My blower has been dying for the better part of a year now - howling wookee noise. Felt a tiny bit of play at the shaft but nothing crazy, but boost has been steadily dropping to the point that I barely feel anything, and my fuel economy has been hovering in the 22-24's, down from 26-30.

Worked with Ed over at PSE superchargers and wound up ordering a stage II sprintex kit, mostly because they were out of stock of the stage I and another production run wasn't planned until Jan, when it'll be too cold in my garage to happily do the work anyways. He is sending me both pulleys and belts of the kit so I can run the higher or lower boost. My car has 140k miles but is in very good shape with pristine compression and leakdown, and I never autox or track my car, rarely redline, usual full throttle pulls shift around 6k. Ed seemed to think that was a safe playbook for the engine at that mileage. Per his discussion with Sprintex, the JCW's standard, bigger injectors and tune won't require their tuning kit or any injectors, and the car will adjust itself (only engine mods include MSD ignition, cold air intake, and a JCW cat-back with deleted resonators.) I'm only used to tuning OBDI and earlier, where standalones and piggybacks were mandatory for any real performance change. Am I going to be okay without the tuning kit?

I have torn my engine down to the blower to change the oil shortly after purchase (about 1.5 years ago) with a full gasket and hose swap, so I'm familiar with taking off the car's little face. But the sprintex kit switches the water pump to electric. Will I need to cut and wire anything, and if so, if the directions aren't overly helpful, what power sources should be tapped? Any other advice for the install?

What kind of performance can I expect with my stage II kit on a JCW with these mods? I'm thinking around 250WHP, is that about ballpark? Either way, I'm excited. My car has to be making around 140 right now. Is the stock clutch up to the task, or will a new clutch be on my short list of the next things to change? (right now it's a worn wheel bearing and my rear sway bar mounts are toasted, the bar is flopping around in the socket and making unhappy noises)

 

Just curious why didn't you go with the TVS-900?

 

Honestly didn't know about it. I did my research based on mini mania and my talk with a couple blower shops, finally with Ed at PSE who seemed extremely knowledgeable.

But looking at it now... Almost 5 grand is a lot more money, especially for a roots blower over a twin screw. I am guessing it'll heat soak like a ****.

 

To answer some of your questions, with the kit in its stock form (69mm pulley) it should make slightly more power, but most importantly it will improve your low rpm torque and power, which is what you can really feel.
And with the smaller pulleys it has the potential outdo the boost of an M45 by 2 psi or more. But the smaller pulleys will require a tune and I wouldn't run the 60mm too hard in hot weather without W/M.
As far as the installation and electrics, the instructions are very detailed and the install can be done by any decent backyard mechanic, let alone a professional.

​​​​And the stock clutch ore Valeo replacement is plenty for it as well

 

Good to hear, thanks!

 

On one hand, the, TVS-900's twisted four lobe rotors, might act very much like a screw rotor design, air temperature wise. In that there will be much less "pounding" (heating) of the air by the three lobe rotors.
Both...the contraction (pressurizing) of the air and the lobe action into the air, both contribute to higher air temperature.
But in general, the screw blower is a much "softer" design as far as heating the air from the lobe action beating the air.

That would be an interesting test. Both blowers, tested at the same "pressure" (not overdrive %), and see which one produces the highest air temperature, before the intercooler.
Even throw in the OEM blower to see how it fairs.

Mike

 

From what I understand there really is no situation where a roots blower will ever take down a screw, particularly due to the massive comparable parasitic loss. The only reason a top fuel drag car uses one is due to regulations (and the fact that they're well into the horsepower range where the induction source is irrelevant, as the massive amounts of nitromethane cool the cylinder and charge so much and the cars are traction limited) You don't really see roots blowers in no limit tractor pulls.

When we're talking MINI's though, the IAT is definitely a concern for reliability and a 4 lobe is still not really "meshed" like a screw is. undoubtedly better than the stock 3 lobe, but I just don't see the appeal of sticking with roots. Also the TVS900 looks closer to the stage 1 sprintex kit, and the stage 2 has a completely different blower (I wanted the stage 1 but they were out of stock and sprintex wasn't going to run another manufacturing set until jan.) also, the 900 is substantially more expensive from what I see online, in the $5000 range, whereas the stage 2 sprintex (complete kit) was $3400, shipped to my door. So even if it was a better kit, I am already humping a little past my budget for what is ostensibly a repair job. I still have my rear sway bar bushings and front right wheel bearing to replace, too. I don't know what sway bar kit my car was upgraded to, other than that it came from mini mania. I think a 22mm, but I need to get under the car and measure it (it's red is all I can tell thusfar but it's banging around unhappily)

 

At the end of the day it is all what you plan on doing with the car. The stock Eaton blower is not a bad unit and with pulley ratios of 19-21% smaller you can get some good performance. Throw in some water/meth injection for cooling and for most it work very well. With the higher pulley ratios you would be bouncing off the ECU limit but with a cam or a header your overall boost would be decreased so the ECU limit may not come into play.

