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Speedo only goes to 85, what happens if I pass 90?

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Speedo only goes to 85, what happens if I pass 90?

Old 04-16-2019, 10:43 PM
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Speedo only goes to 85, what happens if I pass 90?

Driving home today, a Mopar charger wanted to play on the highway. I was willing to oblige, but I had to back off at 85 because around the 90mph mark, my speedometer needle will be touching the trip reset pin. It raised the question of what would happen if I were to go 95-100 mph. Would the needle break? Would it just float against the pin?

Obviously I need to upgrade to a higher mph speedometer, in case I ever meet Mr. Mopar again 😜. But I figured it probably would be a good idea to know what would happen with my current speedometer. Anybody have any insight? I'm genuinely curious, just not enough to risk breaking something, haha.
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Old 04-17-2019, 06:23 AM
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Re: Speedo only goes to 85, what happens if I pass 90?

Originally Posted by Venom_1138 View Post
Driving home today, a Mopar charger wanted to play on the highway. I was willing to oblige, but I had to back off at 85 because around the 90mph mark, my speedometer needle will be touching the trip reset pin. It raised the question of what would happen if I were to go 95-100 mph. Would the needle break? Would it just float against the pin?

Obviously I need to upgrade to a higher mph speedometer, in case I ever meet Mr. Mopar again 😜. But I figured it probably would be a good idea to know what would happen with my current speedometer. Anybody have any insight? I'm genuinely curious, just not enough to risk breaking something, haha.
It will not hurt anything. It will just stop moving when it hits the trip reset button.
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Old 04-17-2019, 06:31 AM
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Re: Speedo only goes to 85, what happens if I pass 90?

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Old 04-17-2019, 07:33 AM
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Re: Speedo only goes to 85, what happens if I pass 90?

At 88mph you go back to 1985
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Old 04-17-2019, 08:02 AM
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Re: Speedo only goes to 85, what happens if I pass 90?

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Old 04-17-2019, 09:02 AM
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Re: Speedo only goes to 85, what happens if I pass 90?

… It would be bad… Try to imagine all life as you know it stopping instantaneously and every molecule in your body exploding at the speed of light.

No, wait, I think it's OK. It just goes past 90. Dang, where are my notes...

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Old 04-17-2019, 09:08 AM
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Re: Speedo only goes to 85, what happens if I pass 90?

Do us all a favor and keep that third gen under 85 mph....
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Old 04-17-2019, 11:47 AM
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Re: Speedo only goes to 85, what happens if I pass 90?

Originally Posted by GASPEDDLER View Post
Do us all a favor and keep that third gen under 85 mph....
I'm just happy to see Fez is still getting work.






So seriously... Thirdgens with speed rated tires from the factory, don't have any limiting controls. When you get into the later EFI cars without Z rated tires you see they don't have the 140mph clusters, and if you hold the WHAAAAAAAAAAAA peddle long enough, when the needle gets to 115mph or so, you'll feel the brick wall and the car slowing down suddenly. After it drops down it'll let you push it back to 115, but at that point the ECM presumably cuts fuel and forces you to stop accelerating. Getting around it, is another topic, but if you want to know what happens when you put a 140 cluster into a 85mph car...

Sorta depends on the car. The old dual needle speedo in my 83 would roll past 85, and wrap around into the KM half of the scale. No trip odometer, no ecm control, with more then 14hp maybe it would have just kept spinning?

Btw, round these parts, late model Chargers are Po Lease. Saw one this weekend, think it was Junction City PD, was hard to tell because it was all black with black windows, all the gear behind the grill or inside behind glass and the PD/Call 911 markings were all done in flat black. Ergo, watch your cornhole.
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Old 04-17-2019, 01:40 PM
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Re: Speedo only goes to 85, what happens if I pass 90?

Used to have an '84 Chrvy Chevette, standard with four gears, that had a speedometer that only went to 90. Drove it on the Autobahn for about a year and half and the speedometer would peg at 90 while the accelerator would go further. I would usually keep up with traffic.
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Old 04-17-2019, 02:32 PM
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Re: Speedo only goes to 85, what happens if I pass 90?

Haha, my first thought when I saw him was that he was a cop... but the cops around here don't have custom mag wheels, blue-tipped chrome dual exhaust or a big ol' Mopar logo on the front fender. They're just not that sneaky, lol.

