pump mods

[Northern RD]

Any idea of just how much you removed with the grindstone? I`m thinkin` I could do it on the lathe but I`m not sure of how far I can go before I run into trouble.
Thanks,
N.

Who? me? I trimmed about 2mm off of the timing piston. The most difficult part with getting an accurate reading was being able to hold the piston in place consistantly.

Yup, you!
Seriously though how did it work out? Any issues with thin metal, finish etc? :?  :?

[Baxter]

HHmmm, got my old 10mm head and rotor left over from when I had my Mechanical TDi pump built, that now has an 11mm head and rotor..
I also have a spare JX pump with lay flat LDA..
I can see a hybrid pump coming up for the freshly rebuilt JX for the van!
I've got a few spare pumps now, surely must have enough to build something!

[vwmike]

Any idea of just how much you removed with the grindstone? I`m thinkin` I could do it on the lathe but I`m not sure of how far I can go before I run into trouble.
Thanks,
N.

Who? me? I trimmed about 2mm off of the timing piston. The most difficult part with getting an accurate reading was being able to hold the piston in place consistantly.

Yup, you!
Seriously though how did it work out? Any issues with thin metal, finish etc? :?  :?

The metal really isn't all that thin. I didn't get a chance to use it yet, but now that I made the clearanced cover I see no reason for it. I now intend to use the pump on my car since I can be sure that it is in good shape. I would like to learn more about rebuilding them, but right now I can't really find the parts anyways.

[Northern RD]

Any idea of just how much you removed with the grindstone? I`m thinkin` I could do it on the lathe but I`m not sure of how far I can go before I run into trouble.
Thanks,
N.

Who? me? I trimmed about 2mm off of the timing piston. The most difficult part with getting an accurate reading was being able to hold the piston in place consistantly.

Yup, you!
Seriously though how did it work out? Any issues with thin metal, finish etc? :?  :?

The metal really isn't all that thin. I didn't get a chance to use it yet, but now that I made the clearanced cover I see no reason for it. I now intend to use the pump on my car since I can be sure that it is in good shape. I would like to learn more about rebuilding them, but right now I can't really find the parts anyways.

Unfortunatly getting any info from Zertex about rebuild stuff fer IP`s is like pulling wisdom teeth. It took me weeks of emailing just to get them to admit that the do sell seal kits to the general public,... :cry:  :cry:

[vwmike]

You can actually buy just seal/gasket sets from VW, but to my knowledge they do not sell any of the internal parts.

[fatmobile]

I pulled the top of my pump off and swapped in the 1/16" washer, in place of the intermediate spring.
 Big difference. I've got a friend that does some autoX racing with VWs (gassers). He gets a chance to drive it before/after I mess with it. He got in and before he got going said he might not notice the difference because he last drove it quite awhile ago ... but he barely got going and his face lit up. He noticed  :shock: .
 Before the mod, it was surging right around where the turbo starts to kick in. Surge drop, surge drop. Just cruising at that speed was kinda weird. It doesn't surge at all now.
 It also had a noticable drop off in power before this stainless 1/16" washer with the 3/16" hole was swapped in place of the spring. It acted like it wanted to take off, then just didn't. Now it pulls well through the range. Until the boost tops out at 10 psi.
 I've got the 2.5" turbo outpipe and exhaust so far. EGT and boost gauges ... and with this washer it's finally starting to feel powerful. It must really fly in a Rabbit, which weighs about 1000 lbs less than this 4 door, '91 Golf.
 Next comes a tach and boost controller followed by some adjustments in the LDA.

[fspGTD]

Excellent fatmobile - thanks for the report.  Disabling the intermediate spring is such a wonderful mod.  And yes I agree it is noticeable and make performance driving quite addictive!

