Hi TGO,

I'm in the market for a wideband o2 sensor kit to go with my EBL flash in an L98 87 GTA. I'm new to this (of course) and have spent a few hours reading up on different systems to learn what I can first. I haven't been able to nail down a good comparison or installation example, however, of a dual bank vs single bank o2 sensor setup. Zeitronix seems to have a good setup if you combine a ZT-2 and ZT-3 (one each side of the Y-pipe), but would someone be able to explain how the second sensor could be used with the EBL flash and how much of a benefit it would have compared to a single bank setup below the y-pipe connection?

Even though the ZT-2 will accept the ZT-3 as a secondary input for datalogging and other things, will the flash be able to use a two bank input (via 2 ADC inputs) and actively use them both for engine management? Likewise for the VE Learn capability.

Thanks!

 

If you are using batch fire ignition, why don't you use one wideband and two bungs. Compare the output on logs to see. You can't easily adjust it, so you're really looking for the leaner bank. Then use that bank to log until you change something to effect engine air flow.

 

Definitely a thought. So with the batch fire approach TPI uses, it doesn't sound like there is really any benefit from being able to monitor data from both manifolds?

 

To 99% it's pointless to always monitor both.

 

ok, thanks

 

Since you can't tune any injector without affecting the other 7 I can see what you are getting at here, but wouldn't it still tell you the overall condition of one side vs the other? You may not be able to tweek the fuel on one bank but it would be a good diagnostic tool for finding out if something has gone wrong on "the other" side.

I have been considering a second wide band for these reasons. But getting to the bigger point here I am starting to feel like the batch fire method leaves a lot to be desired. With my Holley Stealth Ram intake, which is front fed, I always get leaner plug indications for the front 4 compared to the rear. In fact I have been tempted to go to a single plane intake but the more I think about it a sequential firing ecm may be a better use of resources. Then, WB on both side could be of real value.

 

Based on the reading I've done since posting this and given the batch fire design of the TPI is more that 30 years old now (already?!), it seems like SFI is the best way to go if you have the time and resources to put into it. Dual bank widebands may actually be useful at that point for tuning, but realistically not all that useful before since you can't use the information the second bank would provide for tuning anyway.

The '411 ECU swaps on the board are good reads in themselves and aren't really all that expensive to do, by the looks of it (compared to an SFI engine swap, anyway). Just time consuming.

 

Which is why I put in the "always" in the wording you quoted. Always monitoring is pointless, but diagnostics is one reason one is inclined to do so.

 

Search for "split BLMs", SFI isn't the answer.

RBob.

 

What do you mean? I searched as suggested but didn't really get it.

For my application, I can't seem to get even fuel distribution from front to rear (I don't know about bank to bank) and was wondering if SFI would help. Currently using EBL flash and would like to stay with it but had wondered if a 411 type ecm would give better control.

 

Check out this link, it's a good read on what a split BLM is, what it's caused by and a possible solution:
Here's another, more exotic solution for a miniram (which apparently really has an issue with a split BLM):Explanation of what a BLM is:



PS, thanks for the suggestion rbob. Just learned something new.

 

Thanks for that link. I understand the IAC function but don't exactly understand why it would affect the bank to bank blms. Does the stock intake have separate passages for the idle air? Or is there somethine else I am missing?

Still, I don't know if I have split blms or not. I have distribution issues from front to rear. Now if I could plumb idle air back to the rear group of ports that may help and something I have considered.

 

Wow, you must have added the other links while I was replying!

Very interesting info.