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Old 7th-December-2010, 06:22 PM   #1
just chevy

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Thumbs down msd digital 7531

anyone running the msd digital 7531 what a pain n the ***
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Old 7th-December-2010, 06:35 PM   #2
1320quick

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What's the problem with the 7531??? I'd love to have one in my 275 drag radial car. We use a 7530T now and I don't know how we could get down the track without it. Is it perfect, no probably not but I'd rather have one than not have one.....
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Old 7th-December-2010, 07:32 PM   #3
just chevy

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Red face msd

i gonna quiz u here, here gos i had a msd 7aL2 in my vega the motor trans and converter where all new, i made 19 passes on this motor trannie an converter ran to much bottle an burnt 4 pistons on the 19 pass the last pass was 5.35 n eight mile, so i pulled motor an trannie an built 67 nova i had the car wired by the same person that wired the vega he called an said lets go with the 7530t i said im no tv repair man, against my better judgement i said ok go ahead with th digital box,he wired the car an installed the 7530t along the same motor and trannie an converter,got the car back an when i transbraked it the converter would only stall at 4000 it would stall at 4800 with the 7AL2 in the vega, the rev launch was set at 5000rpm so msd blamed it on my converter my converter guy blamed it on the box so i had the converter cut open it checked out ok, so i sent the box back to msd they said it checked out ok but they said they would send me another 7530t just for customer satifaction, i told msd send me the 7531 now the 7531 stalls at 3000rpm when i trans brake it an rev launch was set at 5000rpm i moved the rev launch up to 12000rpm an saved it to msd it still stalls at 3000 rpm

Last edited by just chevy; 7th-December-2010 at 07:35 PM.
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Old 7th-December-2010, 08:22 PM   #4
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Not sure how many times you posted this statement on this site but I responded in the Drivetrain & Performance section.
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Old 7th-December-2010, 08:45 PM   #5
just chevy

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msd

Quote:
Originally Posted by Seattle_Mike View Post
Not sure how many times you posted this statement on this site but I responded in the Drivetrain & Performance section.
im going to delete my post at drive tran an performance an keep my post here, i saw your post there i understand that setting the rev launch at 5000 will not make my converter stall at 5000 when it will only go at 4800, with the 7530tit will only stall at 4000 even though i have the rev launch set at 5000 why is that ??? and with the 7531 it only stalls at 3000 with rev launch set at 5000 and rev launch set again later at 12000 it still only stalls at 3000 why is that ????

Last edited by just chevy; 7th-December-2010 at 08:53 PM.
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Old 7th-December-2010, 09:05 PM   #6
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The ignition box has nothing to do with where a converter stalls. If you are saying it's on the rev limiter, that's something totally different. Do you have the very last item in the programming tree set to Arm LaunRevLim ? Can you E-mail me your MSD xxx.IGN file you are using? I'd be happy to take a look at it. documike@comcast.net
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Old 7th-December-2010, 10:23 PM   #7
just chevy

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Unhappy msd

Quote:
Originally Posted by Seattle_Mike View Post
The ignition box has nothing to do with where a converter stalls. If you are saying it's on the rev limiter, that's something totally different. Do you have the very last item in the programming tree set to Arm LaunRevLim ? Can you E-mail me your MSD xxx.IGN file you are using? I'd be happy to take a look at it. documike@comcast.net
ill have to see if i can email that, i understand the rev limiter is different then the rev launch the rev limiter is set at 7800 and the rev launch is set at 5000, i dont no about the very last item in the programming being set to arm lauch rev lim, but i do no that the rev launch is set at 5000 joe ponda at msd went over all this with me over the phone while i had the laptop connected to the box
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Old 7th-December-2010, 10:32 PM   #8
just chevy

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Quote:
Originally Posted by Vin63 View Post
I ran one in an Outlaw 10.5 car awhile back...in my opinion, our race program would've been a lot more difficult without it. Are you having any other issues besides the launch RPM? I would double check the wiring (connections, etc.), then the battery/voltage levels (we had a bad battery that caused some issues before), then I would test the unit in that order.
ill find out if i have any other issues this weekend, i havent gotten over this hump yet went to the track only 2 times this year dident go back because it woulent let the converter come up to the 4800 stall at 4000 it wouldent even spin the tires when i let off the transbrake button with the 7530t box, all my wiring is correct scott walter who was tony christen crew cheif wired this car
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Old 7th-December-2010, 10:46 PM   #9
David&Melissa_h

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Quote:
Originally Posted by just chevy View Post
ill find out if i have any other issues this weekend, i havent gotten over this hump yet went to the track only 2 times this year dident go back because it woulent let the converter come up to the 4800 stall at 4000 it wouldent even spin the tires when i let off the transbrake button with the 7530t box, all my wiring is correct scott walter who was tony christen crew cheif wired this car
That doesn't mean he didn't make a mistake. I would double check...
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Old 7th-December-2010, 10:58 PM   #10
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You should be able to E-mail the file as an attachment. The light blue wire should be going to your Line Lock and the dark blue wire to your transbrake. When the transbrake gets released, it triggers the box to begin the programmed sequence. If the box is not being reset or some other programming or sequencing issue, it can appear like it's not functioning correctly but in reality it's doing exactly what is being asked of it. I'm wondering if maybe it's not getting the 12v signal to activate the RevLaunch function. Send your file if possible, there may be something programmed incorrectly. Here's an extract from the 7531 Help File that describes how the RevLaunch functions.

