Sum up R32GTR Build before tune - Parts ?

[Dose Pipe Sutututu]

On 24/01/2023 at 10:24 AM, GTSBoy said:

Yeah nah. Flex fuel sensor should be put in the low pressure return line. No need to punish it with several bar of static P.

P sensor in the rail feed line is sensible. But the obvious answer here is to buy an adapter to put an aftermarket pressure reg on the tail of the fuel rail and use the gauge port on the reg to mount teh P sensor.

I'm not a fan of putting it on the return side, you have issues when say there's not enough fuel flow, god forbid air pockets,  and your ethanol sensor isn't sampling correctly. This could happen say during a high G event.

Sure you can set sampling thresholds such as you need x bar of fuel pressure, y RPM however better practice to have it on the feed side.

OEM cars run deadhead systems with the flex sensor on them without issue, also those Continental flex sensors will happily take nearly 10 bar of fuel pressure.

FWIW (also subjective) I run mine on the feed between the main tank and surge tank.

[GTSBoy]

1 hour ago, Dose Pipe Sutututu said:

I'm not a fan of putting it on the return side, you have issues when say there's not enough fuel flow, god forbid air pockets,  and your ethanol sensor isn't sampling correctly. This could happen say during a high G event.

Sure you can set sampling thresholds such as you need x bar of fuel pressure, y RPM however better practice to have it on the feed side.

OEM cars run deadhead systems with the flex sensor on them without issue, also those Continental flex sensors will happily take nearly 10 bar of fuel pressure.

FWIW (also subjective) I run mine on the feed between the main tank and surge tank.

All true. I just follow the policy of fewer high pressure hose connections is better high pressure hose connections.

Also, there will always be fuel in the return, and it will get refreshed often enough. You'd have to be on full noise, maxing out the pump capacity such that there is no return flow, continuously, while a substantial change in fuel ethanol content arrived at the engine, for your concerns to be realised as engine damage. Any little burp of the fuel reg to release some fuel will always put some fresh stuff past the sensor.

[Murray_Calavera]

Is anything going to happen if the flex sensor isn't sampling fuel for a period of time? 

I mean the e content of the fuel is the e content, after a few minutes of driving, the mixture never changes. 

I could only ever see this being an issue after filling up the tank and before the current mixture was established. 

Is there something I'm missing?

[Dose Pipe Sutututu]

33 minutes ago, Murray_Calavera said:

Is anything going to happen if the flex sensor isn't sampling fuel for a period of time? 

• Timing drops - loss of power
• Lean out - misfires and/or engine protection triggers 
• Shit lap time.

lol

[BK]

55 minutes ago, Dose Pipe Sutututu said:

• Timing drops - loss of power
• Lean out - misfires and/or engine protection triggers 
• Shit lap time.

lol

But it won't happen realistically. Even if the sensor starves it has little to no effect as the sensor is so saturated it takes minutes to register any sort of dramtic change, and that's before even talking about the sampling threshold settings.

[Dose Pipe Sutututu]

29 minutes ago, BK said:

But it won't happen realistically. Even if the sensor starves it has little to no effect as the sensor is so saturated it takes minutes to register any sort of dramtic change, and that's before even talking about the sampling threshold settings.

True, but at SAU we like to over think things for no reason  

[Murray_Calavera]

2 hours ago, Dose Pipe Sutututu said:

• Timing drops - loss of power
• Lean out - misfires and/or engine protection triggers 
• Shit lap time.

lol

Ah ok.

I was thinking that if the sensor was starved of fuel, it would not send a value to the ECU. So the ECU would just keep using the last known value. 

But what you are saying is, if the sensor was for example, just plugged in to the ECU with no fuel flowing through it at all, it would still function as expected and send a value to the ECU for 0% ethanol? 

 

[Dose Pipe Sutututu]

3 minutes ago, Murray_Calavera said:

Ah ok.

I was thinking that if the sensor was starved of fuel, it would not send a value to the ECU. So the ECU would just keep using the last known value. 

But what you are saying is, if the sensor was for example, just plugged in to the ECU with no fuel flowing through it at all, it would still function as expected and send a value to the ECU for 0% ethanol? 

To be honest I do not know the answer, however there have been discussions about this on Facebook's Haltech group not long ago.

