# Speed Limit Defender, 84 300zx turbo



## adamlamaster (Sep 29, 2004)

My friend just ordered a Greddy BCC speed limit defender and we cannot figure out how to hook it up to the computer (ECU). Does anyone have or know of any place to get a diagram of the computer so we can see which wire controls the speed.

84 300zx turbo


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## 0341TODD (Nov 15, 2003)

Holy crap dude, how fast are you going to go? I didnt know that there was a speed limiter on any of the Z's especially the 80's Z's. Some of the guys on this forum have had their cars to over 130 with no problems at all. A factory service manual would tell you what wire that you need to use though...........


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## Zen31ZR (Mar 24, 2004)

0341TODD said:


> Holy crap dude, how fast are you going to go? I didnt know that there was a speed limiter on any of the Z's especially the 80's Z's. Some of the guys on this forum have had their cars to over 130 with no problems at all. A factory service manual would tell you what wire that you need to use though...........


 Speed is limited to 135-137 on all the turbo cars. The "purple wire" mod can defeat this , however you will lose all trip mileage/mileage-to-empty functions. No big deal. It's useful for those that can run faster than 130 in the 1/4. That's 10's , if I'm not mistaken.


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## '85 fairlady (May 1, 2004)

i've done nothing like that to my car and have gone 140 but then backed off.


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## Zen31ZR (Mar 24, 2004)

[QUOTE='85 fairlady]i've done nothing like that to my car and have gone 140 but then backed off.[/QUOTE]
I don't beleive the NA cars had a limiter , or maybe it was higher. The turbo cars definitely have the limiter.


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## asleepz (Feb 24, 2004)

Yep we hit ours once on the air base.


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## RocketRodent (Jun 21, 2004)

N/A's dont have this limit... they just have a rev limiter to try to keep the speed down.... Still its good for 142 mph, yes downhill... (that the highest I've seen). Kinda scary considering the rust bucket was almost as old as I am.


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## Marc Z31 (Jul 25, 2004)

...CUT THE PURPLE WIRE... it tastes like burning.

Turbo cars go 140... unless you cut the wire.
The 84 AE non turbo can go 165, yes 165. It takes forever to get there, but YES 165.


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## JAMESZ (Mar 12, 2004)

Marc Z31 said:


> ...CUT THE PURPLE WIRE... it tastes like burning.
> 
> Turbo cars go 140... unless you cut the wire.
> The 84 AE non turbo can go 165, yes 165. It takes forever to get there, but YES 165.


Ummm you do know that the only NA 50ths were in Australia and none of them came to the U.S. The Shiro was taken to 155 by Nissan but there is only gearing to about 160 then were dead. The NA cars can't even go as fast as the turbos plus the NA would lose the battle with friction way before 165.


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## Zen31ZR (Mar 24, 2004)

Marc Z31 said:


> ...CUT THE PURPLE WIRE... it tastes like burning.
> 
> Turbo cars go 140... unless you cut the wire.
> The 84 AE non turbo can go 165, yes 165. It takes forever to get there, but YES 165.


I already mentioned this mod, thanks. And the difference between 135 and 140 is really basically nothing big.


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## asleepz (Feb 24, 2004)

[email protected] said:


> I already mentioned this mod, thanks. And the difference between 135 and 140 is really basically nothing big.



Agreed your not going to notice at much as from 25 to 30 from 135 to 140


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## Zen31ZR (Mar 24, 2004)

RocketRodent said:


> N/A's dont have this limit... they just have a rev limiter to try to keep the speed down.... Still its good for 142 mph, yes downhill... (that the highest I've seen). Kinda scary considering the rust bucket was almost as old as I am.


 Most all cars have rev limiters.  The turbo Z31s is set at about 6400-6500. I have a pic of fuel cut at 6400 rpm, but I took the pic a bit late so I'm guessing 6500.


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## morepower2 (Apr 19, 2002)

Marc Z31 said:


> ...CUT THE PURPLE WIRE... it tastes like burning.
> 
> Turbo cars go 140... unless you cut the wire.
> The 84 AE non turbo can go 165, yes 165. It takes forever to get there, but YES 165.


I don't think the NA's can go 165. Where is your proof?


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## Zen31ZR (Mar 24, 2004)

morepower2 said:


> I don't think the NA's can go 165. Where is your proof?


 Downhill with a tailwind, or if you throw it off a cliff, maybe.


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## 0341TODD (Nov 15, 2003)

Good thing I finally hooked my S-AFC and RSM up to the car. Now I can disable the speed limiter with the rsm so I can go 190 mph and I can conveniently add fuel while Im doing so-LOL

I dont know that I will be taking my car past 100 until I do the suspension and make sure the tie rods arent going to break on me......b/c that would suck.


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## TheJackal (Aug 18, 2004)

if all your doing is cutting that wire, why not hook it to a switch on your dash to disable it when you want to go fast, but still have all your trip/mileage and miles to empy active?


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## 0341TODD (Nov 15, 2003)

then how do you tell how fast youre going?
I guess you could get a gps


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## Zen31ZR (Mar 24, 2004)

0341TODD said:


> then how do you tell how fast youre going?
> I guess you could get a gps


 Shouldn't affect speedo operation. Just trip functions and etc.


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## Zen31ZR (Mar 24, 2004)

TheJackal said:


> if all your doing is cutting that wire, why not hook it to a switch on your dash to disable it when you want to go fast, but still have all your trip/mileage and miles to empy active?


 Yeah that should work. I'd thought about doing that myself but I really have no need to go that fast yet.....


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## 0341TODD (Nov 15, 2003)

unless youre running from the cops


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## Zen31ZR (Mar 24, 2004)

0341TODD said:


> unless youre running from the cops


I could do that on foot around here. A big NA Crown Vic at 5500 feet goes nowhere fast.......


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## 0341TODD (Nov 15, 2003)

I keep forgetting you live in the clouds...literally


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