[FoundNemo]

So, my buddy's car is on the way to a very reputable (top 5 shop) and he found out they dont intend to tune his car with widebands (stock intake, stock pulley, longtube headers and tune only going forth).

I know Jannetty installs a wideband for tuning purposes pre-cat.

Is tuning via the OEM non-wideband cats a good idea? Seems odd. They also said they could add a wideband but it would be after the cat, which seems like it would throw off the readings.

[Jaxcam02]

every time I have been to a tuner, they use a wideband. i am unsure why you wouldn't

[Camaro1973]

Originally Posted by FoundNemo

So, my buddy's car is on the way to a very reputable (top 5 shop) and he found out they dont intend to tune his car with widebands (stock intake, stock pulley, longtube headers and tune only going forth).

I know Jannetty installs a wideband for tuning purposes pre-cat.

Is tuning via the OEM non-wideband cats a good idea? Seems odd. They also said they could add a wideband but it would be after the cat, which seems like it would throw off the readings.

A very reputable shop wouldn’t be tuning without a wideband. You simply cannot go by the commanded AFR. The wideband needs to go before the cats (if there is any) on headers it’s the front most o2. Some will use the front o2 ports and some will install a bung in the header.

Some just toss a sniffer in the tailpipe, also a bad idea.

[Joshinator99]

Originally Posted by Camaro1973

A very reputable shop wouldn’t be tuning without a wideband. You simply cannot go by the commanded AFR. The wideband needs to go before the cats (if there is any) on headers it’s the front most o2. Some will use the front o2 ports and some will install a bung in the header.

Some just toss a sniffer in the tailpipe, also a bad idea.

Bingo.

[radz28]

There are way to use short term and long term fuel trims and calculate errors based off MAF airflow. It's a pretty complex set-up (to me) but it doesn't use WB input. It's all based from fuel trims.

I'm used both and think I'm a convert now. The argument for this configuration is there one is eliminating outside influence and other data in the information stream in the car using this method. That seems to make sense. This comes from an alleged (OEM calibrator).

When you do some digging, professional tuners have posted after WB-tuning they back-check the tune with these same trims and information, so it seems to have a good base of integrity. It's easier and more reliable because you can tune the MAF and the VVE at the same time. On some cars, getting the car into SD is tough because the car throws a MAF error and won't let you get into boost. I've run into this on cars. I've done both and end-up coming out with MAF/VVEs that are usually pretty dead-on each other.

It's up to you. Everyone's got their idea of what's right. I don't know which is, but I hear good comments about both. I've also had good luck with both, too. I'm certainly NO expert.

[Joshinator99]

Originally Posted by radz28

There are way to use short term and long term fuel trims and calculate errors based off MAF airflow. It's a pretty complex set-up (to me) but it doesn't use WB input. It's all based from fuel trims.

I'm used both and think I'm a convert now. The argument for this configuration is there one is eliminating outside influence and other data in the information stream in the car using this method. That seems to make sense. This comes from an alleged (OEM calibrator).

When you do some digging, professional tuners have posted after WB-tuning they back-check the tune with these same trims and information, so it seems to have a good base of integrity. It's easier and more reliable because you can tune the MAF and the VVE at the same time. On some cars, getting the car into SD is tough because the car throws a MAF error and won't let you get into boost. I've run into this on cars. I've done both and end-up coming out with MAF/VVEs that are usually pretty dead-on each other.

It's up to you. Everyone's got their idea of what's right. I don't know which is, but I hear good comments about both. I've also had good luck with both, too. I'm certainly NO expert.

I use that for idle and part throttle tuning. You cannot do that for WOT since the car only knows if it’s richer or leaner than 14.7...not helpful under Power Enrichment. Need to know a lot more accurately than that and the WB is how you do it.

[hawk02]

Originally Posted by Camaro1973

A very reputable shop wouldn’t be tuning without a wideband. You simply cannot go by the commanded AFR. The wideband needs to go before the cats (if there is any) on headers it’s the front most o2. Some will use the front o2 ports and some will install a bung in the header.

Some just toss a sniffer in the tailpipe, also a bad idea.

In my experience, most tuners use the the tailpipe sniffer because it’s easier. You know, “Time is money”.

