OEM cam differences, modifying fuel pressure.

[Crunk81us]

Originally Posted by steve99

Their is no reason an NA car should run lean due to maxing out fueling even on E85 their is plenty of headroom.you jist nned to get the tune fixed, i assume the motec should be able to run both pi\di fueling systems.

why do you need a motec for an NA car seems way overkill ?

No it's not maxing out it is the tune. I am stuck with this tune.
I cannot retune it. This is not an option.

[steve99]

Originally Posted by Crunk81us

No it's not maxing out it is the tune. I am stuck with this tune.
I cannot retune it. This is not an option.

no motec tuners in toowoomba ?
can you put stock ecu back in and tune that ?

maybe try coyote tuning in brisbane think he does motec and haltec ecu tuning

[C4RBON]

Increasing the inlet fuel pressure to the high pressure pump won't increase the amount of fuel injected. The high pressure pump's flow is determined by its displacement (which is fixed based on cam geometry) and the electronic control of a valve. The valve is open during the suction stroke of the pump, and closes for a calculated time during the compression stroke. The pump fills up on every suction stroke, and you can't shove more fuel into the pump than will actually fit.

[Crunk81us]

Originally Posted by steve99

no motec tuners in toowoomba ?
can you put stock ecu back in and tune that ?

maybe try coyote tuning in brisbane think he does motec and haltec ecu tuning

nah I have to run this tune.. no choice.

[Crunk81us]

Originally Posted by C4RBON

Increasing the inlet fuel pressure to the high pressure pump won't increase the amount of fuel injected. The high pressure pump's flow is determined by its displacement (which is fixed based on cam geometry) and the electronic control of a valve. The valve is open during the suction stroke of the pump, and closes for a calculated time during the compression stroke. The pump fills up on every suction stroke, and you can't shove more fuel into the pump than will actually fit.

thanks so much for the answer!

[Wayno]

Originally Posted by Crunk81us

nah I have to run this tune.. no choice.

Locked Motec tune = Toyota 86 Racing series obviously.

[Wayno]

Mate, I raised this in the 86 drivers facebook group when they announced the specs for the series and the control parts including how some people would be severely disadvantaged by the control tune, and as with any tuning issue in Australia on social media, was immediately spat on and stoned to death from afar by the keyboard warriors.

I have two very distinct MAF scales for aussie cars, one is 5% richer than the other in open loop (about 0.6 AFR).

The Richer one runs on MY12 MT, MY13 MT and most MY14 MT.
The Leaner one runs on some MY14 MT, and most AT's.

It might be possible that they've created the tune on an MY14/MY15 and it runs leaner if your mar is an MY12/MY13 as it has different sensor calibration/tolerance.

You could try swapping out the O2 sensor and/or maf sensor for starters to see if that fixes things, might be cheaper investment than ****ing around with cams.

Or raise the issue with the series management / bates motorsport.

Or you have some kind of leak you should be able to determine with data.


13.5 is REALLY not good on these high comp engines on 98/E0. The heat will cause so much knock and pulled timing it would be ridiculous.
11.6-12 under 7000 and 11.5 above 7000 rpm would be better.

I still don't understand why they're not running E85, it would be much more forgiving, should give closer results with less knock, and it's already a controlled fuel at all these events.


You should have logging in the motec dash, what AFR's does the stock O2 sensor read?
What does it log in terms of fuel trims? How does it handle fuel trims? Trims might be completely disabled, so with a couple of small hardware issues could cause it to run that lean and not be able to trim down.


Side note: Was the fire in the strongman car from the oil cooler? Looked like it to me.
Front mount oil coolers on cars that are guaranteed to get hit in the front every race


Attached is what I would think it should AT LEAST be making. That's with a free tune on pump 98 with EL 4-1 headers.

Plus a couple of 100% stock ones too.

Originally Posted by Crunk81us

yes my motec is locked. only headers, no cat, big pipes.
No i can't unlock it.
did a dyno run and it appears to run lean.
I am trying to ascertain why and if there is anything i can do about it.
I see people run anywhere from 11.5-12.5:1.
Mine is 13.5ish!

