CLASS RACER FORUM - Fuel injection? Open or Closed loop?

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Re: Fuel injection? Open or Closed loop?

Ed, What style of manifold do you run and where exactly is the Air Temp Sensor loacated?

Re: Fuel injection? Open or Closed loop?

Hogan sheet metal, the sensor is in one of the bungs, above the distributor, on the back end of the plenum.

Re: Fuel injection? Open or Closed loop?

Quote:

Originally Posted by cmracing (Post 526089)

I get about 200 or so passes on an NTK sensor using unleaded race fuel, sometimes more. This is with the Holley system. The Bosch sensor is about half that. If you limit your correction to +-5% or less, then if a sensor does go south, it won't kill the tune that bad. But, you do have to look at your datalogs and keep an eye on things....... I run Closed Loop in both of my cars, but also limit what I allow it to do.

I'm curious.....how often do you look at your data logs once you have it tuned? I'm still new so looking at most of the data logs but now they all are looking the same. Thanks.

Re: Fuel injection? Open or Closed loop?

Darrel,
I log every run and generally look at the graph after every run. I run a FAST system in open loop and like being able to review the data after each run!

Nick

Re: Fuel injection? Open or Closed loop?

Quote:

Originally Posted by SS3718 (Post 534453)

Darrel,
I log every run and generally look at the graph after every run. I run a FAST system in open loop and like being able to review the data after each run!

Nick

That's what I've been doing except when I'm lucky enough not to have time between runs to look at them ;)

Re: Fuel injection? Open or Closed loop?

Darell, are you running it in speed Density, or Alpha N?

Re: Fuel injection? Open or Closed loop?

Quote:

Originally Posted by Ed Wright (Post 534459)

Darell, are you running it in speed Density, or Alpha N?

Density

Re: Fuel injection? Open or Closed loop?

Quote:

Originally Posted by Darrel Goheen (Post 534476)

Density

Me too. Once I have run it, and got my A/F right on the row for that Baro, next time I run there (Great Bend, KS, Noble, don't use the same row in my VE table as Ennis, Houston, etc. Don't have to touch it. I have just about quit logging every run. Never have to touch it anymore.
In low gear, Closed Loop doesn't make corrections fast enough. If off at (for instance)7000, the ordectuon would end up at 7500, when it's referencing the 7500 cel, which needed no correction. I ended up trying to set the delay so corrections would not start until 2nd gear. I got it so Closed Loop was not making corrections in the upper gears anyway. I just put it back into Open Loop. With the IAT sensor, it's always dead nuts. The car repeats really well. Wish the driver did.

Re: Fuel injection? Open or Closed loop?

Quote:

Originally Posted by Ed Wright (Post 534483)

I'm getting very little correction at WOT. I've tried shutting off closed loop but it barely runs in the pits then so I have to turn it back on. I just need to get that area tuned in OL. So if you go to say Denver would you turn CL back on for a couple passes or just select the whole table and take a percentage of fuel out? Do you save a tune for every track? In CL I think my launch AFR is way messed up because of 2 step. As soon as I launch it adds quite a bit of fuel. Here's my thought at this point and please correct me if I'm wrong. Footbrake a couple passes to get launch area AFR close, turn off CL and get pit area tuned and then slowly adjust AFR according to data log? Racing gets critical now starting with Topeka Nationals. ;)

Re: Fuel injection? Open or Closed loop?

More thoughts......

Since I most likely can't win a heads up based on performance I should quit worrying about getting every last hundredths of ET out of my cars. I should just get them tuned to where it's consistent and leave it alone. Agree?