building boost, but butt dyno says less power

robert weinberg centaurus3200 at
Sat May 9 09:29:06 PDT 2009

yes, i'm aware that the gauge will read lower. the deal is this. used to be once i hit 1.2 bar, she got going, then 1.4 bar, things got interesting. then 1.5-1.8 bar, we were flyin'.

now, there seems to be minimal difference between 1.4-1.8 bar. sometimes, it will give the kick in the pants like before, but not always. who knows, maybe it sucked a squirrel into the intake ;-)

i doubt it can be an exhaust restriction if it's hitting 1.8 bar, correct?

any other ideas? some obscure sensor or something? 034 had the turbo out about 6 months ago and said it was like brand new.

on a side note, the autocheck chirped that the coolant temp sensor failed. i just replaced the bastard 6 months ago! 


----- Forwarded Message ----
From: P.A. <sleepyq2227 at>
To: robert weinberg <centaurus3200 at>
Sent: Saturday, May 9, 2009 7:58:41 AM
Subject: Re: building boost, but butt dyno says less power


The stock gague will always read in the 1.7-1.8 Bar range. Because you changed the MAP sensor you have to multiply by 1.5 (or something like that) to get the true boost pressure. If you put in an aftermarket boost gague it will give you a true reading because it isn't calibrated assuming a stock 2 Bar map sensor. Basically....the engine is seeing more than 1.7 that is indicated. Sorry if I don't what the multiplication factor is for you but I'm running the normal 2.5 bar upgrade as oppossed to 3 bar. 

On Fri, May 8, 2009 at 2:35 PM, robert weinberg <centaurus3200 at> wrote:

hi all,

probably just my imagination. car runs pretty good, but just curious. what would be some reasons as to why my car hits 1.7 bar on the stock gauge every time. it's running an IA3+ with a 3 bar map sensor so the gauge reads lower than without the chip. but the 1.7 bar these days, feels less frisky than it's usual 1.7 bar - throw you through the back window - sort of rush.

car runs smooth, pulls to redline. just wondering what would contribute to solid boost, but less of a kick in the pants?

hopefully this makes sense.

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