Forced Induction Buyer's Guide | $5,000 +/- (otd) | Daily Driver Spec

[tendogy]

Originally Posted by CSG Mike

The factory narrowband bottoms out at about 12:1 AFR. This is rich enough that being lower won't be an issue (unless you're so rich the car will barely idle). It does, however, accurately read up to 18:1 AFR, and maxes out at 20:1 AFR.

Thanks, that is great information (and saves me $474)!

How accurate is the OEM MAP sensor once supercharged? The Scangauge reads that too, but I was planning to not trust it (based on no reason at all).

You know... I think the Scangauge might also be able to display AFR... I'll have to look it up.

Edit: Looked it up, and I was correct. So in summary, a Scangauge II can display Oil temp, AFR, MAP, Intake air temps, and Coolant temps. It can display up to four simultaneously. The refresh rate on the readings is a bit slow, but plenty sufficient for daily monitoring.

[CSG Mike]

Originally Posted by tendogy

Thanks, that is great information (and saves me $474)!

How accurate is the OEM MAP sensor once supercharged? The Scangauge reads that too, but I was planning to not trust it (based on no reason at all).

You know... I think the Scangauge might also be able to display AFR... I'll have to look it up.

It reads up to 20.0 PSI absolute, but starts to get inaccurate over 19.3 PSI. The ECU will also read barametric pressure, and you need to subtract the barometric pressure from the MAP pressure, to get your actual boost pressure (but again, the MAP sensor maxes out before you hit peak boost).

Most OBD2 readers will be able to read Lambda, which is a raw voltage value for AFR. If we see 0.8-0.9 raw on that under WOT, we're happy. It's "close enough". We also read the catalytic converter temp (also available through the ECU), and that'll tell us very quickly if we're leaning out, as the temp will skyrocket past 1600F. I don't think we've ever seen it go over 1500F under hard use, and normally sits around 1100-1200F cruising, and 1450F under sustained load (going uphill, WOT, etc.)

[86-tundra]

Originally Posted by CSG Mike

It reads up to 20.0 PSI absolute, but starts to get inaccurate over 19.3 PSI. The ECU will also read barametric pressure, and you need to subtract the barometric pressure from the MAP pressure, to get your actual boost pressure (but again, the MAP sensor maxes out before you hit peak boost).

Most OBD2 readers will be able to read Lambda, which is a raw voltage value for AFR. If we see 0.8-0.9 raw on that under WOT, we're happy. It's "close enough". We also read the catalytic converter temp (also available through the ECU), and that'll tell us very quickly if we're leaning out, as the temp will skyrocket past 1600F. I don't think we've ever seen it go over 1500F under hard use, and normally sits around 1100-1200F cruising, and 1450F under sustained load (going uphill, WOT, etc.)

lambda is perfect for reading AFR , just do the calculations like mike said. I look for around .83 on WOT.

if you are really serious about boosting, i'd recommend getting an afr gauge still. simple enough, cheap enough, worth it

[jamesm]

i wouldn't drive a boosted car without a wideband. you could maybe ditch the boost gauge on a supercharger (certainly not a turbo car. wastegate lines DO pop off). you just never know, and a couple hundred bucks on gauges can save your bacon. right @Frs300?

$200 isn't much when you consider the cost of windowing a block. there are a lot better places to save money.

[CSG Mike]

The factory narrowband reads plenty accurate in the danger areas of running lean. Doesn't hurt to have a wideband, but we choose not to.

[Frs300]

Originally Posted by jamesm

i wouldn't drive a boosted car without a wideband. you could maybe ditch the boost gauge on a supercharger (certainly not a turbo car. wastegate lines DO pop off). you just never know, and a couple hundred bucks on gauges can save your bacon. right @Frs300?

$200 isn't much when you consider the cost of windowing a block. there are a lot better places to save money.

$200 vs $10k...i should have installed mine from the get go instead of being lazy and wanting to take it down the street and back.

BANG CLANK BOOM

[jamesm]

'can' and 'would' are very, very different things... but to each his own. i can't say i've never done it...

[Pete156]

Originally Posted by Frs300

BANG CLANK BOOM

I've heard that song before

[CSG David]

Originally Posted by Pete156

I've heard that song before

You mean this song? By the way, I love Just Kidding Films and their YouTube friends like the Poreotics...lol

[ame="http://www.youtube.com/watch?v=fw1My4WtcDc"]No More Power No More Gas | OFFICIAL MUSIC VIDEO - YouTube[/ame]

[ecko04]

No way anyone should be boosting without a proper wideband. The factory AFR sensor is fine for closed loop operation but a wideband is necessary for open loop (WOT).

There's no point in having the sensor (narrowband) if the sensor can't read the measurement accurately, hence the need for a wideband.

I use a standalone wideband as a way of checking the narrowband against each other. I had a fouled narrowband, it never threw any DTC but it's readings were horribly off compared to my wideband. The wideband readings were inline with what I was expecting to see. I replaced the narrowband and both readings were spot on. Not to mention who doesn't want to monitor their tune?

The boost gauge is also important. Yes, you'll know if you're losing boost but you may not be able to tell if you're over boosting, which could lead to disaster. The butt gauge is about as effective as the butt dyno.

Even if you use a gauge like the P3Cars vent gauge where you can program the gauge to flash if you bypass the set boost even if you're not on the boost screen, you'll know something is wrong and to let off if it flashes.

Wastegate lines can become frayed and no boost cut will work if that happens. For engine longevity, I recommend one with an FI build.

[cdrazic93]

Originally Posted by ecko04

The butt gauge is about as effective as the butt dyno.

Huh, I gotta tune my butt gauge and my butt dyno again

Nothing makes you take your foot off the throttle like a flashing light or smoke from the engine!

[CSG Mike]

Originally Posted by ecko04

No way anyone should be boosting without a proper wideband. The factory AFR sensor is fine for closed loop operation but a wideband is necessary for open loop (WOT).

There's no point in having the sensor (narrowband) if the sensor can't read the measurement accurately, hence the need for a wideband.

I use a standalone wideband as a way of checking the narrowband against each other. I had a fouled narrowband, it never threw any DTC but it's readings were horribly off compared to my wideband. The wideband readings were inline with what I was expecting to see. I replaced the narrowband and both readings were spot on. Not to mention who doesn't want to monitor their tune?

The boost gauge is also important. Yes, you'll know if you're losing boost but you may not be able to tell if you're over boosting, which could lead to disaster. The butt gauge is about as effective as the butt dyno.

Even if you use a gauge like the P3Cars vent gauge where you can program the gauge to flash if you bypass the set boost even if you're not on the boost screen, you'll know something is wrong and to let off if it flashes.

Wastegate lines can become frayed and no boost cut will work if that happens. For engine longevity, I recommend one with an FI build.

I think this post is absolutely spot on for Turbo applications.

[jamesm]

Originally Posted by ecko04

Wastegate lines can become frayed and no boost cut will work if that happens. For engine longevity, I recommend one with an FI build.

not true . ecutek racerom custom map... can read the MAP directly and cut fuel (or do anything else) when appropriate.

aside from that i agree with you whole-heartedly lol

[cdrazic93]

Originally Posted by CSG Mike

I think this post is absolutely spot on for Turbo applications.

Exactly. I like turbo applications, I like gauges, because racecar.