I am having a hard time understanding what the difference is. Do they both not do the same thing? You have a wideband O2 sensor hooked up to either the M-300 or the SM-AFR and they both just give you the read out for the AFR, correct? Then you need either a stand alone or a piggy back to actually adjust the fuel, right? I have read the description page on PLX's site and unless I missed something, the M-300 is called a AFR "controller", but I don't see how you would make adjustments with it alone. The SM-AFR, on the other hand, isn't called a controller, but it basicly says the same things that the M-300 says. So far the only difference aside from apperance that I can discern is the price with the SM-AFR being the cheaper of the two (even with the DM-5 gauge that you need for the readout).

Long story short, I need to be able to adjust fuel because I am running a 3" RB REV TII system with an FCD and a Blitz boost controller and I want to make sure I'm not leaning out. I have decided that PLX is the company I want to go with as far as AFR monitoring and the Apexi Neo for fuel adjustment. Is this a wise choice aside from a full stand alone ECU? Am I missing something along the way here?

Link to the M-300:
http://www.plxdevices.com/products/m300/

Link to the SM-AFR+DM-5 combo:
http://www.plxdevices.com/products/dm5/afrsmcombo/

 

Both are just monitoring the AFR they do not control anything.

I have one of each. I havent installed the afr yet, but i amgoing to be using it with no gauge (for a while) and just have it plugged into my RTEK. Latter I plan on adding the fancy gauge that can monitor everything and use it for boost and afrs, and then egt latter.

Get the ARF combo, its small and will work great for you. I have been using the 300 for about 2 years now and I love it! They have great support and make a fine product.

The neo should be fine for your fuel but it is somewhat limited. If you can find an extra $150 you should consider the Rtek. It will do alot more than the neo.

 

If you have an S4 TII, you can always go Rtek7 and ditch your FCD.....it's better than a piggyback since you can control both fuel and timing.

 

It's actually an S5 euro spec TII vert. Eventually, I plan on going with a full stand alone ECU, but for the time being I just want to be able to control the fuel enough that I don't lean it out and be able to accurately monitor the AFR levels. So just to clairfy....They both do the same thing (monitor AFR levels only)? I wonder why the more antiquated looking M-300 is more expensive? Any one have an answer for that?

 

As best I understand, the M-300 can data log where as the SM-AFR cannot.

 

The R-300 has the datalogging capablilties not M-300, but it does have an output to hook up to somekind of datalogging device.

 

They both have the ability to hook up to 3rd party hardware. I just don't understand a $45 difference when the M-300 looks so antiquated compared to the SM-AFR. Why would you pay $45 more for something that does the same thing as a cheaper and better looking alternitive. This is the part where I think I'm missing something. As far as I can tell they both have basicly the same features other than looks. Does the M-300 do something that the SM-AFR doesn't?

 

i'm not really sure aboujt the price difference, except that the 300 does have the leds on it. But other than that i don't know. they both have the same capibilities. If fact the AFR is a bit moare adaptible.

 

Cool! Thank you guys for your help!

 

I was responding to j_man1100.



The only real difference with the m300 and the SM-AFR looks to be that you can daisy chain with the other sensors if you plan on datalogging or just using less gauges.




I have the M300 right now and I love it. Its been in the car for about 4 years and it still reads accurate. The only thing is that about 5 months ago I had to send the main control unit back because a couple of LED's died and it was hard to read the display. They put in a brand new one and it works perfectly.



I might be going with the SM-AFR later on down the road and throwing the M300 into my DSM.