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best boost pin and spring for power without smoke
by
Alleslowbuged
on 17 Feb, 2008 07:19
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Hello,
i know christmas is past, but here is my gift for all, who knows why a good diesel make three black strips on the street when accelerate hard.
I think everybody knows about the poor spring under the boos pin in a stock fuel pump. Because of the low spring rate is make all the possible way at approx 8 psi, and this is much to early for a good power and a agreeable smoke level. Also the most boost pin are not very nice designed for what we wand to do with them.
But here is the solution, best of all the parts a original bosch parts, so nice quality and plug and play. The boost pin has a bigger pitch and is exentric, so nice for a good fine tune. The spring has a bigger rate, so 100% way is at approx 16psi.
Spring: 1 464 617 710 - 000 (circa 5€)
Pin: 1 463 123 470 - 000 (circa 40€)
I allways increase the possible working way of the pin in both direction.
That means, that i cut the upper end of the pin, above the diaphrame (nut) and make place in the cap, so that the pin came to a higher position at no load. Than i installe the pin with approx 2-3mm pre load and drive a while for getting the sample line. Then i reinstall the pin and measure the rest way between the sample line end and the pitch end. Than i smaller the distance ring, so that i jused all the possible way. It possible to get say 95% of possible power without smoke so and getting 100% power with only smal amount of smoke.
By getting the no load position of the pin higher, you have to increase fuel amount on a other point (basic set screw or rotating of the pin..)
some stock and "wild style" pins
[http://www.golf1.info/forum/attachment.php?attachmentid=16622]
the good parts as mention above
[http://www.golf1.info/forum/attachment.php?attachmentid=16574]
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#1
by
jimfoo
on 17 Feb, 2008 07:27
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Ok good people of the list, where can we order Bosch parts such as these over here? Having an AAZ pump, I have no starwheel to adjust my pump with, so a stronger spring would be very good.
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#2
by
Alleslowbuged
on 17 Feb, 2008 07:33
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Hello,
do you not have any bosch dealer in the usa?
Here we have a bosch dealer in every bigger town, and they sell these parts. I can give them the number and then they order the parts. If there is a request and a problem for getting the parts in the usa, i think a can can ship a few sets.
Best regards
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#3
by
jimfoo
on 17 Feb, 2008 07:41
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None around where I live. Maybe if I went to a Diesel shop, they might be able to get them for me. Doing a search on the Bosch USA site just shows me where to get Bosch spark plugs. :evil:
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#4
by
jimfoo
on 18 Feb, 2008 10:39
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Well, I'm going to a diesel shop to see if a Cummins spring is stiffer, and to get a real boost pin instead of the stupid 1.9 one I have. I called a lot of shops, and none seemed to be able to order Bosch IP parts. :roll: Guess if it isn't bolt on performance, no one knows anything about it. Sad!
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#5
by
jimfoo
on 19 Feb, 2008 07:34
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The Cummins spring is way stiffer than the AAZ spring, but looking at pictures, it looks like the spring that is used with a starwheel as it is shorter. It seems like it should work fine though. The cummins boost pin looks like it gets thinner than the pic of a 1.6 pin.
When I compared the two springs, it took 8lbs for the AAZ spring 17lbs for the Cummins spring to compress them to a height of .9", and 11 lbs for the AAZ and 40 lbs for the Cummins spring to compress them to .55". So I'm thinking the Cummins spring will work much better with actually having a cone on the pin as the AAZ spring would probably let it just go straight to full fuel.
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#6
by
KTZed
on 19 Feb, 2008 08:30
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Props for testing those springs jimfoo. This is what I plan on doing when I take my 1.6 pump apart. I have a request however.
From what you have measured, you can find the spring constant of each spring. If you measure the diaphragm diameter, you can then figure out at what boost pressure the pin will start to move, and at what pressure it will bottom out. That would be nice to know.
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#7
by
jimfoo
on 19 Feb, 2008 09:12
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Ok, from my not super accurate calcs as I'm using a 40 year old bathroom scale....
The pressure required to START moving the pin is
AAZ 2.4 PSI
Cummins 4.0 PSI
The pressure required to bottom out the pin is
AAZ 3.0 PSI
Cummins 11.9 PSI
So what I think would be best is an even stiffer spring, though maybe a tiny bit shorter if you are pushing over 12 PSI. But it shows that you really need to change springs out when replacing or modifying an AAZ pin!!!
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#8
by
KTZed
on 19 Feb, 2008 09:25
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2.4 - 3 psi :shock:
Wow thats terrible. I need to test the 1.6 one now to see how it compares
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#9
by
jimfoo
on 19 Feb, 2008 09:27
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Well don't forget the AAZ pin has NO slope to it, just flat with one small step.
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#10
by
jimfoo
on 19 Feb, 2008 10:51
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One other thing I found is that the Cummins spring should be opened up slightly at the bottom so that it fits over the steel sleeve at the bottom of the LDA, otherwise it might start rubbing off metal as it rides on the lip of it. I didn't take this extra compression into account in the above figures.
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#11
by
Tomallus
on 19 Feb, 2008 10:59
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Hello,
some stock and "wild style" pins
[http://www.golf1.info/forum/attachment.php?attachmentid=16622]
the good parts as mention above
[http://www.golf1.info/forum/attachment.php?attachmentid=16574]
Can you paste text or pics from these links? We can't see anything without registering.
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#12
by
Alleslowbuged
on 19 Feb, 2008 11:40
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Hello,
here is my original 1.6 boost pin (germany version with 69hp)
here is the mention pin and spring (sorry for the bad quality)
and here are the "wild style pins"
sorry i can't find the the picture on my Pc for the moment, but i look for it and add if find it