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Discussion Starter #1
I am owner of Alfa 147 JTD 8v (115BHP, 275Nm, 2001) with following configuration:
1) Removed pre-cat and main cat,
2) New back-box,
3) New intercooler pipes,
4) Blocked EGR valve,
5) BMC-CDA 80-150 air intake
6) First remap
7) Second remap (with max. turbo pressure of 1.37bar),
8) Actual remap (with 1.55bar max. turbo pressure)...
In diagnostic procedure by use of Alfa diagnostic software (on the road, with 4000rpm in 3rd and 4th gear) I measure maximum of 2.40bar of pressure (sum of atmospheric pressure (1.0bar) and turbine (1.4bar), I believe...
Is it measured (1.4bar) turbine pressure quite enough according to actual remap max. turbo pressure of 1.55bar?
Three months ago I have one car accident and vacuum actuator which moves turbo vans was little deteriorated... Make my turbine adequate pressure in these circumstances?
Best regards from Dusan.
 

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Discussion Starter #3 (Edited)
Some AO members with tuning experience told that turbo pressure may rise to 1.7bar with 147 JTD 8v original turbocharger (Garrett GT1749V) before than the solenoid valve cut the pressure to about 1.5bar, I suppose.
Best regards. Dusan.
 

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Discussion Starter #4
Mentioned vacuum actuator (which moves turbo vanes in GT1749V variable geometry turbocharger) was knocked and flattened in down side. I think this is reason for insufficient pressure especially for low RPM. What is your opinion?
Thanks for help. Dusan
 

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worth a try to replace it, might not function fine...

btw, do you have any idea what turbo is used for the 136 bhp 2.4 JTD? And what boost can be had from these?
 

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Discussion Starter #7 (Edited)
In a 2.4JTD is used a Garrett GT2256V turbocharger, but I don't know pressure parameters...
In a few days I will be go in service station for turbocharger diagnostic. Maybe my turbine need reparation and cleaning...
About the MAP sensor: where is the location of MAP in 147JTD 8v engine bay? Is the original MAP sensor in 147 1.9 JTD 8v a limitation factor for tuning?
Thanks in advance for answers... Dusan
 

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the 2256 is a big turbo for a 1.9, it doesn't really boost till 1800-200rpm and max boost is around 2500rpm on the 2.4.

I assume your ecu has overboost? - this alows extra boost for a second or two before limiting, stock, the overboost is within the map sensor parameters, when tuned overbppst will be over and above what the map sensor can measure, before bringing it down to something it can measure, ie. up to 1.55bar with standard map sensor.

it should be located on the inlet manifold, connected via a 3-pin plug. The 2 bar map has a 4-pin plug as commonly found on vauxhalls, should you wish to change it?
 

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Discussion Starter #9
According to information from my friend who remaped my Alfa a 147JTD 1.9 8v ECU has no overboost capability, but I am not sure if it is correct. Maybe someone from this Forum knows details about overboost existence in my 1.9 JTD 8v ECU (Bosch EDC15C7)...
Any help is welcome. Thanks from Dusan.
 

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According to information from my friend who remaped my Alfa a 147JTD 1.9 8v ECU has no overboost capability, but I am not sure if it is correct. Maybe someone from this Forum knows details about overboost existence in my 1.9 JTD 8v ECU (Bosch EDC15C7)...
Any help is welcome. Thanks from Dusan.
I've had a custom remap on my 147 1.9JTD 8v and the tuner told me that there is an extra parameter in the software that needs to be altered to get above the 2.4 bar absolute pressure.
(Just altering the values in the tables is not enough)
With this mod you can have 2.5 bar continue and overboost of 2.7 bar absolute.

But, with more upgrades as in my case the boost cannot be controlled anymore when it's higher than 2.4 absolute. This is because the turbine is too small, and exhaust flow is too high even with the VG vanes on max. opening angle. When you are too long outside the range of the standard MAP sensor (2.5 abs), the ECU will fall in error and cuts off power.

Of course, you can fit a MAP sensor with broader range but fact remains the standard turbine is the bottleneck in this.
 

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Discussion Starter #12
Thank you JS JTD for the useful advice. Would you explain, with more specific details, where is mentioned overboost parameter in the custom map?
Best regards from Dusan.
 

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Thank you JS JTD for the useful advice. Would you explain, with more specific details, where is mentioned overboost parameter in the custom map?
Best regards from Dusan.
Well, I'm not into software so I don't know.
And to be honest I don't think the tuner (Squadra tuning) will make it public.
But, surely there are people on this forum that know the details.
 

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you could simply fit a map sensor from a 16v, it won't solve the turbo bottle neck, but you will have a wider boost range which is totally controlled rather than fudging the mil lamp.
 

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Discussion Starter #15 (Edited)

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can't comment on a 1.9 8v, neber tried it, but I have on the 2.4 10v with no probs at all.

For the sake of 40quid, its worth a shot...
 

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The ECU can be remapped for the 3BAR sensor...and it should be!!!
 

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Dusan: I've read in another topic that you have tried the 3 bar map sensor.

Did you got a fault on the display when you turned the key?

Because according to Squadra tuning, there is another pressure sensor in the system and the values of this and the MAP sensor are compared when making contact. So different values can cause a fault before even starting the engine.
 

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Discussion Starter #19 (Edited)
I didn't have any error with 3.0bar sensor and you might to try it. In one of the previous post:

http://www.alfaowner.com/Forum/tuni...e-diameter-jtd-what-size-should-i-pick-3.html

I explained incompatibility problems because of the difference of the voltage characteristic between 2.5bar (standard for 1.9 8v) and 3.0bar (standard for 1.9 16v) MAPs. Custom remap, as sad kgb, could solve any problems.
Hardware incompatibility didn't problem (different number of pins and fixation position) and I gave drawing about these hardware issues.
Best regards from Dusan.
 

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I didn't have any error with 3.0bar sensor and you might to try it. In one of the previous post:

http://www.alfaowner.com/Forum/tuni...e-diameter-jtd-what-size-should-i-pick-3.html

I explained incompatibility problems because of the difference of the voltage characteristic between 2.5bar (standard for 1.9 8v) and 3.0bar (standard for 1.9 16v) MAPs. Custom remap, as sad kgb, could solve any problems.
Hardware incompatibility didn't problem (different number of pins and fixation position) and I gave drawing about these hardware issues.
Best regards from Dusan.
Thanks. I know putting the 3 bar sensor will immediately raise boost because of the voltage differences.
I will mount the sensor as well as some other differences (bmc airbox) and get a new custom remap.
 
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