Author Topic: What controls when the car makes boost  (Read 1438 times)

Offline animal47

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What controls when the car makes boost
« on: 18 June 2016, 21:54 »
I am trying to work out whether or not my car has a bad map or if there is something else causing my boost to come in later than I want. The engine is an AUM with s2000 filter and stage 1 map.
I can hear and just about feel the car starting to make boost at just under 2k but it isn't very strong until it hits 3k when it really starts to pull hard but waiting for 3k seems to take an age at times.
I have just replaced all of the pcv pipes as one of them was split but it hasn't made a difference and I can't find any boost leaks other than through the oil filler and dipstick when under pressure.
The car drives smoothly and is quick when on full boost but it just seems slower than it should be below 3k as the wife's 180 TT seems to pull much harder from low revs.
Funnily when I bought the car it used to boost very hard from 2k and was great fun but it had a dodgy maf so had been disconnected so first job was to fit a brand new Bosch maf and the boost moved to 3k as soon as the new maf was fitted, I have since tried disconnecting the new one to see if it restores boost but it makes no difference, my first thought was that perhaps I had damaged something when wrestling the new maf into place but I can't find anything wrong.
Anyone know where I should be looking for faults, vcds shows nothing.

Offline Wazzzer

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Re: What controls when the car makes boost
« Reply #1 on: 18 June 2016, 23:02 »
Can you do a full throttle run with VCDS and check the requested boost vs actual?


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Offline animal47

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Re: What controls when the car makes boost
« Reply #2 on: 19 June 2016, 13:21 »
Yes I could if it can be done with vcds lite although tbh I really have no idea what I am supposed to do.