Nice Feature on Gen 7 +

[norbs]

I will be testing this feature today to make sure it works. This is where the aftermarket ecm's show there stuff.

Overboost rev limiter. This could have saved me, if i had it back then.

Over Boost Control
A new ignition limiter based on Manifold Pressure. This can be used in Supercharged or
Turbocharged applications to prevent an overboost condition. The ignition will begin to
drop cylinders at the value entered in this table. As the MAP reading rises, more cylinders
will be cut until all cylinders are shut off at 0.75 PSI above the value entered in this table.


You can adjust at what rpm the max boost is allowed every 400 rpm,

The qustion is, does the fast xfi also have such a feature?

 

[HighPSI]

I don't think I would want to use this feature with a CCCI ignition.

Yes, the XFI could do something similar on the AUX #2 Output

 

[norbs]

What could happen? If i use this feature on a dis ignition?

 

[HighPSI]

What could happen? If i use this feature on a dis ignition?

Unless they are doing the rev limiter in a way I am not familiar with, I would be concerned about misfires damaging the engine.

 

[norbs]

I have tested at low boost seems to work silky smooth. However i am running a type II ignition system fed by 3 accel +300 boxes.

 

[norbs]

Tried a bit more boost seems to be getting a bit more violent, i have to talk to Craig smith about this

 

[Otto J]

The original fast i believe did its revlimiting with fuel for that sae reason,You can cut one cylinder without sutting another on the same fire, The XFI has a sequential rev limiter but it will not work with coil pack ignition also,Works great with a distributor

 

[HighPSI]

Give Craig a call. I have already spoken to him and passed my thoughts on to Lonnie D. about rev-limiting a CCCI module.

 

[summit]

Interesting. Does that same theory apply to 2 steps on a MSD DIS box?
My car threw another lash cap today and trashed a pushrod tip. Second time this has happened in 3 years. Not sure what happened either time. Can sitting on the two step on a transbrake cause something like this? Still running coilpacks and using a Innovative to control launch boost and the two step to limit the rpm. Should I let it stay loaded against the convertor and just use the boost controller to control launches?

Greg Kring

 

[Otto J]

One would thing Greg, I did use a DIS 4 for a while and dont remember having any problems,Maybe with the multi spark it can be done

 

[Joe Lubrant]

..................................................................................,Maybe with the multi spark it can be done

Thought Multispark limited to 3000 Rpm and below?


Joe

 

[gewroo]

The problem with the rev limiting from the ECU is that the CCCI module could become unsynchronized from missing EST pulses while rev limiting (at least until the cam sync occurs again).

The MSD DIS4 gets its control from the CCCI module and and not the EST signal so it has no effect on CCCI synchronization.

 

[Otto J]

Thanks for the info

 

[bruce]

A simple cure is just going to the later, Quick Start ignition set-up. Using the 3x, and 18x triggering wheels gives an instant response to which coil to fire process. Drop the EST all you want, and the system recovers in the absolute worse case synchs up in 240d crank rotation, usually in 120d.
Oh, and another benny is not having to wait for a cam pulse when starting.

We'll also ignore that the system is still in use, and parts won't be going obsolete for a long time.....

Drat, and I missed that EFI course......

 

[norbs]

Whats involved to change over to this?

 

[bruce]

Whats involved to change over to this?

As it turns out the late DC 3800 have a problem with the crank balancers failing, so if you can snag one of the bad ones from a shop, then all you need to do is fab up a little adapter ring on a lathe. There's an early and a late, the later having over a .25" gap between the two rings. You'll also need the later module, and coils. Then just wire it up, per the late model diagrams.

Once you get the adapter ring machined, then use 3 long allen bolts to bolt it into the back side of the original balancer. So that you wind up with 3 bolts, and 3 studs holding the pulley on.

Orienting the shutters to the key way is critical. You have to eye ball the shutters, and grind 3 thur holes to mount them with. The original mounting on the SC used 4 holes in different locations.

 

[norbs]

DO you think this would cure the problem of the backfiring during the rev limiting process on the aftermarket stuff?