[steve99]

yeah if it a 86 series car that would be good info to provide
if you legally allowed to swap maf sensors then that might work as way no suggested

if you need to talk to organisers as @Wayno said

[Crunk81us]

yeah i spoke to them.. they are staying the line of "they're all tuned the same, the power is appx the same"...
I didnt want to mention the racing series here because i dont want people to think i am cheating! I just want a friggin fair go!

[Wayno]

Originally Posted by Crunk81us

yeah i spoke to them.. they are staying the line of "they're all tuned the same, the power is appx the same"...
I didnt want to mention the racing series here because i dont want people to think i am cheating! I just want a friggin fair go!

Unfortunately the control tune is the one thing that could completely disadvantage some and advantage others by about 10%, maybe 15% if you have any kind of leak that the locked down ecu can't compensate for. And if you haven't found out yet, tuners are defensive as fuck fuckers, particularly here.

The only way to work around it will be to swap in oem parts from later models I think. There won't be any rules against that.

[C4RBON]

There is a fuel pressure sensor on the right side high pressure fuel rail. The rail pressure should be used by the pump as feedback (via the ECU on a stock control system). If the actual rail pressure is 15 MPa but the sensor reads 14 MPa, the pump would respond by providing more flow (thus 1 MPa higher pressure). Now you'd have 16 MPa in your fuel rail, which would result in a small bump in fuel for the direct injectors.

Swapping O2, MAF, and fuel pressure sensors might get you a little more fuel without changing the tune.

[Crunk81us]

Originally Posted by Wayno

Unfortunately the control tune is the one thing that could completely disadvantage some and advantage others by about 10%, maybe 15% if you have any kind of leak that the locked down ecu can't compensate for. And if you haven't found out yet, tuners are defensive as fuck fuckers, particularly here.

The only way to work around it will be to swap in oem parts from later models I think. There won't be any rules against that.

I really thought this series would be close to fair with all of the rules and hoops we had to jump thru...

Replace parts... but which ones? my budget is already empty preparing and entering the series..

so far i have found, cam gears, coil packs, rockers, valves, possibly cams/MAF and who knows what else?!! as being different between 2012 and 2015.

which of these do i have to replace to achieve the parity as advertised?

[Wayno]

Data will save you the most time and money. Seems like you're shooting completely in the dark right now. If you can't get the motec cable, beg and borrow one.

Rule out any leaks first, then try a different maf sensor. Try to borrow. There's no point unless you can verify with data though.

If you end up not being able to log any data at all, put the car back on the dyno after letting the ecu adapt for 100km without resetting the ecu, then change the maf sensor from an MY14/MY15 AT and log again without resetting the ecu, then finally reset so you can see for sure if the ecu trims the fuel or not. Actually, you don't need a dyno for that, just an O2 sensor.

There's one more thing only if all else fails. How hard is it to swap the stock ecu back in? We have tunes that will give known behaviour on the stock ecu if you have to troubleshoot hardware problems.

[Crunk81us]

Originally Posted by Wayno

Data will save you the most time and money. Seems like you're shooting completely in the dark right now. If you can't get the motec cable, beg and borrow one.

Rule out any leaks first, then try a different maf sensor. Try to borrow. There's no point unless you can verify with data though.

If you end up not being able to log any data at all, put the car back on the dyno after letting the ecu adapt for 100km without resetting the ecu, then change the maf sensor from an MY14/MY15 AT and log again without resetting the ecu, then finally reset so you can see for sure if the ecu trims the fuel or not. Actually, you don't need a dyno for that, just an O2 sensor.

There's one more thing only if all else fails. How hard is it to swap the stock ecu back in? We have tunes that will give known behaviour on the stock ecu if you have to troubleshoot hardware problems.

Thanks for all the help Wayno!

I will do as you've said above.. The oem ecu plugs straight back in takes maybe 2 minutes if it goes horribly wrong haha

finding parts to borrow or steal will be hard as I live in bumfuck nowhere. and as I can only drive the car on the track, It might be a bit hard to rack up 100 kms.. I should probably go back in to the dyno and run the oem ecu and see what it does? then swap out the "begged, borrowed, stolen" parts.. and run again.. etc.. Also I am waiting to hear back from NBM with regards to this issue, I am not the only unhappy camper!