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Discussion Starter · #1 ·
Hello everybody! I'm finishing up my poor mans lightning build and I have a few questions about what I could safely set my rev limiter and shift points to. I'm posting to this forum because it seems a lot more active than the truck one. it is a romeo 2v 4.6
My upgrades are:
PI head swap
Truck PI upper intake
NPI lower
Stage 2 MHS N/A cams
Pac 1218 Valve springs good for .600 lift
"cold air" K&N intake
BBK shorty headers and catted straight pipe for the time being.
high flow oil pump
alum. rad
will eventually convert to e fans
SCT x4 Tuner currently with 5 Star Tuning's base tune, waiting for the rest of the tunes to come.
I'm not sure if they are going to adjust rev limiter and shift points, if they don't, what would be a good ballpark? I'd like to be able to to take it to 6 grand, would that be safe? I know these autos like to shift pretty early, I'm thinking going to about a 5-5750 range? any input is appreciated, Thank you!
 

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All of the Ford ECUs from the early 2000s through about 2010 or so fall short of the mark in the ECU processor power department. 03/04 Terminators had an effective 6500 to 7000 max rpm ceiling depending on what you could disable in the tune. Even with everything turned off that could be turned off, high 6,XXX engine speeds were about the end of the line.

Your best option would be an MS3Pro, possibly the PnP version that plugs into the factory harness. The upside is that all the OEM ECU limitations are gone, but the downside is emissions testing and potentially dash support. The PnP versions are configured at manufacture by DiyAutoTune to support the factory instrument cluster in 03/04 Mustangs. That may or may not work for your application; DiyAutoTune can tell you if it does or does not support your dash. If it does not, you can buy a non-PnP version and piggyback it on top of the OEM ECU for just engine management and let the OEM ECU do everything else.

Importantly if your state has a detailed emissions testing program that you must pass to get an annual SMOG certificate, you will only be able to pass that with an OEM ECU — the certification software at the testing station looks for that. Aftermarket ECUs will not pass muster.

p.s. With the OEM ECU disconnected from the engine, there is a high probability that the emissions testing and qualification software at the test station will turn this up and fail the car.
 

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Discussion Starter · #3 ·
All of the Ford ECUs from the early 2000s through about 2010 or so fall short of the mark in the ECU processor power department. 03/04 Terminators had an effective 6500 to 7000 max rpm ceiling depending on what you could disable in the tune. Even with everything turned off that could be turned off, high 6,XXX engine speeds were about the end of the line.

Your best option would be an MS3Pro, possibly the PnP version that plugs into the factory harness. The upside is that all the OEM ECU limitations are gone, but the downside is emissions testing and potentially dash support. The PnP versions are configured at manufacture by DiyAutoTune to support the factory instrument cluster in 03/04 Mustangs. That may or may not work for your application; DiyAutoTune can tell you if it does or does not support your dash. If it does not, you can buy a non-PnP version and piggyback it on top of the OEM ECU for just engine management and let the OEM ECU do everything else.

Importantly if your state has a detailed emissions testing program that you must pass to get an annual SMOG certificate, you will only be able to pass that with an OEM ECU — the certification software at the testing station looks for that. Aftermarket ECUs will not pass muster.

p.s. With the OEM ECU disconnected from the engine, there is a high probability that the emissions testing and qualification software at the test station will turn this up and fail the car.
Very useful info, thank you!
 
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