I know alot of the auto guys have problems with not enough vaccum to power the brakes. Well I was going through my parts stash and found a vaccum pump from a mkiv jetta. The vaccum port looks the save size as the 4g63 booster port, so it should be easy to T it into the brake booster line.

pins 1 and 2 need ground, and pin 5 gets +12v
different plugs might have different pinouts, so test it first



I blocked off the vacuum port and T'd my boost gauge into it



Boost gauge reads a couple in-hg too high



It holds it at 22-23in-hg



This is how I would set it up.




BTW if anyone wants the pump- pm me

Does the pump have a part number on it and is it off of a tdi?

No. The tdi vacuum pump runs off the cam. This was off a 1.8t. My A6 with a 3.0 non-turbo also has one except the plug is different. Both are 2002, but I'm sure other years had them. This one is gone, but ill get the part# off the A6 one.

I think all gas jetta/golfs have them. The 1.8T definatly has them. I believe they are used to get the cylinder temperatures up during a cold start to help reduce emissions.

You're thinking about the secondary air pump. It the one that sounds like a vacuum cleaner. Secondary air injection - Wikipedia, the free encyclopedia

This is a vacuum pump to help the vacuum system. It's located between the subframe and body under the driver on the mkiv's.

You're right, that is what I was thinking about.

Have a part number for future reference?

This is a good idea. How long does it take to full vacume? I am having problems with breaking in trafic with my set up. The booster dose not allways get enough vac in stop and go traffic. Or if I have to hit the breaks right after boosting.

With just the gauge it's almost immediate. I'll hook it up to the brake booster and see.

part number ????

8e0 927 317

So you are only using this for launching? Have it wired up to a switch? Does it constantly run? Turn off at set vac level?

In theory you could leave it running constantly. you would have very touchy brakes, I guess.
I think the primary use is for launching. While youre building boost the brake booster obviously has no vacuum so its hard to put force to the brakes. Activating this before you launch would make it much easier to apply fully brake pressure without having to cram on the brake pedal so hard. It could run all the time, but i see no reason to do so.

How about wiring up to the brake pedal switch? Hit the brakes, vac pump turns on.

02 VW Passat 1 8T Brake Vaccum Pump w Hose 8E0 927 317 | eBay

Looks different

I've never used it. i have a manual. I would wire it with the brake switch through a relay. On the vw/audi's they're activated by the ecu when the map sensor reads low vacuum. There's going to be slight differences between then.

It's a vane pump if anyone is curious about the internals. Vane Pumps

I've been running this same pump on my auto for a few months now, it works perfectly. I had to put a second one way check-valve in the line to the vacuum pump, I used one of those .45 cent units from US plastics. I mounted the pump using a big hose clamp and clamped it to the rear roll stop mount under the intake manifold. I cut a piece of stock 1G rubber intercooler hose to "cusion" the body of the pump and the motor mount, it's on there pretty solid and isn't going anywhere.

The harness for the brake light switch, up above the brake pedal, has an extra "pigtail" with a spade connector that provides 12v when the brakes are pressed. I was able to plug a spade connector into that, and then use it to energize a relay that sends power to the vacuum pump. I ran the relay ground wire through a switch I mounted on a panel beneath the stereo. I used the same wire on brake light switch to energize a relay that grounds the base timing terminal. Let me tell you, using the vacuum pump and timing retard, makes the car a breeze to stage at the track. I was always having issues pulling through the brakes every now and then, but now, it holds rock solid.

Vid of it in action:
https://vimeo.com/77255666



These two mods as well as an ignition box that provides a spark cut 2-step, are a must have for anyone wanting to launch an auto consistently.

-red97rum- said:

I've been running this same pump on my auto for a few months now, it works perfectly. I had to put a second one way check-valve in the line to the vacuum pump, I used one of those .45 cent units from US plastics. I mounted the pump using a big hose clamp and clamped it to the rear roll stop mount under the intake manifold. I cut a piece of stock 1G rubber intercooler hose to "cusion" the body of the pump and the motor mount, it's on there pretty solid and isn't going anywhere.

The harness for the brake light switch, up above the brake pedal, has an extra "pigtail" with a spade connector that provides 12v when the brakes are pressed. I was able to plug a spade connector into that, and then use it to energize a relay that sends power to the vacuum pump. I ran the relay ground wire through a switch I mounted on a panel beneath the stereo. I used the same wire on brake light switch to energize a relay that grounds the base timing terminal. Let me tell you, using the vacuum pump and timing retard, makes the car a breeze to stage at the track. I was always having issues pulling through the brakes every now and then, but now, it holds rock solid.

Vid of it in action:
https://vimeo.com/77255666

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These two mods as well as an ignition box that provides a spark cut 2-step, are a must have for anyone wanting to launch an auto consistently.

