I was just wondering if anyone knows? Also does anyone know what kind of wideband they are allowed to use?
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I was just wondering if anyone knows? Also does anyone know what kind of wideband they are allowed to use?
They are running McLaren ECUs.
http://www.circletrack.com/enginetec...ems/index.html
http://www.nascar.com/news/111018/in...tor/index.html
http://www.nascar.com/news/120316/dr...ion/index.html
I believe they're semi locked out, if not totally locked out of them. A couple of the class limited road course guys I work with use similar systems, where you have only a limited availability for tuning.
if I understand it correctly they have the ability to adjust the fuel to each cylinder? How does the ECU get the data from each cylinder? Are they using a wideband in each exhaust?
I doubt it is individual cylinder WB feedback. At the most I would think it is EGT. That being said, I'm not sure they have calibration tune-ability for individual cylinder fueling. I would think they are probably doing it with precisely calibrated injectors. Need more fuel in one hole, install a slightly greater flowing inj. Need less, just the opposite.
They're being very hush hush about what exactly they can and can't do in the calibration. They aren't tuning them like we tune the GM controllers, or even the aftermarket stand alones.
Wish I could get my foot in the door somewhere to tune for one of those teams... Whoever is currently working on them needs to stick to carb's!
The actricle I read the injectors are way up in the runners far from the valves so one team doesn't have a advantage over another team because of the different valve angles the teams run. They aren't even close to the ideal area.
Some teams can't seem to get warm start right. I've seen multiple video clips of some of the partial throttle areas that were nearly un-manageable. The list goes on. Aparently they didn't get any EFI tuners to help them either, the people that have been tuning the carb's for years are now "playing" with "the laptop".
Actually the teams have everything they need for tuning etc. Well except for the experience to get what they are looking for out of their adjustments. It have been a bit of an on going chatter within the pits between the have and the have nots for being able to dial them in.
Nascar also does not distribute them they are purchased directly from Maclaren sealed with the RFID chips serialized already.
Nascar gives the box a given tuning range to work within and plugs into the box to check the software during tech inspection. They look at the current software ref and make sure that the table boundy limits are still in place.
This is the McLaren ECM they're running http://www.mclarenelectronics.com/Pr...oduct/TAG-400N
2 Lambda inputs, so I assume 1 wideband per bank. There are 22 other analog inputs, separate from the 7 temp inputs...I don't know what they have connected to them though.
I also wonder if they'd actually use closed loop wideband feedback while racing...or if they'd use it to tune and then shut it off to not need to worry about the possibility of a sensor failing mid race...not exactly easy to swap an O2 sensor during a pit stop. But I suppose there could also just be something in the computer that turns the feedback from the wideband off if it's outside of a certain range during specific conditions...it seems like a fairly powerful processor, so it should have some pretty solid diagnostic capabilities.
surely they are just running a SD type tune
more likely they are running alpha-N (TPS) based, with the camshafts and intake setups of most race engines SD (MAP) based can be inconsistent to tune. The engines need a lot of fuel on decel to cool components also.
Idealy it would be a hybrid SD/Alpha-N based tune. I assume it does run in a closed loop setup because it does have dual channel widebands.
closed loop isn't all that bad if it's wideband o2's in the system. Most nicer standalones these day's have this option. It will track a commanded lambda. Like I said I'm not sure they do or not because with healthy overlap camshafts can even fool widebands too however during the run I'm sure it would help. Usually there are conditions that would fault the CL system if it varied to a certain point. There are also usually programmable limits to how much correction can be applied. It's not a bad system especially with some of the races these car's see with varying weather.