RevLaunch provides a multi-function. This function is activated when
the dark blue wire is switched to +12 volts to enable the RevLaunch revlimit
RPM value, the Launch Retard timing value, the Gear 1 Retard Curve, Launch
RevLimit Curve, resets the Shift Light sequence to the first RPM value,
Gear1, enable the Launch light and to arm the Launch History record. Also the
RevLaunch wire disables the Slew Rate Revlimiter. The launch retard is adjustable
from 0 to 15 degrees and is summed with Step1, Step2, Step3 and the Gear 1
Retard Curve retard values if they are also enabled by these wire inputs and
above the programmed speed value.


The Launch Revlimit limits the engine RPM to the RevLaunch RPM value
programmed until which time the dark blue wire is opened (removed from
+12 volts). When the RevLaunch wire is active and the Burnout Revlimiter wire
is deactivated, the 7531 is armed to record the Launch history record.
The record begins when the launch wire is active and the engine RPM
increases until the launch revlimiter is active, if AcqArm is set to
ArmLaunRevLim; at this time the record begins recording the prelaunch
and once the launch wire is removed from +12 volts and the vehicle is
launched and begins recording the data of the race event.
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Old 7th-December-2010, 11:08 PM   #11
just chevy

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Smile msd

Quote:
Originally Posted by Seattle_Mike View Post
You should be able to E-mail the file as an attachment. The light blue wire should be going to your Line Lock and the dark blue wire to your transbrake. When the transbrake gets released, it triggers the box to begin the programmed sequence. If the box is not being reset or some other programming or sequencing issue, it can appear like it's not functioning correctly but in reality it's doing exactly what is being asked of it. I'm wondering if maybe it's not getting the 12v signal to activate the RevLaunch function. Send your file if possible, there may be something programmed incorrectly. Here's an extract from the 7531 Help File that describes how the RevLaunch functions.

RevLaunch provides a multi-function. This function is activated when
the dark blue wire is switched to +12 volts to enable the RevLaunch revlimit
RPM value, the Launch Retard timing value, the Gear 1 Retard Curve, Launch
RevLimit Curve, resets the Shift Light sequence to the first RPM value,
Gear1, enable the Launch light and to arm the Launch History record. Also the
RevLaunch wire disables the Slew Rate Revlimiter. The launch retard is adjustable
from 0 to 15 degrees and is summed with Step1, Step2, Step3 and the Gear 1
Retard Curve retard values if they are also enabled by these wire inputs and
above the programmed speed value.


The Launch Revlimit limits the engine RPM to the RevLaunch RPM value
programmed until which time the dark blue wire is opened (removed from
+12 volts). When the RevLaunch wire is active and the Burnout Revlimiter wire
is deactivated, the 7531 is armed to record the Launch history record.
The record begins when the launch wire is active and the engine RPM
increases until the launch revlimiter is active, if AcqArm is set to
ArmLaunRevLim; at this time the record begins recording the prelaunch
and once the launch wire is removed from +12 volts and the vehicle is
launched and begins recording the data of the race event.
hey little buddie if i get a chance tomorrow ill see about sending u the file thanks for your help
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Old 8th-December-2010, 12:52 AM   #12
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Ever think the converter may be hurt?
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Old 8th-December-2010, 05:59 AM   #13
just chevy

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msd

Quote:
Originally Posted by bowtie0069 View Post
Ever think the converter may be hurt?
msd wonts to blame it on my converter the converter guy blames it on the box i blame it on the box also if u read my second post here u will see that, i think msd has a makes a good product they just have a problem admiting when someing wrong, i have heard of some people who have had problems with there stuff that when they send it n to msd msd says theres nothing wrong with it and when they get it back it works, my issuie is going to be related to msd, the converter was working fine when i pulled it from the other car now it doesent. it stalls dead nut on 3000rpm now with the 7531 box with rev launch set at 5000rpm
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Old 8th-December-2010, 06:03 AM   #14
just chevy

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msd

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Originally Posted by David_H View Post
That doesn't mean he didn't make a mistake. I would double check...
no he dident make a mistake i have already took the car back to him, its going to be all msd related
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Old 8th-December-2010, 06:49 AM   #15
lktna
 
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If MSD says nothing is wrong with the box and your converter guys says nothing is wrong with the converter and "you" think it is the box seems to me that you have no other choice than to pull the box out and replace it with another one. If it is to complex for you to figure it out then send it to me and I will send you my Digital 6 plus box which has been on my car for less than 2 weeks. Not trying to seem like a butt here but you don't even want to take anyones advise here. You already have your mind made up it is the box and nothing else. So guess you will have to change it and hope you don't waste another $800 on a box that may or may not be the problem.
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