Boost gauge and stock pressure

[JTaylor2005]

Hi all,

I had a look on Auto data the other day and found out stock boost @ 2000rpm is supposed to be 0.9-1 bar. I am going to get a boost gauge soon. Where would this have been read from do you think? The turbo wastegate pipe or further up in the manifold etc?

Also on a stage 1 would the boost be higher do you think? 

Thanks, Jack

[Toms306]

That's not measured is it? Just the expected figure given the turbo map? I can't see autodata fitting boost gauges myself.

The boost will be the same on a stage 1, need to alter the wastegate to increase the boost on these (stage 2).

[Poodle]

You're over-thinking it again.

[MrBigMac]

not sure OP, but mine was 14psi standard and gauge is connected to inlet elbow

[JTaylor2005]

Okie dokie cheers. So to fit one on standard setup the easiest way would be to cut the wastegate pipe, stick a t-peice in and then just run a pipe into the car up to the dash board?

[MrBigMac]

drill and tap inlet elbow, you want boost reading as it goes into engine not at turbo

[Poodle]

But don't forget to account for pressure loss between turbo and inlet else you could easily end up over-working the turbo.

[mr_fish]

Fit both.

Because all of the gauges

[JTaylor2005]

Haha. I saw one not long ago dunno if it was on here but it had about 5/6 gauges haha.

And as for drilling and tapping I have heard its hard to seal etc. I can't be bothered to take it out of the car haha. There wont be much drop from a turbo to an inlet manifold that has a 6" pipe going directly between the two surely haha?

[MrBigMac]

i never had any problems sealing it when i drilled inlet, did one on car and when fitted fmic drilled elbow on bench, i use a push fit connector 6mm hole and it has o ring as a seal at top of thread and the 4 mm M6 barb i use sealed well to, its all in the drilling and tapping

[Ruan]

Boost at the manifold is all well and good, but are you looking at saving your turbo, or knowing how much pressure there is in the manifold... That's for you to decide!

Frankly on a stock setup, as you say, there's going to be very little pressure drop, but once you add an intercooler - the pressure drop will increase! I've seen some intercoolers cause a 4psi drop across them - the difference of 4psi can be the difference between popping your turbo and it being just fine.

[JTaylor2005]

Think I will do mine at the turbo for now as I still am yet to plan anything more than a stage 1. Then when I go to change it over to the stage 2 inlet elbow I will properly mill it at work and drill at tap it on a nice flat surface while its off the car.

Can't be bothered getting all swarf dropping inside by doing it on the car haha. Cheers

[Ruan]

Don't extend the wastegate pipe too long - otherwise you'll get overboost due to it taking more time for the actuator pipe to fill

From personal experience that one!

[JTaylor2005]

Ahhh dammit, How did you notice the boost spikes? Did they show on the gauge? Would running it into the car and onto the top right of the dashboard be enough length to cause issues?

[Ruan]

Might do, you might see it on the gauge, but you'd especially notice it once you have it plumbed into the inlet... My advice is to get a gauge with an electronic sensor remotely if you're doing that, then you can place the sensor far away from the gauge.

[pro_steve]

I would advise to put it in the intake manifold because that's where we want to know how high the pressure is. We can make the assumption that it's a bout 2-4 psi higher at the compressor outlet (with or without an IC), and we know that running 20 psi at the inlet manifold is safe because people have been doing it for about 10 years on these cars.

Stock boost is 14 psi, when you stage 1, the extra fuel flow takes it up to 16 psi without any adjustment, from that point on you will need a boost controller to get a bit more boost.

Ruan is right about the long boost controller pipes, it does make it spike a bit, but then it's easier to adjust if it's at the top of the engine bay. Try to minimise the length of the pipes as much as you can.

Once you fit an intercooler it will likely drop back to about 14 if you have a stage 1 and a big intercooler.

[JTaylor2005]

Okie dokie cheers fellas

Just found a spare inlet elbow in my garage which I forgot I had so will try and get that drilled and tapped