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All out N/A engine timing curve
https://www.slantsix.org/forum/viewtopic.php?t=66172		 Page 1 of 1
Author:  Greg Ondayko [ Wed Sep 08, 2021 6:59 pm ]
Post subject:  All out N/A engine timing curve
I have been thinking about possible reasons why my Ruster is somewhat slow off the line.

Since I trashed the distributor back in 2014 or so I have been running fixed timing as I do not have a vacuum feed to the megasquirt... yet

So I was thinking of Drilling the carb and adding a full vacuum feed to the data input of the ms3 so it can get map data.

If I do this I can then run a map based on load and rpm.

Do you think this will be advantageous... getting a better 60' time?

Greg

Greg
Author:  DadTruck [ Wed Sep 08, 2021 7:51 pm ]
Post subject:  Re: All out N/A engine timing curve
So you have the MS3 only controlling ignition? And the fuel side is a carb?
In Tuner Studio do you have an ignition option to ‘use table’ under the Ignition Settings tab? You should be able to have a variable user defied ignition curve regardless of the fuel setting. My MS3 Pro does not use Map or kPa or a vacuum signal to adjust the timing curve. kPa is an input for constructing the VE and AF tables. But those do not link to the ignition timing table.
Author:  slantzilla [ Wed Sep 08, 2021 9:03 pm ]
Post subject:  Re: All out N/A engine timing curve
What was your 60' if I may ask Greg?
Author:  slantzilla [ Wed Sep 08, 2021 9:08 pm ]
Post subject:  Re: All out N/A engine timing curve
What was your 60' if I may ask Greg?

Leaving off a brake the curve should be irrelevant. Timing should be all in well before launch rpm.

I know my junk was dead to the 60 when I had 38° total in it. 32° really woke it up.

Have you tried leaving off the footbrake to take the 2 step out of the equation? Sometimes it can get so fat on the 2 step and it takes a little while go clear.
Author:  Dart270 [ Thu Sep 09, 2021 5:39 am ]
Post subject:  Re: All out N/A engine timing curve
If you control timing with the MAP sensor, you should try it. However, I agree with a high stall converter this really shouldn't matter much at all. Manifold should have a vacuum port/plug on it. I like Dennis' idea. My bet it is the fuel mixture, not ignition.

Lou
Author:  Greg Ondayko [ Thu Sep 09, 2021 6:53 am ]
Post subject:  Re: All out N/A engine timing curve
Well Right now the car has MS3 for timing only.

Fuel is run by the carb.
O2 Sensor wires crapped out on me while doing 12 hrs of trailering so I cannot get fuel / O2 data but I would also surmise that with WOT Carb on spark cut it's super rich on the brake/2 step.

I also can do the Transbrake and shut the 2 step off.

I have some experimenting to do, and can definitely go back to the footbrake and try it out.

if I had Electonic injection I could tell MS3 to Cut fuel and spark, but not yet.. it's on the wishlist. Too many cool projects /Ideas and not enough time.
Hey Lou.. need some R&D time on the ITB's?!?!? :D :D

@ Slantzilla - the 60' times are slow like in the 1.66 area - I would like to be ~0.2 Sec's Faster than that.

Greg
Author:  slantzilla [ Thu Sep 09, 2021 4:40 pm ]
Post subject:  Re: All out N/A engine timing curve
I'm not sure you have enough steam for a 1.46, but you should get in the mid .50s.
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