Plumbing!

These are pics of the various turbo boost pressure hoses connected to the sensors on the right-hand bulkhead in my engine bay. I was wondering, are they connected the right way? Which one is the MAP sensor? Is one the Electronic Boost Valve? One appears to have nothing connected to it (arrowed). Should it have and what is it? Appreciate if anyone can clarify matters for me, thanks.

The one on the left is the map sensor, the right one is for the boost gauge. The one thats not used is a dummy blank, but its used on other Renault turbos with that mounting for a boost cutout switch. The Alpine doesnt need this as the boost cutout is built into the Map sensor system.

Thanks David. Just needed reasuring they were the right way round!

Great stuff! Diagnostic over the net by digital photo Particularly like the arrow and what is this bit U should start charging David!!!!!!

Peterg, If it is not required, you should get it out of your car and save a little weight, being in the rear it has to be worth it.

I'm fitting a boost gauge (when it arrives!). Am I right in thinking the best place to plumb it in would be the hose on the right (yellow band), as this already sends the boost pressure signal to the dash? Just want reassuring! Cheers.

No.

That hose is positive pressure only, as it comes off the V6 intake pipe, and is before the throttle body. This means it never sees vacuum.

Tee into the feed to the dump valve or even better to the actuator.

Ah ok, cheers for that.

Ever since I got my car back from having the heads done and turbo reconditioned I've always thought the power delivery felt softer, without the turbo 'kick' it used to have. And after fitting a boost gauge today, it seems my suspicion has been confirmed - the gauge was only reading a maximum of 0.4 bar!

However, I would like to check first with those more knowledgable...

This is how I've plumbed the gauge in:



Is this ok and what reading should I be expecting here?

I think David suggested an alternative place to plumb it in would be the feed to the actuator, but I think the boost upgrade valve I plan to fit should plumb in here and I don't want to plumb both into the same place:




So, have I done my plumbing correctly, and if so, how should I rectify the low 0.4bar boost problem. Should I try adjusting the actuator until the gauge reads a standard 0.7bar, then fit the boost upgrade valve.

Or should I just fit the boost upgrade valve and use this to adjust the boost, until the gauge is reading the 1.0bar I'm aiming for?

Thanks, any help much appreciated.

My bad, you can't fit the gauge to the actuator feed anyway because its positive pressure only again.

Its difficult to know if the car is running 0.4 bar, when you are teeing off the original dumpvalve, as they fluctuate the reading. If you have an aftermarket dumpvalve with a stiff spring, there is normally not a problem. Simon Taylor had this exact scenario.

For testing you can use the original gauge feed, as it will show exactly what boost you are running at full throttle, it just wont't show vacuum.

Ok David, thanks. A couple more questions...

Where I've teed off, isn't it getting the pressure from the manifold before it reaches the dump valve? Or does it flow the other way?

And for testing, which one is the original gauge feed? The right hand one with the yellow band in my original picture?

And finally, if I try it wth a different feed and still get 0.4bar, should I adjust the actuator, or adjust using the upgrade valve which I'll be plumbing into the actuator feed?

Cheers.

Ok David, thanks. A couple more questions...

Where I've teed off, isn't it getting the pressure from the manifold before it reaches the dump valve? Or does it flow the other way?

And for testing, which one is the original gauge feed? The right hand one with the yellow band in my original picture?

And finally, if I try it wth a different feed and still get 0.4bar, should I adjust the actuator, or adjust using the upgrade valve which I'll be plumbing into the actuator feed?

Cheers.

It does get pressure, but the reading is affected by the diagphragm moving in the dump valve when the engine comes on boost. Because the spring is weak, it moves easier.

The original gauge is the one with the yellow band.

If you still get 0.4 bar, yes, wind the actuator in till you get around 10-12, then do the rest with the valve.

Ok David, I'll try that. Thanks again.

[Alpineandy]

If you still get 0.4 bar, yes, wind the actuator in till you get around 10-12, then do the rest with the valve.

Wow, 10-12 Bar, That'll really go... For a second and a half...

I assumed he meant 10-12psi