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Anybody know anything about Megasquirt???? 
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Joined: Tue Oct 30, 2007 8:44 am
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Post Anybody know anything about Megasquirt????
As some of you know I'm running a 1293 A series in basically MG Metro spec apart for a 266 cam and 1.5 roller tip rockers. I'm looking to convert from the HIF44 on an MG Metro manifold to twin injectors driven by a Megasquirt ECU.

I want to use a pair of BMW boxer motorcycle throttle bodies as they are pretty much self contained and also include the injector mounts and a throttle position sensor.

Image

I have basic machining facilities and intend to make a couple of manifold stubs to mount on the cylinder head then connect the throttle bodies using flexible tubing as on the bike.

I have read around this and it seems that there can be a problem with fuel distribution or charge robbing with twin injectors due to the siamesed inlet ports on an A series so here is where I need the help.

Why does this problem occur with injection when it doesn't happen with twin SU carbs, a DCOE Weber/DHLA Dellorto or split Webers?

If I run the injection as continuous rather than pulsed or timed does this overcome the problem?

If I move the injector further from the port does the problem lessen and if so what's the safe minimum distance?

Does the problem occur with any power output?

Is it worse with different cams?

Any help will be gratefully accepted.

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Wed Jan 23, 2008 9:07 pm
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Post Re: Anybody know anything about Megasquirt????
Due to the shared ports there is always a problem of one cylinder breathing better than the other, only way around is 7 port, 8 port, KAD, Or to improve on it a Scatter cam, this will help a bit. doesnt matter if its carbor injection it just happens.

With it being injection the only real issue from reading around the subject years ago is the a series, seems to prefer a less atomised fuel spray, such as a webber etc, this is only true for max HP, altho the injection should give a more drivable car and thereby will be faster and more of a joy.

Prob the best place to place the injector is far away from the valve as sensible, reason behind this is, give the fuel chance to mix with the air and hopefully not all the fuel going to one cylinder, a more homegenous mixture, [think that the right word for what im thinking, had a couple]

an exmaple of this is on a twin injector setup on a very high performance car, you have the injectors close to the valves for emmisons, idle, low speed driving, for higher rpm, you have second injectors which are placed further away, as due to the higher air speed it can be advantagous to have the fuel injected further up the intake tract, thus allowing time for it to achieve the a nice homegenous mixture. only real way to find out how far is by dyno tunning. [one example is a bike engine the injectors always seem to be near the throttle body this may be due to the high engine/air speeds]

some food for thought, this is from some items i have read etc, can not say it does or does not work for myself.

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Wed Jan 23, 2008 9:24 pm
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The Terrible Tims

Joined: Fri Sep 28, 2007 7:56 pm
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Location: In the garage,Sileby, LEICS
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Post Re: Anybody know anything about Megasquirt????
I don't know the answers, but the guys on the turbo mini forum seem to have alot of experience between them on this sort of thing.

I'd have a search of their site and if you can't find any answers I'm sure that someone will know.

http://www.turbominis.co.uk/forums/index.php

PS I'm going to use megasquirt on mine, when it gets built as it gives a far smoother engine on a tuned/turboed A series

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Wed Jan 23, 2008 9:29 pm
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The Terrible Tims
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Joined: Sat Sep 29, 2007 12:23 pm
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Post Re: Anybody know anything about Megasquirt????
Yes the problem seems to worsen with "hotter" cams, there's been a lot of discussion on this on the megasquirt forums which you may have already seen. If you look on Emerald's site (Dave Walker) there was an article on injecting a Midget which you may find interesting. :wink:

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Thu Jan 24, 2008 12:10 am
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The Terrible Tims
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Post Re: Anybody know anything about Megasquirt????
There's another option, Bmw k100 head, 8 ports, itb's, 16 valves and twin cam :!: :twisted: Its been done several times and appears to be a much more cost effective than the KAD :wink:

From what i've read in the past it seems this cylinder robbing problem worsens as power goes up, there are a lot of claimed 90bhp injection minis around, so i would assume it would work quite well at that level. I do recall that many of these kits used high lift rockers as opposed to longer valve timing. Also Minispares did a special cam for tuned injection A series. Hope my memory has'nt failed me and this helps :?

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Thu Jan 24, 2008 11:50 am
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The Terrible Tims

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Location: In the garage,Sileby, LEICS
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Post Re: Anybody know anything about Megasquirt????
http://www.turbominis.co.uk/forums/inde ... tid=198360

Apparently someone has done it recently, might be both buying as copy and having a read.

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Thu Jan 24, 2008 12:21 pm
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Joined: Thu Oct 25, 2007 2:10 pm
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Post Re: Anybody know anything about Megasquirt????
Practical classics ran an article a couple of months ago about converting and A40 to full engine management (not megasquirt, but similar idea from what I remember), with very good results - aroung 22% power / torque gain (albeit from a 29bhp starting point).

System used MPI mini manifold and throttle body, and looked quite straightforward.


Fri Jan 25, 2008 1:42 pm
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Joined: Tue Oct 30, 2007 8:44 am
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Post Re: Anybody know anything about Megasquirt????
Keep it up chaps. All this is solid gold!!!!!

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Sat Jan 26, 2008 10:44 am
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Joined: Wed Jan 07, 2015 1:19 pm
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Post Re: Anybody know anything about Megasquirt????
Just wanted to rejuvenate this thread as I am also very interested in the Megasquirt option - has anyone here actually implemented this on an A-series in their GTM ?


Tue Jun 16, 2015 9:22 am
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Joined: Fri Aug 15, 2014 4:49 pm
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Post Re: Anybody know anything about Megasquirt????
Join up on the turbo mini forums, www.turbominis.co.uk there is lots of people who are using and experienced with megajolt and megasquirt


gtmdriver wrote:
Keep it up chaps. All this is solid gold!!!!!


Tue Jun 16, 2015 8:35 pm
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