Any more squirts per cycle can cause a lean condition rather than a clean cut. I would not use fuel cut where there is closed-loop (O2 correction) or if the cylinders share injectors (TBI or split runner manifolds, etc.) for this reason, even though i don't like to send raw fuel into the exhaust with spark-cut - especially on a street car with mufflers. Retard is a good option if your valves are not too hot already.

Different forms of racing may need different rev limiters.

Hope that helps,
David

[lander]

Actually, I prefer fuel-cut on both street and race IF I am using 1 squirt or 2 squirts alternating. Any more squirts per cycle can cause a lean condition rather than a clean cut. I would not use fuel cut where there is closed-loop (O2 correction) or if the cylinders share injectors (TBI or split runner manifolds, etc.) for this reason, even though i don't like to send raw fuel into the exhaust with spark-cut - especially on a street car with mufflers. Retard is a good option if your valves are not too hot already.

Different forms of racing may need different rev limiters.

Hope that helps,
David

1) I solve the problem with VR pots. Today I get only on spike, dont know why.

2) About rev limiter. Spart retard is not working on my engine. I set revlimiter to 5000 and retard12 and engine was reving to over 6000 without any noticable lost of power. In Megatune it shows me change from 24 degree to 12 degree. So I change revlimiter to fuel cut and it working perfect. Like revlimiter in stock ECU. I have now rev limiter on 8800 rpm.

3) I also modified today my VE map. I change AFR table from 12:5 at WOT to 13:1. As I get infos, 13:1 will be better on my racing engine.

As I calculated rev/s from VE 12,5:1 and VE 13:1, I get on each gear few tens rpm / second.

I also worked today on AE, but I set it too rich, so had to set number lower. But no other time to test it. I drived my car soo hard (up to revlimiter) and then stop to modify data in Megatune, that my water gets over 100 degree of celsius. I hope that I didnt broken my engine, but water didnt boilt. I have to install radiator fan (not mounted) for better cooling when my swift is staying and doesnt matter if engine is running or not.

At friday I am going to first hillclimbing race with running megasquirt. I am little afraid if everything will work correct.


Filip

[mops]

good to hear you are making progress.

you can again try spark retard rev limitet, but retard the spoark more. try 20 degrees.

defintely reinstall cooling fan.

it's cool that you are going racing, just make sure your engine it tuned before racing... you wouldnt want to damage it due to poor tune....

[lander]

good to hear you are making progress.

you can again try spark retard rev limitet, but retard the spoark more. try 20 degrees.

defintely reinstall cooling fan.

it's cool that you are going racing, just make sure your engine it tuned before racing... you wouldnt want to damage it due to poor tune....

I tryed to set in revlimit 20 degree, but maximum what is able to set in megatune is 13 degree

Yeah, I will reinstall cooling fan. After race i will need to cool down the engine.

I think that during last few days i did lots of work on setting. For now I have at WOT AFR from 12.5 to 13.2 all the time

I have set shiftlight at 800 rpm, so I will sure shift before 8500 rpm, so I hope that I will have no problem with VR and tach spikes.

I will sure post experiences and results from weekend race...

And also tomorow I will post pics of engine and installed megasquirt

Filip

[PSIG]

...2) About rev limiter. Spart retard is not working on my engine. I set revlimiter to 5000 and retard12 and engine was reving to over 6000 without any noticable lost of power. In Megatune it shows me change from 24 degree to 12 degree.

That's correct. Eric may give more insight, but in the MegaTune version I have, you enter the actual timing you want when retarded. So if you put Rev Limit Retard of 5 it will give you 5 actual degrees of crankshaft timing (5° BTDC). Maybe try that.

[mops]

another way to implement it would be as follows:
-assume you want your rev limit 9000rpm

in the ignition table have two last rpm bins at 9000 and then 9100. at 9000 you got all proper timing, but at 9100 you set timing to, say 2 deg or something ridicolous like that....you could combine it with fuel cut at say 9200rpm, to implement like a 2 stage rev limiter - first-soft gradual timing retard followed by a hard fuel cut.

again if you are running 2 squirts alternating then it's very nice to have it bouncing of fuel cut limiter with tyres smoking