Ecu ?

[Rixster]

Ok, my sled had a square ECU on it. I have located a replacement, it is a circle. I have talked to a few cat mechanics about it. I have been told, that there could be a 5% difference and I have been told it is more like 1.5% maybe a MAX of 2%. So here is how i understand it.
The ecu and the fuel injectors are matched. Square ecu = square injector . You get the idea.
So What I have been told is one is richer then square and one is leaner then square. Does anyone know?
So if I run the circle ecu with my square injectors am I leaner or richer then square?

Also, if they are just matched then why are they all different costs?
The square ecu is the most expensive from cat. and the circle is the cheapest. Same with the injectors ?????

 

[900kingkitty]

i kinda went though this before as well and had a real hard time finding out exactly what i was looking for but what i did find was, there are 3 different ecu's and injectors because each set of injectors circle , square or traingle flow different amounts , the injectors themselves are "richer or leaner" so the ecu's have different programming to accomidate this. i was told they were 3% difference between each. my dealer doesn't know which, but they have ran different ecu's and injectors"unmatched" and they either run really well or really bad.You could try the ecu you have and just check your wash and you might work out o.k.i would like to know how you make out if you try it...

 

[Rixster]

Oh I am going to try it. The circle ECU is on the sled right now. It seamed to start and rev very nicely. I wont get a chance to try it probably until Saturday.
I kinda figured that the stock setup was a little rich, so if I am lucky enough to get a leaner setup it should run great. We will find out! Here's hoping !!

 

[Pedersen]

If there's difference in the fuelflow howcome companies like Boondockers only have one set of numbers for their setups?

 

[WyoBoy1000]

say the square map is leaner and the the square injectors are bigger and the circle one is richer and the injectors are smaller/leaner. the amount of fuel is the same just a different way to get it in the motor.

 

[RACINSTATION]

From what I have seen and know.....this setup with square injectors and a circle ECU will be about 1.5-2.0% leaner than square on square. It should be fine.

When the sleds hit the assembly line they flow test the injectors. The have an A B and C parameter. They then match an ECU to that measurement.

Most ECUs are square. If you buy a new ECU it will be a square unless you request programming. If you special order a circle, they will take a square ECU and reprogram it.

Hope this helps.

 

[kane13]

From what i have read injectors are supposed to be changed as well, correct me if i am wrong.

 

[RACINSTATION]

Yes, in a perfect world.........in a perfect world I would have all ten fingers on my left hand so I could use my right hand solely for punching!

 

[05snopro440]

I've always been told to match them, but if you want to try it to lean it out a bit give it a try. It's not my motor

 

[kidrman]

Just unplug the ethanol wire on the first ride and see where it is at. They are so rich to begin with a couple % leaner won't hurt a thing.

 

[900kingkitty]

well. how did you make out?

 

[Rixster]

I haven't been able to get out yet. Wednesday is probably the first chance i am going to get. I will report as soon as I get home.