to bypass o2 or not to bypass o2

[nickmpower]

Well we are usin a power commander and I am wonderin what you guys think about bypassin the o2 sensor. I had planned on connecting the narrow band output of our LC1 to the stock wiring but now i see that dynojet makes a bypass which im guessing sends a 14.7 afr sinal to the ecu.

right now i think we are more just trying to have a running car then squeeze out every last HP so it seems like i should go ahead and give the ecu a o2 signal so it can help us slightly with tuning.

what do you guys think?

[nickmpower]

Well we are usin a power commander and I am wonderin what you guys think about bypassin the o2 sensor. I had planned on connecting the narrow band output of our LC1 to the stock wiring but now i see that dynojet makes a bypass which im guessing sends a 14.7 afr sinal to the ecu.

right now i think we are more just trying to have a running car then squeeze out every last HP so it seems like i should go ahead and give the ecu a o2 signal so it can help us slightly with tuning.

what do you guys think?

[Grant Mahler]

I think if the bypass always shows 14.7 your stock engine controller is not going to react the way you want it to.

How about starting with your school, what engine and year, WTF you are trying to do specifically, and where you are in the process.

[Diablo_niterider]

the narrow band o2 isnt going to help as it gives only two values high and low to the ecu,

and i believe dynojet guys sell what they call o2 eliminator as i believe power commander doesnot work well with o2 corrections...

[Mustang Mac]

Ran a similar setup my first year on a CBR600F4i, with wide band O2 on dyno/tuning in car, then no O2 for comp. My suggestion would be get the thing running this year, next year look at moving into a stand alone ECU. The powercommander will work, but not the best and your don't have a lot of capability with it.

We moved into a performance electronics unit for the next 2 years and once we outgrew that system we moved onto the Delfi mefi4-b, which has since been bought up by MSD. We were the first school to use it and I can't say enough good things about it. Will do just about everything a motec will do at a tenth of the price.

[nickmpower]

I am part of the Santa Clara University first year team. We have a small budget and even smaller workforce.

We are using an 06 F4i, with a power commander

As I said, at this point we are just trying to get the car running rather then find a couple more horsepower.

I am thinking that if I give the stock ECU an o2 signal then the ecu will help slightly with the tuning of the car. I have no experience with the power commander though so I am unsure of how hard or easy tuning is going to be.

I will probably try to give dynojet a call today in hopes they could give me some advice as to whether or not I should bypass the O2.

Does anyone know if the F4i has any sort of limp home mode or if the maps change when certain sensors arent connected?

Mustang Mac, could you give me some tips for using the power commander? What did you find to be the quickest easiest method for tuning? (I am not sure we will be able to get it on a dyno) Did you just have to reduce fuel accross the entire range? (more so at higher rpms?) What AFRs did you find worked best?