Turbo

[Elkhound]

This is the first time I've owned a car with a Turbo charger.  Can you tell when the turbo kicks in?  A friend of mine use to have an old SAAB and there was a guage showing the amount of boost being used......

Is there a tell-tale sign?

[budrichard]

Turbo is always spinning from the exhaust gases. More throttle, more exhaust gases, more turbo until the waste gate opens limiting the boost. Actually on the XC's after about 30 seconds of full boost, the whole system kind of shuts down to avoid what I presume would be either cooling system or engine damage. -Dick

[Art]

IPD sells an in dash boost gauge that plugs into the OBDII port underneath the dash. http://xc70.com/iB_html/non-cgi/emoticons/smile.gif

In-Dash Boost Gauge (http://www.ipdusa.com/ProductsCat.aspx?CategoryID=1447&NodeID=4541&RootID=629)

[ifnt420]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (budrichard @ Aug. 21 2003,16:35)</td></tr><tr><td id="QUOTE">Actually on the XC&#39;s after about 30 seconds of full boost, the whole system kind of shuts down to avoid what I presume would be either cooling system or engine damage. -Dick[/QUOTE]<span id='postcolor'>
I know that the XC&#39;s 2.4T engine runs 0.6bar of boost, so does that mean after 30 seconds of full boost at 0.6bar, the engine runs at 0bar of boost? That doesn&#39;t sound right.. I&#39;ve done runs with WOT from 0kmh to 200+kmh and it seems like there is always boost, and it takes much longer than 30 seconds to do these runs. &nbsp;
Perhaps you are thinking about the AC shutting down at WOT?

Boost On&#33;&#33;

[Supertoyz]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Elkhound @ Aug. 21 2003,13:28)</td></tr><tr><td id="QUOTE">This is the first time I&#39;ve owned a car with a Turbo charger. Can you tell when the turbo kicks in? A friend of mine use to have an old SAAB and there was a guage showing the amount of boost being used......

Is there a tell-tale sign?[/QUOTE]<span id='postcolor'>
I&#39;ve owned a bunch of turbocharged &amp; supercharged vehicles over the years and the XC certainly is the most transparent application of a turbocharger that I&#39;ve owned. &nbsp;It&#39;s a very low pressure system which really leaves little reason for a guage. &nbsp;Without knowing it was turbocharged most folks would probably never realize that it was. &nbsp;A turbo is always spinning when the engine is running but it usually takes a few seconds after throttle is applied before it produces any significant boost, this is why older systems and sytems with larger turbo&#39;s or higher boost have more lag followed by a more perceptible rush. &nbsp;The Volvo system being a small turbo and low pressure virtually eliminates the typical slingshot feel that turbo&#39;s are known for.

[thomaslally]

Unfortunately, I feel te slingshot &nbsp;http://xc70.com/iB_html/non-cgi/emoticons/crazy.gif &nbsp;In the previous V70XC (1998) the S mode prevent me to feel the lag

Thomas

[SpudRacer]

1. Does anyone know how many pounds of boost the turbo produces at max boost?

2. Has anyone read or heard of anyone dialing up the boost or replacing the turbo with a larger Garrett for slightly increased boost levels? &nbsp;
**I&#39;m sure these mods would likely void the factory warrany, at least on the engine, but could be an option for increased power levels once the warranty expires.**

I welcome any thoughts. &nbsp;I don&#39;t know how the rest of the driveline would stand up to substantially increased power levels, but an extra 25-50hp can&#39;t do too much harm if used judiciously and under the right conditions.

SpudRacer

[GeorgeXC70]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Elkhound @ Aug. 21 2003,15:28)</td></tr><tr><td id="QUOTE">This is the first time I&#39;ve owned a car with a Turbo charger. Can you tell when the turbo kicks in? A friend of mine use to have an old SAAB and there was a guage showing the amount of boost being used......

Is there a tell-tale sign?[/QUOTE]<span id='postcolor'>
You should be able to feel the difference when you realy press down the gas pedal while crusing at almost any speed steadily. The amount of time it takes the increased exhaust output to spin the turbo upto speed is the lag between when you stab at the accelerator and &quot;almost&quot; nothing happens.

Once the turbo is up and running, if you keep pressing you hear a faint whistling, which the waste gate opening when the turbos upto max pressure.

It was definitely noticable on the Saab 93 we used to have... especialy with the major amounts of torque steer.

The turbo wasnt as noticable on the TT I have now since it has five valve per cylinder which sort of widens the torque curve . It&#39;s a straight uninterupted pull from 1400 - 4750 rpm.

You shoudl be able to feel the turbo kick in at almost any speed when you start to accelerate hard.

-G

[ifnt420]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (SpudRacer @ Aug. 24 2003,21:22)</td></tr><tr><td id="QUOTE">1. Does anyone know how many pounds of boost the turbo produces at max boost?

2. Has anyone read or heard of anyone dialing up the boost or replacing the turbo with a larger Garrett for slightly increased boost levels?
**I&#39;m sure these mods would likely void the factory warrany, at least on the engine, but could be an option for increased power levels once the warranty expires.**

I welcome any thoughts. I don&#39;t know how the rest of the driveline would stand up to substantially increased power levels, but an extra 25-50hp can&#39;t do too much harm if used judiciously and under the right conditions.

SpudRacer[/QUOTE]<span id='postcolor'>
Hi Spud Racer:

1. The XC has max boost of 0.6 bar. &nbsp;Many chip makers up the boosts to almost 1bar on the stock Turbo.
2. &nbsp;I haven&#39;t seen any XC with upgraded Turbos yet; it would be interesting though to see how the car performs with a different Turbo. &nbsp;I believe the Stock Turbo is a Mitsubishi TDO4, perhaps the R&#39;s KKK will bolt right up. &nbsp; http://xc70.com/iB_html/non-cgi/emoticons/tounge.gif

Cheers

[Willy]

Most modern turbos use variable geometry: by means of movable fins they can change the inside volume. At low revs the fins are alligned to each other, creating a small volume. When the engine revs, the fins open and the volume increases. The result is a turbo that combines the advantages of a small with that of a big turbo (fast response and high volume) without the disadvantages (lag and lack of top end power).
In the XC, the engine is geared towards a wide powerband (maximum torque of a wide range of revs). Since the engine delivers maximum torque at 1500RPM you will have a very high and linear power output, a turbo lag or turbo boost is almost non-existent. I know this is the case for the 2004 (and probably 2003) model, I don&#39;t know what goes on in the older versions. This could be one of the major differences between the 2.4T and the 2.5T.
Willy