Ignition retarding at high rpm

Dave-R · Post by **Dave-R** » Thu Sep 18, 08 11:10 am

I thought the MSD retarded by about 15 or 20 degrees or something? I would have thought it would have been too much in any case?

Dave-R · Post by **Dave-R** » Thu Sep 18, 08 11:15 am

Ah! No.

I was thinking of the start retard. The other retard is anything up to 10 degrees isn't it?

Pete · Post by **Pete** » Thu Sep 18, 08 11:18 am

Only below 800 RPM Dave, a useful (essential) feature. I would never be able to start the motor without that and a starter-saver; the Hi-torque mini starter says "your having a laugh!" without it.

The timing tickets seem to indicate that the motor loves lots of timing at the start of the run, but less at mid track and at the end.

I was looking for an elegant solution that let me play with the additional facilities of the MSD 6 D - they might not have worked, but maybe I could pick up 3 10ths, which would put me at about 9.80's (my target for that engine).

Dave-R · Post by **Dave-R** » Thu Sep 18, 08 11:36 am

If I was you I would be getting one of these to see what is going on.

http://www.innovatemotorsports.com/products/lm2.php

I have an older LM-1 on its way in the post to me I bought from a mate for $200. Not as versitile as this new version but pretty good.

Dave-R · Post by **Dave-R** » Thu Sep 18, 08 11:53 am

My thinking is you are too rich at the start and getting leaner as you progress. A rich mixture effectively retards the ignition - requiring more ignition timing.
A lean mixture effectively advances timing - requiring less ignition timing.

Anonymous · Post by **Anonymous** » Thu Sep 18, 08 10:54 pm

Yea , lost many a teeth on a few vertors tryin to start the motor with high initial. (chinese crap):roll: $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

Remember Al splitin a £200 starter down the middle , was only a day old , face was a picture.

Dave-R · Post by **Dave-R** » Fri Sep 19, 08 8:50 am

My LM-1 meter and wide-band O2 sensor arrived yesterday.

All I need now is the accessory input cable that allows you to record RPM, manifold vac, throttle position etc at the same time as air/fuel mixture. Up to six inputs in fact. Even NOS solenoid operation or an accelerometer for G-force in any direction.

Some of you guys could really benefit from data acquisition like this. It takes a lot of the guesswork out.

It records 44 minutes of data (sampled 12 times/sec) which you download to a PC or laptop.

It is accurate enough to show the mixture as each cylinder fires. If one cylinder does not fire at any time it shows as a clear spike on the graph. The run can be played back in real time on "gauges" on the pc screen. Any part of the graph can be analysed in detail.

I will probably only use air/fuel and rpm to start with. Although manifold vacuum might be handy too. Not sure if it would be possible to fit some sort of throttle position sensor on a six pack or not.

Dave999 · Post by **Dave999** » Fri Sep 19, 08 9:25 am

not as good as what daves talking about but

put a megajolt on

crank trigger

any advance at any rpm based on RPM and or load

rev limiter shift light output

dual maps
swap on the fly mid track if you want

TPS or MAP===boost retard if you need to

programmable outputs trigger the NOS, water injection, gearvendors,bunch of flowers, oil slick, smoke screen, flak cannon

data logging. full graphing functionality.....no wide band though its just an ignition

cheep as chips and the quality of the implementation and circuit build is up to you....build it with gold band resistors and 5 watt instead of 1.5 pot the lot in silicone putty (silly putty) and it should be bomb proof

one day i'll get mine installed and you can all have a mootch point laugh take the P or be amazed its functionality....

it'll be sic! dude

Dave

Dave-R · Post by **Dave-R** » Fri Sep 19, 08 10:21 am

Because they have brought out the LM-2 meter, the LM-1 is now selling at $299.

Mine cost $250 to my door thanks to a mate. Although it is "used" but he only used it twice. It is like new in the box.

AllKiller · Post by **AllKiller** » Wed Oct 29, 08 6:12 pm

Pete wrote:Only below 800 RPM Dave, a useful (essential) feature. I would never be able to start the motor without that and a starter-saver; the Hi-torque mini starter says "your having a laugh!" without it.

The timing tickets seem to indicate that the motor loves lots of timing at the start of the run, but less at mid track and at the end.

I was looking for an elegant solution that let me play with the additional facilities of the MSD 6 D - they might not have worked, but maybe I could pick up 3 10ths, which would put me at about 9.80's (my target for that engine).

Mine is the same Pete, loves 42 degrees on C16, (no Gas) but a little less at the top end, would increase my top end speed
I was considering a manual switch on the wheel or shifter, hit 3rd and push the button till the traps
My MSD add on box has the option to use this too
I think its the only way or an RPM switch for top gear assuming you pull more RPM in top to activate in that gear ??
Manual switch i think

Anonymous · Post by **Anonymous** » Wed Oct 29, 08 7:53 pm

Are you confusing fuel issues with ignition timing? , maybe the motors leaning out mid track wanting less spark advance.

AllKiller · Post by **AllKiller** » Wed Oct 29, 08 8:09 pm

High speed retard increases top end Speed MPH and thus improves ET

Guy · Post by **Guy** » Wed Oct 29, 08 9:34 pm

Anonymous · Post by **Anonymous** » Wed Oct 29, 08 11:35 pm

What RPMs are we talking here? , 3000 to 6500? , obviously any engine will require a change of spark lead between these RPMs as the fuel needs to be ignited earlier as the engine spins faster & faster , what makes matters worse is the use of to high an octane if the motor does'nt need it , C16 is generally used for nitrous/boosted motors , if you run it in a street motor that lives pretty well on 97 octane with 40* of advance then i can't see any advantage , all your doing is losing power as the motor will require sooo much spark lead @ high rpm to burn the fuel.

Maybe we can use two cells with different octane ratings in em , switching cells mid track.

Just talkin out loud.

Anonymous · Post by **Anonymous** » Thu Oct 30, 08 12:27 am

Sorry Dave Rob , just seen your previous post on fuel issues , think your right.

Steve , back off the lash & i bet it picks up some.

Have you stopped grittin yer teeth?