Soarer Central: Archive through April 13, 2006

Soarer Central Mechanical - V8 SMT6 Piggyback ECU finally working V8 SC400 Archive through April 13, 2006

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Peter Taplin
Tinkerer
Vic
UZZ32 V8 Supercharged & UZZ32 V8 NA

Posts: 37
Reg: 08-2005

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Wednesday, April 12, 2006 - 05:47 pm, by: Peter Taplin (Mrfourwd)

Hi Guys

Sorry I have been tardy with my replies..

I have been speaking to Perfect Power and we may be able to get the SMT6 to run as an SMT6D and allow closed loop tuning, this will provide the economy most people are looking for and more tune ability from the unit..

I have fitted a wide band sensor to my vehicle for the purposes of tuning and a mod to remove the knock sensor signal to the ECU without an error code being generated.
This was vital for me as at high boost (10lb)as soon as the ECU saw a knock it pulled the timing back, what I need is to be able to set the timing using the SMT6 to remove the knock without interference from the ECU, this will also enable more timing down low where it is needed, I also notice that the code in the Mines ECU removes some of the sensitivity to knock, and when it does pull timing out it pulls it out less quickly.

Peter Taplin
Tinkerer
Vic
UZZ32 V8 Supercharged & UZZ32 V8 NA

Posts: 38
Reg: 08-2005

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Wednesday, April 12, 2006 - 05:54 pm, by: Peter Taplin (Mrfourwd)

Hi Anish

The timing has been shifted across the whole map by the SMT6 put -3 (or more) in your AMP settings and you will find you get a great idle and no stalling, I am surprised your tuner did not check the base timing as this would have shown it too far advanced at idle.

Some of the feedback on the forum is showing we still have some way to go to get this perfect but hang in there and I am sure we will.

this will also shift the whole map so additional timing will need to be added to the rest of the map, except around 500/1000 rpm mark

Justin McLernon
TryHard
Western Australia
UZZ32

Posts: 229
Reg: 01-2006

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Wednesday, April 12, 2006 - 07:32 pm, by: Justin McLernon (Zz32)

Peter how does one set a -3 input for AMP?

Are talking about Global Settings--->Switch--->AMP? The range of values for this function is "OFF" to 1.0

Anish I just examined your dyno-tuned fuel map and it looks VERY suspect to me. There are only 7 cells (from a total of 128 cells) for which your tuner has modified the values and that is for a VERY narrow window (full throttle at between 3600 and 6000 RPM)!

Justin McLernon
TryHard
Western Australia
UZZ32

Posts: 230
Reg: 01-2006

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Wednesday, April 12, 2006 - 07:43 pm, by: Justin McLernon (Zz32)

This is your fuel map Anish, note the only changes are the removal of fuel in the top RHS cells (and the "6" in the cell towards the bottom left, presumably to assist idle).

Anish Varsani
TryHard
QLD
V8 UZZ30

Posts: 224
Reg: 07-2005

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Wednesday, April 12, 2006 - 08:25 pm, by: Anish Varsani (Yomama)

I didn't notice that 6. I think it's a stuff up. The car keeps stalling when pulling corners at low speed closed throttle even with the ignition cell changed from 2 deg to 1 deg.

I'll take it out and see what happens.

I wasn't too impressed by the tune myself. The guy didn't seem to interested. They only charged me an hours dyno time so I didn't complain. I've heard of people with unichips getting 4 degrees down low. The tuner said they had a jig to scan for knock. I havn't seen any such thing myself. He may have been talking crap, I don't know.

I'll wait and see what other people get when they get their units tuned.

I'd like to be there next time the tune is done. This mob wasn't open on saturday so I didn't have much choice.

Justin McLernon
TryHard
Western Australia
UZZ32

Posts: 231
Reg: 01-2006

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Wednesday, April 12, 2006 - 08:33 pm, by: Justin McLernon (Zz32)

What do people think about this: two V8 Soarers both identical (including compression ratios) but one is supercharged to 10psi and the other is standard, NA. Both have an SMT6 fitted.

Is it reasonable to assume that the NA V8 could safely run more timing advance than the supercharged Soarer? Or does the question require more sophisticated analysis - fuelling etc?

Dan McColl
Goo Roo
Victoria
UZZ-32 V8 Soarer #138

Posts: 1031
Reg: 07-2005

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Wednesday, April 12, 2006 - 08:37 pm, by: Dan McColl (Hoon)

It depends on amount of fuel and quality of fuel, Also carbon deposits and small differences in combustion chambers will make a difference to knock resistance.

Justin McLernon
TryHard
Western Australia
UZZ32

Posts: 232
Reg: 01-2006

Rating: N/A
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Wednesday, April 12, 2006 - 08:43 pm, by: Justin McLernon (Zz32)

Yeah, Anish I thought when you said you had spent $785 all up that your car must have only had an hour or so on the dyno.

I think there is definitely something else causing the stalling, because 1 degree vs 2 degrees advance is a relatively trivial difference. Perhaps it is the global ignition setting Peter has referred to (though I personally cannot identify what value Peter is talking about). Change the 6 back to a 0.

As for your tuners fuelling tune, it looks really basic (quite a woeful effort). They've done nothing other than pull out a •••• load of fuel at full throttle between 3500 and redline. Your fuelling for cruising, launch, light to medium throttle through all loads will be unchanged (other than only minor changes as a consequence of the minor ignition timing advances on your ignition map).

