at idle, what should my 3-5 bar FPR be set for giac J31 software...

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11-22-2003, 08:39 PM

mmart6545

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at idle, what should my 3-5 bar FPR be set for giac J31 software...

stock was 3.5 bar. I tried 4.25 bar and I get a little detonation under WOT. thanks

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11-22-2003, 08:55 PM

Audi2ptzero

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What injectors are you running?

The J31 chip was tuned to be run on the stock injectors with a 5 bar fpr.

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11-23-2003, 01:34 AM

Audi2ptzero

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Yes

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11-23-2003, 06:21 AM

PDXA4

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Should be 5 Bar...

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11-23-2003, 06:49 AM

one8t

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Re: 5 bar at idle?

Don't you go 4.5 at idle and it will rise to 5 under load/boost? Just like the stock 4 bar runs around 3.5 at idle.

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11-23-2003, 07:10 AM

Big Nodge

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you need a VAG if you don't already have one

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11-23-2003, 07:32 AM

Audi2ptzero

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The fpr is set at idle with the vac line disconnected.

So I would have to think that the stock 5 bar actually runs at 5 bar without any vacume and then adds more fuel pressure in the rail as the fpr gets boost pressure.

Now if you leave the vac line on you might end up seeing fuel pressure at 3.5 bar for a 4 bar fpr or 4.5 bar for a 5 bar fpr. But that would mean your actually setting the fpr while it is seeing vacuum already.

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