EVOscan Ceddy Mods and Speed Density (hardware / wiring)?

[Cox Abele]

I'll be switching to Speed Density at some point this year. Looking at Ceddy's site, it says, and I'm paraphrasing here...

IAT
The IAT is wired into the MAF plug, pins 5 and 6. (Pin 8 is unused for reference)

MAP
The MAP is wired into the stock MDP sensor.

I will be using a GM-style map with a vac line since I run a EVOIII intake which doesn't have an MDP port. This is not a concern. The AIT placement is a no-brainer. It's the wiring that has me full of questions.

I really like the idea of plug-and-play. My goal is to drive my car to the tuner on the stock MAF, then allow him to take logs to build the tune for speed density. The sensors will be installed, then we simply plug them in with this pre-made harness- no cutting or soldering required.

http://www.extremepsi.com/store/product.php?productid=18023&cat=0&page=1

I like this idea because it always gives me the quick option to change back to a 2g MAS if necessary.

Ceddy says the AIT is wired into the MAF, so the harness makes sense. He then goes onto saying the MAP gets wired to the MDP plug. Well, the harness clearly puts the MAP to the MAF wiring. Additionally ceddy says...

You now need to simple drive with the MAF still in place and you MAP Sensor hooked up, and log these two items.
The goal is to get MAF and SD AirCounts to match under all conditions.

I can see logging the MAF and MAP if the MAP is wired to the MDP. The AIT is unimportant for this part. But say, you are setup to log these two sensors, then eliminate the MAF and run SD with the additional plug-n-play cable, clearly the MAP signal would be sent to the MAF pins and not the MDP. How does this all work?

I could do as he says and wire the MAP to the MDP since I still have the wiring intact. Would I then nip out the air temp wires from the MAF plug and run the AIT while still using the factory MAF?

 

[kanusky1990]

"I could do as he says and wire the MAP to the MDP since I still have the wiring intact. Would I then nip out the air temp wires from the MAF plug and run the AIT while still using the factory MAF?"

This is the approach I was about to do until I stumbled upon this post. I already have the MAP wired in and I am in the process of building my VE map. What I wanted to do was log my IAT to watch my post turbo IAT's while I set my boost to make sure I am not turning it into a hairdryer.

I assume the MAF has it's own air temp sensor, and if you wire in the IAT sensor into the MAF wiring, while still using the MAF, worst case scenario is that the ECU will be basing the "ignition trim vs Air temp" off of a sensor that is post turbo and obviously getting higher temps than the MAF is seeing. Without adjustment, this would make the ECU pull timing because it thinks the air coming into the MAF is significantly higher than it really is. Therefore this table would need to be either re-scaled or shifted higher to account for this change.

This was just my logic to this, and if anyone has any other opinion feel free to comment. I am using a H8 ecu with ceddymods.