I've always backed off around 85 mph because years ago a friend had a Ford Probe he was restoring and building to race (don't ask me why, lol). He had his gauge cluster sitting out and another friend began screwing around with it, notably the pin that connected the speedo to the cable. He cranked it all the way over to the end, where there was a little stopper peg on the speedo, and the needle broke off. Given that my Trans Am can easily hit about 90 without me even having the pedal to the floor, I kind of figured the folks at GM would have made sure that didn't happen... but I didn't want to find out I was wrong the hard "oh crap, now that's broken!" way.

And the 80's movie references... love it. You guys are my kinda people, lol. Thanks for all the input, glad to at least put that question to bed!
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Old 04-17-2019, 02:38 PM
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Re: Speedo only goes to 85, what happens if I pass 90?

Nothing happens to the speedo over 85, what happens to you is another story. How lenient are the police in your neighborhood? Next you'll be singing, "I can't drive,,, 55"
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Old 04-18-2019, 08:52 AM
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Re: Speedo only goes to 85, what happens if I pass 90?


you just go faster and faster.....
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Old 04-18-2019, 10:13 AM
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Re: Speedo only goes to 85, what happens if I pass 90?

Originally Posted by 427seven View Post

you just go faster and faster.....
Nice. How Far did it take you to get there? You must have your odometer disconnected?
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Old 04-19-2019, 07:35 AM
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Re: Speedo only goes to 85, what happens if I pass 90?

PLEASEEEEE dont go over 85. once you do, itll send you into a wormhole. believe me, this happened to me!
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Old 04-20-2019, 12:38 AM
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Re: Speedo only goes to 85, what happens if I pass 90?

Dang, dude! Nice looking gauge cluster, very bright! I redid mine with LED's and chromed the inside plastic for a brighter look, but yours looks absolutely brilliant.

Originally Posted by 427seven View Post

you just go faster and faster.....
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Old 04-20-2019, 05:27 PM
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Re: Speedo only goes to 85, what happens if I pass 90?

added extra light for the midnight run.... actually 3 a.m. run.... too bright, zeroing in on the right intensity...
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Old 04-20-2019, 06:53 PM
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Re: Speedo only goes to 85, what happens if I pass 90?

Originally Posted by Degweiser View Post
At 88mph you go back to 1985
We really do need that LIKE button. Great comment!

A cable driven mechanical speedometer has a magnetic coupling. So if you "pin" the needle, nothing bad happens.
It's not like overwinding a clock or wristwatch until it goes "pop" and never works again.

Last edited by NoEmissions84TA; 04-20-2019 at 07:02 PM.
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Old 04-21-2019, 12:28 AM
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Re: Speedo only goes to 85, what happens if I pass 90?

Originally Posted by Degweiser View Post
At 88mph you go back to 1985
Beat me to it!

"Back To The Future" was a great movie!
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Old 04-27-2019, 05:25 PM
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Re: Speedo only goes to 85, what happens if I pass 90?

I'm forever tempted by Hawks' 160MPH speedo.......but they're bloody expensive and I'm unsure about taking the cluster out anyway.........
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Old 04-27-2019, 06:08 PM
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Re: Speedo only goes to 85, what happens if I pass 90?

Originally Posted by 427seven View Post
...............you just go faster and faster.....
How did you calibrate that Speedo Head to be accurate to the custom face-plate ?


200MPH and not even 1/10th of a mile traveled !!


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Old 04-27-2019, 06:31 PM
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Re: Speedo only goes to 85, what happens if I pass 90?

hey 427 where did you get those white needles from for your gauges
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Old 04-28-2019, 11:05 PM
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Re: Speedo only goes to 85, what happens if I pass 90?

Originally Posted by TOM305T/A View Post
hey 427 where did you get those white needles from for your gauges

made em
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Old 04-28-2019, 11:17 PM
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Re: Speedo only goes to 85, what happens if I pass 90?

[QUOTE=John in RI;6298231]How did you calibrate that Speedo Head to be accurate to the custom face-plate ?


Long story, but the key piece is from Dakota.

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Old 07-19-2019, 03:01 PM
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Re: Speedo only goes to 85, what happens if I pass 90?





For all those Canadians, we can only wish....
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Old Yesterday, 12:49 PM
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Re: Speedo only goes to 85, what happens if I pass 90?

Nothing. You just won't know how fast you're going. If I'm wot I'll be on the bottom of 4th gear when I hit 85. I bought a gauge off eBay with a speedo for 160 just to know how fast I am going. I took it to 120 the other day.

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