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comp-plus
10-30-2006, 01:14 AM
I have replaced my 7530T with a 75301 about a month ago.The 7530T was working very well and I am happy with all the features. Currently I have the engine out of my car and have been trying to use the MSD ignition tester to get things going. The tach works, the spark is good at the test plug and the air shifter is doing its thing.

For the life of me I cant get the data acquisition to work. Does this sytem work with a tester or for some reason is the engine required to be running. On the acq file I have constant 4993 rpm and no sign of a graph but the tach and averything else works fine. The prodata tach shows the same rpm as the tach.

I have been activating by the release of the transbrake button which also sets the launch rpm.

msdtech4
10-30-2006, 08:03 AM
comp-plus,

You must hold the trans brake button down and bring the tester up so it hits the limiter. Once the launch limiter is active (no spark at the test plug) and let off the trans brake button and accelerate the tester like you would during a pass. You MUST have the dark blue active and be on the limiter when you release the trans brake or the acq will not work.

Thanks,

MSD tech4

comp-plus
11-04-2006, 04:30 AM
Two more questions.

1. I don't often use the burnout rev limiter. My dragster needs all the help it can get in a burnout. Top gear with big tyres means that the track pulls the engine down. I heard a rumor from another source that said: You need to activate the burnout rev limiter to arm the data aquisition. Even if you don't use it you still need to put power to it for a short time. Is this the case??

2. The two functions for starting the aquisition seem to be:

ArmLaunch: RevBurnIn is Off and RevLaunIn is ON

OR

ArmLaunRevLim: RevBurnIn is Off and RevLaunIn is On and Engine in revLimit.

Does this mean that if you select "arm launch" that you can release the transbrake button at a rpm much lower than the set launch rev limit and still start to recording process.

Thanks

Thanks

Eric David Bru
11-04-2006, 09:59 PM
Two more questions.

1. I don't often use the burnout rev limiter. My dragster needs all the help it can get in a burnout. Top gear with big tyres means that the track pulls the engine down. I heard a rumor from another source that said: You need to activate the burnout rev limiter to arm the data aquisition. Even if you don't use it you still need to put power to it for a short time. Is this the case??

Thanks

Yes, you should have the burnout limit active during your burnout and prior to staging. If you want you can set a very high limit so the limiter never activates, but you will still want to apply 12v to the light blue wire. Once you get close to staging you will remove 12v from the light blue wire and then your acquistion will work.

comp-plus
11-05-2006, 11:45 PM
Thankyou Eric.

Yes indeed this is why I have been unable to get it to work. Why wasn't this in the instructions??

Another question Eric. If after burnout I backup with my finger on the transbrake button will I have to activate the burnout limiter again prior to staging.

Again Thanks :)

msdtech4
11-06-2006, 07:02 AM
comp-plus,

No you do not as long as the engine is not shut off you do not need to cycle the light blue again.

Thanks,

MSD tech4

comp-plus
11-06-2006, 11:22 PM
Thanks tech 4 and Eric.

I still have an unanswered question from my previous post.


The two functions for starting the aquisition seem to be:

ArmLaunch: RevBurnIn is Off and RevLaunIn is ON

OR

ArmLaunRevLim: RevBurnIn is Off and RevLaunIn is On and Engine in revLimit.

Does this mean that if you select "arm launch" that you can release the transbrake button at a rpm much lower than the set launch rev limit and still start to recording process. Launch rev limit could be 7000 but I could launch the car at an estimated 5000. The engine would then climb up to 7000 and beyond as I approach the 60ft timers.

This is a methanol engine. I do not want to be sitting on a rev limiter on the startline waiting for the green. It just cools the combustion chamber down too much. As it is I already have a dedenbear linkage stage control device to control stage rpm.

msdtech4
11-07-2006, 07:49 AM
comp-plus,

That function is not selectable on the 7530T or the 75301 even though it is in the tree. It is defaulted to armlaunchlimit(non adjustable). This function is how the dark blue wire is activated. This means you must launch the car against the limiter for the unit to recognize zero time and first gear and on the 75301 it starts the acquisition. The launch limit, burn out limit and max limit are not affected by this wire, it does not delay the units response etc.

Thanks,

MSD tech4