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Discussion Starter · #1 ·
Has anyone looked into this device as a way to modify the throttle response in the CVT-equipped cars? I would be interested in understanding much more about how this would affect our cars. Will it help or hurt?

There is already one thread started in the Engine & Drivetrain Forum of MINI2:
Engine & Drivetrain Tuning: SprinterBooster

The SprintBooster website:
SprintBooster
 

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Discussion Starter · #3 ·
Has this device been tested with the 1st gen MINI Cooper CVT?
Do you have references to cite, or testimonials from CVT-users to post here on MINI2?

The MiniMania/BMW-Mania websites implied, maybe just my reading, that it was targeted at the 2nd gen MINI Cooper Auto, a much more traditional setup with automatic gearbox and torque converter, not the push-belt CVT and clutches of this machine.

I'd be excited if this device interfaced flawlessly on the CAN-network to spark up the throttle response we see in the CVT-equipped cars.

Link to the MiniMania website:
MiniMania SprintBooster
-- this website clearly states "2002 or later MINI" and splits the product line into two models; Regular (auto) and Plus (manual). It also includes the judgment statement that the Plus "has a slightly more aggressive mapping more suitable for the manual transmission", which I am more than willing to accept but it should have some explanation related to the CVT.

Link to BMW-Mania's website:
BMW-Mania SprintBooster
-- this website also has two models, NME1901 Perf Throttle Remap Std and NME1900 (same as MiniMania inventory number), that may be the Plus?

Link to SprintBooster website:
SprintBooster
SprintBooster testimonials
-- there are a couple of MINIs in there, but nothing that hints at CVT.
-- The Nissan Murano, which also uses the ZF CVT, is not a listed model, only the 350Z.
 

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Discussion Starter · #6 ·
Well, that's excellent! Thank you.

I hadn't replied earlier (apology all around) because of travel commitments. We'll follow this closely and look forward to updates and opinion.
 

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Well I received my Sprint Booster today. Very easy to install. Took all of 5 min for the whole job. One word of caution. The tab that holds the accelerator assembly to its base is very stiff. I also found in colder weather very brittle! Snapped mine off. I will probable need to replace the base.

Any way took out for a quick road test. the Unit made a immediate and noticeable difference:smile: the car from a standing stop now feels more like when the car would normally hit the meat of the power band. I don't find the throttle overly sensitive. It just feels more right. Much like installing a quick turn throttle on one of my race bikes.

Do I feel it's worth the money? That depends. The feel of the car is greatly improved, but I do think it is somewhat over priced. Would I recommend it to someone else. Definitely!
 

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Discussion Starter · #8 ·
Wow.

For those who have poured through this Forum on the CVT-equipped cars, you'll recognize the sheer amount of time that was given to first understanding how the components worked, and then how to drive this ZF technology to bring out the advantages we recognized to be there. So many good people contribute.

One of the things searched for is the way to use, mitigate, compensate for, adjust, change, fix, modify, work around, enjoy (lots of words are tried) the throttle response characteristics and the behaviors of the gearbox and control computer(s). There are some interesting threads.

This thread may turn into one of those classics, depending on what is discovered.

Some questions:

What happens when you first shift from Reverse to Drive, Sport Drive, or !st? In the unmodified early cars, there was some 'sorting out' time there. Some drivers developed a timed right foot delay before applying throttle to permit the car's electronics to catch up to the moment.

You describe a starting from a standing stop. Is there a difference between D, SD, and 1st? Do you have the throttle depressed all the way (past the detent, 'shifting' engine rpm pattern) or do you use an at-detent throttle position (engine rpm held steady)?

Do you think there might be actual performance improvement (acceleration) or is it the driver control and response that is improved (I would expect this only, and that's way OK)?

Does the device change the pressure needed to depress the throttle pedal?

We need to figure out how to even talk about "throttle response" in this Forum!
 

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Some questions:

What happens when you first shift from Reverse to Drive, Sport Drive, or !st? In the unmodified early cars, there was some 'sorting out' time there. Some drivers developed a timed right foot delay before applying throttle to permit the car's electronics to catch up to the moment.
With the Sprint Booster installed the delay in changing from reverse to forward motion is the same. You still have the "Sorting out" time.

You describe a starting from a standing stop. Is there a difference between D, SD, and 1st? Do you have the throttle depressed all the way (past the detent, 'shifting' engine rpm pattern) or do you use an at-detent throttle position (engine rpm held steady)?
The response from any of these modes from a standing stop is basically the same. That is all have nearly zero delay on initial throttle response regardless to actual position of the peddle. Nearly all of the "spool up" time that was originally present is removed. You notice the biggest difference or sensation at light to moderate throttle pressure in "D", what would normally be your take off pressure.
Once rolling each respective mode will act the same overall as their normal OEM operation in the mid to upper regions. All of the enhancement is off idle to say 3000 rpm (where OEM programmed delays would be present). You do not need to be at or past the detent to feel the effects of the device.

