Your intercooler boots might be leaking. It would be a good idea to get uprated ones. Also, if you are getting that list of mods, and you can afford it, get the piston rings replaced while the car is appart. Then break them in according to the following site to seat the rings well. http://www.mototuneusa.com/break_in_secrets.htm This principle works for any internal combustion engine.

 

New pulley belt, new clutch, new air filter, new spark plugs, new engine oil and higher tires pressure , you will see a gain back from some that you've lost.

 

clutch?

 

It might have slipping in clutch.

 

If everything else is OK like no belt slip, no leaking boots, good ignition, no engine knock (will show in the graph), clean filter, good cat converter...try doing compression test.
JCW is over-priced for the amount of power that they are showing during dyno sessions consistent from different dynos and different locations. No wonder some call them crap but cheer up, mod it up & get RMW tune if possible and you'll get there.

 

Check for a boost leak... could be a faulty bypass valve.
Compression/leakdown test is also a good idea.
It may also be the dyno...it could read low, have any other minis been on the same dyno and if so what are there numbers like?
I know Aussie dynos read lower than US and European dynos...dont know why they just do!

 

Altitude definitely will have an effect on your reading. Here is a good site to tell you your density altitude (altitude corrected for temperature/pressure/humidity)

http://www.pilotfriend.com/calcs/cal...rs/density.htm

It also gives you a percentage vs. air at sea level. For pressure I used 29.92in Hg as that is "standard" its the same thing as 1013mb. I guessed your dew point and put it fairly high at 20C. In this case your % was 81. So theoretically your car should make 81% of the power that it would at sea level on a "standard day". 165 * .81 = 133 ...so theoretically you car would make 165hp CORRECTED...thats NOT bad

I wouldn't go checking for a faulty bypass valve or boost leaks yet, I also wouldn't be horribly worried about "fixing" the car before modding it. It doesn't sound like your car is far off. As an 03' you should expect slightly lower readings compared to a newer car as the tolerances were not as tight. Also, your car probably has some miles on it and isn't operating as strong as it did the day it came out of the factory. That other guy had a JCW with a header and he dyno'd 169...corrected figures, you aren't far off him.

Now, if you replace your air filter, change your oil, and change you plugs and do a dyno...that is probably the best you will see for now considering that you are due for some regular maintenance. If you do have a slipping belt, you'll find out after your pulley install, I wouldn't worry about it much before then. However, I WOULD do a compression check now before you start modding it so that you have a baseline for how you cylinders are performing. I checked mine not long ago and got ~ 155 +/- 3 across the board.

Good luck!

Eric

 

Oh yes I forgot, I'm also getting the ALTA intercooler couplers so that's also taken care of.

I'm going to see if I can get the piston rings locally. Do you know the specs I would be needing? My car only has 35,000 miles now.

 

I'm garaging the car since 3 weeks go and I haven't touched it since. My tire pressure indicator was blinking on the way to the dyno. I didn't bother getting it checked before hand so I'm guessing that must have had an effect on the outcome. I got the tires inflated after and the front left was a bit deflated compared to the right.

 

I had the clutch changed 1000 miles ago with another OEM one from BMW. They didn't skim the flywheel though and it's making this "OOOOOOH" noise sometimes when I pull away. Would this have an effect on the end result?

Edit: I forgot to mention the flywheel (at least that is what I think is causing the noise) only started making those sounds after the new clutch was installed. Never had them before ever.

 

I'm a noob, I have no clue how to check for engine knock on the graph I'll scan my dyno in and upload it here. Results are in kw and NM though.

 

Wow I love this forum! Very informative and great crowd! What you are saying does make a lot of sense. Where can I get my compression checked? Would BMW be able to do this for me?

 

I think before you get that in depth, try changing the $25 belt and the $40 intercooler boots and see if you recover that power. Those are by and large the most likely places for you to be losing that power. At our dyno day in Seattle someone recovered 30 hp by changing the belt alone.

 

Sure BMW could do it. You could probably do it yourself too...its quite easy. Simple buy a Compression Tester at an automotive store, they are normally ~ $25 USD over here. Then pull all the spark plugs and plug wires. Then screw the tester into the spark plug hole (just like you would the plug). Have one person holding the tester, have one person turning the key to start the car. Obviously it will not start without compression in the cylinders or having the spark plugs in. You also do not want the fuel injectors spraying so the person starting should also have the accelerator pressed 100%. Simply crank the engine over (mentally note where the gauge lies at about 5 cranks) and stop cranking when the gauge peaks which should be at about 10 cranks, don't crank much more then 10 though, if you need to then something is wrong. Repeat for the other cylinders. It should take 30min max. But if you want BMW to do it for you, I'm sure they could.

In all honesty Jan says that the MSD coil pack is junk, the plug wires are not worth it, the Alta intercooler couplers aren't as good as stock, and well theres a lot of things you can save yourself money on and probably save your self from loosing power as well.

 

if you're doing a compression test, disconnect the leat TO the coil, not just the spark plug wires. Otherwise the high voltage is still created, and it WILL find a way to get to ground....

Matt

 

^ yes that too don't zap yourself!


Though in all honesty its not that bad 40,000 volts wont kill you when there isn't an amperage behind it. I've been shock by plug wires before and its a good zap, but nothing too dangerous. Disclaimer* this is my own experience and I am not suggesting you try it nor that it can not effect you

 

I take the fuel pump fuse out as well when doing comp check so it does not put fuel in when you are testing

 

That is a sure fire way to be positive no fuel is going in...I just have never been sure if that might throw a code which I is why I didn't do that. But with throttle at 100% it is not SUPPOSED to spray fuel, I didn't smell any when doing my test, so?

 

No codes

 

compression and leak test and also check the lower wishbone bushes as if they are worn dyno results can be way out

 

Now you guys are getting too technical for me to understand

 

lol...you can just take it to BMW, or any mechanic shop for that matter as it is an easy job. The charge should be equivant to 1 hour of labor or less.

 

Thanks //MZero! I'll have it checked.

In the meantime here are the dyno sheets are promised.

First one is of my Mini Cooper S JCW. Does everything look normal here? No clutch slippage etc?


My friend's Fiesta ST that was dyno'd right before me. Car is stock except for aftermarket cams and CAI.

 

That looks like a normal dyno graph with skewed numbers to me. Carry on with your search. What have you actually checked/replaced at this point?

 

yea...numbers that are uncorrected for the altitude he dyno'd at!