Looking at your maps, I'd be surprised if you could feel any discernible differences on your "butt dyno". It needs more time on the dyno without doubt and nexttime I'd take it elsewhere...

Anish Varsani wrote on Wednesday, April 12, 2006 - 08:25 pm:
I didn't notice that 6. I think it's a stuff up. The car keeps stalling when pulling corners at low speed closed throttle even with the ignition cell changed from 2 deg to 1 deg.

I'll take it out and see what happens.

I wasn't too impressed by the tune myself. The guy didn't seem to interested. They only charged me an hours dyno time so I didn't complain. I've heard of people with unichips getting 4 degrees down low. The tuner said they had a jig to scan for knock. I havn't seen any such thing myself. He may have been talking crap, I don't know.

I'll wait and see what other people get when they get their units tuned.

I'd like to be there next time the tune is done. This mob wasn't open on saturday so I didn't have much choice.

Justin McLernon
TryHard
Western Australia
UZZ32

Posts: 233
Reg: 01-2006

Rating: N/A
Votes: 0 (Vote!)

Wednesday, April 12, 2006 - 08:44 pm, by: Justin McLernon (Zz32)

Dan, assume EVERYTHING is identical other than NA / supercharged difference.

Dan McColl wrote on Wednesday, April 12, 2006 - 08:37 pm:
It depends on amount of fuel and quality of fuel, Also carbon deposits and small differences in combustion chambers will make a difference to knock resistance

Anish Varsani
TryHard
QLD
V8 UZZ30

Posts: 225
Reg: 07-2005

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Wednesday, April 12, 2006 - 08:59 pm, by: Anish Varsani (Yomama)

Peter, I'm not using a MAP sensor so the black/white wire is connect to ground and the map scalers set accordingly as per the developer's manual so this setting won't do anything to my map.

Anish Varsani
TryHard
QLD
V8 UZZ30

Posts: 226
Reg: 07-2005

Rating: N/A
Votes: 0 (Vote!)

Wednesday, April 12, 2006 - 09:02 pm, by: Anish Varsani (Yomama)

I'm not sure of the circuit inside the ecu that reads the knock signals but the easy to fool the knock sensor is to put a resistor in series with or a resistor divider in parallel to the ecu input to scale the signal down.

It's not something I want to play with myself.

Jeff Harper
Trader
NSW
UZZ32 Active V8

Posts: 1047
Reg: 07-2005

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Wednesday, April 12, 2006 - 09:15 pm, by: Jeff Harper (Jeffh)

Quote ... "The ecu only went open loop at full throttle, not 75% as I'd read."

If that is the case at 100% switchover, no fuel piggyback will ever be able to adjust fuel as the factory ECU will relearn and adjust to what it wants.

So what is the purpose of the exercise?

Or does it really switch over at, say 75% or less?

Dan McColl
Goo Roo
Victoria
UZZ-32 V8 Soarer #138

Posts: 1033
Reg: 07-2005

Rating: N/A
Votes: 0 (Vote!)

Wednesday, April 12, 2006 - 09:50 pm, by: Dan McColl (Hoon)

Assuming everything is identical except for the amount of fuel going in, then you should be able to run more timing on n/a before it reaches critical knock pressure.

(I think)

Justin McLernon
TryHard
Western Australia
UZZ32

Posts: 234
Reg: 01-2006

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Wednesday, April 12, 2006 - 10:59 pm, by: Justin McLernon (Zz32)

Dan, that's exactly what I thought.

If Peter T can safely run 4-6 degrees timing advance across the board on a boosted V8 Soarer, similar timing advance ought be safely achievable on an NA V8 (unless his motor's compression ratio has been modified).

Anish Varsani
TryHard
QLD
V8 UZZ30

Posts: 227
Reg: 07-2005

Rating: N/A
Votes: 0 (Vote!)

Thursday, April 13, 2006 - 05:55 am, by: Anish Varsani (Yomama)

Correction: Looking at the drawing, the TPS has a 3 bit output (8 different voltages). So open loops at STARTS at the highest voltage level.. So in this case 87.5% upto 100% throttle.

Happy?

As far as I know, the motor internals are stock. I've been running Optimax so I'm assuming that the insides of the combustion chamber are clean. With a datalogger, it'd be easy to monitor when the timing is being cut back due to knock and also the AFR vs RPM vs Load.

Until a few others here in Queensland get there's done, I'm not going to get another tune done. I want to see the maps and get opinions of how the car drives before I go to another tuner.

Jason Kingsmill
DieHard
NSW
UZZ31 Soarer V8

Posts: 571
Reg: 07-2005

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Thursday, April 13, 2006 - 05:55 am, by: Jason Kingsmill (Jason_k)

Anish Varsani wrote on Wednesday, April 12, 2006 - 09:02 pm:
I'm not sure of the circuit inside the ecu that reads the knock signals but the easy to fool the knock sensor is to put a resistor in series with or a resistor divider in parallel to the ecu input to scale the signal down.

The knock sensor is a Peizo device that oscillates at a specific frequency....a voltage divider will reduce the amplitude of the signal, but in theory should have little effect on the ECU sensing knock. Unless the amplitude was much too low, in which case I would have thought it would throw up a knock sensor fault code?