Correct me if I'm wrong but doesn't the transmission have its own control unit, which is separate from the engine ECU?
Yes, they're separate.
The Engine Control Unit (N3/10, also called the ME-SFI [ME] control unit) is in the rear passenger quarter panel area (near right rear turn signal) and the Transmission Control Unit (N15/6) is under the driver's seat carpet behind where the factory subwoofer would go.
i didnt ask where the computer is. i was wondering if the shift times are the same, questioning the clutch longevity, and if the top speed is the same as factory? seeing how 4K (+/-) rpm is 90 mph, 6K rpm should equate to 135mph +/-. Now that speed may wipe the smirk off of a redneck in his Dodge Ram 2500 Diesel.... or Metrosexual in his 330i....
Does the top speed remains 90 mph, and the trans still take a long time to shift? I realize the trans shicting is a design issue, how about clutch longevity? do you have any 0-60 numbers?
The 90mph limit is still there.We dont reflash the ECU.The tranny shifts like it normally would but everyhting happens alot faster between the shifts.So far we have not hear dof any engine or drivetrain faliures! We have not done any 0-60 numbers withthe new tune yet.But we wil shortly and will post the results.
The default boost for Stage I and Stage II are controlled by the wastegate actuator. These are nominally 5 PSI and 8 PSI, but wastegate actuators allow for peaks 3 to 5 PSI higher. The "upgrade" tune is probably the timing/fuel maps in the piggyback ECU. Depending on the intake air temp, boost and other variables the piggyback ECU will pull timing advance and run richer to avoid detonation. A more aggressive tune allows more timing advance and more optimal air/fuel ratios. SFR probably set the piggyback ECU at a very very conservative level initially. As they gain experience with the setup, they can run the piggyback at more optimal levels to take full advantage of the boost.
The piggyback ECU has no effect on the Smart's ECU under non-boost conditions and it doesn't change the 90 MPH "speed limiter." However, given that the Smart's ECU wasn't expecting any boost -- it may be that the boosted air can still force it's way through a partially closed throttle thereby getting around the speed limiter. Boris or Rachel would probably have to comment on this, but I believe that they have easily exceeded the limiter's speed.
I've found that the Smart trans shifts much faster with the A/C on. The A/C compressor pulls the engine's RPM's down faster between shifts. This has been an issue on many sports cars with normal manual transmissions -- the emissions systems keeps the engine RPM's up to avoid HC emissions, which makes it hard on the tranny's synchros. Defeating the throttle opener/positioner emissions system can help shifting, but it often results in backfiring, burbling and FLAMES coming out the exhaust when letting off the throttle. I don't know of an easy way to defeat this system on the Smart, so I just turn the A/C on.
OK, I confess I find myself getting more and more interested here. For me a turbo would come after a body kit, which has been on hold since early this year (the toy money has temporarily dried up). But, planning is half the fun. I have questions…
fficeffice" />>>
1- Loudness. Some of you may recognize the fact that I have spent a lot of time kvetching about the noise from aftermarket exhausts. Larry’s system in the YouTube video is pretty loud. I’ve got more into my smart’s sound system than I’d probably end up spending on a turbo. There’s a reason for that and it’s because music is important to me. Can this system be quiet enough? >>
2- Ease of swapping out. Need to pass smog, gents. From the sounds of it, the entire system comes out fairly easily, but it still needs to come out. For a guy who quit changing his oil 20 years ago because it took too much time, that means every two years I’d need to have to schedule a turbo removal and replacement. I’m guessing that’d add up to about an extra $500 to the cost of the turbo every two years. That’s a lot. Any insights into this? >>
3- turbo v. nitrous oxide injection. I’d like to see a pro/con of each. Obviously a nitrox system means a bottle that needs to be refilled, but I don’t have a sense of how often or how expensive. I think I’m leaning more toward a moderate amount of power increase…. And thinking that a nitrox system would be easier to do, and would be “clean” on smog day (remove the bottle). But I also confess that while I’m a little knowledgeable on the basics of turbos and nitrox, I’ve owned neither. And as they say, a little knowledge can be a dangerous thing. Anyone out there willing to state a pro/con of each? >>
geosynch
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.
ffice" />
Today
Linear Mode
