Fitting a turbo boost gauge to a T4

[timway]

Thanks for the offer! :D Whereabouts are you in bristol?
The gauge and filter arrived in the post this morning :-)

I've actually managed to get it connected up now, I used the tube going from the throttle body to the fuel rail, because that had a little plastic pipe joining the two rubber tubes, so I replaced that with the 3 way adaptor that came with the gauge.

Like you say, the difficult bit is going to be mounting it properly in the cabin, and I dont really want to start drilling holes in it...
At the moment its just wedged between the dashboard and door, and the vacuum pipe is going through the door seal and the gap between the offside wing and bonnet (I couldnt find any gaps in the bulkhead to poke it through). Where's the best place to connect the electrical wires for the gauge to?

I've done a road test with the gauge fitted now, at idling it was reading about -0.6/0.7 bar, and at maximum acceleration in 3rd it would peak at about 1 bar, then back off to about 0.8-0.9 bar.
I think thats about normal for a standard T4, suggesting it probably hasn't been chipped??

[pyaap]

I live quite close to the BRI so its quite central. Using the hose you've tapped into is fine, but just make sure there are no kinks in it because that might cause fuel delivery issues under boost, which is best avoided. The easiest hose to tap into the one going from the recirculating valve on the turbo, to the throttle housing. Tapping into that anwhere along its length will work just as well.

To get into the cabin, you could pass the boost hose through the rubber grommet on the nearside firewall, which is where the ECU wiring loom enters the engine bay. You'll need a decent length of boost hose for this. I just tapped into the electrical wires under the steering column and it works just fine.

Standard boost on a T4 is 0.9bar but current atmospheric conditions could probably explain the slightly higher boost of 1bar. It sounds like the car is still stock because modified cars tend to run run anywhere between 1.1 and 1.3bar.

[Ross9]

Sounds like standard to me. My other half has a modified T4

Jacquelines is taken off of the nipple under the smaller plastic cover at the front right of the engine, where the throttle arm etc is all located. The actual guage is a Blitz one, never spend just £30 etc on a guage, get a good one.

0.9 bar is standard T4 boost.

Jacqs is running a peak of 1.4 bar at the mo on the TME/MTE remap. Makes good torque but the standard turbo cant hold that boost as its too small. This amount of boost on an unremapped car is unrecommended, with just a mechanical boost controller we had it at 1.2 bar and it would get intermittent detonation that the ECU had to counteract with retard on the ignition timing, with the MTE/TME remap it is mapped for this boost so it does not occur.

Ross

[foggyjames]

I'd like to point out at this point that although I only paid £35 for my Autometer gauge...it is a good one. It's more like twice that here, shipped.

It's interesting that the T4 seems to be the only Volvo which runs a 'normal' boost level (~1 bar) as standard...with the usual models being virtually 'light pressure' in comparison.

cheers

James

[PAZ3154]

I fitted one in a mate's S40 recently. i fitted the gauge itself under the radio using a volvo blanking off panel which i drilled out with a 51mm hole saw.the part number of which is 30800677 @ £6.40. the end result is quite neat,looks almost factory fit. though of course you can only use this option if you have a single DIN radio unit as opposed to the double eg.SC805. the feed for the instrument lamp i took straight off the cigarette lighter bulb. i passed the vacuum/boost pipe behind the glovebox and through a free grommet in the n/s bulkhead.hope this helps :-)

[timway]

Hi,
My radio is a double DIN one I think so I can't put one there, but I was thinking of putting it in the little cubby hole between the ashtray and radio - I would just need to get an angle bracket with a 51mm hole made up somewhere then stick it underneath the radio. Won't look like factory fit but will at least be fairly discreet.
Using the supply for the cigarette lighter bulb is a good idea :-)

How do you get access to the bulkhead behind the glovebox? Just remove all the carpet/trim in that area?

Thanks for the advice :-)
Tim

[PAZ3154]

well i took the glovebox out to give easier access which is a simple enough job.but you could just remove the carpet below the glovebox and poke the pipe through the bulkhead and feel for it coming through behind the glovebox. there's a large 2 inch grommet just next to the n/s suspension turret which is perfect. just drill a hole in it for the pipe and feed the pipe inwards and downwards. you should be able to grab the other end from behind the glovebox easily enough.hope this helps :-)

[Andru]

I fitted a boost gauge to my '98 2.0lpt a few months ago.I fed the vac pipe through the baulkhead on the passenger side behind all the carpets and then out of the air vent by the drivers side window.I dissasembled the airvent mounted a piece of 1.5 mm aluminium (sprayed mett black) over the vent hole and machined a 52mm hole into that.For the first attempt it looks ok.
Still cant get it to hold more than 10psi with a upsolute chip.I have spent about £500 on different rolling road garages for each one to tell me something different and to change different items at a furtune to me.
So far i have fitted a new turbo accuator,turbo control valve,changed all the small vacuum hoses still no joy.I have checked all the large turbo hoses for leaks and they all look ok.
I know its off the subject but would anyone else have any more ideas on why it wont hold boost.

Thanks

Here are 2 very small images of it.

[foggyjames]

At what RPM is the boost tailing off? (I'm guessing that's what's happening). Have you tried swapping in a standard ECU?

cheers

James

[Andru]

I have tried a std chip in the ecu as they are swappable the boost only goes upto about 6/7 psi before dropping off.If i hold it in 3rd/4th the boost goes upto about 10psi(with the upsolute chip) at about 5000 then just tails off to about 6psi.i then change up a gear and the same happens again upto about 5000 and then it tails off.