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Does the ECU know what gear you're in?

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Old Dec 11, 2002 | 03:32 PM
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Question Does the ECU know what gear you're in?

This may seem to be a stupid question, but oh well....
I've read other posts about the Z 'feeling' slow, even though in reality it's accelerating fast. It seems to me, by using the trusted butt dyno, that 1st and 2nd gear don't 'feel' quicker than 3rd. My baby feels like she has 287hp in 3rd, 4th, and 5th. (Especially 4th.... My favorite. You can really feel the pull). But, in 2nd, I'm left wondering if I'm still in my old 2000 Eclipse GT.
Someone in another post said something about the ECU retarding the throttle response a bit to keep people from accidently spinning out. Could Nissan have lowered the power output for 1st and 2nd to keep the TCS from kicking in all the time? Or is it something mechanical like a heavy flywheel, which would be less of a factor at a higher gear? Thanks.
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Old Dec 11, 2002 | 03:55 PM
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well, there is extra power loss from gear change, 5th being the most efficient.

but none the less, I think it may just be that the engine can move the car faster then it can actually accelerate, specially in first where it feels like it has a lack of burden on it.
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Old Dec 11, 2002 | 05:02 PM
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I don't understand how anyone can say 1st, and 2nd feel slow, and not very powerful. Have any of you actually done a romp to 60 with the pedal to the floor? Taking first to redline with the pedal to the floor is freakin VIOLENT. It even scares me sometimes, and I'm not a stranger to driving fast cars. Second is way smooth, but the accerleration is still there, certainly more than third. I raced my buddy in his NSX the other night, and I hit my fuel cut-off before I even realized I was at 60 already. (My buddy drives a '91 NSX, and his car just BARELY edged mine out cause the nsx has much taller gearing. He can get 45 mph in first). But anyway...to answer your question, I don't know, but I would assume the ECU would know what gear you're in. But you know what they say about assuming...
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Old Dec 11, 2002 | 05:05 PM
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Also, I've noticed that the throttle response on the Z in general is a bit laggy. Just rev in neutral a few times. You stomp the pedal to the floor real quick, and release, and you'll be lucky to get to 3000 rpms.
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Old Dec 11, 2002 | 06:22 PM
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Default very possible

I think this is very possible, some of you sportbike guys might remember the ignition retarding system they use on the new sportbikes(gsxr's, busa, zx-12 couple of others) 1st and 2nd gear the computer actually retards the timing , the bikes are so powerful its become a safety hazard.. but of course the aftermarket has picked up on it and eliminate it.
I feel the same, the power comes on so strong in the higher gears and can't help but think to myself whats up with 1st and 2nd. WEre is the crazy mad of aftermarkets parts for this car
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Old Dec 12, 2002 | 07:34 AM
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NO per the sevice manual but the TCS system can come on and effect the cars responses it uses brake force, fuel reduction and less throttle plate angle to control and it anticipates wheel spin and takes "apropriate"? action to precieved traction issues with traction being #1 priority. Get a service manual !!! The engine managment section alone has 640 pages, the section with control systems for the TCS/SBS is 42 pages and that just controls that system. If you have TCS/ABS/VDC system in your car that control system diagnosis/repair is 62 pages long. lots of theory and logic controls in car, all systems are controlled through the CAN network and ECU.
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Old Dec 12, 2002 | 03:16 PM
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Yeah I've noticed there's a LOT of punch in 2nd. I sort of accidentally punched it maybe using 70% throttle and scared my girlfriend to death. Then again, I have the base so maybe VDC & TCS aren't interfering...
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Old Dec 12, 2002 | 03:22 PM
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we can turn all that off, and 1st gear seriously is violent, at no point during full acceleration in 1st do the wheels really have "traction" they sorta border on breaking traction the whole time. then into second it still pulls hard, but your going a tad slower through the RPMS so you have a little more control over it. then 3rd is quick, but reasonable, you can relax in 3rd.
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Old Dec 12, 2002 | 04:59 PM
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On my Grand Prix, switching the TCS off doesn't turn it completely off, it just seems to get more leanient but still pulls timing. Only way around is to pull the TCS fuse. Maybe the same is true for the 350Z?
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Old Dec 14, 2002 | 09:53 PM
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Originally posted by Fyrestrike
On my Grand Prix, switching the TCS off doesn't turn it completely off, it just seems to get more leanient but still pulls timing. Only way around is to pull the TCS fuse. Maybe the same is true for the 350Z?
Nope. Off is off. You can feel it: it cuts in agressively when on, and you can spin the wheels all day long when off.

First gear pulls so hard that when you do a hard launch, you hit redline almost before you know it. I tried doing a fast 0-60 time the other day (measured 5.45 sec on the stopwatch!) and I couldn't believe how quick I had to shift to 2nd. (0-60 is nice because 2nd hits redline right at 60.)

The only way I can see 2nd feeling slow is if the TCS is kicking in. I find that flooring it in second pins you back pretty hard indeed.
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