Mechanical boost gauge help

[andis3]

Hi Guys,

After recently purchasing my Mk1 golf with a G40 motor install,i'm looking for a bit of advice regarding the mechanical boost gauge that is fitted...As it doesn't appear to be working.

From what i can see,at the back of the gauge there are two electrical wires connected...I'm guessing live and Earth for the illumination?And a plastic vacuum pipe,following the pipe into the engine bay this connects to rubber hose coming off the bottom of the inlet manifold,directly underneath the throttle body.Does this sound right?As i thought it would be taken off a boost pipe somewhere (only guessing)?

Can anyone advise if this is correct as it is,or do i need to alter it?

Any help/advise much appreciated.

Thanks Andy

[GR40]

Most people connect them to a preexisting vacuum line like the one going to your pressure regulator using a T piece. That being said all the lines on the g40 engine take their feed from a line under the inlet. So it is probably connected correctly. Unless the gauge has gone bad or there is a leak somewhere it should be reading correctly from that feed. What are the symptoms that make you think the gauge is not reading correctly?

[andis3]

Thanks for your reply.

The gauge doesn't move at all and being as I've not had the car long,i was curious to see what boost the charger is producing.I would take a photo of the place where the feed is taken but it is quite well hidden.

Think i will see if i have a split vacuum pipe first and report back.

Can you advise anywhere to take the car to make sure all is well,i suppose a bit of a health check somewhere in the east midlands?

Cheers Andy

[Jezza-7]

That hose under the inlet manifold is the one that connects to the ISV, and has a pipe coming off for charcoal canister (probably removed), i have personally never heard of people using that one.

The best place to take it from is the fuel pressure regulator vac pipe. Also check to make sure its not split as it goes into the gauge. I've had one of my gauge feed lines split there where it was taken on and off a few times.

If you can, try get some pressure in the line to make sure that the gauge is working. Try using a pump or try blowing down the feed if your lungs are strong enough.

If you could get a pic that would be good though.

[andis3]

Hi Jezza,

Thanks for the info'.I've been trying a few things this morning...

- I removed the pipe and attached a pump as you suggested and the gauge worked as it should.
- Could you tell me where the fuel pressure regulator vacuum pipe is located please?

Cheers
Andy

[Jezza-7]

Ok, this is where it is:

Regulator on the left, silicone pipe with t-piece, goes to big vac pipe coming off manifold (has 2 small ones coming off it, 1 for ecu, other for this vac pip)



t-piece it like this

[andis3]

Thats brilliant...Really helpful thanks mate.

In my mind,i was thinking it had to go somewhere in the boost pipe to register boost pressure???
I take it you are running a similar mechanical boost gauge?

[Jezza-7]

Yeah i did, now run electric one now. Still use the existing vac pipe though. 

[andis3]

All sorted now...Spot on mate

Boost is peaking at a shown 12-13 PSI not sure how accurate that is???

Thanks Andy

[Jezza-7]

What mods you got?

10 Psi is standard charger and pulley

12-14psi is normally 65mm pulley

14psi+ is normally ported charger. But it does depend on charger seals etc as they could be leaking boost slightly. I once had my R1 charger boosting at 17psi with a 65mm pulley.

[andis3]

Current spec' is...

- 65mm toothed psd set-up
- Stage 4 Jabba charger
- G60 injectors
- Stainless steel manifold and Jetex stainless system
- Green cone filter
- LSD

I was considering some cylinder head porting and maybe a cam,also getting the charger serviced and ported to the next level.Then maybe live mapped as apposed to a chip to suit the mods.

Could you recommend anyone for the work i have in mind?

Cheers
Andy

[Jezza-7]

Boost is about right then.

Stage 4 is the max porting that jabba do now, they used to do R1 spec. Do you know when it was done? If it was a long while ago i would say it it was a stage 4 when R1 was about, so you might be able to get more porting. There are some guys that do aqua blasting and porting, search for it on the forum under the supercharger section.

PSD Full blend and R1 chargers pop up for sale and can sometimes be cheaper buying one already done and rebuilt.

Rebuilds, i'd ask if peteg40 on the forum could do it for you. Great prices and he's the best around.

[andis3]

Thanks for the pointers mate.

I will contact Pete to discuss.

What spark plugs are people using?I've read a thread on this subject and some where saying use the NGK equivalent to the Bosch,as they do the same job for half the price.

[Jezza-7]

Yeah speak to pete.

NGK BP7EVX is the old one, new one is NGK BP7EIX, about £8 a plug or £28 a box of 4. If you have a local car parts place speak to them. I once got a set £20 cash

Bosch were W5DP0, now WR5DP0 or something. GSF sell them for about £16 a plug online, £14 on ebay! Euro car parts got them at just over £12 a plug at the mo.

[andis3]

Jezza,

I've just had a quick search for the NGK BP7EIX plugs...but nothing comes up???

Or is it...NGK BPR7EIX WITH THE ADDITION OF THE 'R'??