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Food for thought, camfire ignition system?
- Thread starter GTIspirit
- Start date
1: I have the dyno sheets to prove it.Hogwash. To see those kinds of changes your fueling curve would have to be terrible.
2: Never touched fuel, afr was hovering around 13:1
3: Just because say 32 deg timing works best for peak power (at say 6700rpm) it doesn't mean it's best at 5000rpm or at 7200rpm. If you've ever monitored timing with a scan tool on a modern efi car you'll see that the timing is very dynamic. Even above 4000 rpms. The manufacturer does it for economy and emissions but it can be tuned the same way for power.
4:A year ago I would have said the same thing. but after 9 megasquirt installs and hours of tuning them on the dyno I know differently.
"found 15ft/lb wtq at 5000 rpm (numbers went up 15 ft/lb) and 10whp at 7000 rpm. the power curve and torque curve used to be bell shaped and now they are both pretty darn flat"
Since HP equals torque @5250rpm, sounds like you gained about 15hp@5000! and 10@7000-- and that seriously flattened the power curve? Only if you started with a disaster (quite possible w/DIY TuneItYourself systems-where do I start?) But then you say a/f was 13/1 thruout. I hear that you have "data". And I know what I know. Somethings wrong with this picture. For these values to flatten the curve, you would have to start with a huge hump in the middle; if timing was locked at some sensible value thru-out, you wouldn't get this result-what was your timing control and what were your tq and hp peak values and rpms? What dyno?
Since HP equals torque @5250rpm, sounds like you gained about 15hp@5000! and 10@7000-- and that seriously flattened the power curve? Only if you started with a disaster (quite possible w/DIY TuneItYourself systems-where do I start?) But then you say a/f was 13/1 thruout. I hear that you have "data". And I know what I know. Somethings wrong with this picture. For these values to flatten the curve, you would have to start with a huge hump in the middle; if timing was locked at some sensible value thru-out, you wouldn't get this result-what was your timing control and what were your tq and hp peak values and rpms? What dyno?
Bell shaped is a bit of an exaggeration but the torque rose rapidly and steeply to peak at 5300 or so and the hp dropped rapidly after peak at 6800 or so. Torque at 5000 was 115 it's now 130. Hp at 7000 was 130 it's now 140.
Timing has never been outrageous 30-34 degrees max but small changes of 1 or 2 degrees above where a tradional curve would be constant seems to work well.
This is an SIR motor so that may have something to do with the unusual gains. But I still have seen gains on IT motors of 2 to 3% by messing with the timing above 4000rpm.
As far as timing control, the megasquirt is directly driving an Electromotive 4 cylinder DFU (waste spark coil pack). It's using a 36-1 tooth crank trigger for rpm/tdc. Timing is very accurate and contollable to .5 degrees.
All of our testing was done on a portable dynojet, outside air and it's VERY consistant.
While I'm well aware of the fact that standalone systems can create a disaster, I have a lot of experience with megasquirt (as I said 9 installs with tuning in the last year) and once you know your way around it it's very friendly.
Timing has never been outrageous 30-34 degrees max but small changes of 1 or 2 degrees above where a tradional curve would be constant seems to work well.
This is an SIR motor so that may have something to do with the unusual gains. But I still have seen gains on IT motors of 2 to 3% by messing with the timing above 4000rpm.
As far as timing control, the megasquirt is directly driving an Electromotive 4 cylinder DFU (waste spark coil pack). It's using a 36-1 tooth crank trigger for rpm/tdc. Timing is very accurate and contollable to .5 degrees.
All of our testing was done on a portable dynojet, outside air and it's VERY consistant.
While I'm well aware of the fact that standalone systems can create a disaster, I have a lot of experience with megasquirt (as I said 9 installs with tuning in the last year) and once you know your way around it it's very friendly.