Switch to Extra code from B&G with Ford TFI

[h82crash]

I built the v3.0 board according to the MS2/V3 assembly guide and the DIY mod for Ford TFI. It has a 100 ohm resistor from s12 to ign/igtbout jumper. MS Extra guide shows a 1k resistor there and a 330 ohm between top of igtbin and top of r26. I've been thinking of switching to the extra code and read the DIY tfi mods were intended to work with the extra code. Do I need to make the changes for it to work?

Also, it appears I lose the auto mixture control to gain 16x16 tables, and load%, what I might use. Is it worth switching?

Thanks, Tom

[jsmcortina]

Automatic mixture control is potentially risky as there is no guard against a failing wideband and it could in that condition damage your whole VE table. That is one of the reasons we removed it from MS2/Extra.

If your ignition is running now, you should be able to swap across without any re-wiring, but you will need to preserve some settings.
- Ignition input capture
- Spark output polarity

In MS2/Extra you'll need to set "JS10" as the Spark A output.

Before starting the swap, be sure to Save Tune As so you have a copy to revert back to if necessary.

James

[h82crash]

Thank you! It's not running on a vehicle yet. Everything works on the stim. Currently installing on a Windsor 5.0 and will be running an individual throttle body intake (8 stack). Plan is to run solely off alpha-n and if features of the Extra code will aid in tuning it's good to know the switch is not too involved.

I read a person ran dual or (blended?) tables where he ran MAP at idle low rpm and transitioned to alpha-n at higher rpm and loads. Should I be able to find a good state of tune on just alpha-n? TKS

[rickb794]

If you are not set on individual runner throttle bodies, I would not go that direction.

Here is a clip from another post.
-----------------------------------------
ITB's make my head explode!
They are still used in some forms of racing for other reasons than making power.
They are marginally better than a carb power wise on a Dyno.
There is huge potential for gains by fixing what is wrong with the systems you see used.
They are a crude throwback from a long gone era.

You don't have a tuned intake if you have a throttle shaft and blade intersecting airflow. This ruins airflow in the intake column.
This flies in the face of all I know about intake tract tuning.

When we did our R&D on the throttle valve we patented we discovered a 20% loss in flow NA with a shaft and blade.
Thus most ITB's with shaft throttles are over sized to make up for the flow loss.
Also making a motor with ITB's streetable is difficult at best, it is very hard to modulate 4 over sized holes at part throttle. (ITB's work more like an On Off switch)

Having to oversize the passage to make up for flow losses, kills flow velocity.
Speeding up and slowing down air velocity in the column is like throwing out an anchor and negates any gains of a tuned individual runner intake.
The objective of an individual runner is to get the air turned smoothly and gradually accelerate the column by squeezing it slightly and ram it past the valve.
To do this perfectly you need a bell shaped entry and straight sides with a consistent cross-section gradually tapering to the valve.
Minus points for any variation of this program, putting a cross shaft and a blade or changing the taper of the cross-section in the mist of it's journey throws the gains all in the trash.
Unless you are going to use a Cosworth barrel throttle or one of my CenterFlow valves (that have no cross-shaft and smooth sides at WFO),
the only logical way to take advantage of a tuned individual runner intake is to join the runners in a plenum with the air valve in the plenum where it will not disturb port airflow.
This way you take advantage of having the required flow at the highest velocity, this is like supercharging a NA motor, a boosted motor will also see further gains from this style intake.

You can even make further gains with this setup by injecting some fuel in the top of the runner (at the right time) to change the WEIGHT of the column which effectively changes the tuned length of the runner.
Another plus is you have only a single air valve so idle and part throttle operation is done much easier and smoother, you also gain a plenum which will supply a nice vacuum signal for a MAP.

Tuning a car is a series of interconnected compromises, a bad choice in one area can negate gains in other areas or even lay to waste an entire scenario.
Some compromises create massive tuning nightmares and if those compromises do not produce gains that justify the effort required to make them even run, some re-thinking may be in order.

[rickb794]

On another less ranty note.

I would ony use the TFI for a signal source, and let the MS handle the ignition output.
Using a TFI output does not allow for full control of ignition events.

I would not actually use a TFI either, as there are EDIS crank triggers used on oem versions of your motor.
MS2 will do 8 cylinder wasted spark for a complete distributorless ignition and will easily read a crank wheel.

[h82crash]

Thanks for your response. As far as the ITBs go, I'm not after ultimate HP. It's going on a throwback car, my 65 cobra replica. I Have been running the stock EFI and was not making much of an impression when I opened the hood. But, a test on a 408 showed a 10% increase in power over a 750 cfm carb.

A fellow cobra owner is running the wasted spark setup on his 408 Windsor and it seemed more involved than I wanted to do just yet. Maybe once I get it up and running on the ITB and Megasquirt. One step at a time, it's the route he took.

[lukep6470]

Hi,

I have been running ITBs on my 289 successfully as a daily driver for over a year now with TFI. The only problem I've been finding is that my V8 very rarely sees over 2000RPM in normal traffic and carbons up on anything less than 98 octane (Australia). It's an AOD automatic and a manual would probably get rid if this problem.

My car is very drivable using ITB mode and idles under 800RPM. I'm using a manifold with a common vacuum chamber under it and 46mm Mikuni throttlebodies from a snowmobile of all things. I've heard if you use cheap throttlebodies you will struggle to get an idle under 1000RPM on a V8. I am using the Bosch IAC and it works a charm.

The most surprising thing I've found is the off idle pickup is so much more than with a 4 barrel holley. I have a 67 Mustang with a basically stock 289 and it will kick sideways doing the taxi driver stomp on the throttle on a dry road.

I will be moving my setup to a warm 347 (470HP) in March.

[boofhead]

I have been for a run in Lukes car and his setup is most impressive for a basically stock 289.
I was surprised by the low RPM pickup.

[h82crash]

Thanks for the input. Luke, how did you run an IAC? Through the plenum? I chose not to run one and will adjust idle with the throttle. Read a few people complain the throttles stick if they close completely.

Started checking sensors today. Fuel pump did not come on. I tried integrating the MS2 with the stock FP relay in the 88 Mustang harness I'm using and I guess I didn't get it right.

[lukep6470]

Hi,

Yep there is a common plenum under the manifold. My throttles don't jam at all. I've also found setting the default idle lower and using the IAC to raise it a bit makes it a lot smoother. It evens out the airflow a bit.

So if you set the idle without the IAC just 20-50 rpm lower and let the IAC lift it you can still drive the car without it stalling if the IAC fails.

[h82crash]

Tks, glad you works well.

All testing complete and successful. Tried to start and it fires right away but dies immediately. Raised the after start enrichment but didn't seem to help. Could my VE table be way too lean? I used the generate table tool but it doesn't look anything like another guy's table with a similar setup.

Also, is there a manual or tutorial that explains how to use the row of tools at the top of the VE table? Hoping to make changes go quicker.

[jsmcortina]

Tks, glad you works well.

All testing complete and successful. Tried to start and it fires right away but dies immediately. Raised the after start enrichment but didn't seem to help. Could my VE table be way too lean? I used the generate table tool but it doesn't look anything like another guy's table with a similar setup.

As ever, attach your MSQ and a datalog to get help.

Also, is there a manual or tutorial that explains how to use the row of tools at the top of the VE table? Hoping to make changes go quicker.

They are covered in the Megasquirt-2 TunerStudio Reference Manual.

James