running this setup on a 700 horse blown small block 350

General Megajolt Questions and Answers

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darkostoj
Posts: 2
Joined: Fri Dec 12, 2008 5:50 pm
Location: Detroit

running this setup on a 700 horse blown small block 350

Post by darkostoj »

I am really excited about all the features of this setup and would like to set it up on my 67 camaro with a blown small block, but I had a few questions

will the map sensor that uses load for calculating ignition advance work for a setup that has boost(positive pressure). naturally aspirated setups have vacuum that drops to 0 for maximum load conditions, but on mine I go positive so I was wondering if that would work.

Can I somehow run a knock sensor that would limit spark advance or take out timing if I get into detonation?

is there enough spark energy to full burn a mixture that has 20pounds of boost pressure and a total output of 700 horsepower?

Is it possible to setup a 2 step rev limiter (for an ex. a limiter of 7k rpm, and a limiter at 3k rpm wired to a switch)

I read that you can hook my wideband up to it, what does that allow me to tune with the ignition setup

thanks!
1967 camaro blown small block

cng1
Posts: 282
Joined: Mon Dec 06, 2004 7:56 pm
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Re: running this setup on a 700 horse blown small block 350

Post by cng1 »

darkostoj wrote:
will the map sensor that uses load for calculating ignition advance work for a setup that has boost(positive pressure). naturally aspirated setups have vacuum that drops to 0 for maximum load conditions, but on mine I go positive so I was wondering if that would work.
Yes. The map sensor will read boost.
is there enough spark energy to full burn a mixture that has 20pounds of boost pressure and a total output of 700 horsepower?
The current-day ultra-lean mixtures of modern production cars are far harder to ignite than a nice and rich boosted engine. So lucky for us your bog-standard ford coilpacks are extremely good.

darkostoj
Posts: 2
Joined: Fri Dec 12, 2008 5:50 pm
Location: Detroit

Re: running this setup on a 700 horse blown small block 350

Post by darkostoj »

cng1 wrote:
darkostoj wrote:
will the map sensor that uses load for calculating ignition advance work for a setup that has boost(positive pressure). naturally aspirated setups have vacuum that drops to 0 for maximum load conditions, but on mine I go positive so I was wondering if that would work.
Yes. The map sensor will read boost.
is there enough spark energy to full burn a mixture that has 20pounds of boost pressure and a total output of 700 horsepower?
The current-day ultra-lean mixtures of modern production cars are far harder to ignite than a nice and rich boosted engine. So lucky for us your bog-standard ford coilpacks are extremely good.
b
are you sure? Wouldnt the richer much much denser boosted a/f ratio be MUCH harder to ignite than a naturally aspirated normal car
1967 camaro blown small block

brentp
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Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Welcome darkostoj,

Actually, the system was originally designed for an application not so different to what you are looking at!

We were targeting a 1.6L turbocharged application running up to 20 lbs of boost; at proper tune the engine was producing about 250 HP. So that nets about 156 HP/Liter.
A little write-up of our R&D vehicle is here:
http://www.autosportlabs.net/Research_a ... a_MR2_AW11

The MJLJ is equipped with an internal MAP sensor capable of measuring absolute pressure up to 250 Kilopascals, which represents about 22.5 lbs of boost at sea level.

The Ford EDIS system already produces very strong spark- however, what's more important, the spark load is shared across multiple coil packs. This means at higher RPMs the individual coils have more time to charge, resulting in consistent, strong spark energy.

In the case of my 4-banger the coils fire 1/2 as often as a distributor-based setup, which was especially helpful with a 7600 RPM redline.

The 90-97 5.0L mustangs were fitted with the EDIS-8 module, and enthusiasts boosting these engines have reported success up to about 20 lbs of boost as well.

With regard to switchable rev limits: The unit supports dual ignition configurations which can be switched on the fly. So, you will be able to set one rev limit on Map 1 and a different rev limit on Map 2.

The unit has an auxiliary input which can be used for a variety of purposes. Primarily, it can be used to 'correct' the ignition advance based on the voltage measured on the input port. An example of this would be to handle warm-up by reading a temperature sensor. Another use may be reading the input from a wideband sensor. adjusting ignition advance, and so on. For knock control there is an ongoing discussion on how best to integrate an external knock control unit and having the Megajolt react to this signal in the appropriate way.

Aside from correcting advance, you can also use the Aux input to trigger user defined outputs which can control accessories, indicator lamps, etc.

Wideband datalogging with Aux input: http://www.autosportlabs.org/viewtopic.php?t=2072
Advance correction using Aux Input: http://www.autosportlabs.net/MJLJ_V4_Op ... rrection_2
User Input configuration: http://www.autosportlabs.net/MJLJ_V4_Op ... figuration

Hope this helps, please let us know what else we can help with.
Brent Picasso
CEO and Founder, Autosport Labs
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