[sam_a156]

Life with a MINI would be way too easy and boring without some weekly trouble shooting.

I just managed to get my clutch fixed last week and was a happy man - finally nothing urgent to fix or modify, time to enjoy the car and have some fun. Err...not.

First I wasn't 100% happy with the 0-60 results I was getting with GTech and then even less happy with the dyno results (even with a jar of salt)...yup, seems that somebody has stolen some of my ponies - my out-of-the-hat figure is some 20hp down from the 220-230hp I should be at in ideal conditions.

My current setup:
- '05 MCS JCW with 42,000km
- JCW CAI flap mod + Madness JCW filter upgrade
- GTT manifold
- GTT +3% crank shaft pulley
- GTT modified bypass valve
- GTT IC + snoot boots

Possibly something has happened during the clutch change...or then this is something else entirely. I already exchanged some messages with Roland and Paul (thanks for your support). Got some pointers from Roland to check the T map sensor, belt slippage and boost leak - latter two I guess are the usual suspects in a case like this.

Today I also learned that during the dyno test my AF (air to fuel) ratios were around 13 below 3500ish RPM - I was told that there was too much air compared to fuel (the correct term I believe is "running lean"?).

What is the safe AF range? I remember seeing a post somewhere (NAM?) that the std AF would be around 8 and that 11 should still be ok...any views on this?

The guys who run the dyno shop also do ECU tuning and (not so very surprisingly) strongly recommended a custom ECU map. Now, this might be a good idea in any case and I have been contemplating with the idea - but I just would not like to start doing that before I am sure that the 'hardware' is in a good shape.

My plan is to do the checks Roland recommended but I would welcome any comments to the above if you have had similar experiences. I was also trying to search info on how a faulty T map sensor would affect the car's performance, but did not find anything very specific.

Sam

[chuntington101]

i would check everything to make sure its not something obvious like a leak or belt slip. then its time to take it to the tuners and let them do what they get paid for, to TUNE YOUR car with its mods!

sorry but in these modern times when its relativley easy to get a proper remap, i cant see why people dont bother! yes ok upping the injector size or running a higher fuel rial presure MIGHT get you by but come on guys thats a pretty naff answer.

there is a very popular saying that sums tunning in the 21 centry, "its all in the tuning". get that right and you can have more power and keep the car reiable to!

as for the ARFs sam i'm not sure on the specifics for the mini, but most boosted guys look for 11-1 under boost. this is normaly with turbos and not sure if the mini needs a little more fuel to cool the intake air.

thanks Chris.

[sam_a156]

Quote: Originally Posted by chuntington101 (original)

as for the ARFs sam i'm not sure on the specifics for the mini, but most boosted guys look for 11-1 under boost. this is normaly with turbos and not sure if the mini needs a little more fuel to cool the intake air.

Thanks Chris,

I believe you are right. I did quite a bit of research @ NAM last night and the consensus seemed to be that 11 should be more or less ideal and 13 too lean for MINI.

Booking my car in first for some basic checks at the dealer next week. Was supposed to fix some little troubles with windows anyway...

Later I might take the plunge and get a new custom ECU map too. What I liked about their approach was the fact that they were not trying to sell me crazy power gains with the new map, but rather they kept emphasizing the safety aspects. This sounded like a prudent attitude...well that, or then they are good sales people

[roland2003]

hi sam, 13 :1 is typical of a JCW/GP/MTH remap at around 3500rpm, and is fine at this rpm. Having said that stock maps run a bit more fuel in this area (which I prefer...less flat spots ). Its the area above say 5000 rpm it MUST richen up more ......yep about mid 11's would give better results.... GTT Adjustable Fuel Pressure Regulator should achieve this . A remap cant give any more injector duration than the time available. -Increasing the fuel pressure will give the extra fuel required without maxing out your JCW injectors.

[sam_a156]

Hi,

Eventually found a post from NAM where sb had copied his JCW's AF logs from a dyno run. Like you Roland said, he was also running around 13 lower down and around 11is higher up. So nothing extraordinary here then.

I must confess that suddenly a small investment into additional gauges starts to make sense. Boost gauge would be a nice start and why not oil temperature and A/F ratio thrown in too (assuming that you can get A/F data...I presume you do?). At least you would know where to start...

[Minipnut]

no reduction pulley ? isnt the jcw map tuned for the 15%~ ?

[sam_a156]

Quote: Originally Posted by Minipnut (original)

no reduction pulley ? isnt the jcw map tuned for the 15%~ ?

My car is a '05 MCS JCW (upgraded in '06) so it has the JCW reduction pulley. There seems to be some confusion about the exact reduction %, I have seen anything between 11% and 14%...probably the latter is closer to the truth (?)

[sam_a156]

More evidence that something weird is going on. My fuel economy has become ridiculous: 16L/100km in the city (that's SUV beating 17.5MPG! )

To compare, driving from GTT to Dover on a highway I averaged record breaking 7.9L/100km (35.5MPG) and even in the city I believe I was around 12-13L/100km prior to my clutch "fix".

This would be pointing towards a t map sensor problem...or perhaps they accidentally remapped the ECU (I had the engine light on and to fix this they also were fiddling with the ECU).

Booked in next Thu to do the checks.

Will post if I learn something from this...

[Tifun]

Can the mini tuners not pull timing when adding or pulling fuel? That will help a lot with detonation and running high AF's