Advice needed! Supra Dyno/Running Lean

Hi guys,

Just needed some hlep and advise really based on my recent dyno run.

Had a dyno run last week and we discovered that my supra was running lean.

Was advised that this shouldnt be the case even at my bpu level.

My current engine setup is as follows:

93 Supra Twin turbo with hyrbid twins from whifbitz.

264 cams.

Aftermarket induction kit.

FCD.

Standard ECU.

440cc injectors.

Walbro fuel pump. (I was advised by previous owner that this had been fitted)

Full decat echaust system. HKS silent hi power.

New Greddy Profec Boost Controller. Set to 1.0bar low boost and 1.2bar high boost.

The 264 cams, fcd and boost controller were installed most recently.

The car idles a little bit rough for the first minute or so due to the 264 cams. I was told that this was normal for the type of cams on my standard setup. This can be corrected with a different ecu and remap i was advised.

In regards to the car running lean, Im just wondering whether it may be due to the new cams possibly?

I basically trying to get some insight into what the causes may be and what should be looked into?

We were considering fitting a Syvecs S6 ECU kit to remap the car as it is now and adjust fueling etc. Or would this be overkill for my hybrid/264 cam setup?

Also are my current 440cc injectors ok at my current level or would different injectors be required?

Any help on this would be greatly appreciated.

Regards

Ash

It will probably be down to the hybrid turbos and cams allowing for more airflow than the ECU can cope with, even though the std ECU will run the injectors at 100% DC when it sees over 4 to 4.2v, so your going to need a piggyback or stand alone ECU and some bigger injectors, Syvecs would be over kill if your not intending to take things any further, but its a good ECU to have if you are intending to tune more.

Out of interest how lean was it running? and was the AFR probe far enough up the exhaust? as this will influence the figures.

Sorry bud, not really sure on what the figures were off the top of my head. I could probably get them from my dyno guy. I can ask regarding the AFR aswell. Not sure how far it was.

In regards to the injectors, could i not still use the 440cc injectors with syvecs and just map it with those?

Also what other ecu's would be a good alternative?

Like Ricky said, astandalone would be overkill for this setup. Usdm 550cc injectors and a s-afc should do the job!

Your 440cc injectors will do depending your goals and currenct DC.

How old is you fuel filter? A clogged filter can be the cause running lean.

Yeah I will get the fuel filter checked as I dont believe that has been changed in a long time. Defo not since I got the car 2 years ago.

Are the super air flow converters any good? Would it help to cure the supra running lean?

I should note that in my dyno run at higher boost when it showed running lean, they did also mention they noticed slight knock whilst listening in, so stopped the run as they wanted to sort the car before going back on the dyno.

Also I know that the Syvecs is a bit overkill, but would it not be a worth while investment. Dont mind if its going to be the more reliable option.

Sorry bud, not really sure on what the figures were off the top of my head. I could probably get them from my dyno guy. I can ask regarding the AFR aswell. Not sure how far it was.

 

In regards to the injectors, could i not still use the 440cc injectors with syvecs and just map it with those?

 

Also what other ecu's would be a good alternative?

IF..its running lean at 1.2bar and the injectors are maxed out, adding a different ECU wont help, you will need larger injectors,

As I said probably due to the hybrid turbos and the cam enabling the engine to shift more air flow than the injectors can compensate for.

Also I would avoid going the SAFC route as alibabba suggested as there is not provision to adjust ignition timing, which is a must, at a minimum I would go Emanage Ultimate.

IF..its running lean at 1.2bar and the injectors are maxed out, adding a different ECU wont help, you will need larger injectors,

As I said probably due to the hybrid turbos and the cam enabling the engine to shift more air flow than the injectors can compensate for.

 

Also I would avoid going the SAFC route as alibabba suggested as there is not provision to adjust ignition timing, which is a must, at a minimum I would go Emanage Ultimate.

In think we only ran low boost on this dyno run so 1bar just to be on the safe side.

It was on low boost during the dyno run that we noticed it running lean and the knock.

If I did need to go to larger injectors, say for example 600cc injectors. Would I still be able to map the car for around 400bhp? As i don't really want to go above that at this point in time.

Thanks for you help so far

You need to find out how lean , say 11.6 is lean but still safe when used with decent fuel , so you could well be safe but still lean if you get my drift,

Sorry just read your other post about knock at higher boost , piggy back and injectors is the cheap way or the cheapest way is turn the boost down

In think we only ran low boost on this dyno run so 1bar just to be on the safe side.

