HP Tuner question
Thoughts and suggestions?
you can tune idle and cruise off narrow band factory o2 sensors. but that's not the correct method. their data can be off by a mile and influenced by way to many factors to make them reliable. as for WOT a wide band is the only thing you can tune off. the narrow band mV aren't accurate enough nor do they have enough resolution to determine and accurate AFR from.
you can remove the factory o2 sensors and turn them off in the tune. install your wide band in one bank and calibrate your airflow tables from that, swap it to the other bank and compare the data and make sure its the same.
I'd add that if your "tuner" didn't suggest this,, RUN.
No tuner worth the money will be without a wideband and access to a dyno somewhere..
Wideband is not that much money for someone who is tuning for a living.
But yes, you do not need a specific bung in your exhaust to have him use a wideband.
You still gotta pull plugs for WOT rips. aint no way around that.
but for the average joe who just wants a fun cheap ripper, china 7875, JY 5.3 decaps and a single 450
sure I street tune those. ****, you can almost phone those in haha.
still use a WB on 'em tho
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consistent load at a controlled acceleration rate that is repeatable is what you want. you wont get that anywhere else.
especially for boosted combos that make decent grunt.
for cruise etc I'm all for data logging and calibrating on the road.
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But yes, you do not need a specific bung in your exhaust to have him use a wideband.
Most people who don't own a dyno say that.
consistent load at a controlled acceleration rate that is repeatable is what you want. you wont get that anywhere else.
especially for boosted combos that make decent grunt.
for cruise etc I'm all for data logging and calibrating on the road.
There is no ******* way, all that cars that I tune, that I would take all of them out and do WOT blasts on the street to tune it. That's ******* stupid. It's a huge personal risk, risk to the shop and my customers vehicle.
And as a customer, I wouldn't want someone taking my car that I have spent thousands, if not tens of thousands of dollars on, to go make WOT blasts on the street. I've only had to tune 2 cars on the street because they were AWD and I didn't like it at all.
From a tuning standpoint, a loaded dyno is superior.
From a common sense standpoint...any dyno makes sense.
For really high HP cars, yes, IMO you are going to have to finish tuning them at the track. I tuned our shop car on the dyno. Took it off, went to BG and ran mid 8's then went straight drag week and placed 2nd in our class.
Did some more track tuning, went high 7's.........then we lifted the heads...
There are a lot of reasons why a dyno is better. One being I would not like someone driving my car WOT, trying to watch the road and the Lambda gauge at the same time.
Just my .02
There is no ******* way, all that cars that I tune, that I would take all of them out and do WOT blasts on the street to tune it. That's ******* stupid. It's a huge personal risk, risk to the shop and my customers vehicle.
And as a customer, I wouldn't want someone taking my car that I have spent thousands, if not tens of thousands of dollars on, to go make WOT blasts on the street. I've only had to tune 2 cars on the street because they were AWD and I didn't like it at all.
From a tuning standpoint, a loaded dyno is superior.
From a common sense standpoint...any dyno makes sense.
For really high HP cars, yes, IMO you are going to have to finish tuning them at the track. I tuned our shop car on the dyno. Took it off, went to BG and ran mid 8's then went straight drag week and placed 2nd in our class.
Did some more track tuning, went high 7's.........then we lifted the heads...
There are a lot of reasons why a dyno is better. One being I would not like someone driving my car WOT, trying to watch the road and the Lambda gauge at the same time.
Just my .02
1) If you're doing your own tuning, you can tune up to 4000 RPM using shortterm/longterm fuel trims.
2) Wide band is superior every where, from 0 to WOT.
3) A street tuner doesn't have his eyes glazed at the AFR gauge - maybe a glimpse. The whole point of data logging is so that you can pay attention to the road while you hit the necessary cells. I'm not saying street tuning is better, because the risks are still far greater. I'm just saying, I've safely tuned my car for WOT on the streets. You use common sense. Maybe I'm just lucky. But there is a very long stretch of empty road at my disposal. I understand not everyone has access to this. Still, I agree with LilJay that doing all of this is just far safer and easier on a dyno.
4) No matter what, no matter who you are, you're not going to be able to tune for MBT on the streets. The only thing that can get you close is using knock sensors + Wideband, and A LOT of time on the road.... hence, the mention above about risks vs tuning on a dyno.
5) NO ONE (I don't care who the tuner is) is going to care about your vehicle like you do. With all the time it takes to dial in the VE, then dial in the MAF (if you're going to use one) then dial in the WoT... there is a lot of time that goes in to it. You can get lucky with a good tuner... but I would say, buy an HPTuner anyway, to learn and verify the tune that was done by a pro. If your tuner claims he can tune your newly built vehicle in an hour, RUN. And don't. Look. Back.
If you're dead set on tuning WOT (or anything else for that matter) buy a wideband.
With a wideband, you will be tuning in openloop as others have mentioned. Open loop = your o2 sensors are offline. Use your stock O2 locations, or o2 locations on your long tube headers. Once you have the driver side bank dialed in accurately, you start over with the passenger side - but just for the sake of monitoring to make sure results are nearly identical. If they're not, it's time to look at your injectors and other ignition system areas.
You use Bank 1 sensor 1
You use Bank 2 sensor 1
Bank 1 = driver side
Bank 2 = pass side
Sensor 1 = before cats
sensor 2 = after cats
Sensor 2 is post-cat. You don't want to use this.
I can tell you right now that if I was to go out and pay $500 or more for a tune, that tuner better know his sh**. Because you better believe I will be looking at the tune to see what all has actually been addressed, and what has been neglected. But I respect the pros. I believe they know best, but sometimes, they slip - and with your $15k+ investment in the engine bay alone, it would be nice to catch that slip before damage is done.
Long story short, I trust people on this board more than I trust a self-proclaimed "pro tuner" with a dyno.
Last edited by AndyTA; Jan 12, 2019 at 05:07 PM.
It takes forever and in the city where I live I have to risk making high pulls in public areas. I don't live in the country.
A few days of street tuning can be done in an hour on a dyno and is safer. To each their own












