Okay, so I have a sneaking suspicion that something's not quite right with my R53's power delivery. It's an '06 with 6 speed manual. Well, we just got done doing some work on my girlfriend's '05 with a 6 speed automatic. Upon taking hers for a test drive, it was pretty clear that her car is FAR faster than mine and the power is much more instant, as well as more plentiful on the top end. I also noticed the whine of the supercharger is much more obvious than it is in my car. Both cars are completely stock, except I have a JCW intake with Alta foam filter. All this & her car has 30k more miles on it than mine

I have also noticed a very difficult to describe sound coming from my car whenever I accelerate, but it is very consistent. It sounds like its coming from the engine bay, directly in front of the driver's seat. It sort of sounds like a very fast brushing noise, which I always attributed to being the sound of the transmission since it's right in front of the driver, but maybe it's related?

When I recently had the supercharger off to service the oil, I checked the spring return of the bypass valve & all seemed well, but I suppose it's possible for the diaphragm to have a hole in it inside? What would be the best way to test for this?

Another thought I had is the belt tensioner. The tensioner on her car really doesn't jiggle around all too much, though mine does. I have a new tensioner assembly being delivered this next week, could that damper being shot have that noticeable fo an effect?

Any other ideas you guys have or tests I could run would be greatly appreciated!

 

Any lights on the dash? Temp okay? Was it powerless before you did the supercharger service or did it start afterwards?

 

If the Tensioner is going bad it will allow the drive belt to slip and under power it will not be allowed to produce the power you are use to...

Check your belt and pulleys for worn belt material evidence.

Motor on!

 

One easy way to tell is to buy a boost gauge....see how much boost your SC is actually making. If it's low, you know you either have a leak, have a bad BP valve, or have a bad supercharger. A boost gauge is cheaper than guessing and spending a bunch of money on something that isn't broken

 

Check your SC boots...they might not be on right or you might have one split. They DO get hard with age...
Guess it is also possible something did not get assembled right...you used new gaskets when you put it together right?
Might want to rev it a bit, and use a smoke stick or something as a poor mans smoke test to check to see if you have a boost leak....

 

Thanks so much for the replies everyone! After doing more research last night, I decided to pick up some new vacuum tubing at the store & double check everything when I got home. Well, the short bit of tubing that plugs onto the BPV was rock hard and came off with the slightest push, so I'm sure that was contributing. The second culprit I found was inside my JCW intake's airbox. The small diameter tube that is T'd off of the BPV line had come disconnected inside the air box. I re-connected that and replaced the two shorter lengths of vacuum hose after the T (couldn't get to the line below to replace it as well but it seemed softer & more pliable than the two I replaced).

So, I reset the ECU & took it out for a spirited test drive. MUCH better!! Smoother off the line & I could hear the SC whine! However, after driving for a good 20 minutes, I felt that the car was starting to get a bit sluggish again. Not nearly as much as before, yet not as zippy as it was right after the ECU reset.

No lights on the dash (except for the stupid airbag light from the pass. seat sensor).

Okay, I'm glad you mention this. I also noticed that the new Goodyear Gatorback belt I recently installed has stretched beyond where it is supposed to be over the span of the past couple weeks. The first hole on the tensioner is no longer visible. I'm just running a stock pulley & ordered belt number 4060547. Is this belt known to be just barely too long or something? Would a failing tensioner cause this somehow?

I would LOVE to get a boost gauge! If there's one thing that drives me nuts about this car, it's the lack of water temp and boost gauge. So ridiculous. One reason I haven't gone this route just yet is because all of the mounts seem to be designed to mount behind the single tach configuration, rather than the tach / speedo configuration that mine has since mine came with Nav. Does anyone have a recommendation for a good mount I could get for my setup? Looks like there would be -just- enough space to the left of the stock gauges, to the right would just be blocking that dash vent...

Yup, I used new S/C gaskets & have some Alta silicone intercooler boots being delivered this week, since I noticed the original driver's side boot was pretty full of shallow cracks, though not all the way through as far as I could tell.


Another thing I should tag onto the end here is that while I was looking at my belt tensioner situation, I noticed that the ticking I thought I'd solved by replacing the timing chain tensioner seems to still be there possibly louder? What's weird is that it really doesn't sound like it's coming from under the valve cover, it sounds like it's coming from just outside of it but I can't for the life of me figure it out. Has anyone else experienced this?

 

Check out Cravenspeed for their 52mm boost cup and Z bracket. I have the dual gauge setup too (tach and speedo) and mounted mine with an autometer 20psi ultra lite gauge in silver. At night this lights up perfectly and has the same or very similar background lighting to the stock gauge. Have you pressure tested the motor? Might be a head gasket issue...

 

Also, I have a set of barely used DDM red silicone Intercooler boots. $28 shipped to your door if you'd like. You can always return the ones you got!

 

I wouldn't recommend doing the ECU reset again (or at all) until you're sure you've fixed the issue. Whatever is making the car sluggish is a sign and putting a temp fix on the sign can make it a lot worse. I don't like how people just keep resetting it thinking that's the only thing wrong . One thing that happened to me after my S/C job, the MAP hose that goes down into the air duct on the driver side, that had gotten pulled and busted off the MAP sensor, but was throwing an SES. Smoke test would be best for you to find the leak. Cheaper than replacing a bunch of unnecessary things. Best of Luck! Motor On!

 

Well, I was pretty sure I had fixed the issue by replacing the obviously leaking vacuum hoses, which is why I reset the ECU. I know the ECU isn't the cause of the issue, I just wanted to give it a fresh start on a properly running motor, though it looks like I'm not there quite yet.

So this afternoon, I logged some of my driving in DashCommand on my iPhone. After looking the data, it looks like my long term fuel trims are jumping between +4 & +9. So, it looks like I'm still looking for a vacuum leak or possibly a bad MAP sensor. I should probably look more into this smoke test everyone keeps talking about to find leaks....