slew rate

A

Anonymous

Guest
another msd waste. Its only for cars that are perfectly dialed in looking for some starting line control.

but i'm sure somebody will post up how great it is and their friend uses it to get his 4000 horsepower 10" tire car down the track.
 

CutlassRacer

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Helped us win the Drag Radial class at the US Street Nationals in Bradenton earlier this year. :)

I think its pretty cool myself, but not needed until after you science the car out on a perfect track and log a run with zero tire spin.
 
A

Anonymous

Guest
I think it is like an adjustable rev limit to help control starting line power. Seen turbo people use it, but here it is a no-no with nitrous cause of it being a rev-limiter.
 

slow67

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Apr 1, 2007
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Its my understanding that it controls the rate of acceleration by retarding the timing.
 

10secBu

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May 21, 2003
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I haven't used one, but here's my understanding of the MSD digital 7 programmable.

It's got two potential "traction control" functions.

1. timing retard which is fully programmable to amount taken out, how long to bring in 100%, and the agressiveness of the curve.

2. Slew rate. RPM limiting just like the rev limiter only you set a curve which mirrors your engines excelleration rate that way if the tire spins and rpm wants to spike, the limiter will hold it's rate or excelleration.
 

ILLEGAL REGAL

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Jan 1, 2005
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10secBu said:
I haven't used one, but here's my understanding of the MSD digital 7 programmable.

It's got two potential "traction control" functions.

1. timing retard which is fully programmable to amount taken out, how long to bring in 100%, and the agressiveness of the curve.

2. Slew rate. RPM limiting just like the rev limiter only you set a curve which mirrors your engines excelleration rate that way if the tire spins and rpm wants to spike, the limiter will hold it's rate or excelleration.
I asked about this on yb and pretty much got the same thing out of it.

If I'm correct what you'd do is get a data logger and you can see where you have tire spin. Then in that rpm range you can set a rpm limit and if the tires spin and the rpm's trigger the function it will retard timing to where you set it to and slowly ramp back in at the rate you set to bring traction back and apply power. What does the word "slew" come from or mean in the ignition world?

It sounds very confusing but I think if thats the way it works it's quite cool, but with n2o and your timing retards in that department of the box things will really get tricky. I'll try it.


Todd, you run a logger right? Which one and how expensive does it get just to be able to detect and read tire spin, and that same box can record a wideband also right?
 

10secBu

MalibuRacing Junkie
May 21, 2003
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ILLEGAL REGAL™ said:
10secBu said:
I haven't used one, but here's my understanding of the MSD digital 7 programmable.

It's got two potential "traction control" functions.

1. timing retard which is fully programmable to amount taken out, how long to bring in 100%, and the agressiveness of the curve.

2. Slew rate. RPM limiting just like the rev limiter only you set a curve which mirrors your engines excelleration rate that way if the tire spins and rpm wants to spike, the limiter will hold it's rate or excelleration.
I asked about this on yb and pretty much got the same thing out of it.

If I'm correct what you'd do is get a data logger and you can see where you have tire spin. Then in that rpm range you can set a rpm limit and if the tires spin and the rpm's trigger the function it will retard timing to where you set it to and slowly ramp back in at the rate you set to bring traction back and apply power. What does the word "slew" come from or mean in the ignition world?

It sounds very confusing but I think if thats the way it works it's quite cool, but with n2o and your timing retards in that department of the box things will really get tricky. I'll try it.


Todd, you run a logger right? Which one and how expensive does it get just to be able to detect and read tire spin, and that same box can record a wideband also right?

I have the basic unit from RPM Performance. http://www.rpmperf.com

I paid $549 last year. It monitors engine & driveshaft rpm as well a battery voltage. It's fully expandable to 12 channels. I later added a WEGOII WBO2 from Daytona Sensors, stocked and sold by Randy at RPM Performance.
 

Excelerater

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May 22, 2003
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you cant slew a nitrous motor or your blow that thing up.......
you can do a gear retard or any retard on a nitrous motor
which is what I am learning to do

MSD does a very poor job with thier software and instructions
not to mention its a VERY old school looking program,afterall
the software is actually over 6 years old when I got my first Dig7
 

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