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This seems very interesting. I just started looking into the vacuum pump and now you have me thinking even more. Any more information on the timing retard/vacuum setup you have? You can PM me or post it here. Is there a thread talking about them?

I use ECMLink for the two step and antilag. The two step alone builds boost but does try to pull thru brakes, antilags builds more and doesnt pull thru brakes as bad.

Boomdeeze said:

This seems very interesting. I just started looking into the vacuum pump and now you have me thinking even more. Any more information on the timing retard/vacuum setup you have? You can PM me or post it here. Is there a thread talking about them?

Click to expand...

Sure I'll PM you some more info about my setup.

TalonSpeed said:

I use ECMLink for the two step and antilag. The two step alone builds boost but does try to pull thru brakes, antilags builds more and doesnt pull thru brakes as bad.

Click to expand...

I've seen quite a few people have issues with the fuel cut type 2-step on the autos. From my experience, the RPMS drop too much in between each cut cycle, which sometimes leads to a bogged launch, or since the stock ecu controlled 2 Step uses the VSS, every now and then it would cut the RPM right as I launch, when the converter flashes and before the ECU sees the VSS signal. I was able to make it work for a couple years, but it always bugged me because every now and then I would have an effed up launch because of it. With the spark cut though, it's smooth and holds whatever rpm steady, in my case, I'm launching at 3800 rpm.

I can see the anti-lag providing pretty much the same thing as the timing retard off the base timing pin that I'm using. Effectively limiting torque, making it a bit easier to hold the car back on the brakes. May also aid with building boost, although it's probably minimal with an auto in my experience. I'd like to give it a try, but since I run the Werewolf Speed Density tuning software, I don't have an anti-lag option.

Here's a vid of my car a couple years ago doing what I was talking about, this one wasn't too bad though, it usually fell on it's face a lot harder than that.

[ame]http://www.youtube.com/watch?v=foB7vKdfPL4[/ame]

Compare that 2-step with the spark cut from this vid:
https://vimeo.com/77255666

Sorry, they are both pretty crappy quality.

Are you retarding the timing as soon as you put the brake on? I understand why this would be helpful holding the car once it's on its two step, but does it make it more difficult to get up to your two step with that timing retarded the whole way? I have heard two schools of thought on this as far as timing on stall goes. One says advance as much as possible, while the other says retard to increase EGT's. I am having an issue where I can't stop building boost where I would want it to stop (about 15lbs) when on a 100 shot. It continues climb up even with the ign. two step active. Ignition cut holds rpm, but doesn't stop the boost ramp. I wonder if this base timing trick would help that issue.

mondale said:

Are you retarding the timing as soon as you put the brake on? I understand why this would be helpful holding the car once it's on its two step, but does it make it more difficult to get up to your two step with that timing retarded the whole way? I have heard two schools of thought on this as far as timing on stall goes. One says advance as much as possible, while the other says retard to increase EGT's. I am having an issue where I can't stop building boost where I would want it to stop (about 15lbs) when on a 100 shot. It continues climb up even with the ign. two step active. Ignition cut holds rpm, but doesn't stop the boost ramp. I wonder if this base timing trick would help that issue.

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Well since I'm hitting it with a 75 shot, it's not difficult to get up to the two step, but I can see the logic in your question if you weren't using spray to stall up on the line. I have my base time set at 2* instead of 5* too. I have my two step set to 3800 (3600 on street tires) on the S366 and it builds right around 15psi. Each time the spark is cut, it bounces between 17-18ish and 15psi, seems to hold pretty steady. I'll have to check through a log and see what the map sensor reads, but I don't remember seeing it ramp up until I let off the brakes. Hell, it's worth a try, it only takes a couple minutes to set it up for a test.

I've tried stalling up with the timing pin grounded and without it grounded. I'm able to hold the car back with just the foot brake (still use the e-brake just in case) if the timing is retarded. But without the timing retarded I'm barely able to hold the car back both standing on the foot brake and yanking the e-brake. Car ran a 6.80 @ 108.9mph 1/8th mile on street tires in the vimeo video.

I am on a E16g, launching with 15psi feels pretty week. Launching at 30psi is ripping out the whole with too much wheel spin (read crappy tires).

Are you guys spraying wet or dry? Before turbo or after turbo? Just for launch or down the track?

Dont reverse the polarity or you will fry the pump. Then it will short out even if the polarity is reversed back to the correct way.

I am mounting mine under the engine bay fuse box and wiring it up to the passenger side found light harness. I will also wire the fog light fuse to the radio relay for power when the key is on. Pump will only work when fog button is pressed.

My car doesnt have fogs or radio.

two check valves are needed or the engine will suck vacuum thru the pumps little outlet hole. The other valve has to go between the T and the pump, only allowing air to flow into the pump and out the small outlet hole.