shardul

iTrader: (1)

http://wenku.baidu.com/view/d810de04...3d5bb75ab.html

some stuff in chinese will appear but them the page will load

NRL

Awesome

shardul

iTrader: (1)

i just spent the last 2 hours reading the whole document. Very informative.

Boost is bleed starting at 158F IAT
IC Pump turns on at 116F IAT
IC Pump turns off at 95F IAT

Welwynnick

It takes a long time to download, but its an absolute gold-mine. How to bleed the I/C system for example. Has anyone figured out how to save or print it?

Great find, Nick

Edit: Also available here, in two parts:

http://www.docin.com/p-169235979.html

shardul

iTrader: (1)

No didn't figure out how to do that.

WHTEVO

Read the whole thing too. Thanks!

Aaron

Welwynnick

This bit is particularly interesting, and I've been wondering about it for a long time, trying to understand my car's schizophrenic behaviour. Now that I can finally put my foot down in my V12TT, I find that sometimes its ballistic and sometimes its merely quick.

The IC pump behaviour may explain it - it seems to operate in a closed-loop type of thermostatic control over the intake air temp. I suspect that for much of the time, the pump is off. When I've been dawdling around with no boost, then floor it, it doesn't really take off (even if the tranny does down-shift). Do that a few times though, and power comes back.

My impression is that the pump tends to stay off, and the whole intake system gets pretty hot, including the IC's, the HE, the pipes and all the water. When the pump does come on, it takes time for the water to circulate round the whole system and cool everything down - before it can start cooling the air down. When I say it takes time, I mean a few seconds rather than a few minutes, but that's still an overtaking opportunity lost.

And then, when the IAT is brought down below the lower threshold, the pump is switched off again! Therefore what happens if we all rush to our favourite tuner for a new and improved heat exchanger? As soon as the pump is switched on, the IAT comes cracking down, but the system then turns the pump off, and defeats the point of the upgrade.

This may be why a pump upgrade is worthwhile. The Meziere 136 and the Johnson CM30 may not be able to keep the IAT below 95F any better than the stock pump, but if they can circulate the water faster, and get to START cooling the intake air faster, then there may be a clear perception of improved performance.

Just a thought,

Nick

shardul

iTrader: (1)

I had a extra Bosch pump laying around that I installed it in series with the factory bosch pump. Just by seeing the flow when bleeding the system I can tell it has increased about 2x. Now I just need to direct wire the pump to the ignition.

Welwynnick

I think both those measures would have a significant effect on real-world performance. The pump really ought to be running slowly all the time - if only to stop the water in the pipes from boiling. Imagine what that does to the IAT when the pump switches on.

Maybe the pump is too greedy or too unreliable to be run all the time, but if a clever tuner could work out how to program a better algorithm than "all-on/all-off" I think there'd be a lot to gain.

My view is that the pump should at least run whenever there's positive boost; or at a variable speed, maybe proportional to the manifold air pressure or air temp.

Nick

mkhurley

Wouldn't even need a tuner to do it, assuming the pump is turned on/off with the voltage side, simply cut the positive feed to the pump and wire a relay to a switched power source on the normally open side and when the system decides to turn the pump on have it activate the relay and provide power to the pump via the closed side of the relay.

No codes thrown because the system is still doing what it thinks is right and when the system isn't powering the pump, it's working off a switched power source.

If the pump is activated via the ground, then it's just swapping some wires around for that configuration.

iyad.2010

awesome

Oxygen

I've been trying to figure out how to save or print this for a while...

greekviking

The pump is turned on and off via input from the IAT sensor. If it goes over a certain temp it turns on.

Welwynnick

I have a word document of the training slides - drop me a line if you want a copy (regular contributors only).

Alternatively have a look here for a similar downloadable PDF document on the Maybach engine:

http://www.mercedestechstore.com/pdf...2008-06-03.pdf

Anyone fancy their chances decyphering this?

biker349

thanks.

Blackbird76

How can I check that my pump is actually coming on when it supposed to or would there just be a serious lack of power if it wasn't working at all?

ZephTheChef

Go for a spirited drive and then pop your hood and feel of the intercoolers. If they are warm then everything is working properly, if they are HOT then you could have a problem. That's probably the simplest check. You could also try taking one of the caps off and depressing the intercooler bleeder valve after it's good and warmed up/heatsoaked under the hood. If it sprays coolant out then your pump is probably working.

erxberx

PDF Version: http://fotifixes.com/M275-initial-training.pdf