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Citroen Al4 Gb


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#31
leeinred

Posted 20 October 2010 - 01:05 PM

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QUOTE (chedebt @ Oct 19 2010, 08:36 PM) <{POST_SNAPBACK}>
If you zoom in the pic it actually says Made In E.U./Fabrique en U.E.


The words in picture clearly said: "Made In U.E." but if want to read from another direction can read as E.U. smile.gif Anyway next time we can have product that "Made in Asia" as well smile.gif

#32
bm_dp

Posted 20 October 2010 - 02:06 PM

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Interesting info shared here. However, i also want to share mine too. AL4 GB.I have put oil/aft cooler and with a fan in front of the car. I also have temperature gauges positioned to measure temp of atf coming out and going back into the GB. My findings are:
1) Taking temperature is also a consideration. Th reading you get depends on where you are reading them. So, dropped from 85C to 45C? I dun believe that achievable... not unless we have outside temperatures 15C perhaps?
2) Worst, temp reading is in traffic jam on a hot day, say 42C. It can go up as high as 85C. In fact, anything about 65C the GB starts to get jerky in changing gears or worst case momentarily refuse to change andthe a big "thug" and jerk forward.....
3) At standstill, with the fan ON, in a hot traffic jam condition, temperature diff between in and out, at best 4C only. So if its at 80C, 76/75/74C going back into GB isn't gonna help.. so cooler or no cooler, GB is stuffed... but this is the worst scenario.. the current heat management design is just pure rubbish in our climate!

I owned a Fiat Ulysse, as you knwo, its redressed Evasion/806. has AL4 and EW10J4 init. Been trying to figure out a solution for this w/o breaking my bank account and still searching. But from the looks of it, all this passive approach just ain't gonna cut it. Good luck with the search for a solution, although, I haev some leads, just dun haev time to go and research and test them yet...Just my 2 cents. I would liek tohear from others who have done their research also just to compare notes sake. All are welcome.


#33
ojtee

Posted 20 October 2010 - 04:39 PM

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bm_dp,

your feedbacks on the AL4 GB on the pug forums is really an eye opener, i was following your postings some time back, good to see you are here join the debate !

my findings so far
1. the GB suffer from performance due to excess heat, which temp is it suppose to perform at its optimum? possbily below 70 C
2. excessive heat comes from the engine no doubt, but due to close proximity and enclosed compartment heat will travel to a cooler environment, i.e. GB
3. current design is good for outside temp of 20 C and below coz by the time hot oil travels to and fro the oil cooler, it should be in optimum temp when it returns to the GB.-humidity plays an important factor here and affects rate of heat transfer.
4. different country have their different service interval addressed - i think australia has a much shorter service interval, read this on the aussie french car forums.
5. how large an oil cooler can you instal wihout compromising other factors of the GB design? plus the fact if you are in a stop n go traffic daily, it isn't gonna help much.
6. if you look at the current designs of most PSA/Renault cars, you'll find some space constraints and compactness of the engine bay, imagine that temp in middle of the afternoon, stop n go traffic, if your fans are blowing at full speed, it will burn the fan relay in no time! ( speaking from experience)

my conclusion and if i do get my renault/pug/cit with an AL4 GB variant, i would do the following
1. larger and possibly use a current one that is on a current model . i.e. C5 GB oil cooler
2. aux fan as close to the GB valvebody as possible
3. custom made cooling fins, as large and deep as possible attached to the GB undercarriagebody, this helps dissipates heat at a faster rate.
4. lower the fan cut in operating temp to about 80 C and high speed fan to 85 C - use a lower rating radiator temp sensor
5. convert single fan to twin fans system - 1 fan on when a/c on, 2 fans on when temp at 80 C, 2 fans full speed at 85 C

hopefully that will be able to extend the life of the GB oil to 30k or more

keep the comments coming in, we might be able to get a better solution then!






#34
bm_dp

Posted 21 October 2010 - 01:37 AM

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Ojtee,
Thanks for the recognition... been in the AL4 talk ever since I bought my MPV and with the GB flashing lights... self help is the only option IMHO. Not really to debate who is better, but to share and inform others just so that they are aware and not easily sweet talked by the mechanics into overhauling GB or changing them unnecessarily than they have to.

