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I'd like a faster spindown

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Old 04-30-02, 08:49 PM
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I'd like a faster spindown

Hey guys... you know when you shift up... but your RPM VERY SLOWLY reduces?? Thereby causing it to slip for a second? I think this is unneeded wear on my clutch, and also, i think i could shift alot more smoothly if the RPM dropped a little faster as soon as i release the throttle. Is there any way to modify the reverse-throttle-response??
Thanks
-Ross
Old 04-30-02, 08:50 PM
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lighter flywheel..

maybe something is wrong with yours? cable sticking?
Old 04-30-02, 09:36 PM
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Re: I'd like a faster spindown

Originally posted by Fingers
Is there any way to modify the reverse-throttle-response??
Rotational inertia is what causes your engine speed to drop like that. To lower the rotational inertia you need to lower the rotating mass. The easiest way to do that, like Scott said, is with a lighter flywheel. If it's a daily driver, don't go below 15lb, you'll regret it, trust me! Otherwise, a 10lb like I had will make a huge difference. You'll love it!
Old 04-30-02, 09:43 PM
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How much do stock flywheels weigh?

me = n00b .... even though i have een registered for a while, ive just been looking into rx-7's ... as well as about 100 differnt cars.
Old 04-30-02, 09:51 PM
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NZ i was just wondering why you say that one would regret it if they had a less than 15lb flywheel for a daily driver.
Old 04-30-02, 10:10 PM
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It makes it a bitch to drive in traffic.
Old 04-30-02, 10:14 PM
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check your dashpot too. it's that too far in the rpms will take too long to drop.
Old 04-30-02, 10:19 PM
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Maybe its a pain to drive if your a giant wussy....
But seriously it's not really that much harder to drive then a stock flywheel. I think I stalled mine once with a 9 lb flywheel..but I was in a pothole so I don't count it.
Old 04-30-02, 10:27 PM
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http://www.mazdatrix.com/faq/flywheel.htm
Superman-
You'll find the weights of your flywheels on there.
Old 04-30-02, 11:01 PM
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Traffic. ehh i suppose but who cares. 9lbs of pure spinning mass is ok with me .
Old 04-30-02, 11:21 PM
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i think its around 30lbs, i forget though. Mazdatrix has a chart of flywheel weights.

damn unique tii already posted it, 21-27lbs for stock FC flywheels
Old 04-30-02, 11:22 PM
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It's not JUST the weight of the flywheel that matters--it's where the weight is located. If i recall correctly, the stockers, while being heavier, also have a great deal of the weight to the outside, making the moment of inertia higher than if it were closer to the inside. Most aftermarket ones are designed so that less rotating mass is on the outside, making it more than "just a 15 pound drop in weight"...

Spinning weight is terrible--not only does weigh down the car like anything else, but it takes assloads of energy to spin it up in the first place! energy that could be better used to propel your car.

-Tesla
Old 05-01-02, 01:23 AM
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Originally posted by RevinRx7
NZ i was just wondering why you say that one would regret it if they had a less than 15lb flywheel for a daily driver.
Like my 7, my Cosmo was my daily driver. Foolishly, I decided a 4-puck clutch and 10lb steel flywheel would be no worries. Now I get stuck in traffic every day (1st-2nd gear stuff), no that set-up was a bitch! Admitedly it was probably more due to the clutch than the flywheel, but I still would only put a 15lb into the 7. However, if your car's a weekend warrior, that clutch/flywheel combo would be sweet. Away from traffic, I loved it.
Old 05-01-02, 07:54 AM
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Thanks for all your help guys, but i am not so sure that it's the flywheel. I mean that is a big difference... but i've driven other RX7's and they're not like this. I think it might be a spring that's not returning the throttle to the idle position fast enough. Does anyone know what i might be talking about? Exactly what is a dashpot? what's it's purpose? where is it located? is it adjustable?
Thanks
-Ross
Old 05-01-02, 08:35 AM
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Originally posted by Fingers
Thanks for all your help guys, but i am not so sure that it's the flywheel. I mean that is a big difference... but i've driven other RX7's and they're not like this. I think it might be a spring that's not returning the throttle to the idle position fast enough. Does anyone know what i might be talking about? Exactly what is a dashpot? what's it's purpose? where is it located? is it adjustable?
Thanks
-Ross
DL the factory service manual for the 88 from fc3s.org (guessing you have a S4). The dashpot is adjustable. It controls how fast the rpm's drop when you let off the throttle. I'd tell you where it is on my car, but I dunno if that'd be too different. It adjusts with a screw on the top. I'll look in the FSM for mine (already dl'd) and see what it says when I get some free time at work .
Old 05-01-02, 08:38 AM
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Ok, i'm pretty bored here . If you have an NA, download or look up in section 4a fuel and emissions control non-turbo in the section called "Deceleration Control System"
Old 05-01-02, 06:46 PM
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Thanks buddy. I checked the dashpot... seems to be fine. Ah well, i'll deal with it. Thanks
Old 05-01-02, 08:31 PM
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Re: I'd like a faster spindown

Originally posted by Fingers
Hey guys... you know when you shift up... but your RPM VERY SLOWLY reduces?? Thereby causing it to slip for a second? I think this is unneeded wear on my clutch, and also, i think i could shift alot more smoothly if the RPM dropped a little faster as soon as i release the throttle. Is there any way to modify the reverse-throttle-response??
Thanks
-Ross
'

Get a piston engine
Old 05-01-02, 09:15 PM
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ROTF!!! That will be the day I already dread the fact that my winter car is an Intrepid. It will be a cold day in hell when i get rid of my rotary for pistons
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