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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

What is a safe Rev Limiter?

  • Thread starter Thread starter Shadrack
  • Start date Start date Nov 22, 2005

Shadrack

New Member
Aug 2, 2005
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Nov 22, 2005
#1
  • Nov 22, 2005
  • #1
I searched the threads and concluded that the stock rev limiter is at 6250 rpms. However, I have been convertered to carb and need to know what a safe rev limiter would be?

I currently have a 6000rpm pill in my MSD 6AL box. It actually kicks in right around 5700 rpms. Just above my shift point of 5500 rpm. I'm thinking of getting a 7000 rpm pill, but is that too high? Possibly damgage the motor? I have a stock bottom-end/rotating assembly.

Would a 6500rpm pill be a better choice over the 7000 rpm pill?
 

srothfuss

Last night I stabbed the same guy 7 times in a row
Oct 17, 2004
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Woodward Ave.
Nov 22, 2005
#2
  • Nov 22, 2005
  • #2
It is totally dependent on the motor and how it was built. If it was balanced and put together correctly there should not be any problem Reving the motor over 7,000 RPM. However, your setup (cam + heads) probably stop making power @ or below 6,000 RPM.
 
F

fiveohGT

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Jun 22, 2004
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Nov 22, 2005
#3
  • Nov 22, 2005
  • #3
I know AFM makes high revving cams if you're looking to go that route
 

vristang

15 Year Member
Mar 31, 2005
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Nov 22, 2005
#4
  • Nov 22, 2005
  • #4
Using the pills is kinda expensive if you want to change the rpm limit.

The better way to go is with the adjustable dial limiters. With the turn of a knob you can set the limit between 6-7k, at 100rpm intervals. If my memory is still working. I have one set to 6200, I think?
 

BooWFO

New Member
May 10, 2005
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Louisville, KY
Nov 22, 2005
#5
  • Nov 22, 2005
  • #5
Back in my 5.0 days I knew several people with the rev extender that would rev them to 6500-7k. If your good at watching your tach/shiftlight I'd say a 7k if your not so good at it a 6500.
BTW I hope your not basing your RPM's soley off the factory tach, I've seen them off as mush as 500rpms.
 
D

Daggar

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Jul 19, 2004
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Nov 22, 2005
#6
  • Nov 22, 2005
  • #6
I may have missed some there in that I'm not familiar with what a "pill" is however.....

My interpretation is that this "pill" is for the MSD ignition box. If that's true, then all the pills in the world won't take your rev limit to anything over 6250 unless you have the EEC program modified to change or remove the factory rev limiter. The factory limiter is controlled by fuel and not spark (pretty crappy if you're running a power adder).
 

Shadrack

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Aug 2, 2005
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Nov 22, 2005
#7
  • Nov 22, 2005
  • #7
I have been converted to Carb. Computer and everything have been trashed. Stock TACH has been disconnected as well as most other gauges except voltage and fuel level. I currently have a 5" AutoMeter Ultra-Lite Tach with shift light/memory. It's hooked directly to the MSD box, therefore I know it is as accurate as it can be. I'm actually about ready to remove the whole instrument cluster and replace with Autometer gauges. Therefore, the only rev limiter I have is with the MSD Pill in the 6AL box. Nothing else is hooked to the motor to "limit" it in any other way. I have aftermarket electric fuel pump, etc, etc.

I would like to have my shift point right at 6,000 as that is where 95% of the stock 302's (that I have seen) stop making power on the dyno. I have to shift at 5500 rpm, which I feel like is slowing me down because I don't think i'm getting the most power @ that shift point. I'm thinking a 64-500rpm MSD pill (or chip, however you want to look at it) would probably be better.

Just didn't know if the 7000rpm limiter could "overspin" the motor. I think the 6000rpm is a little on the safe side, which is fine with me when i'm driving on the street. When I start dragging next season, I hope to shift @6,000 rpm going down the track.
 
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