It sounds like your TD autocrosser project is coming along nicely.  I'd imagine you've embarrased more than your fair share of gassers on the track already, if not then sure you will soon. :wink:

[fatmobile]

I've been working on several other projects this summer (turned 4 Rabbits into two diesels that run), almost done with a vegy conversion on a '77 Mercedes that is kicking my ass, made a 2.5" turbo back exhaust for this Golf and honestly, until this last mod didn't really understand what everyone was talking about as far as power goes ... so I've never been to an autoX with it.
 I just bought an '84 GTi from Steve-o (he's got 4 VWs and a Quatro that we work on ... and still had a hard time giving up this one) and have a worn out turbo diesel to rebuild for it. I've been collecting parts all summer, found a starion intercooler that looks like it will fit. It should be a great winter project.
 As far as racing goes, I'm a long ways behind you.
 Last thing Steve-o said after the drive was he was going to have to start looking for a turbo diesel. Before this mod he wasn't impressed ... and he knows there is more power to come.

[TD_vento]

wow that dyno graph looks awsome, around 95hp, is that a td idi 1.9 engine?  What are the capabilities of the aaz engine hp wise??

very informative thread

[fspGTD]

I did the intermediate spring shim mod on my 1.6lNA diesel injection pump before shipping it off to an interested and enthusiastic buyer.  While doing the mod, I noted that the naturally aspirated governor capsule had much more intermediate spring travel than an '84 turbo diesel governor capsule that I had sitting around, and was able to compare side by side.  So, shimming the naturally aspurated motor's intermediate spring would have an even greater performance increase than it does on a turbo diesel!  Owners of 1.6lNAs seeking to improve performance, take note!

[Maarten]

wow that dyno graph looks awsome, around 95hp, is that a td idi 1.9 engine?  What are the capabilities of the aaz engine hp wise??

very informative thread

That was a plot from a 1.6TD as far as I know.

This is the plot of my AAZ on the dyno:

http://morninglight.demon.nl/a3/dyno1.jpg

124.8hp/244nm  :wink:

I've used a intermediate spring from a 1.6NA pump (stiffer) and added 1 washer, after I upgrade my gearbox/clutch I'm going to remove the spring. I'm pulling thru my clutch and trashing my CV joints  :evil:

fspGTD:

That will result in a bit more top end, but that comes with a lot of smoke... :?:

[TD_vento]

wow Marteen, that is very impressive, almost double the hp from stock.

WHat are your modifications, like turbo ect.

I have the head off and will port it, the exhaust ports look very restrictive, also there seems to be a ridge on the exhaust port, if you look at it from top of the valve you know what I mean.  they have machined hte head for the valve as far as they could, where they stopped the bump is right there.

[fspGTD]

Although it doesn't change the peak fueling amount injected per stroke, it may add a bit of smoking at high RPMs that wouldn't have otherwise been present due to the fact that the peak fuel quantity injected per stroke is maintained to a higher RPM.

I remember when autocrossing my GTD with pump setup up for very high fueling before the intermediate spring shim mod, that it would smoke very heavily at low-mid RPMs until the intermediate spring started to kick in, at which point the engine lost torque and the smoking would suddenly disappear!  I would often have bystanders advise me "you need to hold the throttle through this section", as they thought I was lifting whenever the smoking stopped.  Little did they know I was keeping the throttle pegged, but it was the intermediate spring pulling back the fueling whent the RPMs rose up past a certain point!  After the intermediate spring shim mod, the problem was fixed, and I am now able to make it smoke (and deliver torque) virtually whenever I want it to. :twisted:

[Maarten]

wow Marteen, that is very impressive, almost double the hp from stock.

WHat are your modifications, like turbo ect.

I have the head off and will port it, the exhaust ports look very restrictive, also there seems to be a ridge on the exhaust port, if you look at it from top of the valve you know what I mean.  they have machined hte head for the valve as far as they could, where they stopped the bump is right there.

here are pics of most of the mods:

http://vwcaddyforum.com/showthread.php?t=5872

KKK K24 turbo @1.2bar
70mm downpipe/60mm exhaust w/ 1 cherrybomb
Renault Master intercooler, 2.25" plumbing
Mild Governormod : http://morninglight.nl/a3/governor2.jpg
1.6GTD LDA pin

I didn't pull the head (yet ) so I can't say anything about the head, please post pics of your mods in a new topic, maybe we can dump all our succesful mods of the AAZ into one topic?


fspGTD:

I understand that it won't add more fuel but only keeps it longer fueled, if anyone can try it on their 1.6NA?

[Master ACiD]

i want to try it on my 1.6 na!

this sounds like a great mod.