Do you think there might be actual performance improvement (acceleration) or is it the driver control and response that is improved (I would expect this only, and that's way OK)?
I would say YES there is a performance improvement since the delay in forward acceleration is removed and the car experiences much more urgent forward motion. Not just making noise and waiting. The best way to describe the feeling would be like adding a numerically higher gear to the drive line. But since were not actually changing it were not sacrificing any of the top end performance of the vehicle.

Does the device change the pressure needed to depress the throttle pedal?
Pressures required to physically move the throttle are identical to OEM. All were talking about here is a "pig tail" in series with the accelerator pot under your foot and the ECU.

We need to figure out how to even talk about "throttle response" in this Forum


I myself would describe throttle response as improvement or degradation to forward movement when throttle pressure is applied.

I hope that I have adequately described the Sprint Booster's effect on a CVT. If not I'll try my best to clarify.

..
 

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Discussion Starter · #10 ·
The response from any of these modes from a standing stop is basically the same. That is all have nearly zero delay on initial throttle response regardless to actual position of the peddle. Nearly all of the "spool up" time that was originally present is removed. You notice the biggest difference or sensation at light to moderate throttle pressure in "D", what would normally be your take off pressure.
Once rolling each respective mode will act the same overall as their normal OEM operation in the mid to upper regions. All of the enhancement is off idle to say 3000 rpm (where OEM programmed delays would be present). You do not need to be at or past the detent to feel the effects of the device.
Thanks for the good job of observing and detailing these changed characteristics. I'll express the earlier reaction again, wow.

I don't really understand why this thing is working as it is...

The CVT-equipped cars take electronic throttle outputs through the Siemens ECU over the CAN network in the car to another computer on the ZF gearbox.

It is the shape of the plotted voltage pattern (slope only, not voltage range?) that is being modified by this device. Do I understand that part correctly?

"Detent" is a term invented by our motivated crowd on MINI2 to describe physical travel of the trottle pedal and a "click" sound that comes from a switch activated near the end of the pedal travel. The switch signals the computer(s) to engage the faux/simulated shifting behavior that can't/couldn't be avoided when the throttle is fully depressed.

Does that shifting behavior change still exist with SprintBooster installed (this might be big)?
 

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I don't really understand why this thing is working as it is...

The CVT-equipped cars take electronic throttle outputs through the Siemens ECU over the CAN network in the car to another computer on the ZF gearbox.

It is the shape of the plotted voltage pattern (slope only, not voltage range?) that is being modified by this device. Do I understand that part correctly?
I would think you are correct. The device seems to modify the initial part of the throttle curve, thus improving response time is: elimination of lag.

"Detent" is a term invented by our motivated crowd on MINI2 to describe physical travel of the throttle pedal and a "click" sound that comes from a switch activated near the end of the pedal travel. The switch signals the computer(s) to engage the faux/simulated shifting behavior that can't/couldn't be avoided when the throttle is fully depressed.

Does that shifting behavior change still exist with SprintBooster installed (this might be big)?
The action of the shifting behavior at full throttle is the same as an un modified unit.

After using this device for a couple of weeks I still love the enhancement is has made to an otherwise stock Mini :D
 

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Discussion Starter · #12 ·
Are there any objective SprintBooster tests available to document this intervention in the drivetrain electronics that we might extrapolate to the CVT-equipped cars?

Going back to some of the earlier work here on MINI2, we are "driving software" as a result of the specific control inputs passing through the ECU to the gearbox. There must be very specific modifications to the behaviors of the gearbox as a result of the altered signal signature coming from the electronic throttle.

kenatMiniMania may have some suggestions. I may be able to re-ignite some exchange with MINI or BMW Group in the background. uber-r1 has the device installed. Have any others joined? We should rely on these people to help assess the impact this mod could have for the cars.

In that earlier work, lots of comments and working frustrations are recorded with what could easily be called "throttle response"! Remember the "spooling up" observation and the analogy to clutch karts? Would this device directly mitigate those observed performance factors? It sounds like the answer is "Yes."

The idea of not 'anticipating' right-foot application of the throttle in SD while still left-foot trail braking before the apex of the corner (a footbox dance of the feet) is very appealing.

Even more important could be re-exploring the joys of manual mode ("Steptronic"), one of the characteristics that makes the CVT-equipped MINI unique in the automotive world. Because it is directly coupled to the drivertrain by clutches, not a torque converter, the CVT-equipped MINI can honestly be driven as a manual. It can also be steered with the throttle, especially useful in the wet. Throttle response is critically important to make this work well, and it is a limiting factor today.

Manual: "Virtual sequential six-speed manual (software-based) puts fun and control into driverdefined situations. The transmission “holds a gear” (even under significant loads) unless the engine limits at 6000rpm (creates upshift) or drops below a set rpm (creates downshift: 2000rpm 6>5; 1800rpm 5>4; 1600rpm 4>3; 1400rpm 3>2). Full stop resets to “2” (Pullaway function). 1st must be manually selected. Fixed ratios (“gears”) are 0.562:1 6th, 0.675:1 5th, 0.847:1 4th, 1.117:1 3rd, 1.622:1 2nd and 2.416:1 1st, and 5.76:1 constant ratio."

This Steptronic functionality could be the important application to build a recommendation for SprintBooster. Thus the question: Does it make a difference in this situation?
 
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