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PSI/Bar


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Does anyone know the conversion of psi to bar? As far as I knew, around 10psi read 0.9 bar which is about right for stock with 2nd decat?

 

Reason i ask is my boost gauge reads upto 20psi, and after having my fcd fitted today (first decat is still to be fitted, as are plugs) the boost is now 15psi. now is that because i have a cheapo gauge or is it normal?

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cheers for that info :thumbs:

 

just another thing.. as i mentioned it now does around 15psi when i boot it, and that on the chart shows as about 1.03bar, so if i add my 1st decat, plugs and restrictor ring will it overboost? :(

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Ok got the bar/psi thing out the way. does anyone know that by just fitting a 2nd decat and an fcd does it raise the boost more than .9bar? because as far as i knew it wouldnt until i added the 1st decat also? yet now from 10psi its showing 15psi on the gauge?

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does anyone know that by just fitting a 2nd decat and an fcd does it raise the boost more than .9bar?

Huh? Read that back to yourself Maz. It doesn't make sense to me.

 

because as far as i knew it wouldnt until i added the 1st decat also? yet now from 10psi its showing 15psi on the gauge?
Quite possible. Results vary from car to car. Exhaust flow (and therefore back pressure) is one consideration.
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Huh? Read that back to yourself Maz. It doesn't make sense to me.

 

Quite possible. Results vary from car to car. Exhaust flow (and therefore back pressure) is one consideration.

 

Sorry mate will try that again.

stock boost is around 0.8bar right? Now when i had my 2nd decat fitted it didnt go up by much at all, if anything it was showing 0.9bar, and today after having my fcd fitted its showing 1.03bar on the boost gauge, even though my 1st decat is not yet fitted.

 

I have a restrictor ring, only thing im worried about is when i have my 1st decat fitted will it overboost? I dont want to blow the turbos etc..

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Yes stock is around 0.8 bar somewhere. It seems to vary a bit.

 

So you're saying that the max boost level you're seeing has changed from 0.9bar to 1.03bar and the only thing different on the car is the FCD? Well the FCD can't affect the boost level like that so I guess it's just down to atmospheric conditions. It is bloody cold out at the mo, so the air is denser. That's my bet anyway mate.

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If you have just over 1 bar with the 2nd cat out then you will almost certainly see 1.2 bar and over with the 1st one gone. You will need the a properly sized restrictor ring to keep it to 1.1/1.2 bar.

 

i have a ring that i bought with the decat pipe which measures 45mm / 1.77inches diameter. would that be about right to maintain between 1.1/1.2 bar?

 

Yes stock is around 0.8 bar somewhere. It seems to vary a bit.

 

So you're saying that the max boost level you're seeing has changed from 0.9bar to 1.03bar and the only thing different on the car is the FCD? Well the FCD can't affect the boost level like that so I guess it's just down to atmospheric conditions. It is bloody cold out at the mo, so the air is denser. That's my bet anyway mate.

 

i thought that at first aswell but im just trying to explore all my options before having to resort to a boost controller at this point :)

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You'll have to just try it and see what boost you get with both decats and the restrictor and take it from there.

Even if you're lucky and the restrictor size is correct for your car in cold weather you will find that the boost level is much lower in hot weather. In which case you would still need a boost controller to raise the boost up to the level you want. Either that or put up with the lower boost on hot days. :shrug:

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hmm well if all goes to plan then ill be getting the first decat and plugs fitted tomorrow. i suppose if its ok for now i will get a boost controller before winter is over. only reason im trying to avoid it at the moment is im looking to get a few bits for the body aswell at the same time :D

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You'll have to just try it and see what boost you get with both decats and the restrictor and take it from there.

Even if you're lucky and the restrictor size is correct for your car in cold weather you will find that the boost level is much lower in hot weather. In which case you would still need a boost controller to raise the boost up to the level you want. Either that or put up with the lower boost on hot days. :shrug:

 

UK cars don't suffer from this.;)

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See carlos at the moment ive not even got the restrictor ring fitted. just the 2nd decat and an fcd. i suppose yes the weather etc could be a factor as to why its boosting higher, but on my way down to the place yesterday it wasnt boosting over about 10/11 psi, and then on the way home after having my fcd fitted its doing 15/16psi.

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