 

It was on low boost during the dyno run that we noticed it running lean and the knock.

 

If I did need to go to larger injectors, say for example 600cc injectors. Would I still be able to map the car for around 400bhp? As i don't really want to go above that at this point in time.

 

Thanks for you help so far

You can run whatever power you like by controlling airflow/boost, so its not an issue, I would check with the RR guy to find out at what boost and power the lean AFRs and knock took place,(presuming you where not using low octane fuel?) then let us know and we can better advise you.

You can run whatever power you like by controlling airflow/boost, so its not an issue, I would check with the RR guy to find out at what boost and power the lean AFRs and knock took place,(presuming you where not using low octane fuel?) then let us know and we can better advise you.

yeah i will have a chat with my dyno guy tomorrow and see if I can find out the info.

The knock happened on the high rev range on 1 bar boost, so low boost if thats anything to go by.

At the time of dyno in regards to fuel, i was using Shell V-Power premium unleaded. So the fuel should have been perfectly fine.

Dont want to turn the boost down to cure the problem either, as it should be able to handle 1.2bar normally. It must be as said either a fuel filter issue, a ecu issue or my 264 cams and hybrid turbos are causing the lean problem.

Just curious as well. I have asked a few garages about the piggy back ecu's and they have always told me that they are not very good?

I think that maybe your confusing boost pressure with air flow, because the hybrids your running will likely have larger and more efficient inducer and compressor turbines, They can be pushing considerably more air into the engine at any given boost pressure, add the cams which accomplish the same scenario, and you will have your reason for the lean running IE the ECU map and injector combination running out of resolution.

It wont hurt to check the fuel filter, which could cause a restriction, however I would lay money that increased airflow is your problem, people who say piggybacks are not any good either have no real experience of them, or are quoting hearsay, there is nothing wrong with a decent piggyback set up correctly on the right application, I ran an Greddy Emanage Ultimate on my single turbo Supra making 550BHP with no problems.

Have to agree with ricky, a piggy with anyauto supra is the best option , from what I have seen most if nof all standalone ecu controlling the auto box shortens the life dramatically

Ok, so should i ask whether they can fit and map me a emanage ultimate for my current setup or would it be a worth while investment to go for the syvecs?

From what you have told me thus far, I pressume I will need larger injectors, is that correct?

Also I had a brief look at injectors on whifbitz and found 650cc SARD injectors. They are high impendence. Would these be a straight forward swap?

http://www.garagewhifbitz.co.uk/sard-828.html

Have to agree with ricky, a piggy with anyauto supra is the best option , from what I have seen most if nof all standalone ecu controlling the auto box shortens the life dramatically

Ok, there may be a bit of confusion here. my fault really lol. I have a manual 6 speed v161 supra with stage 1 clutch and spec light flywheel. No auto here

You need to find out why the thing is running lean. Chucking money and piggybacks at it isn't going to get to the root cause.

You need so much more information when coming onto the forum with such a question.

How lean is lean, what RPM is it lean from/to. What fuel are you running (thinking of the knock). What sort of power are you seeing with it as it is? Where is the lean condition being measured (exhaust or downpipe?)?

You advertised your car as newly built with everything changed for new. How on earth would you miss a basic service item like a fuel filter?

I'd be amazed if it's anything other than a fault causing the lean condition as the car stands.

You need to find out why the thing is running lean. Chucking money and piggybacks at it isn't going to get to the root cause.

 

You need so much more information when coming onto the forum with such a question.

 

How lean is lean, what RPM is it lean from/to. What fuel are you running (thinking of the knock). What sort of power are you seeing with it as it is? Where is the lean condition being measured (exhaust or downpipe?)?

 

You advertised your car as newly built with everything changed for new. How on earth would you miss a basic service item like a fuel filter?

 

I'd be amazed if it's anything other than a fault causing the lean condition as the car stands.

yeah I realise I do need more info on the issue which I will try to get and inform you guys.

Im not entirely sure about the fuel filter in all honestly. It had a massive service by whifbitz when i first got the car, loads spent, so It may well have been done then.

When you say anything other than a fault, what do you mean sorry?

This is the reason why its running lean, its not just basic BPU.

My current engine setup is as follows:

93 Supra Twin turbo with hyrbid twins from whifbitz.

264 cams.

Aftermarket induction kit.

FCD.

Standard ECU.

440cc injectors.

Walbro fuel pump. (I was advised by previous owner that this had been fitted)

Full decat echaust system. HKS silent hi power.

