Spamby
Meat Product Toy
How accurate would that reading be, being pre turbo ?
What type of gauge is better?
- Thread starter OldManSTI
- Start date
How accurate would that reading be, being pre turbo ?
Grinder34
Track Monkey
You'd put the wideband post-turbo, so your gauge and the ECU are getting a post-turbo reading. I havent dont this, and I think there are some problems (like the wideband o2 sensor failing), but from what I remember reading it was an appealing option to give the ECU the best information.
HolyCrapItsFast
Drinks beer!
You might think this is best for the ECU but there are things to consider... One of them being what you already suggested, and that is Exhaust temperature effecting the longevity of the sensor but, the other thing to consider is the time it takes the gases to reach the sensor versus the moment the exhaust pulse was created in the cylinder. The further away from the pulse origin the sensor is, the less accurate the C/L corrections will be because of a significant delay between them. So the correction that is being made now is based on an exhaust pulse that occurred then and the current condition may actually be different than what is being compensated. In the EJ this is a potential issue because the manifold/header runner length is enormous compared to other engine designs and the turbo is much farther from the source. This can be compensated for but I don't believe we have access to the right tables to adjust for this. Plus I don't think enough tuners even know to consider this or understand it.
To be honest I don't have enough experience with this on a Suby to know if it is an issue but I do have data from when I had my 240 and the AEM to know that there was a significant delay when I moved the sensor form the stock location and that it had to be compensated for. And thinking that the distance in a Subaru is greater, then I would conclude that it could be an issue
HolyCrapItsFast
Drinks beer!
It's not a bad place to put it.
HolyCrapItsFast
Drinks beer!
Yours is a better location for monitoring WOT runs because the results are much smoother and the delay has no real effect because there is no C/L compensation and it is reference only.
For overall readings the better place is near the turbo, but when we are tuning, I don't care about Closed Loop wide band AFR's because I reference the stock O2 sensor and not the wide band.
In regards to which gauges match the factory cluster... I like Defi gauges in Amber. The color matches perfectly and the gauges perform the same start-up needle movement that the factory gauges do. I myself prefer to mount 3 of them in an ATI clock pod; Boost (psi, not bar), EGT and Oil Temp or Pressure.
SudoSTI
Member
I had Maddad gauges in my old car and I would highly suggest you steer clear of them. Every couple weeks for no reason they would fail. They would make the loud screech/beep, do the opening ceremony, then repeat until I shut off the car. Wasn't so awesome on my half hour commute to work. Plus, this is just a personal annoyance, the motors are SO LOUD. It sounds like someone is cranking a wind up toy every time they move and the movement is very "notchy." I have been told the notchiness is due to them being so sensitive that the stepper motor can't keep up but to me that doesn't justify it. I have heard that any of the Taiwanese manufacturers (Prosport, Maddad, STRI, etc) are all very similar. My buddy bought Defi BF gauges for his STI and they are absolutely silent, quick, and smooth. I will be ordering a Defi CR boost gauge (matches my Zero/Sports cluster better) soon for my car. FYI Defi makes gauges for MANY OEM manufacturers of all industries including high sensitivity and high accuracy aviation and military grade gauges so they know what they're doing and IMO the added cost is worth it.
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