Mos tot my Autocross customers really like my 43/56 turbo I make Its spools very quick but makes about 30hp more than the JCW. Also anddont an Electronic Boost Controller, block off plate, BOV and Tial wastegate will give you even faster response.

Mario

mQubed Motorsport Manic & RPM Power Tuning

I guess it all boils
down to what your definition of
turbo lag is
few months back i finished a
build for a guy
that is running a GT 47mm
along with a
RPM stage 3 flash " 1.45 bar "
i got to run it
at the last autocross event
honestly i feel
the turbo lag is so minimum
i wouldn't even consider
it lag

regardless what turbo you go with
am sure you will have no problems with either of them.

BTW mario wife like them green suckers you
set the last time around.

I’m quite happy with my JMTC JM40. Spools as quick as you want and feels quick too, which is important for me. I have installed a 42mm on a very similar R60 to mine, the only real difference was that mine is an automatic and the other is a manual. The 42mm turbo makes great power! No complaints at all. But, and I fully acknowledge that it may just be me, but for some reason mine felt quicker. And I could tell the difference in lag time going from one to the other and back. That’s said, I think you would be perfect happy with a 42, I would be.

if you're in the states
check out
gpopshop
I've had really good luck
with them
I do quite a bit of business with them

I think with any of the 3 or 4 there you would be happy. They all spool pretty quick. Other things will affect it too, like Mario stated. The JM40 is basically the same as a JCW turbo, they are both 40mm. I guess it just depends on how big you want to go! I would recommend, if it’s an option for you, to try do drive a few similar Minis with different turbos to get a feel for what you want. I realize that may not be as easy as it sounds, especially depending on location. But other than speculation, others opinions, or plain old trial and error of putting a few on your car....a bit of work......that’s really the only other way to know for yourself.
When I ordered up my turbo, I had no idea, lol. I needed a new one and decided to go a tad bigger, but initially wasn’t going to get a tune. But as these things go, then I bought a new DP and it just kept going from there! The 40mm is a direct bolt-on that can be run without a tune, but is much better with one.
If I had it to do over again, I probably would have bought a 42 or 45, but am totally happy with the 40, so I’m in no hurry to change it again. It’s a huge improvement over the stock 37mm for sure!

YEah GpopShop can pretty much do
what ever you like.
HOWEVER!!!!!
you would have to get a hold of them
an chat it up
am just a Mandingo on the forums
don't want to be putting words in there mouth
I've had really good luck with them tho
especially with the vw / audi stuff

but if your looking at making more power or
bigger turbo things
might as well just go a head and get a
bigger turbo
" 45 / 47 mm "

As far as witch turbo spools faster
i feel like its kind of a loaded question
like the other guys are saying
the 40 / 42mm are basically your OEM upgrade
personally i feel like mini doesn't have a
spool / turbo lag problem .
its a 1.6 along with baby turbo
i feel like its more of a throttle responses problem
along with a heaver flywheel
OEM flywheel weights in about 26.4555 lbs or 12kgs
along with poor throttle responses
its going to have a hell of a lag feel to it
especially when looking at the tech slowing going up
nothing a good tune or clutch set
up cant fix's

on my personally mini
i run a 47mm with a light weight clutch set up
helix single-mass
4-paddle clutch
so going off of what lohen web page say's
the helix single-mass
measured weight is 6.2kgs or 13.6687 lbs
that a prettty big jump
from the oem 26 lbs
if you want to go lighter
you could go with a
TTV lightened flywheel dual-mass
measured in at 4.9kgs or 10.8027 lbs

i guess where am going with this is
spooling up fast isn't
necessary a turbo problem
more of a perception thing well maybe
hopefully It makes half way sense
but regardless what you do or go with
it will be loads of fun.

Yes, you can run everything on a stock file, but the car really won’t be faster and I would keep it below 5K RPM until it’s tuned.

Mario

mQubed Motorsport Manic & RPM Power Tuning

Mario can probably give you a better answer, but my guess would be that because you are pushing more air volume even at the same psi, it can throw your air/fuel ratio off, and since these cars run lean for emissions to begin with, you don’t want to cook your motor.

pretty sure it
pops a code
over 5k
but you will be fine for daily

I was looking for a thread
that talks
about this very topic
just did a quick search
but no luck
I'll post if I find it.

Yeah, I was kinda guessing there since I only have experience bolting on the JM40 without a tune. It felt good, but with a tune it’s so much better!
I know that a 40mm will go right on without issue, because I did it for a while before I got tuned. Not sure about anything bigger personally. The 42 I installed for someone else, already had a tune installed.

seems like a lot of
guys like the
42mm
especially the auto x guys ..

Let me know, I’m a JMTC dealer, I can also package the ECU tuning with the turbo as well
thanks Mario

mQubed Motorsport Manic & RPM Power Tuning

if you can swing it
try to get the tune with it right away
very good possible there might be some disappointment right off the bat
without that tune.

I agree with BigBoost, try to get the tune right away to really realize the upgrade. I know when I did mine, unless I adjusted the wastegate to make it run higher boost, which isn’t really good for AFR’s I imagine, I didn’t notice a huge difference, but when it gets cranked up to 20 psi or more with a tune, you will know that it’s a real improvement. Especially up top where smaller turbos start to run out of breath, hell mine still does a little bit, but you have to really push it, because it’s still a pretty small one. The tune is really the big difference maker.

Heck yeah they are! No matter what you end up doing, as long as you are happy with it, that’s all that really matters anyway.

Another reason is the downpipe. You probably are going to want to upgrade your downpipe when you do your turbo. And a lot of catless and ho-flow downpipes will give you a CEL. It won’t hurt anything but it’s annoying, until it gets coded out with a tune.