StuartVRS 
Member 
 
Registered: 9th Feb 03
 Location: Bromley Common, Greater London 
User status: Offline 
 
 | 
 
Hi Guys, need some help and advice.  
 
After we had our A3 1.8 turbo chipped, we had it rolling roaded at a little over 200 bhp. After a while, we changed Dv's and had it rolling roaded again after the service, again, at a little over 200 bhp. Anyway, 2 months later we had it on a rolling road as it felt a bit sluggish and as we were off to santa pod, thought it best to check it out first. It came out at 187 bhp and the bloke put it down to the high temperatures. It was boosting to 15psi and dropping to 11 psi. Well, now, we have noticed even less power and on our boost guage we are peaking at 9 psi and dropping away. Could you guys give me any reasons as to why it would do this? 
 
I know it isnt the DV, cant see or hear any boost leaks. Only thing i can think of is actuator, MAF sensor, or the turbo is giving up. What do you guys think?
 | 
DAYZEE 
Member 
 
Registered: 13th Nov 00
 Location: Stevenage, MR2 Turbo, 328i Coupe, CBR600F 
User status: Offline 
 
 | 
 
Actuator spring may be getting weak, opening the wastegate too early. 
Thats what I'd go for first.
 | 
StuartVRS 
Member 
 
Registered: 9th Feb 03
 Location: Bromley Common, Greater London 
User status: Offline 
 
 | 
 
ok mate, is it easy to test or will it be a case of change it and find out if that was the problem? Also, are they expensive?
 | 
A1EX 
Member 
 
Registered: 29th Mar 00
 Location: Turku, Finland 
User status: Offline 
 
 | 
 
just out of interest what dv are you using?
 | 
Drew 
Banned 
 
Registered: 24th Nov 01
 Location: County Durham 
User status: Offline 
 
 | 
 
quote: Originally posted by DAYZEE 
Actuator spring may be getting weak, opening the wastegate too early. 
Thats what I'd go for first. 
   
 
dont know much about turbos even thou i got one - but this was my thought - heard about people who boost to ??psi then drops off, and its been cause of wot Dayzee says
 | 
StuartVRS 
Member 
 
Registered: 9th Feb 03
 Location: Bromley Common, Greater London 
User status: Offline 
 
 | 
 
using bailey dump valve, should be boosting to 15/16 psi and its not getting anywhere near, its hitting a peak of 9, sometimes 10. My first thought was the actuator, but i really dont know   I thought a dodgy actuator would just make the boost tail off as drew said, not stop it from hitting its peak boost
 | 
vibrio 
Banned 
 
Registered: 28th Feb 01
 Location: POAH 
User status: Offline 
 
 | 
 
I suspect a doggy MAF.  when you accelerate in high gear does it feel funny.  not smooth.  I very much doubt it's the actuator.  
 | 
StuartVRS 
Member 
 
Registered: 9th Feb 03
 Location: Bromley Common, Greater London 
User status: Offline 
 
 | 
 
Vibrio, it just feels slower to be honest, doesnt seem to feel rough. An MAF fault should show up in the ECU fault codes wont it, might call the AA out and get them to plug their computer in to check.
 | 
vibrio 
Banned 
 
Registered: 28th Feb 01
 Location: POAH 
User status: Offline 
 
 | 
 
it might not show up on the dash
 | 
J da Silva 
Member 
 
Registered: 10th Apr 03
 Location: The FACTory 
User status: Offline 
 
 | 
 
and your sure there's no lagging? 
 | 
John_C 
Member 
 
Registered: 5th Mar 03
 Location: South east, Bromley 
User status: Offline 
 
 | 
 
a car gettin pissed   
 
alright stu, can't help u but thought i'd say hello  
 |