New Greddy Profec Boost Controller. Set to 1.0bar low boost and 1.2bar high boost.

But agreed more info is needed hence my asking for all the specs from the dyno run including just where the AFR probe was positioned, if not pushed far enough up the tail pipe it can read lean from atmospheric air, but it was stated that the run was aborted due to not only AFR but knock detected.

I will do my best to get that info for you. I am by no means trying to mess anyone about, really appreciate everyones input so far.

Yes the car is advertised as newly built as it has had a tremendous amount of time and work put into it and it really is a great car. If I am to go through the whole ECU and mapping, I think I may well keep the Supra at this rate for a bit longer

But let me as said see what happens over the next few days with my garage. They are very good at what they do and I am sure they will solve the lean issue and find the cause

This is the reason why its running lean, its not just basic BPU.

 

 

My current engine setup is as follows:

 

93 Supra Twin turbo with hyrbid twins from whifbitz.

 

264 cams.

 

Aftermarket induction kit.

 

FCD.

 

Standard ECU.

 

440cc injectors.

 

Walbro fuel pump. (I was advised by previous owner that this had been fitted)

 

Full decat echaust system. HKS silent hi power.

 

New Greddy Profec Boost Controller. Set to 1.0bar low boost and 1.2bar high boost.

 

 

But agreed more info is needed hence my asking for all the specs from the dyno run including just where the AFR probe was positioned, if not pushed far enough up the tail pipe it can read lean from atmospheric air, but it was stated that the run was aborted due to not only AFR but knock detected.

That little lot at 1 bar shouldn't run lean though. At BPU there's still plenty of fueling headroom with common AFRs being around the 10.5 mark. I wouldn't worry about anything up until 11.5 and I wouldn't imagine it being dangerously lean with knock until 12+.

I will, however, accept that it's possible the above is causing it. If it's putting down 450hp+ on the rollers then I would agree that there probably isn't enough fuel to support this. At 1.0bar we would be at a worlds first though.

Well just for comparison I ran a pair of hybrid turbos in TTC mode (not that that will change peak RPM/load fuelling requirements) and had to go to 560cc injectors as before with 440cc it was leaning out past 12AFR at just 1bar at peak load areas, and so it was quite obvious that airflow greatly exceeded normal BPU fuelling requirement's, which could go as rich as the high 9AFRs with the std ECU running injectors at 100% DC.

Well just for comparison I ran a pair of hybrid turbos in TTC mode (not that that will change peak RPM/load fuelling requirements) and had to go to 560cc injectors as before with 440cc it was leaning out past 12AFR at just 1bar at peak load areas, and so it was quite obvious that airflow greatly exceeded normal BPU fuelling requirement's, which could go as rich as the high 9AFRs with the std ECU running injectors at 100% DC.

Was that due to the lean spot at the transition? As you say, it shouldn't have affected the peak requirement but around the 4-5krpm mark I understand there's a bit of a worrying dip (this is the reason I asked the op about the RPM of the issue )

Yes there is a dip in both fuelling and timing, but that only if in TTC mode, the OP is still in sequential, however my fuelling running lean was as I stated at peak load areas, the std ECU could not supply any more fuel, even though I had an EMU tweaked for TTC, its still cant add any more fuel than the injectors allow, like I said once the ECU sees airflow of 4 to 4.2/4.3V (clamped at 4.35v) it will run the injectors at 100%DC so there is nothing to be done bar adding larger injectors and a way of controlling them.

Yes there is a dip in both fuelling and timing, but that only if in TTC mode, the OP is still in sequential, however my fuelling running lean was as I stated at peak load areas, the std ECU could not supply any more fuel, even though I had an EMU tweaked for TTC, its still cant add any more fuel than the injectors allow, like I said once the ECU sees airflow of 4 to 4.2/4.3V (clamped at 4.35v) it will run the injectors at 100%DC so there is nothing to be done bar adding larger injectors and a way of controlling them.

Mine does the same in sequential. Going from turbo one to then turbo two coming online, there is a dip in power before it then shoots back up again.

The car started to run lean during the higher rpms at 1bar on the dyno.

So at the moment im guessing by me adding the hybrid turbos and 264 cams, that has increased air flow quite a bit, causing it to run lean.

 

So at the moment im guessing by me adding the hybrid turbos and 264 cams, that has increased air flow quite a bit, causing it to run lean.

Errr that's what I have been telling you for the last two pages ....LOL!

Enough airflow to run lean on 440cc injectors at the upper end of the RPM scale has to be 450hp+ though. It would all need to add up surely?