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Discussion Starter #1
I have a 7530T MSD Ignition and already have the wiring done to activate the n2o as the transbrake is relaesed,at the same time I'm pulling 14* timing.I'd like to pull an additional 3-4 degrees and ramp it back in by 1.5 seconds.How is this accomplished ?
 

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I would guess you should be able to trigger two stages at the same time, leave the first retard alone and ramp the second in the way you want.
 

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I don't think this is a hard wire configuration, but more to do with software configuration within the Digital 7. Maybe the gear retard curves could help you achieve the result you are looking for.
 

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Discussion Starter #4
What happened to my post from 8/16 ? I received an e-e mail that there was a response, that's gone too.
 

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Sorry but the provider of this site had a hardware crash. All posts since 8/14 were lost. Im looking to switch providers right now and need to learn how to transfer the data.. No one seems to want to help... :(
 

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Per my post before the board went down. I’ll repost.
The best way to get the result you are looking for from this ignition, is to use the Gear Retard Curve. Although this is RPM based, it is easier to manipulate good track / bad track conditions.
There is a launch retard, but the problem with using the launch retard is that it goes active on the Trans Brake. In most cases, you don’t want to pull timing while on the Trans Brake, the engine will never get up on the convertor and it will ultimately effect 60’ times.
With the Gear Retard Curve you can pull the additional 3 to 4 degrees you’re looking to pull as soon as you let go of the Trans Brake.
For example: If you leave at 4800 RPM you would program into the Gear Retard curve to pull timing at 4900 RPM, (then calculate RPM over time). At what RPM would you be at 1.5 seconds out? A data recorder is a good aid for this, but if you don’t have one you can guesstimate.
I would go like 1500 to 2000 RPM out, as a starting point. Start to Ramp timing back in at 6200 RPM. You can make this a sharp curve, so that all the timing is back in at 6500 RPM or you can make it more gradual and have it all back in at 7800 RPM.
This is where the flexibility part of the ignition comes into play. Depending what your car wants and the track can handle will dictate how this curve is manipulated.
On a bad track carry the curve out further. If the track is awesome and the car can handle it, shorten up the curve. This will help aid in preparing your car for track conditions.

A quick note on Gear Retard Curves and other timing aids. With the ability to pull timing and being able to ramp timing back in. Remember, you can never advance more timing in then what the total timing setting is. Example: If you’re running 36 degrees timing and you pull 12 degrees with a step retard, with an additional 4 degrees with the Gear Retard curve, putting you at 20 degrees. With the Gear Retard Curve, you can only advance 4 degrees back in. Once the step retard is deactivated, that will put the 12 degrees back in. But you can never advance back in more then the total timing setting, which in this example is 36 degrees.
 

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Excellent post Mike. Sorry you had to repost that but am glad you did as I missed the first time you posted it.. Dang did that make sense. Anyway, that box seems to do a lot more than my 7530 box..
 

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Monty,
Actually the 7530T Box replaced the 7530. There are a bunch of upgrades into the T box over the 7530. One of the biggest new features in the T box was Traction Control Detection. This ignition was approved by the NHRA for Pro Stock Competition. Since the 7531 Slew Rate Rev Limit box was banned by the NHRA.

This feature will detect T/C controlling devices. It then shuts the ignition down to 4500 RPM and can only be unlocked by a NHRA official.

A couple of others features are a faster processor and the Gear Retard Curve.
The 7530 box has a launch Curve and a Run Curve, which works great for a powerglide. With the 7530T Box you have 6 curves you can tailor, which works great if you have a 3 speed auto, or a Liberty.

A 7530 can do the same function as I explained above, you would just apply the same process to the Launch Curve.
 

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Very cool.. I have the old 7530 box and ended up buying the 7531. I wish I would have asked mre about the 7530 box before I got the 7531.. or is the 7531 a better choice?
 

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The 7531 Box is an excellent choice, being that you’re going the Turbo route now.
I say that because the 7531 Box has the ability to support a MAP Sensor, along with a Boost Retard Curve. Instead of putting a big load on your Fuel Injection system with fuel management and timing control, you can actually let the 7531 Box control all of your timing function.
With a faster processor (40-MHz) then most aftermarket EFI units, it only makes sense to let the 7531 control the coil. The faster you can get the timing out of the engine, the less likely you’ll hurt it.

The 7531 also has the ability to record data of various ignition functions within the Ignition box.
You can’t and don’t need to add external sensors, it is all set up by MSD within the box.
This is another piece of information to look at which will also aid you tuning the car.
 

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MCMIKE sorry to hijack this thread.. :oops: I will ask more about this box when I get closer to tuning it up. Im glad I didnt waste my money.. :D
 

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Oops, Sorry MC.

Monty,
If you need any help, I would be more then happy to help you with it.

On another note, MCMIKE I can set up a curve with what your tring to do and E-mail it to you, if that helps.
Sparky
 

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Discussion Starter #13
Sure, I would appreciate that e-mail.I don't have a data recorder and will have to bring the car up on the brake to see exactly where the converter stalls at.I think I can program that rpm retard with my Hand held programmer but what prevents the run retard from activating during the burnout or while in 2nd and 3rd gears?
 

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You have 6 gear retrads curves in the box. When you start the car the ignitioni is in last gear, which can also be tailerd in the Data Editior. Once you activate the trans brake or apply power to the dark blue wire. it will reset the Gear Retard Curve to first gear, along with some other parameters.
When you set up a retard curve it is only active in that gear unless you apply it to other gears.
 

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So the first gear retard does not activate until you reach launch rpm and release the trans brake? But....launch retard is active on the brake?
 

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Jim,
Depending how and where (in the RPM Curve) you set up to pull timing, will dictate were the timing is pulled.
If you launch a 4800 RPM and set the curve to pull timing at 4500 RPM then yes, it will pull timing when your on the brake.
But if your set it up to pull timing at 4900 RPM to 5000 RPM, then it will not pull timing when your on the brake.

The Launch Retard option does go active on the trans brake and stays active for the amount of time programmed into it.

Does that help?
 

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Yes, I thought that the launch retard would make a car too lazy on the brake. Let's say a turbo car that you are trying to spool up. :-D The gear retard could be used to manage power without affecting how you stage the car. Pretty cool. 8)
 

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Discussion Starter #18
Does anyone have software such as Desktop Drag, where I can duplicate a run off the info on my timeslip.What I'm trying to do since I don't have a data controller is set up an RPM curve graphed with time.I thought some of the old DeskTop Drags simulated a run giving you time vs RPM,how long in each gear etc.I just need a baseline to calculate approximately a conversion of 1.5 seconds to RPM.
 

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MCMIKE,
We don't have to get that specifc. I just basically need the version of ignition you have. It might tell you with the hand held programmer, I'm not sure though, I usually use a laptop computer. A laptop will tell you which version of igniton you have.
Which to edit the curves I have discussed. a laptop is the only way to edit them. I don't think the hand held deal will edit a Gear Curve.

I can send you a a starting point curve and you can work with it from there as I discussed above.
Let me know
 

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Discussion Starter #20
I'm not sure what you're looking for,but I do have MSD PRO DATA Software version 3.11 downloaded in my computer.If this isn't what you're looking for let me know.

Thanks, Mike
PS, that starting point curve would be much appreciated
 
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