Wideband at BPU nessesary?

Just gone full BPU and everythings runs perfectly. 1.2 bar max and the car seems to run great.

Just wanted the check what your experiences regarding the fuel mixture has been. Is it nessesary to run a wideband sensor at BPU? I'm not looking for opinons as much as expirences with people actually installng the sensor and noting a perfect mix or found the need to regulate the mix.

So chime in if you know something please I think it would a nice thing to reccomend in the faq if it turns out to be nessesary/adviseable.

Always good to know whats going on. EGT is a good gauge to have but make sure the sensor is in the correct place.

You will almost certainly find that the AFRs are pretty rich right up until 1.1-1.2 BAR but you may also find that there will be a lean point as the ECU comes out of closed loop on full boost, and it may also go lean after 1.2 BAR, my advice is run a wideband for peace of mind.

only if you intend on running emanage or some other kind of ecu to change the mixture.

more advisable than nessesary.

With the wideband I could see that after decatting my 93 RZ auto was running dangerously lean at full boost. A new fuel pump solved the problem nicely but without a wideband I wouldn't have known and probably have blown the engine.

Also, a wideband would have saved me from melting a piston that time when the vacuum hose came off the FPR on my 98 Tiptronic. Sadly I didn't have a wideband and did lunch the engine.

You could go to decent Rolling Road and get the car tested and get the AFR readout just to check everything's A:OK

A dash mounted wideband setup is a decent safety precaution as per Jake's scenarios.

What's more worrying is the det that becomes apparent at 1.2 bar - mine had no lean spots, silly rich as expected, but found some nasty cracks of det in the mid range just after the transition point. Pulling a few degrees of timing in this area cleared that up and gave me peace of mind without imparing performance running 11.7:1 - 12:1 AFRs.

Cheers,

Brian.

Is it a EuroSpec or JSpec that you've got?

JSpecs are more 'on the edge' at 1.2 bar

Also 'nessesary' could mean different things to different people. In my view a WB on a tuned turbo car is a must, while others wouldn't even regard it as a 'nice to have' once the car has been set on a RR.

I think it's down to your own level of comfort with how much of the internal workings you want to know about

Does this mean that BPU isn't as 'safe' as I've always thought it was? I knew about the turbos maybe lasting not as long etc etc but no-one (afaik) has even mentioned det and running lean.

Once you cheat the fuel cut, 'safety' becomes a relative term

I.e. beyond 1 bar you're on your own. Until then you are exploiting safety margins built-in by the designers. From then onwards you are pushing components beyond the limits where they are expected to have OEM life expectancy.

1.2 bar can be well into danger territory, partly because it doesn't lead to the same stresses all the time. Boost is not a measure of work or power, it is airflow restriction.

So seeing '1.2' bar on an aftermarket boost gauge on a hot summer day in top gear can be very different to '1.2' bar on a brief RR run in the winter.

One could bring the engine to the edge of destruction, the other could be repeated several times with no tears.

As for the detonation, I was surprised to HEAR detonation on mine while on a hub RR, keeping in mind that it has got the 550cc injectors and it was only maxxing out at 1.1bar on that day. Usually I'd be inside the car under those conditions and the general wind/tyre noise would have drowned it, but this time I was sitting next to the car while someone else was pushing the pedal. I was surprised, and readjusted my WI to kick in earlier than before.

Mind you, it was a bit after an ECU reset, but still I expected no det whatsoever under those conditions. No *audible* det certainly.

So there you go. AFRs are not the be-all and end-all, just another parameter that needs to be monitored.

Ive recently installed a vems afr and egt gauge, nice bit of kit, problem is i spend more time looking at gauges than the road now, but i suppose the novelty will wear off.

Thanks guys, great info!

Is it a EuroSpec or JSpec that you've got?

 

JSpecs are more 'on the edge' at 1.2 bar

 

JSpec

I went for the plx wideband, simply because it has different colour led's round the edge of the gauge which you can tell what the afr is without having to read the thing.

JSpec

It would then be a good idea to check on the WB every now and then, you really don't want to be running lean under boost.

Fuel pump / injector / FPR failures, whatever the reason, why risk the engine eh...

I went for the plx wideband, simply because it has different colour led's round the edge of the gauge which you can tell what the afr is without having to read the thing.

I know the AEM does that, I thought the Innovate does too?

-Ian

Does this mean that BPU isn't as 'safe' as I've always thought it was? I knew about the turbos maybe lasting not as long etc etc but no-one (afaik) has even mentioned det and running lean.

It can definitely run lean on a j-spec pump but part of BPU is chucking in a UK spec or walbro or equivalent I thought. Then it's fine to 1.2bar. Although of course there may be a hidden problem that means it isn't so it's always a good idea to check out the car after a performance mod - afrs and a quick listen on the det cans.

I've heard a few pings around the transition zone as well, on several cars. Not entirely sure why, I thought it was to do with Toyota mapping it to run 14:1 afrs on the first turbo and suddenly we surprise it with 1.2bar, but if Brian sees them as well at 11.7:1, maybe it's just a really hot air charge turning up at torque peak. Either way, a couple of degrees timing pulled and it's sorted.

As to how much damage you do running BPU with no adjustment - who knows? Maybe it contributes to low cylinder pressures later in the car's life. It's unlikely to cause sudden large damage as it's not a sustained detonation event, but it might be slowly eroding stuff. And it if makes a hotspot in the chamber, then then engine might be in trouble.

-Ian

Ive recently installed a vems afr and egt gauge, nice bit of kit, problem is i spend more time looking at gauges than the road now, but i suppose the novelty will wear off.

Did you manage to get in touch with the makers, I have still had no success, and I still think it's a good bit of kit that I'd like to use on some cars?

I know the AEM does that, I thought the Innovate does too?

 

-Ian

Yep Innovate XD-16 does too

I'd always replace the fuel pump on cars like these when modifying - fitting a walbro is par for the course IMO. It's silly to rely on a tired J spec pump especially for the sake of £50 and some fitting time.

My hi stall alters the load characteristics of the engine somewhat so my transition point and ultimately when I hear the det may be different to others.

Cheers,

Brian.

A dash mounted wideband setup is a decent safety precaution as per Jake's scenarios.

 

What's more worrying is the det that becomes apparent at 1.2 bar - mine had no lean spots, silly rich as expected, but found some nasty cracks of det in the mid range just after the transition point. Pulling a few degrees of timing in this area cleared that up and gave me peace of mind without imparing performance running 11.7:1 - 12:1 AFRs.

 

Cheers,

 

Brian.

When you said 'pulling a few degrees of timing' did you mean retard or advance?

When you said 'pulling a few degrees of timing' did you mean retard or advance?

Retard

Thanks

If only i knew what a wideband was before i blew my engine. Without a doubt get one

Retard

I know it was a silly question, but that's not very nice!

Did you manage to get in touch with the makers, I have still had no success, and I still think it's a good bit of kit that I'd like to use on some cars?

Got it through driftworks, egt probe is a pita aint it,