I have a really clean '02 Justa that I really enjoy. It runs great and handles like a go-cart but the power band is too high. Most of my driving is in town and off the line, it's a pooch.
I know there are gizmos that are alleged to improve throttle response but they are stupid expensive and the science behind it is questionable at best. And yeah, I know it is only a naturally aspirated 4 cylinder but I have had plenty of them before that would leave this car in the dust.

Now before you S owners jump in and clamor that I should dump it and just buy an S... My car has been impeccably maintained from day one and is as trouble free as a Mini gets. It has high enough miles that it really isn't worth much. It's already had the all the infamous issues corrected and the suspension is upgraded. If I could buy its evil "S" twin and know it wasn't someone else's money pit POS in need of the everything, I would, but I'm not a gambling man.

Back to the crappy throttle response: has anyone installed an aftermarket cam or had theirs re-ground to a new profile? Did you have to have the ECU tweaked after you did? How much quicker is it and how bad of a hit did your mileage take? Did it make other upgrades necessary and was it worth the trouble?

 

I believe RMW has a cam for the r50, i could be wrong. I know he can tune it. Give Jan a call, he will help you get what you want.

 

Jan definitely has a cam. I don't have it, but I did have him tune my R50 and I'm very happy with the results, it certainly feels quicker and the power band is smoothed out quite a bit. There's a dyno graph in my gallery if you want to check it out.

I'm mostly posting in this thread to subscribe, because I'm thinking about getting a cam and retune as well. I'm in a similar boat as you OP... I'm the second owner of my car and I've taken very good care of it. It's an '06 and it only had 30,000KM on it when I bought it and I'm at 82,000KM now with no major problems. You can see in my sig I've put a lot of money into it, more than is reasonable probably. The Sprint Booster is definitely overpriced, but IMO it's one of the most dramatic changes as far as response and day to day enjoyment of the car. They often come up used in the Marketplace when people are parting out or going back to stock, so I'd suggest giving it a try.

 

My understanding is this regarding the normally aspirated R50.
A mild cam will give a little more oomph in the upper third of the rpm range, mostly
near the top, without hurting low end response much.
A more aggressive cam will give a bit more oomph closer to the redline, at the expense
of idle and midrange power.
Coupling it with a ported/polished head will help a little more.
Don't expect big gains in any case.

 

hey, not going to dump on r50s, i loved mine, it was a great car. Yes, i traded for an R53, but the R50 was awesome, but i'm a horsepower freak. And you're right, you have to be careful buying a used R53. Good luck on your R50 upgrades. Great to see the R50s getting some love.

 

The "crappy" throttle response can be adjusted out with a custom tune...
Having both a sprint booster and a custom tune is overkill IMO...and the tuner can adjust the DSC to be less annoying...so I would suggest a tune once you do your changes ..
One tip/warning...
Most cams are made to improve HP at HIGH RPMS compared to stock ....
So lower rpm/streetabilty can suffer on most installs of cams unless you rev it...
So I would proceed with caution.

 

I am a little old school. I grew up with carbureted and mechanically injected cars. When you wanted better throttle response, you ditched the crappy mechanical injection, zeniths or SUs for Webbers, threw in a cam and re-curved the timing. Although, it may not have not added a ton of horsepower it added response and low end torque which is impressive on the butt dyno.

Aftermarket cams are not just for top end, that's why a popular engine like a Chevy 350 has more than a half-dozen different cam profiles out there. The highest horsepower cams trade revs for idle and mileage, highest torque cams sacrifice revs. Kinda like the difference between a sprinter and a marathon runner. Car companies try to find a happy medium with CAFE standards being a major factor too.

I am asking for someone who has actually installed a cam in their R50 to pipe in so I can avoid unforeseen pitfalls. Our cars are not only electronically managed, the ECUs are the very opposite of DIY friendly. I am really far from a dealer (200 mi) so if it needs an ECU tweak to be drivable, then it's not really an option.

Who doesn't want more horsepower? but I don't really need it, I don't run the nuerburgring. 99.9% of the time I am just zipping around town and the .1% that I have auto crossed, the car never got out of second gear. On the street it's all about 0-60 not 60-120 or top speed.

 

Zippy, any recommendations on a mail order tune? There is barely anyone around me that will repair a Mini, let alone a shop that does custom tunes.

 

Consider talking to Waylen at Way Motor Works, Mike at Thumper Performance, Eric at Helix,
and/or Jan atRevolution MINI Works.
They may have some pertinent direct experience to expound upon.

 

a cam and a bit of head work will wake the mini up a tad. theres a new mild cams which is what you need, thumper also has an adjustable cam gear which can yield a bit more low end torque.


and a simple 5 angle valve seat head grind would help performance everywhere. when you start getting to the larger valves with a port a polish is when you start moving the RPM range more towards the upper areas

 

I don't think that a Chevy 350 is a fair comparison. You're talking 3.5X the displacement an applications that run from high-torque towing to high-horsepower performance so naturally there is a whole spectrum of cams (and head/intake combos for that matter). So I agree with Zippy - you're more likely to find that an aftermarket cam for the R50 is going to move your powerband upwards. Other than a tune, maybe lighter weight wheels and/or flywheel?

 

I don't want you to get the impression that I am Mr. Know-it-all, far from it.
I am merely asking the question because although the engine managment systems, metalurgy, and machining techniques are lightyears from where they were 20 years ago, the way an internal combustion engine works has not changed at all.

I picked the Chevy 350 as an example because it has been around since the dawn of time and has been in put everything from Corvettes to steamrollers and boats. Yes, I am aware some variants had higher or lower compression but there are many examples of the same long block being used in radically different applications with only differences being cams and the addition or subtraction of carburetion/fuel injection. I mentioned this only to illustrate that the cam and induction are key to a motor's behavior.

BTW, I have never owned a 350 or a Chevy for that matter. The vehicles I have owned and done the cam and Webbers thing on were a '72 Porsche 914, '70 MGB, '68 Sunbeam Alpine, '71 BMW 2002 and a '79 Honda Civic CVCC but it got Mikunis instead of Webbers. None were big displacement vehicles with tons of motor variants and every one of them really "woke up" after their mods. I got real boosts to the bottom end on a single one of them but I also don't know if I gained or lost any of the top end either.
When I used to turn wrenches for a living I put a cam and headers in a few older injected BMWs (635 and 325 with Motronic) for customers. Those engine management systems were dirt simple by today’s standards and adapted to the new cam without much tweaking.

I know our Mini motors only have one application and really has no need to have a dozen compression and cam configurations. And perhaps you are all correct that any aftermarket cam currently available will likely raise the power band. That is why I asked for someone that has personally been down this path to chime in. If it proves to be true, I can always get a custom regrind on my own cam. I have resorted to that on other oddball engines I have built before that had no “off the shelf” cam available with good results.

I have not gotten a chance to call the suggested folks about a custom tune and maybe that’s all I will need to get what I am looking for. I started with this line of thought because it’s about time to do the timing chain, tensioner and guides as preventive maintenance and that is an ideal time to do a cam.

The basic question I had remains the same: Does a different cam profile freak out the ECU necessitating a trip to the dealer?