possible boost issue?

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c41lum

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i currently have a standard 59 plate S3 and for the past few days o have been wandering whether i have a boost issue or whether it was simply me becoming used to the car?

somedays the car seems to pull well through each gear however on some occasions and i have noticed it mainly in second gear at say around 20mph and accelerating it seems like there is a lack of boost and the car doesnt start to pull until at least 3200 - 3400rpm

being new to the car i was unsure if i was imagining things or not so i thought i would ask the experts, im currently offshore but i intend checking the Diverter valve for any splits and getting the car vagcom'd once i return to dry land.

any help or advice is appreciated

cheers
Callum
 
For a car your age, without doing anything to it yourself, take it to the dealers.
 
Your car should have the new revision D boost gauge, so no rubbers to split in those.

Boost control valve N75 could be at fault. May also be worth unplugging the MAF and seeing if it runs any differently.

I'm not sure where the turbo's kick in on these cars; can't be much below 3,000rpm (anyone know?)
 
2500rpm. i think you're getting used to the car.
 
Boydie said:
Ditto but how many miles are on the car? can't be that much if you are off shore regularly :S
Click to expand...

im on a 2 on 3 off rota so the car is used quite frequently during the 3 weeks at home, milage is around 2.5k if i remember correctly
 
@warren, thanks i will try these once i get home next week,

@s. thats a possibility mate, if so then happy days but i would still like to investigate all posibilities just to make sure and put my mind at rest :icon_thumright:
 
All you need to do to check if you have a boost leak is some logging with VCDS:

1. Log block 115 for boost and check that Actual boost is meeting Requested boost throughout the rev range as below.
revo_stage_1_boost_timing_6_5_9.jpg


2. Log block 114 for the N75 Duty Cycle (for N75 read wastegate) and check that after the turbo has spooled the N75 is not working too hard. Before the turbo spool the duty cycle should be at 100% as the wastegate is 100% open. After it spools it should remail at 40-60%. Any higher and it indicates a boost leak because your N75 is having to work to hard to maintain requested boost pressure. Here is what a healthy N75 cycle looks like:
revo_stage_1_n75_6_5_9.jpg
 
thank you KRL ill get on to that when i return home and let you know! much appreciated
 
Ive got a 59 plate too & have posted up pretty much the same thread except mine has revo stage 1, evoms intake & forge dv. Did logs boost is fine so cant be dv so I think ive got used to it or the clutch might be slipping on mine
 
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