Hybrid K04 Turbo Discussion

Feel

Veedubya 'velle
Jun 12, 2003
4,918
2
Midlands
What he's saying, Ben, is:

00100101110101001101010010110011110.

:bleh:

:rolleyes: He's saying that vag-com only reports 1.55 bar becuase the ECU only sees 1.55 bar, because the MAP sensor is capped at 1.55 bar, because it outputs a max of 5v to represent 1.55 bar. MAP sensors have been tested at higher than 1.55 bar and have output higher than 5v, but the signal is ignored because about 1.55bar that particular sensor generates an unreliable sensor.

Also what he's saying, is that if you swap your 2.55bar sensor for a 3bar TDi sensor, the 3bar one will output (something like) 5v to represent 2bar boost, so the ECU will see this 5volts and read it as 1.55bar.

Hence, the code/map that you run has to be recalibrated to no that 5v = 3bar, not 2.55bar.
 

J@mes

e46psi.com ;-)
Jun 14, 2004
2,842
0
.
What he's saying, Ben, is:

00100101110101001101010010110011110.

:bleh:

:rolleyes: He's saying that vag-com only reports 1.55 bar becuase the ECU only sees 1.55 bar, because the MAP sensor is capped at 1.55 bar, because it outputs a max of 5v to represent 1.55 bar. MAP sensors have been tested at higher than 1.55 bar and have output higher than 5v, but the signal is ignored because about 1.55bar that particular sensor generates an unreliable sensor.

Also what he's saying, is that if you swap your 2.55bar sensor for a 3bar TDi sensor, the 3bar one will output (something like) 5v to represent 2bar boost, so the ECU will see this 5volts and read it as 1.55bar.

Hence, the code/map that you run has to be recalibrated to no that 5v = 3bar, not 2.55bar.


well im glad someone got it! ;)
 

ibizacupra

Jack-RIP my little Friend
Jul 25, 2001
31,333
19
glos.uk
What he's saying, Ben, is:

00100101110101001101010010110011110.

:bleh:

:rolleyes: He's saying that vag-com only reports 1.55 bar becuase the ECU only sees 1.55 bar, because the MAP sensor is capped at 1.55 bar, because it outputs a max of 5v to represent 1.55 bar. MAP sensors have been tested at higher than 1.55 bar and have output higher than 5v, but the signal is ignored because about 1.55bar that particular sensor generates an unreliable sensor.

Also what he's saying, is that if you swap your 2.55bar sensor for a 3bar TDi sensor, the 3bar one will output (something like) 5v to represent 2bar boost, so the ECU will see this 5volts and read it as 1.55bar.

Hence, the code/map that you run has to be recalibrated to no that 5v = 3bar, not 2.55bar.

someone understands me :D lol
 

ibizacupra

Jack-RIP my little Friend
Jul 25, 2001
31,333
19
glos.uk
You're all stuck in the same boat as billy and I. You fit a turbo and then 2 days later think 'I should have gone bigger'. I've only done that 4 times.

I think I have as much as I want....
just some cams to drop in & then i stop
its fwd FFS so pretty irrelevant other than dyno numbers.

well, stop for now... :p

maybe..

kinda..


never say never.

:doh:
:hide:
 

bentaw

Revo'd LCR
Oct 1, 2004
1,067
0
Hampshire
i think i get it now basically the MAP sensor wont read higher than 1.5bar due to a cap and the reason for this cap is becuase they are not reliable after this or give off false readings. Vag com only records to 1.5 bar becuase the ECU and MAP sensor only record to 1.5 bar.

I am also guessing that when you say 2.55bar sensor that includes 1 bar of atmos pressure, what i dont understand is the 5v bit is that 5 vaults or something else and why do diesels have higher pressure sensors
 

wild willy

Full Member
Aug 4, 2003
2,323
0
Wales
On the hybrid, tuning should be able to control the boost spike to something reasonable, and should be able to max the turbo out at higher rpm.

On a small port 1.2bar at the limiter is about 225g/s. The head won't flow much more at 1.5bar and will only get up to 245g/s ish. From what I have read, the turbo just isn't capable of shifting that much air. VF34 wont shift more than that either.

It looks like it wil give you a solid 20hp over the standard one. I don't know how much you people expect.

The 20 bhp or so that Sie has is plenty for my expectations over stock, my only concern is that after Mitchy had it custom mapped, he hasn't reached the same performance figs.
I was hoping that uprating the map sensor would be a cheap way (without custom remapping) to allow the ECU to see the spike and thus control it. The only reason why the ecu does't control it at the moment is because it doesn't Know it exists ( ie. requests 2540 and gets 2540). I also don't understand why JBS with CC couldn't remove the spiking with the remapping.
 

ibizacupra

Jack-RIP my little Friend
Jul 25, 2001
31,333
19
glos.uk
i think i get it now basically the MAP sensor wont read higher than 1.5bar due to a cap and the reason for this cap is becuase they are not reliable after this or give off false readings. Vag com only records to 1.5 bar becuase the ECU and MAP sensor only record to 1.5 bar.

I am also guessing that when you say 2.55bar sensor that includes 1 bar of atmos pressure, what i dont understand is the 5v bit is that 5 vaults or something else and why do diesels have higher pressure sensors

3bar MAP sensor.. MAP is Manifold Absolute Pressure sensor, so its including atmospheric pressure yes, whatever the weather conditions prevail (high pressure/low pressure)

various sensors on the engine are 0-5v output devices... whatever their scaling ( MAF's 5v output also)

for the same 5v output the MAP sensors range is 2.55bar on petrol or 3bar on PD150

(and its volts, not vaults-which is where banks keep ya money)
 

bentaw

Revo'd LCR
Oct 1, 2004
1,067
0
Hampshire
ah you had to go and make me feel like a dumb dumb didnt ya its cos the rest of my paragraph was to complicated my brain frazzled out by the time it got to spelling volts.

But why do diesels have a higher sensor
 

Wilko

Badge snob
I also don't understand why JBS with CC couldn't remove the spiking with the remapping.

Mostly remappers arn't to bothered about slight overboost, and don't take the time to get it right, as it's uneconomic.

Most customers wouldn't know the difference anyway. If you look at my boost logs on p32 with the IHI, you can see that boost can be very tightly controlled, even running very close to saturating the map without actually saturating it. Both the map for the IHI and 18G on my car took 8 hours+ of on the road mapping to get right on a car with no vac or boost leaks. They were 95% right in an hour. One would be economic as a business the other wouldn't

Mitchy's custom map looks remarkably like a standard k04 boost profile, with no extra boost requested at the top end. May be e mail was down:D
 
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