Here's a few responses from people much smarter than me. 

[BK]

Turn your car on and don't start it for an hour - the ethanol content won't change from the last time it registered fuel flowing through it. It doesn't just return to 0%

[GTSBoy]

3 hours ago, BK said:

the ethanol content won't change from the last time it registered fuel flowing through it

That's probably because the same fuel is still sitting there in the sensor, getting sensed.

[Murray_Calavera]

Does anyone feel like pulling their flex sensor out to see what happens? lol

[Duncan]

surely......if your ethanol % drops from say 80% to 0%, the ECU pulls timing like it was straight 98....so fails safe

[Ben C34]

On 1/25/2023 at 8:19 PM, Duncan said:

surely......if your ethanol % drops from say 80% to 0%, the ECU pulls timing like it was straight 98....so fails safe

Except for the leaning out part......

[Duncan]

interesting point.

we need someone to pull their ethanol sensor plug out on a dyno at full noise

[BK]

13 hours ago, GTSBoy said:

That's probably because the same fuel is still sitting there in the sensor, getting sensed.

Not really. The Haltech remembers what fuel was there and assumes the same fuel is still present even after a significant amount of time unitl the sensor reports something else dramatically different. Even then, it will slowly decrease the % sensed, not drop off a cliff.

12 hours ago, Duncan said:

surely......if your ethanol % drops from say 80% to 0%, the ECU pulls timing like it was straight 98....so fails safe

This is a situation this can never really ever happen. Even small traces of E85 will not let it drop to 0 instantly - you might see a 20 - 30% drop when 98 is first sensed. When I had about 5 litres of 98 and then dumped 40 litres on top of it with E85 it took about 30mins of engine running for the sensor to stabilise at about 70% watching it on the canbus gauge and pc, doing 1% incremental increases every 30 seconds or so with the Haltech flex sensor.

[timmy94]

On 1/25/2023 at 12:12 AM, joshuaho96 said:

 

 

On 1/24/2023 at 11:54 PM, Ben C34 said:

 

 

On 1/25/2023 at 3:36 AM, Murray_Calavera said:

 

Thanks for all your lovely answers. im little confused still about this sensor. the oem fpr is enough to deal with from what i know and i want to replace as few things as possible. The police is very picky also, they literally tried to bring mates car dowm by claiming there isnt the oem brake fluid or something stupid. 

But i also want a relaible car. Idk if my Old link G4 ecu can read fuel pressure. 

If it can, i guess i plug it to the ecu? By a 'T" connection into the fuel pressure side between filter and rail? 

if i cant i guess i place a gauge in the flightdeck so i can keep an eye on the fuel pressure?

 

are these cars so sensitive? i mean, an old volvo, opel or whatever can run dry on fuel, run forever with no oil change or run jet diesel without issues. Can drive forever with broken lambda sensor etc haha!

 

 

 

[timmy94]

How do you do with the lambdasensor? from factory there is 2, right behind each turbo. Do i plug these and place my new one further down where the 2 elbows connect to 1? and only use one input/connector? Usually they say that you shouldnt put the sensor so close to the turbos.

i bought a lambdasensor AEM kit including controller. There is only one lambda sensor in here.

 

1 sensor or 2? can i even run 2 with the AEM controller kit.  Is it better to rum 2 lambdasensor on each elbow?

[Murray_Calavera]

10 hours ago, timmy94 said:

How do you do with the lambdasensor? from factory there is 2, right behind each turbo. Do i plug these and place my new one further down where the 2 elbows connect to 1? and only use one input/connector? Usually they say that you shouldnt put the sensor so close to the turbos.

i bought a lambdasensor AEM kit including controller. There is only one lambda sensor in here.

 

1 sensor or 2? can i even run 2 with the AEM controller kit.  Is it better to rum 2 lambdasensor on each elbow?

The Link G4 can read the fuel pressure sensor provided you have the spare input for it. Yep, you can T in between the rail and fuel filter for the sensor. 

For your wideband O2 sensor, one sensor is fine and you can install it in front of the cat. You'll need to get a bug welded on for where you want to locate it. Where the factory O2 sensors are, you can leave the factory sensors there. I wouldn't install a wideband sensor so close to the turbos.