A £1.50 engine upgrade for D4 VEA owners

[Fursty Ferret]

Also, the reason the new pipe felt slightly loose is that the OEM stuff is 5.2mm internal diameter, not 6mm as stated in the original post...

[v70d5185]

Hello there Tinkler

One of my german written comments, feel free to read it
Topic: Oil consumption:
http://www.srf.ch/sendungen/kassenst...unden-entgegen

V60 D4
2 months ago, after waiting for a long 8 months I received my all new V60 D4 8 Speed VOLVO, a great car indeed, compaired to my previous model, the V70 D5 185HP 6 speed handshift, purchased in 2007, then after 193'000 trouble free Km's I decided it's time to change, my choice was perfect; V60 D4, VOLVO 4 Life.
I've ordered the tube, ID 6mm / OD 12mm, it's due to arrive soon, but I'm having a bit of a hard time to release the original tube, I fear I might damage something, so I might just simply cut the hose with a knife to losen up the tube and make it easier to pull off.
I have roughly measured the length of my original tube, its approx 177mm, never the less, I shall give it a try with your proposed 200mm, once the tube arrives, let's see if we ae in for a suprise.
The car runs really great, consumption is low, current average 5.4 ltr / 100Km and is really fun to drive.

Best Regards / Paul

[v70d5185]

Hello there folks

My experience..xchange the hose, 155mm length to 200mm

Received the hose today, ID 6mm | OD 12mm, installed it, went for a test run, it seemed to me the cars reponse on acceleration and gear change was not as quick and efficiant as it was with the original 155mm hose.
The ID of the original hose I measured is 5.5mm, here with the larger hose with an ID of 6mm, I presume did not fit as tight as the original hose, this could be the cause for the lack of performance.
Never the less, re installed the original VOLVO hose, now the cars response is as it always has been, quick and efficiant.

Cheers to you all

[v70d5185]

ID 5.5mm, OD 10.5mm length 155mm, I presume this is the standard length, on the hose is written; "Volvo part Nr. 31401369", tried to look it up under VOLVO original OEM parts, this item Nr was not listed, respectively noted no longer available.....

Best Regards, Paul

[BB60]

Originally Posted by The Tinkerer

I've been very happy with my VEA D4-engined car since getting it last year, but recently I made a simple tweak which has made me even happier with it, improving part-throttle pick up and throttle response, especially in the up-to-2,500rpm range.

Having a look under the bonnet, I noticed that the vacuum hose highlighted in the image below was curved at a rather sharp angle:



That hose delivers vacuum to the actuator that controls the bypass valve for the high-pressure (smaller) turbo. At idle, or when there is zero throttle input, the bypass valve is open as there is no vacuum in the hose. The open bypass valve allows the exhaust gas to flow equally to the high-pressure smaller) and low-pressure (larger) turbos. This minimises boost pressure at low rpm / zero throttle.

When you touch the throttle, the solenoid switches the vacuum supply to the hose, and the actuator closes the bypass valve. This diverts all the exhaust gas to the high pressure (smaller) turbo, to quickly increase boost pressure off-idle. It's this hose and bypass valve that basically governs driveability and throttle response in everyday driving conditions.

With the hose curving at a sharp angle, I wondered if it wasn't narrowing or kinking the internal diameter of the hose, reducing the rate of vacuum increase seen at the actuator - thereby affecting the bypass valve actuation.

The factory-fit hose is an approx 15cm length of conventional 6mm internal diameter, 11mm external diameter rubber vacuum hose. It's only just long enough to fit between the solenoid and the actuator.

I replaced it with a 20cm length of 6mm ID/11mm OD vacuum hose from my local car parts shop. The extra 5cm length is easily enough to allow a nice, smooth rounded curve in the hose with no risk of it narrowing or kinking. The factory hose simply pulls off the barbed nipples on the solenoid and actuator, and the new hose fitted simply by pushing it in place. You don't even have to remove the engine cover to do it.

Total cost: £1.50 for a new piece of hose. Total time: 5 minutes. Throttle response is now more sensitive, sharper and more positive around town and on the open road. It was good before, but this has made it even better.

Of course, this particular vacuum hose was a just a bit too short on my car. Other people's cars might have a slightly longer piece of hose fitted from the factory, in which case they probably won't experience any difference from swapping the hose. But I'd recommend any owner of a car with a D4 VEA motor should have a look under their bonnet to check if their car might benefit.

Hi there. I have just read this article with some interest but I can't see any of the pictures. As I'm fairly new to this (and any) forum, would you please post the pictures again or advise me where I can view them. Thanks.

[tails]

again,pics please.

[tails]

anyone ???

[1monkey600]

The guy who started this thread hasn't been online since june 2016 so unlikely to get him to update the photos. Maybe there is someone else who can take and upload a photo or too?

[rking314]

I can't see any photos of the vacuum hose?

[RoyMacDonald]

It's a small plastic pipe over at the back of the engine as I remember. Not very long. The original photos were stored on a web page that no longer exists unfortuantly.

Roy