Hey guys I've reported power loss before in my 2010 XFR and I still can figure it out.. my car is going in for oil change with my indie next week where should I have him look. <br /><br />I mean to drive rhe car it still feels powerful and fast so it's hard for me to get my point across . But I know it's underperforming from many examples .. <br /><br />but one is my friends s550 factory standard complete obliterates my xfr on take off.. is this normal? I dont think so right. <br /><br />Where should be areas of investigation? <br /><br />Thanks giys

 

Do you have any warnings on the dash, check eng light? Is it noticeable at all times, or when its still cold, or only once hot?

 

no dash warnings... honestly it's only really noticeable when your up against a car that has no business being up against an XFR .. honestly it may sound silly but that's when most noticeable .

 

Feels like it hangs and take off is just terrible ..

 

i think it has something to do with the R-S badge on your grill

- is the S550 a 4matic? that will cause it to launch faster.
- what kind of tires are you running? maybe you're not getting good grip?
- check the air filters
- clean out the MAF sensors
- clean out the throttle bodies
- check the spark plugs
- throw in some techron cleaner, maybe something is clogged but not enough to cause errors.
- could it be signs that the supercharger might be going bad? a belt or a pulley going bad?

it could just be that you've become immune to it. its strange but sometimes i feel the same, the car felt like it used to be faster. good excuse to get a tune!

 

I'd start at the supercharger, specifically is the boost bypass valve fully closed when calling for power.



The bypass valve is the gold circle, It's job is to bleed of boost when your not needing boost. but if it's out of adjustment it can bleed off boost all the time. It's a pain but it can be adjusted while on the car. Tell your indi max boost should be 11.6 psi, and can be seen with a real time scanner, under the MAP vacuum/boost table

Excessive carbon build up on the valves and ports can cause power losses too, but I really haven't seen a jag with that bad of build up. My XFR with 85kmi was not that bad when I just did my supercharger service and cleaned my ports and valves.

 

Have you run it on a dyno? That might be a good way to put some science behind the feeling - and perhaps indicate places on the curve where there is an issue?

 

It may be a 4matic i need to check.. My tires definitely need to be replaced with better tires.

MAF sensors and Throttle bottle where cleaned previously ill ask again. Spark plugs may need replacing, can this have a big impact?

Techron i have been doing a few times.. As for supercharger, it is so hard to check? Will have pulley and belts checked.

Any other ideas before i take it in?

Thanks guys, Bigwill ill show my guy that thank you..

 

Having MAF sensors cleaned is one thing, whether they are actually reading correctly is another...... I've had multiple cars in the past with no warnings or check engine light with a faulty MAF. Only way to tell is run live data on diagnostics to see what the MAFs are reading in comparison of each other.


Plugs may be an issue - if they are due or fouled, but even then you'd notice some sort of a misfire anyway.


You need to be careful cleaning throttle bodies these days, if you remove the coating on them, can cause issues.

 

any updates on this? im curious.