Mini cooper s JCW 06' plus Megna header no catylitic only +91 octane. I put it on Dyno before 3 days ago it shows me 170 (B.H.P) Flywheel 180HP as the Dyno man told me with 198 Torque (NM).

It has very low HP . Please NAM member help me and also Jan

This is also the result graph:

http://good-times.webshots.com/photo...03528628XlGyim


http://good-times.webshots.com/photo...03528628zTrdGy

 

With no CAT I wonder what the O2 sensors are reading? I wonder how the ECU is reacting to the bizzar O2 readings? Extra lean or rich fuel/air mixtures? Ignition advanced or retarded due to the faulty O2 readings?

 

There is O2 sensor what i mean is there is no catylitic

 

I think it's been said on NAM that going catless actual gives less HP because of not having enought back pressure.

 

It is racing header

 

I'll repeat, these engines make LESS POWER WITHOUT A CAT. Whatever they call it, you'll make more torque and HP with a cat on there.

170 whp isn't that bad. That translates to a little over 195 BHP, which isn't terribly off from where JCW is supposed to be. Your graph says BHP, which is odd. Going catless isn't going to rob you of 30-35 HP.

If you have the AF's that would help a lot in diagnosing any potential issues. I'd also run a compression check to find out what the status of the engine is.

 

How many HP i will gain with CAT ?

 

Is it an original JCW from the factory or retrofit to an 2006 MCS?

Did you retune after installing the injectors?

Do you have a dyno with your air/fuel ratios?

Do you have the ability to datalog using the ODB2 port? If so, you might want to consider doing that.

FYI - The values seen on the chassis dyno are not BHP, they are WheelHP and aren't easily used to calculate BHP. There is a certain amount of power lost in the drivetrain (tranny, diff, axles, turning wheels etc). oftentimes, dyno operators also set a correction factor to account for height above sea level and other factors. Heat and humidity will also affect dyno readings.

Typically dynos are done in the gear that provides a 1:1 ratio (or close to it). Is that 4th or 5th gear on this car?

 

Its not a question of gaining. Its about getting back what you lost. Without A/F maps we can only make guesses. Did the attach a sniffer or get any A/F maps?

 

1- original JCW from the factory
2- It has original 380cc
3- I don't have
It was on 4th gear

 

What is exactly A/F map ?

 

A graph similar to the other two that you posted that shows the ratio of air and fuel mixing in the engine. If it's out of wack, it would explain your HP.

 

I don't think so i have problem in the A/F map

 

Your A/F will tell you if your car is running too lean or rich. Chances are you are running rich and that will take HP away from the car.

 

How I can lean that exactly ?

 

By looking at the A/F map! A/F stands for Air/Fuel. It shows where you run rich or lean. You wouldn't really know you had a problem with the A/F Ratio unless you looked at the map. Why don't you think you have a problem there?

 

i mean if it's whp then 170-180 would sound about right for a jcw car.

 

1+
looks ok to me

You also have to remember different dynos will give different results...

 

Most R53 JCW cars dyno on a Dynojet from the low 170's to low 180's in wheel HP peak. The couple GP's I've had on a Dynojet both made mid 180's in wheel HP peak.

Does your car feel slow compared to other MINI's with similar mods or are you just not happy with the dyno's numbers?

 

I agree, if it's WHP the numbers are close enough that it could just be a weak car. He claimed they were BHP figures (As does the dyno sheet). 170 BHP on a JCW is low (Considering the standard cooper s makes 168).

 

Luys, keep in mind that these are modern cars and as such they run a really fine and delicate balance. The tuning is set from the factory to be extremely sensitive to changes in readings from it's sensors.

An O2 sensor is designed to measure the amount of oxygen in the exhaust stream. This measurement helps the computer know how much O2 is being burnt in the engine. It helps the computer, along with several other sensors to know how much fuel to inject during each cycle. This in cylinder mixture is called your A/F (air/fuel) mixture. If it runs lean you get detonation, if it runs rich you get unburnt gas.

So by running catless your are doing several things:
1. You are violating several federal and state laws.
2. You are violating several good citizenship rules and polluting the heck out of the environment that we all have to share.
3. Your O2 sensor is being gummed up by all the crap in the exhaust that your Cat should be cleaning out of it.
4. Your O2 sensor is getting a really poor reading & over time you are damaging your engine by running a lean/rich mixture.

Solutions for you:

Go read the entire "Suck, Squish, Bang, Blow" series by Mike Kojima so you have a better understanding of how a modern engine works. You can find it on Sport Compact Car's website.

Realize that a header that isn't flow matched to the head is a waste. All you are getting is a lot more noise and, in your case, a motor that will be shot in 20,000 miles.

Realize that this isn't 1970 and you don't have a 302 V8 with a carburetor & as such, taking the cat off is a bad idea.

Good luck with your tuning & keep asking questions. It's the only way to learn.

 

I am not happy with my DYNO number. before 2 month ago maybe Jan put JCW car on Dyno and the result was about 165-175 HP after that he did it 210 HP

 

Ok, As I know if the O2 sensor is not reading well than the fuel economy will be bad but my fuel economy is good. If I put Cat do I will get less HP ?

 

ya but pre-tune your car is turning numbers that i would expect out of a jcw car. with jan's tuning behind it... any mcs is a lot stronger. without it... it's just a normal mcs.

 

There's no rule of thumb here with how it will react. Without looking at the air fuels your guess is as good as any.