Mk7 big turbo mpi dyno number/reliability

[jybyrd]

Yeah I saw the turbo after I commented.

Curious what happened there.

By the chunked block, it looks like the turbo got Extra Fuckin' Rowdy and his fuel Flexed pretty hard.

 

[SugarMouth]

By the chunked block, it looks like the turbo got Extra Fuckin' Rowdy and his fuel Flexed pretty hard.

Yeah I see E10 on his display, maybe had a shitty batch of gas with no headroom (ethanol) to come to the rescue.

 

[Diggs24]

Yeah I see E10 on his display, maybe had a shitty batch of gas with no headroom (ethanol) to come to the rescue.

Lots of pump gases are E10. Actually most are. Hard to find gas without ethanol.

 

[railroader]

Lots of pump gases are E10. Actually most are. Hard to find gas without ethanol.

My Chevron here tested as e12

Sent from my SM-G950U1 using Tapatalk

 

[Ed @ EQT]

Lots of pump gases are E10. Actually most are. Hard to find gas without ethanol.

E10 is fine. But it could have been a really bad tank of gas. I got a tank of 91 about 6 months ago that was causing severe audible knock. It was so bad I'm amazed the engine survived it! And this was from a known 76 that's usually fine. Thankfully the car was just stage 2 back then as I'm sure a similar situation with 28psi+ would have caused some real damage.

-- Ed

 

[SugarMouth]

Lots of pump gases are E10. Actually most are. Hard to find gas without ethanol.

Exactly my point. He had just pump gas in the tank meaning no headroom AKA E30-40-50.

 

[Swoope]

The dry/thin air does not transfer heat well. I have spoke to others also at high altitude with the same issue.

I will see 240+ degrees of coolant temps by lap 3 at High Plains Raceway. The car basically turns unto a Geo Metro in terms of power and I have to do a lap at 50% to cool down. At that point my first hot lap it's overheating again.

Will need a better radiator.

on a side note, what temp do you see throttling?

beers

 

[1jzlive]

Ouch. Stuff can definitely happen when you're pushing twice the stock hp. Unfortunately nothing is absolutely bullet proof.

-- Ed

?????

 

[1jzlive]

Im bout to a have two tunes one 500whp(for when i need to turn it up cuz i got my feelings hurt lol)and 450 daily(longevity) and call it a closed case chances are always there ,amd to be honest i can save the money in a matter of months tbh issue is i cant afford downtime on the car as buikding an engine is time consuming �� I wamt to thank everyone for there experience and 2 cents�� (Ill be back to collect more info on the mqb platform)��

 

[SugarMouth]

on a side note, what temp do you see throttling?

beers

Not sure what you mean? I see 240+ when the car pulls power.

 

[Hoon]

I don't think this is correct. The MAP sensor calibration is a linear voltage/pressure relationship and the ECU interpolates along that line. The limiting factor on resolution is the voltage output of the sensor and voltage detection circuitry in the ECU, and off course the data type that is used by the ECU. Most circuits easily detect changes as small as .01v which would give us at least 400 points across a 4 volt range (most sensors operate at .5-4.5 volts). So the resolution on 1 bar sensor is at least .04psi, on a 3 bar that would be about .1psi, and on a 5 bar it would be around .2psi. Accuracy is the other factor and that generally varies with temperature. This is usually .5-1.5% of the full operating pressure range across the operating temperature range. Most 3 bar sensors are accurate to about .25psi across their operating temperature range. The AEM 5 bar sensor is accurate to .375psi across its temp range and the Bosch 4 bar seems to be at about .88psi, but the inaccuracy is only at either temperature extreme... in a more normal temp range, they're accuracy goes up to about .5psi. But again, resolution is much much higher than that.

Now on to the problem with the Bosch 4 bar... I think its the the pressure range rather than the resolution. The little data I've found on it, says it only reads down .5bar (-7.25psi relative vacuum at sea level). This is not enough for a gasoline engine as they tend to idle and operate at low throttle in the -9psi to -12psi range. So this sensor won't work properly when used on the manifold for load/fuel calculation. It'll work fine as a TIP sensor since it doesn't need to measure vacuum there. The AEM 5 bar, for example reads down to 0 bar (-14.7psi relative).

So this explains why some of you are having idle and low throttle drivability issues with the Bosch 4 bar in the intake manifold. There could be software tricks around this by calculating low load based on baro pressure, temperature, and throttle angle, but that's far from ideal. So until we can find a better a P&P 4 bar solution, it seems that the AEM sensor is the best bet.

Thanks
-- Ed

Thanks Ed, this is clearly a very different system than what some others were (are?) using.

 

[Ed @ EQT]

Thanks Ed, this is clearly a very different system than what some others were (are?) using.

Pretty much every platform I work with works this way. What other implementations have you seen?

— Ed

 

[wy2sl0]

So much misinformation in this thread. The 4 bar problem has NOTHING to do with Eurodyne.

Be wary of people giving out advice when they don't know what the hell they are talking about i.e. 805mk7.

What Ed and Sam said is correct. The Bosch 4 bar is not qualified linear below 0.5 bar which is fine for the diesel cars it was designed for, but not for gasoline ones.

UM is running a more expensive AEM 5 bar map, this is why the car runs perfect. The 4 bar kits everyone is selling for the manifold are not ideal. Throttle pipe is fine and will get you 4-5 seconds of over 3 bar boost (running one sensor) before you get a code.

P.S. Ottawa is a great MQB city. 4 10 second MQB's here and our population is like 800,000. Two will probably be 10.5-10.6 or lower this summer.

 

[THEREALVRT]

So much misinformation in this thread. The 4 bar problem has NOTHING to do with Eurodyne.

Be wary of people giving out advice when they don't know what the hell they are talking about i.e. 805mk7.

What Ed and Sam said is correct. The Bosch 4 bar is not qualified linear below 0.5 bar which is fine for the diesel cars it was designed for, but not for gasoline ones.

UM is running a more expensive AEM 5 bar map, this is why the car runs perfect. The 4 bar kits everyone is selling for the manifold are not ideal. Throttle pipe is fine and will get you 4-5 seconds of over 3 bar boost (running one sensor) before you get a code.

P.S. Ottawa is a great MQB city. 4 10 second MQB's here and our population is like 800,000. Two will probably be 10.5-10.6 or lower this summer.

4?

 

[wy2sl0]

4?

Sam, Scott, Tapp has two (RS3 and S3).