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Joined: Apr 2003
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Hard-core CEG\'er
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Hard-core CEG\'er
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I was under the assumption that when you change your overall tire diameter, it throws off your speedo. I was also under the assumption that cutoff got it's info from the engine rpm. Therefore, it would say 109, but rpms would still be correct for cut off. It sounds a little silly to me for the cutoff to get it's info from the VSS, but ok.
99 SVTC, T-Red, #652/2760-12.8.1998
Mother#@%@!* did I sound abstract?
I hope it sounded more confusin than that!
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Veteran CEG\'er
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Veteran CEG\'er
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In order for the speed limiter cutoff (as opposed to the redline/engine over-rev cutoff) to work off the engine speed, the computer must know what gear you are in. It would also need to know the gear ratios and the final drive ratio. In the case of the 5-speed manual transmission, that would require switches or sensors to tell the computer what gear the transmission is in, which is a lot of additional complexity and cost for NO benefit when there's a perfectly good VSS to use for speed information, which is already wired to the computer. [1]
In the case of the computer-controlled automatic transmission, the computer always knows what gear it's in, but the VSS is still used for the cutoff.
[1] The VSS is used by the computer to provide a dashpot function where it sets the rate at which the idle air valve closes when the throttle is closed, to prevent "lift throttle snatch".
If the cutoff did get it's information from engine speed, tire size would not change the relationship between speedometer displayed vehicle speed and engine speed. Only a gear ratio change or final drive ratio change will do that.
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Joined: Sep 2001
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Hard-core CEG'er
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Hard-core CEG'er
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If you were in 4th gear you might've hit the rev limiter, and not the speed limiter
Mazda 6S, V6, Speed Yellow
5 Speed, Sport package
Bose audio
Painted 'stash and HIDs!
w/Injen 1/4 14.750 @ 94.94
Former car:
99 Contour SE Sport Black MTX V6
SVT plastic...
1/4 - 15.012 @ 90.58
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Joined: Apr 2003
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Hard-core CEG\'er
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Hard-core CEG\'er
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interesting, ok thanx for the knowledge. I'm alway up for learning something.
99 SVTC, T-Red, #652/2760-12.8.1998
Mother#@%@!* did I sound abstract?
I hope it sounded more confusin than that!
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Joined: May 2000
Posts: 2,838
Hard-core CEG\'er
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Hard-core CEG\'er
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Originally posted by NAPALM: I recently tried out my gov on my 95 SE and it cut the throttle at 109 mph instead of what I read as 112.. I was wondering if anyone else has a gov set at 109
You shouldn't be going that fast on public roads anyway ... this was at the track , I assume ???
~~~~~~~ Phil 
Black & Tan 2000 SVT Contour #2137 of 2150
35,000 miles & counting !
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Joined: Aug 2001
Posts: 17,248
CEG road warrior
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CEG road warrior
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My speedo is about 3 MPH off...cuts off at 115.
Hector
2003 Rally Red Mitsubishi Evolution VIII
257HP/259TQ
2005 Lapis Blue Mazda 6s
RET: 00 Cabernet Red Ford Contour Zetec ATX SUPERCHARGED
160HP/141TQ
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New CEG\'er
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OP
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Well I do have a 5 speed so it wasn't an atx rev limiter, and I was late for work at the time going down I-95 south towards old saybrook (all in CT) and I was watchin for the rev limiter every sec and I just so happen to look at my speedo as it hit 109 and the computer cut the throttle. so I figuered I'd ask to see if anyone elses does that since I read on this site that the limiter goes to 112... not much of a difference I was just wondering. I found the limiter on my dad's 5 speed '01 V6 sebring, and that one is set at 130... that was on Route 2 east toward Norwich CT if anyone wanted to know.
'95 SE moonlight blue MTX
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Hard-core CEG\'er
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with all that specific info I guess 5-O will be waiting for you next time on that route
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Hard-core CEG'er
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Hard-core CEG'er
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i love not having a limiter...
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New CEG\'er
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It was only that one time... ussually the cops are all over those highways if anyone lives in CT they know what I'm talkin about.
'95 SE moonlight blue MTX
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