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Is a rev limiter absolutely necessary?

  • Thread starter Thread starter Cannoball888
  • Start date Start date Jan 26, 2006

Cannoball888

New Member
Dec 25, 2005
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Gainesville, FL
Jan 26, 2006
#1
  • Jan 26, 2006
  • #1
For dragstrip, is a rev limiter absolutely necessary? And technically how do they work? I don't see how they can limit your RPMs with the clutch disengaged and the pedal to the metal during powershifting.
 
L

limey66

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Sep 23, 2004
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Northampton, England
Jan 26, 2006
#2
  • Jan 26, 2006
  • #2
If you have a manual trans, and don't want to grenade your engine, they are a must. Imagine that missed shift, you bang your right foot to the floorboards and your RPM's go past the redline into 11k or more. BLAMMO!

They work in different ways, but the most common type just cuts the LT supply to the coil at a pre-set rpm. No spark, no revs. The better ones drop every other spark, progressively to give a softer limit rather than a load of nothing.
 
S

steel1212

Active Member
Jun 24, 2004
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Frankfort, Ky
Jan 26, 2006
#3
  • Jan 26, 2006
  • #3
Yeah, they just cut out the spark. I have the 6al which is ok but I would have rather had the one that cuts it out on 1,3,5,7 and then on the next round on 2,4,6,8 so you don't have a cylinder full of gas!

If you run nitrous you'll want something to shut it off before your limiter though or get smart and pull your finger off the button!
 

LMan

Founding Member
Aug 10, 2002
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Mom's basement
Jan 26, 2006
#4
  • Jan 26, 2006
  • #4
only if you want your engine to last more than, say, 2 or 3 runs.
 

FORCED2DV8

New Member
Jun 6, 2005
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Grand Rapids MI
Jan 26, 2006
#5
  • Jan 26, 2006
  • #5
Its a very good idea, unless you like blowing stuff up. It only takes one slip to go boom, The Rev limiters obove are easy and effective to setup. Well worth the money IMO
 

iskwezm

10 Year Member
May 24, 2005
4,159
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Rowland Heights,California
Jan 26, 2006
#6
  • Jan 26, 2006
  • #6
i have the MSD Digital 6 and wouldnt run with out it,plus it has a 2 step, so when you want to launch, set the rpm to say 4500 RPM, lights start to come down,push the button(also works my line lock)you nail the gas and it will "bounce" at 4500,bam release clutch,the 2nd rev limiter will limit the max rpm you want, mines at 7500, but with the blower im gonna lower it to 6300.Plus the Digi6 has a start retard, so its easier to start and a boost retard so if yoiu run NOS,it will retard 2,4* when activated.
 

FORCED2DV8

New Member
Jun 6, 2005
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Grand Rapids MI
Jan 26, 2006
#7
  • Jan 26, 2006
  • #7
iskwezm said:
i have the MSD Digital 6 and wouldnt run with out it,plus it has a 2 step, so when you want to launch, set the rpm to say 4500 RPM, lights start to come down,push the button(also works my line lock)you nail the gas and it will "bounce" at 4500,bam release clutch,the 2nd rev limiter will limit the max rpm you want, mines at 7500, but with the blower im gonna lower it to 6300.Plus the Digi6 has a start retard, so its easier to start and a boost retard so if yoiu run NOS,it will retard 2,4* when activated.
Click to expand...

I have been looking at these, I have to go try one, sound like a slick setup.
 
8

86bluecobra

Advanced Member
Dec 20, 2004
4,265
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69
B.C. Canada
Jan 26, 2006
#8
  • Jan 26, 2006
  • #8
iskwezm said:
i have the MSD Digital 6 and wouldnt run with out it,plus it has a 2 step, so when you want to launch, set the rpm to say 4500 RPM, lights start to come down,push the button(also works my line lock)you nail the gas and it will "bounce" at 4500,bam release clutch,the 2nd rev limiter will limit the max rpm you want, mines at 7500, but with the blower im gonna lower it to 6300.Plus the Digi6 has a start retard, so its easier to start and a boost retard so if yoiu run NOS,it will retard 2,4* when activated.
Click to expand...
same setup im running and i love it. well worth the money. if you run nos and it is only on a wot switch jacobs makes a nos controller that can close the nos solonoid when rpm limter comes on. it also has a rpm controller on it so nos only comes on at certain rpm or even gradually puts more nos on through rpm band.
 

brianj5600

Active Member
Sep 19, 2003
1,964
2
39
Middle TN
Jan 26, 2006
#9
  • Jan 26, 2006
  • #9
They are needed on any car that has enough power to break stuff. I got away with one once when a rear end broke. Memory tach said 9200 rpm's, but the motor survived.
 

Cannoball888

New Member
Dec 25, 2005
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0
Gainesville, FL
Jan 26, 2006
#10
  • Jan 26, 2006
  • #10
limey66 said:
...The better ones drop every other spark, progressively to give a softer limit rather than a load of nothing...
Click to expand...
I would like to keep it simple but also prefer one as you mentioned that limits every other spark rather than giving nothing. What MSD models do this?
 

iskwezm

10 Year Member
May 24, 2005
4,159
20
79
Rowland Heights,California
Jan 26, 2006
#11
  • Jan 26, 2006
  • #11
Cannoball888 said:
I would like to keep it simple but also prefer one as you mentioned that limits every other spark rather than giving nothing. What MSD models do this?
Click to expand...
the digital 6 does, i like it because is doesnt use "chips" to set rpm limiters, the older ones, the 6 series (a,al,t) use "chips you have to buy and plug in and are the dinosours of the line.

The Crane Hi-6 is also a good choice.
 
L

limey66

Member
Sep 23, 2004
408
0
16
Northampton, England
Jan 27, 2006
#12
  • Jan 27, 2006
  • #12
Yeah,

I use the Crane XR-i ignition module which has simple dial on the top to set the rev limit. Car not really* on the road yet, so I can't comment on it's effectiveness.

My main experience with such things in on European 4 banger stuff, so I can't say what is available to you over there, but I'd follow some of the leads given above.

*Oh, sorry officer, I'm on a shake down run, I didn't realise I needed an exhaust/windshield/proper brakes/insurance/licence plate...
 
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