Xsara 'Overboost'! Anyone shed more light?

Hi,

I read recently of Citroen's Xsara 1.6 litre DTi 110bhp new vehicle with 'Overboost' and was curious for some details.

That is a fairly high power output for a 1.6 diesel. I guess that's with the aforementioned boost is it? What turbo boost pressure is considered 'overboost'? (My old Vectra DTH runs at about 1 bar maximum pressure.)

It seems to be only for short term requirements so what determines the time it is allowed for? In the middle of a difficult overtaking manouvre is it going to time out on you and leave you caught short, or what?

Amyone with inside knowledge of this vehicle out there, could you enlighten me, please? Citroen's website is quite uninformative. This is just out of genuine curiosity - I don't have a broken one.

Tony.

Reply to
Tony
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Overboost - as on many saabs, gives a short period of additional wallop - by keeping the wastegate shut for longer. Saabs are about 10s IIRC and so make for brilliant kick when overtaking.

Reply to
Tim S Kemp

Same as the Mondeo TDCI.

Pete.

Reply to
Pete Smith

I've got the same thing on a dispatch what happens is that when you put your foot to the floor, you get a little bit more boost before the wastegate opens up, therefore giving you more power for a brief period pressing and lifting off and then pressing the pedal again doesn't do shit because it only does it once in a specified time period

which is why I think they are advertising it as having 110 bhp, it's probably the figure for the overboosted power

Reply to
dojj

Just a bit misleading then.

Reply to
Me
[snip]
[snip]

There isn't any particular pressure. It varies from car to car. It's just more boost than whatever the engine is meant to run at continuously.

Colin.

Reply to
Colin Stamp

Many thanks for the replies. I have a clearer picture now and didn't realise there were existing vehicles of other makes that have the same facility. I had never heard the term before and thought new and potentially hazardous ground was being broken.

Tony.

Reply to
Tony

And the same as the Focus TDCI- which is allowed 1.2bar for 30 seconds with a fully depressed throttle- you wont get it unless the pedal is in this position.

Tim..

Reply to
Tim (Remove NOSPAM.

And the same as the Focus TDCI- which is allowed 1.2bar for 30 seconds with a fully depressed throttle- you wont get it unless the pedal is in this position.

Tim..

Reply to
Tim (Remove NOSPAM.

And the same as the Focus TDCI- which is allowed 1.2bar for 30 seconds with a fully depressed throttle- you wont get it unless the pedal is in this position.

Tim..

Reply to
Tim (Remove NOSPAM.

I still think that if the 110bhp is the overboost figure, they are taking the p**s calling it a 110bhp engine, what is the continuous rated figure?

Reply to
Me

You *think* it is? It's not for the Mondeo Di, and I don't see there being any difference with the other HDI / TDCi engines.

It's usually the quoted torque figure that's the overboost one, it doesn't overboost close to full RPM.

On the Mondeo Di, as I recall it makes around 10% of an increase in torque. The maximum torque figure is quoted as being 278 Nm, so perhaps the maximum non-overboost figure is around 250 Nm? It's in the brochure, but Charlie made me get rid of mine... :(

Reply to
DervMan

erm - is the Monnn Day - Oh a 1.6?

Reply to
Tim S Kemp

:)

Point taken, and "not yet." But it uses a similar engine with similar technology...

Reply to
DervMan

Tim S Kemp ( snipped-for-privacy@timkemp.karoo.co.uk) gurgled happily, sounding much like they were saying :

erm - is the Monnn Day - Oh a bit bigger than a Xsara?

Reply to
Adrian

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