Iam running the gamma stage 2 SC kit with the c38-91, I tried renegade fuel at end of summer,it was unleaded 98 octane,iam on the big pulley 7lbs of boost , amazing difference compared to the 91 we have here in Canada,i will be running 109 octane unleaded renegade fuel this upcoming summer, Seb from specialty Z said that it should open the tuning doors wide open with the ecutek,also installing the 85mm pulley, plus cjmotorsports return kit once he gets back to me.

I generally explain to customers that Flex Fuel is 90% ECU/Tuning/Wiring and 10% fuel system. In regards to the fuel system configuration, you only need to add a sensor into the fuel stream. The rest is wiring and tuning. So I personally have not really considered flex fuel as a function of the fuel system itself, but as a function of the engine control system.

If someone needs a source for the sensor, we could supply it to you. But I usually point people to their tuner/installer for it. They will be the ones who have to wire it up and get it communicating and configured within your ECU.

When it comes to integrating the sensor to the vehicle, there are any number of ways to do this. The sensors have industry standard 3/8 Quick-Disconnects on the ends, making it simple to install them. The big question is, where do you want to install it?

Well the first question is: are you going to put it on the feed line, or the return line? 99% of the time, either will suffice. But as most things, there are compromises.

Feed Side Pro: Most accurate and consistent reading
Feed Side Neg: Sensor is somewhat restrictive. Will most likely be a source of pressure drop for twin pump vehicles.

Return Side Pro: No restriction to feed plumbing whatsoever.
Return Side Neg: When you are nearing the upper limits of your fuel system, the volume of return fuel flowing through the return lines will be very low. If it gets low enough, the sensor will get a bad reading. Without any PERSONAL experience to this happening, but having heard from other tuners, when the sensor doesn't get a quality reading, it starts to read to the "less-E" side of the table, meaning the tune going lean.

So there are a couple reasons that CJM does not take control over your Flex Sensor installation. For one, these cars are so jam packed, its difficult to find a great spot for the sensor that will universally fit all builds and forced induction system kits. Also, I dont want to be the one who told you to put it in the return line when your tune goes lean because of it, and I dont want to be the one who told you to put it in the feed line when you start seeing pressure drop because of it.

In the end, integration of the sensor is very simple. If you are not experienced with AN plumbing and you dont wish to become so, just contact me and let me know where you would like to put the sensor in the steam of our fuel system, and I will gladly set you up with the components to do so. But many of you will find that your tuner doesn't mind installing the sensor for you.

Personally, I cringe at the thought of putting the sensor in the engine bay at all. There is hardly enough room in there for the fuel lines as it stands, and there is almost no real estate on the firewalls for mounting extra things. I have been recommending to people to install the sensor directly above the fuel pump top hat. One customer supplied me with this photo of them completing that style integration with one of our older fuel systems. But there is no reason this couldn't be done just about the same with the latest systems. I have attached the photo.

Me personally, if someone drove into my shop and wanted the sensor in... I would probably put it directly at the fuel filter outlet underneath the vehicle. Nice and easy to work with, nothing in the way, and it can be protected by the underbody shield. The only annoyance with this location is having to run the wires for the sensor along side the fuel line for a ways to get them to their destination.

For the record, to clear up some conversation in this thread...

The Walbro 450, 460, 485, "400 E85", or any other name you might find it called, are all the same pump.

The part number is F90000267. Walbro rates them at 450lph. I think that the "485" name might have been derived from "for e85" or something. But nowhere on the published flow chart from Walbro or TIAutomotive will you see its output achieving 485lph. The chart peaks at 455-ish LPH at 30psi. 450LPH would be an appropriate rating for them in comparison to the popular 255LPH pumps.

But ultimately, everyone is talking about the same pump.

There is also a much more rare model of it, some refer to as the "high pressure" version. Since the F90000267 is already a high pressure fuel pump, I would refer to this other one as "higher pressure". Its part number is F90000274.

It is hardly more expensive. The only reason you dont see them as often is because the major distributors for Walbro that all the shops buy from, including me, were not buying and stocking them when they came out.. making it hassle to get them. Just recently one of the major distributors started stocking them, and we will be using the 274 part number now. Might as well, its only like $5 more and it maintains slightly higher output at higher pressures.

As a side note, the Walbro turbine pump that is not E85 rated, was the Walbro 400. When they first came out, they were a hit for a minute. But now with the 450s out, I dont see anyone at all selling or using the 400s anymore. I have the Walbro 400 in my own Z, just to get it out of inventory, nobody was going to buy it. That is the pump that had no issues holding 671rwhp with E85 in my car.

my setup...

450 walbro
cjm fuel return for ehtanol
innovate ecb-1 (ethanol to ecutek via evap vent control signal, not the purge)
aeromotive pump speed controller and canbus tach signal converter
id1050 injectors
hks plugs(1 step colder)

https://www.youtube.com/watch?v=g8kmasenp8w