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Joe Bob |
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Retired admin, banned a few times ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 17,427 Joined: 24-December 02 From: Boulder CO Member No.: 5 Region Association: None ![]() |
Not getting any response on the shop talk forum....project is a blown Type 1 motor. It's a stroker 92/82 displacing 2180ccm and it has the Hideaway turbo kit from CB Performance with a HEI ignition. We put on a Megasquirt-II instead of the Delco ECU to get more tunability. Now I am looking for some pointers for the ignition table. Here is what I came up with so far. Please give me some feedback. (IMG:http://members.cox.net/3.6/images/spark.jpg) |
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ischmitz |
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Newbie ![]() Group: Members Posts: 10 Joined: 24-June 06 From: Santa Barbara, CA Member No.: 6,295 ![]() |
Mark, this is the table from Minami over on the Megasquirt forum that you've mentioned in your link. He claims he has run up to 17PSI boost. Well, he uses water injection under boost to keep the charge cool.
![]() Brett, the timing values are absolut. Megasquirt allows to set the static offset to make all values in the table real. We checked with a timing light and it is pretty close. The dip from 700 RPM to 1000 RPM is something I found in all Bosch Motronic maps. It prevents the engine from stalling by bumping up the advance once the RPM wants to drop below the 1000 mark. To read this table and convert kPa to PSI think about the 100kPa line as WOT. Everything above the 100kPa line is boosted and as we go down to 40 kPa we have vaccum (closed throttle) 120 kPa = 2.9 PSI boost 150 kPa = 7.3 PSI boost 180 kPa = 11.6 PSI boost 215 kPa = 16.0 PSI boost The fuel map will get tuned with an LM-1 as feedback. We will set the cruise area lean to make sure we can afford to drive it with 4$ per gallon here. Under boost it will be closer to 11:1 to make sure it does not burn the pistons. Megasquirt has the option to use the wideband O2 sensor signal and shoot for a target AFR depending on RPM and load. Once the map for fuel is dialed in we will put a narrow band O2 sensor in permanently. Hm, maybe I'll ask Mike to apply for a SMOG certificate with his friends at the DMV if he gets the oil leaks under control (IMG:style_emoticons/default/biggrin.gif) Here is my latest rendition of the ignition map. I smoothed out some of the rougher areas. Remember that Megasquirt interpolates between RPM bins. I guess we just have to take it to the dyno and see how it does and then to the machine shop if it grenades.... ![]() What do you guys think, Cheers, Ingo (IMG:style_emoticons/default/givemebeer.gif) |
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