And with the money saved on the Eaton, you can get more toys.

 

Honeybadgers wrote -.
From what I understand there really is no situation where a roots blower will ever take down a screw, particularly due to the massive comparable parasitic loss.

First, you need to reread my comments. I never said that a Roots blower would "take down" a screw blower. I fully understand that. A very much different design made to both combat the rotors heating the air, and to build more boost.
My comment is...with the four lobe, twisted rotor, what is the blowers output temperature difference ? See, be more careful in your reading..!
As for any difference in parasitic loss, again, better do your homework. In that regard, they are about a draw. But the screw blowers DO in fact spin faster for a given amount of boost..!

And the reason the NHRA does not run them in the Nitro classes, is in fact (as you sort of mention) to limit the horse power.
But you might notice, that they DO let the screw blower run in other classes..!
I've been in and around drag racing a LONG time, this is all nothing new to me, so...well...

Mike

P.s. - And yea, I still wonder about the, preintercooler temperatures between the different configurations.

 

I don't really know you, so I sincerely apologize if any of my comments are presumptuous and I do not mean to offend.

As to parasitic loss, there is a lot of information about how a twinscrew will sap less. I've been in and around old school hot rodding for 15 years myself, but a car with OBDII, much less one with fuel injection, is outside my wheelhouse! Gimme stroked SBC and I'll put it in the 10's with either method, but this little motor has so many intricacies that are way beyond my pay grade.

Here's the very first link from kenne bell (obviously they're a vendor but the consensus is pretty much the same everywhere from my understanding)

http://kennebell.net/tech/supercharg...crew-vs-roots/

That said, I think the more interesting comparison would be the 3 to the 4 lobe, or a 3 versus a heavily twisted 3, because you'd then be within homologation rules of a lot more different racing divisions that may allow roots but not allow a twinscrew.

Still, when we're talking a 1.6 4 cylinder.... we're really nitpicking on either end. MAYBE for the people searching for 300 or more whp, this discussion matters, but for the daily driven cooper S, it's all academic anyways!

 

Got the kit installed this weekend - Two things, I absolutely hate the pictures provided, and the directions can be quite misleading. Also, the wiring kit did require a crimp connector of mine and some cut/solder work into pin 5 on an ecu wire that was shown in a really, REALLY awful place. Also, the mounting bolts for the water pump were AWFUL and a nightmare to get seated. Also, the standard 3/8 coolant hose off the water pump is too short, you need about a six inch piece of 3/8 coolant hose, any auto parts store will have.

Also, the belt tensioner kinda sucks. it has none of the utility of the stock one, uses a gas strut and requires you to have the whole front of the car off in order to change the belt using the tool (the stock mini tool does not work, but they provide the flat bar and give you REALLY obtuse directions as to how it's used)

It desperately needs a VIDEO on installation like the folks at atlantic british do. I wound up needlessly disassembling the water pump from the outlet because I didn't think it could fit after fiddling with it for five or so minutes, resulting in about 3 hours of messing around with the bolts and stock hose. Only to have a leak, remove it, see that the O ring had fallen out on reassembly and that it indeed did slide in ONE specific way,

Overall, myself (experienced with wrenches and with a well equipped shop, and having removed the face of the mini once prior for a supercharger service) and a friend took about 25-30 hours including the leak. Minus the leak, about 20-25 hours including setup and cleanup.

As to performance, on a JCW, I was a bit disappointed. my old blower looked better than expected, so I was expecting more "vicious" acceleration, but instead it just added a TON of low end grunt and a more electric-motor feel of power to the top. it doesn't run out of legs like the stock blower with a 15% pulley does around 4500-5k, and it's got more down low, but the overall effect was a much smoother power curve. I was kinda hoping for something different in the sensation, but I can't deny the results - it's probably got about 30-40 more horsies.