[Camaro1973]

Originally Posted by hawk02

In my experience, most tuners use the the tailpipe sniffer because it’s easier. You know, “Time is money”.

Yeah that’s bad, especially if the car has cats.

[gotswap]

So what you are saying is a dyno tune that has a very much needed street tune has a WB in the tail pipe while driving down the street..... I think not.

[Camaro1973]

Originally Posted by gotswap

So what you are saying is a dyno tune that has a very much needed street tune has a WB in the tail pipe while driving down the street..... I think not.

Wideband isn't needed for street tuning bud, its already dialed in on the dyno. Street tuning is mainly TCM, timing adjustments etc. If the dyno isnt a load dyno the street tune may yield different results as far as detonation or knock. Also, many people run widebands with gauges as well.



I'm not sure i get what your trying to get at here with your reply but it doesn't make any sense oncesoever as far as tuning.

[radz28]

Originally Posted by Joshinator99

I use that for idle and part throttle tuning. You cannot do that for WOT since the car only knows if it’s richer or leaner than 14.7...not helpful under Power Enrichment. Need to know a lot more accurately than that and the WB is how you do it.

That isn't what some people say. I'm not saying I can prove it without a shadow of doubt, but my WB readings are within a handful of the fuel trim readings. I see my cylinder air masses line-up and my MAF/VE/Dynamic all line-up nearly perfectly (until the VE taps-out at 512g/s). Maybe it doesn't work for all combinations, but it seems to work in at least some. That's all I'm saying.

[LiqTenExp]

Originally Posted by Camaro1973

Wideband isn't needed for street tuning bud, its already dialed in on the dyno. Street tuning is mainly TCM, timing adjustments etc. If the dyno isnt a load dyno the street tune may yield different results as far as detonation or knock. Also, many people run widebands with gauges as well.



I'm not sure i get what your trying to get at here with your reply but it doesn't make any sense oncesoever as far as tuning.

Negative, you cannot do VVE without wideband. If you tuner stops at the MAF table on the dyno, walk away and find someone else. This also prevents you from comparing VVE (dynamic airflow) vs MAF airflow values to be able to use dynamic airflow properly as the car was designed for.

It is also the check against NB02 when dealing with setting up NBO2 settings like Rich/Lean vs. Airflow settings.

[LiqTenExp]

Originally Posted by radz28

There are way to use short term and long term fuel trims and calculate errors based off MAF airflow. It's a pretty complex set-up (to me) but it doesn't use WB input. It's all based from fuel trims.

I'm used both and think I'm a convert now. The argument for this configuration is there one is eliminating outside influence and other data in the information stream in the car using this method. That seems to make sense. This comes from an alleged (OEM calibrator).

When you do some digging, professional tuners have posted after WB-tuning they back-check the tune with these same trims and information, so it seems to have a good base of integrity. It's easier and more reliable because you can tune the MAF and the VVE at the same time. On some cars, getting the car into SD is tough because the car throws a MAF error and won't let you get into boost. I've run into this on cars. I've done both and end-up coming out with MAF/VVEs that are usually pretty dead-on each other.

It's up to you. Everyone's got their idea of what's right. I don't know which is, but I hear good comments about both. I've also had good luck with both, too. I'm certainly NO expert.

You can work around the MAF error very easily, simply let the MAF fail via setting the freq limits very low, disable dynamic via rpm, disable O2 via negative value, and disable DFCO. Then when the car starts let it fail the MAF, go into HP tuners Fuel and disable Closed Loop mode... BAM high speed mode will be totally functional without any limitations

[LiqTenExp]

Originally Posted by Camaro1973

Yeah that’s bad, especially if the car has cats.

Agree, if the tuner cannot take the time to install WB02 on dyno they either don't care and just want your money or actually don't appreciate the importance of proper location.

If you install it in the rear tail pipe it will only work well with WOT type environments. Otherwise you will get ambient air mixing in and causing false lean indications, it must go after headers into an exhaust system w/o leaks. You will get venturi exffects sucking in ambient air under light load scenarios if you have a leak at your header to midpipe connection, this will cause false lean and drive you UP THE WALL doing VVE, don't ask me how I know