I've been driving my N14 2012 JCW with the stage 1 FMIC 92 oct map for about 6 months with positive results over the stock mapping. I recently Dyno'd the car prior to removing the factory downpipe and replacing it with a 2.5" catless one. After obtaining a baseline result we dyno'd the car again with the new downpipe installed. The dyno runs were several days apart and while atmospheric conditions weren't identical they weren't that different. I was surprised to see only a 2.5 HP increase with torque and boost staying nearly the same as the pre DP dyno runs. In fact boost didn't change at all which surprised me. The car does dri Keep in mind this catless DP is mated to the FJCW exhaust. Regardless I thought I'd see more of a change.

Does this sound right to those of you who've done similar to your cars? I've emailed Alta but haven't heard back yet.

 

Data log it and send it to alta and have them adjust it.

 

I think that the programming of the Engine Control Unit sets the boost pressure, so lowering the back pressure of the turbocharger wouldn't raise the boost, the tune does that. The turbo would spool up quicker with the catless down pipe and with less restriction in the exhaust path, you would see a small horsepower gain.

Dave

 

Sounds about right from what I have heard....
I think it is safe to say car builders have gotten MUCH better at producing emissions products that don't reduce HP and MPG as much as the past....there is BIG money to be saved/made in doing this!!

 

Thanks for the input folks. I data logged one of the dyno runs and sent it in my email to them. I'm not looking for huge gains but would like to see more. Until I can replace the remaining factory exhaust I have to live with this though after these results I'm wondering how much difference a 2.5" DP back will improve things. I'm sure jumping to stage 2 will tell me at that point. I'm hoping they can adjust the current tune enough to get the most out of it.

I will say, yes, turbo spools much quicker and overall the car runs much smoother. Drop off in boost is far less dramatic and torque doesn't peak and fall as rapidly as before.

 

Sounds like the AP..

A dyno tune can get 10-15WHP out of a Catless DP.

not surprised to see altas weak tunes behind the curve.

 

Whoa man whoa, it is a canned tune of which he is running stage 1. OP what mods do you have done to the car?

 

Thanks for the reply

Besides the 2.5" catless DP (mated to FJCW exhaust) I have a DOS intake, Helix IC and an Alta CRV installed.

As for a dyno tune, ya that'd be nice but I live 500+ miles from anyone that tunes MINI's.

 

Spot on. The ECU is setting the target manifold pressure, and without changing the tune decreasing back pressure is not going to make the boost any higher.

However, as you point out the turbo should spool up marginally quicker. Also the turbo has to work slightly less hard to make the same boost, so there is a marginal increase in efficiency, ie less heat produced etc.

Changing the tune means that potentially the turbo can make a slightly higher boost with the same amount of work it did to make the stock boost, if you get my drift.

However, having said that, some of the cats on hard driven cars have been compromised by prolonged high boost (ie partially melted) and may be more restrictive than a stock cat. This means that the turbo may not achieve the target boost, or even if it does reach target boost it may not flow as much air due to increased backpressure. In this circumstance it is possible that by removing the cat you may see a more significant gain, which is possibly why some people have seen bigger dyno gains, ie there cars were not performing as they should prior to cat removal due to an overly restrictive cat

Over time my JCW rally car almost completely melted the cat, and would hardly boost at all until I removed it

Robbo

 

Thanks for the input. Makes perfect sense.

 

Just put on the stage 2 and you should see some better gains

 

N=1 experience

1. Other local MINI was RMW tuned on a dyno and gained about 40whp(no mods). Went back a few months later with a Akrapovic downpipe(catted) and dyno showed no gains. I was definitely surprised from this. Although I'm not sure if there's a bottle neck elsewhere(no other mods)

2. Too many factors to really pinpoint gains from my personal Akrapovic downpipe experience but I mated mine to a 3" exhaust and turbo spool is almost immediate. I actually surprised myself a handful of times since the tune while accelerating suddenly. Didn't expect the boost to kick in when it did. I'm sure that it is partly due to the downpipe.

 

I've considered trying that but was told by Alta, in the name of all that is holy don't jump to stage 2 with anything less than a 3" turbo back exhaust so I've been hesitant.

 

2.5" vs 3" makes NO power, just LOADS more noise.

This was tested up and down by multiple companies. Alta doesnt know what they are talking about.. after all they didnt even design those AP tunes.

 

Jeremy,

Sorry, that is false, we made all of the maps here on our dyno.

 

mhmm. I will leave that one alone.

Either way, exhaust size has been argued up and down. There is no gain to running a 3" vs 2.5". 2.5" sounds miuch better and has less drown.

 

Jeremy,

You can believe what you want, but we did make all of the tunes here. Jeff literally spent weeks on our dyno making them all!

 

Drone-wars. I had a 2.25 on my r50 and there was LOTS of drone. I think it has more to do with the resonator and muffler than the diameter.

 

Thanks again for the input folks. On another note, i realize some people feel an inordinate amount of loyalty to who they've personally had success with but we should all really leave Internet here say out of these forums.

 

If you want like I said before data log you car with whatever tune you want to run and send it into Alta so they can tailor it a little bit and I bet you will be a lot happier.

 

Good plan, thanks man. I'm sticking stage 2 TPS on tomorrow for some data logging and see what they can do for me.

 

I did stage 2 with the mods in my signature. My exhaust is 2.5 with no cat and no resinator. I have no issues at all and although I have no dyno to prove before and after...it is not hard to notice the difference between stage 1 and catted dp vs stage 2 with catless. Dofference was pretty big. First alta says stage 2 is good for 3" catted or 2.5" catless dp and 2.5" cat back is ok...then it's not ok. I have had multiple conversation with members here who did stage 2 with a 2.5" exhaust with no problems at all.

 

When I had my AP and dynod in @ 200hp/220tq. So you might be somewhere around there with a stg 2 on your JCW. Most likely higher.

 

I have the alta downpipe back, helix front mount, intake, alta spring in bov. I ran stage 3 before and after catless downpipe.. I would have to say that it made a huge difference (no dyno) driving the car. It feels like the whole powerband shifted up 1000 rpms? where are you located that there is no local tuner? Just curious?? Louisville ky??

 

Yep near Louisville. Is your car an R53? Just curious due to your screen name.