RPM Limit

General Megajolt Questions and Answers

Moderators: JeffC, rdoherty, stieg, brentp

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Daryl
Posts: 0
Joined: Mon Mar 01, 2004 3:20 pm

RPM Limit

Post by Daryl »

Brent,
Helping my brother with his 510 racer. Rev limit for his engine is between 9-10,000 RPM. I have searched the web and come across several references in the 8-9000 rpm for the EDIS unit, as well as one for 9500 rpm. Also talked to a Ford service Rep who said the limit should be well beyond that.
So.... My question is....

If the Edis Module will go to or beyond 9500 rpm, can your controller keep up?

I am going to convince my brother to try it anyways, which means I have to get it operating on my car 1st. But I'll be lucky to hit 7000 on mine. If it works well, We should have a test mule for 9000+ rpm.

Daryl

andre saethern
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Joined: Tue Apr 25, 2006 9:43 am

have you testet it yet?

Post by andre saethern »

have you testet it yet?

brentp
Site Admin
Posts: 6280
Joined: Wed Jan 24, 2007 6:36 am

..

Post by brentp »

I haven't tested it on an engine to 9500 RPM but based on the processor overhead it should be able to do the job. Is it a 4 cylinder? the number of cylinders directly affects the amount of work the processor has to do.

I've tested it to over 8000 in my toyota 4AG motor. I damaged my valves due to floating, but that's a different story. :)

Do realize that you're working with an open-source collaborative project for an experimental ignition controller. You may be the first to test it in that unique way. On the other hand, someone else might see this post and report their findings!

So, let us know what you find out.

Thanks,
Brent Picasso
CEO and Founder, Autosport Labs
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4600cc
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Joined: Sun Jul 11, 2004 1:48 am

Rig it

Post by 4600cc »

My question is as follows:

Post was submitted on 3/8/2004, and replied on 4/27/2006. Is there a bug in the forums or it took that long to reply? :)


There is a guy around here with a megajolt test rig, I think it's Steve (Clark?). You might want to think of a way to test on a rig like that. I know that EDIS in combination with ECC-IV EFI controller was ran in formula 1 in the 90s. So basically, if you know capacities of ECC-IV processor, you can compare it to Megajolt and conjecture that it might work or might not work.

If you going to test on the engine I'd do it like this: Have a working rev limiter, make one of the outputs cut spark. Start low, 6,000, and in 100 rpm increments increase rev limit. Your map should be safe, let's say a constant 15 degrees in all 100 bins. Try to hit rev limit and make the spark cut out, while you listen to engine sound, it should sound all the same with no "kicks", or have a brave guy stand there with a timing light. While you do this, watch for maximum recorded rpm in runtime display (MJTUNER). As you increase rev limit rpm, the difference between maximum recorded rpm and your rev limit should be pretty much the same, if it goes up by a large amount it would indicate that megajolt can not keep up.

Record the rpm difference in a table, along with rev limit rpm, we could later graph it.

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