So i have bought a 2011 Mini cooper s r56 N18, It has a full milltek de-cat exhaust, AEM cold intake, performance spark plugs, forge intercooler.

So its running a custom stage 2 map print out is 245bhp and 280 ft/lb.

When putting my foot down its averaging around 14-17 psi depending what gear to be honest im not sure if its still running 245bhp.

I have plugged it in and read the ecu and no fault codes.. also waste gate look ok.

So im a little lost too why it seems down on power.



Would a De-coke maybe fix my problem?



Thanks Kieran

 

14-17psi will not be 245hp on the N18, even at the engine. How many miles? Does it still have an OEM S turbo? Whose tune is loaded?

 

Right okay, So would you say its leaking boost?
Its at 99445 right now, It was tuned in 2017 and it was at 60k miles.
For the tune a company called msl performance in the uk has done it.
Also im not sure of the turbo im think its not the standard turbo.
Thanks

 

Just checked, and you have threads started all over the forum with different issues, so it will be difficult to help you out. First need to get the car current on maintenance, then address any faults that might be lingering. Verify all the installed “upgrades” are installed correctly.

 

All problems have now been fixed. I need to remove them from the forum.
I will check too see if the mods are all ok and go from there.
Would a decoke maybe help me with the lost power?

 

UPDATE
Car does boost too around 20/21psi in 3rd and 4th gear

 

I think i reply once again in similar post.
If car sometimes boost 20+psi and some times boost lower and reverse..
Check selonoid valve.
This valve its impossible ti read a fault by ANY program so you see no faults however you still got problem.

How you take your values?(psi)
Boost tap?Obd?
OBD shows the actual boost that ECU request however the selonoid valve is after the Tmap so if you have an
Ultragauge(reads OBD)
Gauge with boost tap that reads directly with vacum tube...
Then the measurements/values might be the same at low PSI but after 14+ psi you will be able to see lets say....
20psi at your Ultragauge and 15on your boost tap.

If thats happening. CHANGE the valve and you done.

 

I have both too read PSI.

By selonoid valve what one do you mean? I have changed the one at the back of the engine already and same problem.. on the n18 there is two one of the front and one on the back near the intake manifold.

 

He is referring to the "Pressure Converter" or the boost pressure solenoid that controls the waste gate on the turbo.
https://www.realoem.com/bmw/enUS/sho...diagId=11_4556

If the pressure converter fails, the waste gate will not close, causing low boost pressure.

 

Yup...
I am referring to this...
11657599547

https://www.google.gr/search?q=11657...w=2560&bih=975

Many N18 fails in that part and if you dont know it you aint going to find it because as i said..You cant find it as a fault in any diagnostics