Noted your theory about the heat transfer but thats already designed for anyway. The cooling system suppose to handle that... and we now knwo the diff between theory and reality..... no more debate about this.. its fact now.

1) I tried large cooler (somehting like doubling the current one), no signifiacnt improvement. In fact, there is symtoms to suggest that there are significant pressure drop as result of that and it causes it bit jerkiness when changing gears.
2) IMHO, it won't make any diff at all
3) The theory is there, but wether you can enough heat off soon enough is teh challenge. plus there is not much room to instal coolers and fans.
4) Fan will be running on perpetually, eventually, relay and fuses blown. maybe fan also...

I think we need to recognise, from a thermo dynamics engineering perpective, that air is not a good heat conductor. If I recall correctly, the heat transfer co-efficient for air comes to about > 5deg C.

The idea of the bodyvalve area - its actually the atf sump area also. Don't forget also that when torque converter operates , it generates lots of heat due to high pressure. laws of physics. so the solution must be to keep the atf temp regulated within a temp range and keep it there in all conditions... thats the real challenge by the way... still working on it... when i finally get it right, i will sell it...ain't no free lunch for sure...

#35
ojtee

Posted 21 October 2010 - 09:27 AM

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Totally agree about the misguidance of some mechanics and yes it's good to get ideas,experiences and thoughts and possibly some methods that were used by other AL4 users.

I remember some time back coming across some kind of heatsink/cooling fin design that is installed on a surface to double or triple the surface area, this would eventually increase the rate of transfer of heat. Can't recall if it was on a car or a superbike. Maybe this could be a lead to a more efficient cooling factor for the GB, IMHO.

As for a putting in a larger GB cooler, shouldn't it come with a pressure/temp valve of some sort, if volume increases, pressure will decrease, temp increase, pressure will increase, so it's only viable if the larger cooler has some sort of switch, either pressure or temp only releases the flow of the GB oil when pressure/temp increase, thus maintaining a balance ( PV/T)



#36
bm_dp

Posted 22 October 2010 - 01:09 AM

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The formula is correct. Its how you apply it. I am afraid its that simple. pressure in a colse system will remain the same, in this case the cooler has a pressure drop across it. However, being more restrictive to flow, the cooler, it also cause pressure build from the GB side coming out from Gb into the cooler. Thats why the slightly more jerky symtom experience. well, once you experiment with it, you know. The real world is really really somethin else. You'll need to look into the minor details and also as w hole to actually get a good picture of the data you are seeing. Ok, best to keep this here for now. Let others have a chance to share their experience.

#37
leeinred

Posted 18 November 2010 - 03:09 PM

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QUOTE (bm_dp @ Oct 22 2010, 01:09 AM) <{POST_SNAPBACK}>
The formula is correct. Its how you apply it. I am afraid its that simple. pressure in a colse system will remain the same, in this case the cooler has a pressure drop across it. However, being more restrictive to flow, the cooler, it also cause pressure build from the GB side coming out from Gb into the cooler. Thats why the slightly more jerky symtom experience. well, once you experiment with it, you know. The real world is really really somethin else. You'll need to look into the minor details and also as w hole to actually get a good picture of the data you are seeing. Ok, best to keep this here for now. Let others have a chance to share their experience.


Noted many happy continental cars' customers and smiling faces at the workshop since my last posting smile.gif Congratulation to those who choose to follow my advice smile.gif It really save you tons of money down the road after the installations and treatments smile.gif Test drive the cars and you will immediately know the different !!



#38
chedebt

Posted 25 November 2010 - 02:57 PM

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QUOTE (leeinred @ Oct 20 2010, 01:05 PM) <{POST_SNAPBACK}>
The words in picture clearly said: "Made In U.E." but if want to read from another direction can read as E.U. smile.gif Anyway next time we can have product that "Made in Asia" as well smile.gif


I may sound like I'm nitpicking but the label in your pic says Made in E.U. (English) / Fabrique en U.E. (French). smile_clown.gif

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