Brake Servo -Throttle Bodies

Hi guys, When i finally get round to fitting the TB's in the garage onto VWJ1M, my question is where will the brake servo take the vaccum to drive it?

as at the moment its driven from the intake manifold.

 

You can either tap it off one of the TB's or tap all 4 and join them up in a collector (a fuel filter works quite well, or an old 35mm film case). Tapping all 4 is a better option, especially if you also need vacuum for a MAP sensor as it'll fluctuate far less.

 

The grey pipework is the vacuum on these GSXR tb's.

 

do you have any big pictures? what do you mean 35mm film case?

 

No bigger pics at the mo, i'll dig out the digi cam in the morning. Film case - the little plastic cylinder you get 35mm camera films in. A bit of a retro bodge

 

ahhh, i see thanks.

Well im guessing the "tank" is used to store air, so that fast fluctuatations{SP} do not go straight through to the Sensors.

Are these going on yours?

 

Basically, yeah. It's a bit like adding a capacitor to smooth electrical current.

The TB's will be going on mine eventually, there's a few things to do first. I've got pretty much everything i need now, just need to start putting it all together. The plan is to first get the engine up and running on Megasquirt with the standard manifold/single TB. Once i'm happy with that i'll move on to the ITBs. Should be a laugh...
Edited by: martyn_16v

 

Depending on the type of manifold you're using.. there may well be a vacuum take off point on cyl#4. Repeated pumping of the brake pedal will pulse air to/from that cylinder but not enough to effect much..
Or.. tap each runner and add a fitting to each of them, gang them together, into a larger pipe (store of sorts.. smooth pulsations) and then onto the the servo.

My Jetta only ran on #4cyl

 

Likewise.

Chris

 

And me

Rob

 

whats the benifit of either option, and the performace of engine or brakes?

 

I think Bill explained a bit above.

Do #4 only, and you'll be alright.

Chris

 

only ran on number four cylinder?


maybe that's why they were so quick - less reciprocating mass....

 

At this point we'll have to withhold any further secrets....

 

Anyone got the number of the monopolies commission????

 

See if we can find it this weekend...

 

Thanks guys for the info.

will just use No 4 Cylinder.

 

I need to order a pipe fitting for the servo hose to my Jenveys, what do people normally use?

I had a good look through all the usual threads but can't find any info on sizes?

 

From my build thread:

I can dig out the details. PM me later this eve and I'll dig my build files out straight away for you

 

A normal 10mm barbed 1/8th NPT fitting will do the trick, and a bit of 8mm hose.

Something like this Link

You may need to take tee off for your FPR as well.