Help with a 7531 and no2 progressive controller

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supernova
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Help with a 7531 and no2 progressive controller

#1 Post by supernova » Mon Jun 08, 2009 8:00 pm

Ok, I've been asked to help out a good friend with his 7531 MSD box and also a progressive controller set up. His set up is a lot like mine and I'm still learning about the 7531 box. I told him I don't have enough experience using both but will ask some questinos and try to help.

Here goes,
67 camaro 3400lbs; 496 ci 700hp + 300hp no2 system; pg; 4.30 gear, cal tracs; 275/60/15 m/t d/r. Not much differant from my set up thats not running yet.

I have some idea's but need a starting point.

Thanks
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
572 C.I. BBC

Best to date: 1/8
et: 5.28
mph: 134
new wt. 3340 lbs

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Re: Help with a 7531 and no2 progressive controller

#2 Post by John_Heard » Mon Jun 08, 2009 9:12 pm

What's the question? Is he looking for help on how to program the step retards for the nitrous or? Starting from scratch? Since he's got a progressive, doesn't sound like he's planning on using the timing functions to launch I assume.

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supernova
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Re: Help with a 7531 and no2 progressive controller

#3 Post by supernova » Mon Jun 08, 2009 9:43 pm

When David and I talked about it, I don't think he realizes that trying to run both the 7531 box and the n2o (p-controller) on the first outing is a bad idea. What i want to do is get a handle on the car with 7531 box and no n2o first. Have to start somewere. I have a good idea were to start with the launch retard and how to add it back in. I think getting a handle on the thing with the 7531 box is the first step then work the nitrous in is my though. I guess what I'm asking is when we start setting up the progressive to come in. What would a starting point for the progressive? and how should the 7531 be programed for the n2o? Remember this is a small tire.
Helping to get his running good will only help me with mine so I don't mined helping and learning at the same time. This car will run the same class that I will run.
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
572 C.I. BBC

Best to date: 1/8
et: 5.28
mph: 134
new wt. 3340 lbs

silvanova
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Re: Help with a 7531 and no2 progressive controller

#4 Post by silvanova » Mon Jun 08, 2009 10:21 pm

Is he running a plate or a fogger? And what progressive controller? Sounds about what im running
5.004 @142.6

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Pegasus
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Re: Help with a 7531 and no2 progressive controller

#5 Post by Pegasus » Mon Jun 08, 2009 10:41 pm

I dont run the 7531 box but I am real interested in the "slew rates".
It seems all the faster cars run this box.

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Re: Help with a 7531 and no2 progressive controller

#6 Post by supernova » Tue Jun 09, 2009 5:24 am

silvanova wrote:Is he running a plate or a fogger? And what progressive controller? Sounds about what im running
He is running my plate system and progressive. It is a NX pro plate and maximizer 2 progressive. Loaning my system was the only way to get him to the track. My car is far from ready so why not.
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
572 C.I. BBC

Best to date: 1/8
et: 5.28
mph: 134
new wt. 3340 lbs

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Re: Help with a 7531 and no2 progressive controller

#7 Post by John_Heard » Tue Jun 09, 2009 6:39 am

The way I've set up my box in the past with a single stage is use step retard #1 to pull all the timing out for the full shot, in his case 300 hp. You'll have to play with it, but start off with say 40% on the progressive then bring it in as fast as it will take it, say .5 to 1 second. I try and run 0 delay on the nitrous hit and most of the time that works because the progressive is usually pretty smooth.

One thing to realize is that few progressive systems function well at 30% or less, depends a lot on the solenoid design. Not sure about the Max II, but that's something to keep in mind. It might not pulse quite right down real low. Do your own testing on things like this, mfgs won't always tell you the details on that issue.

Also keep in mind that the launch retard function on the MSD box will take the timing out while you're on the transbrake. Which may make it harder to bring it up on the chip. You probably won't need much if any of that with the progressive box, but something you need to know. For example if you're taking some initial timing out, and you use the launch retard function, you may not have much timing when you're trying to get it to go to rev_launch and can make it backfire.

The gear retard function on the other hand doesn't do that, but it can get you in other troubles if the car spins and/or you have to pedal. gear retard is based on RPM so anything that throws that time vs rpm line off will mess with things. I wouldn't use it for more than one gear because if you short shift it, or do something else to get the time line out of whack it will mess things up.

I've been using the gear retard function for launch and a non-progressive 175 shot on mine but it was difficult to get dialed in and get the wheel speed down just right. I'm switching mine around to launch on the fogger/progressive then bring the plate in once it's ready for it.

Hardly anyone uses the slew rate control, they are using the rev limit curve feature - that's what they are talking about when they are saying riding the dots. The rev limit curve works pretty good, but it's a big help to have a real good baseline ACQ trace to work with in order to know where to set that curve at.

I was using that last year and had a progressive malfunction. Both kits came on at launch 100%!... well the rev limit curve held it and the car didn't blow the tires off, but she was on the limiter hard - in fact hard enough that it blew a header tube off #6 when it was popping and banging - stripped the threads right out! It can be violent! You don't want to hit the curve that hard, learned that one quickly.

To get started with the box, I would suggest not playing with the slew rate, or rev limit curves till you get some good baseline runs and feel comfortable messing with those things. Those should be considered "run savers" not something you want to hit unless it's absolutely necessary.

The MSD box is a very useful tool, but it's easy to screw up also if you configure it wrong. And I guarantee you it'll make you scratch your head a while if you do something stupid. LOL - I've got a degree in that now haha.

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Re: Help with a 7531 and no2 progressive controller

#8 Post by supernova » Tue Jun 09, 2009 8:43 am

John,
I learned from your post already. We have been playing with the launch retard out in the parking lot of his shop and got it to work but that's not what we need to be doing. So you have steered me in another direction. The gear retard is what we need to be using. I will check and see if it wired and work with that. We are trying to head to the track on Wednesday afternoon so I will have to look at it tonight.
Now on the gear retard I plan on launching at full timing and instantly dumping it all out at .010 of the run. How fast to bring it back in would be a starting point? And how will effect the n2o?
Bear with me here I know I will have lots more questions.

As far as the progressive goes, NX did tell me to start at 30% so it sounds like you hit the nail on the head with that one. LOL I wanted to started at 20%.
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
572 C.I. BBC

Best to date: 1/8
et: 5.28
mph: 134
new wt. 3340 lbs

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Re: Help with a 7531 and no2 progressive controller

#9 Post by John_Heard » Tue Jun 09, 2009 9:05 am

I'm not sure I'm clear what you're saying about .01 w/full timing? You mean no additional retard other than the step 1 N2O retard? Do you think you'll need that to get it up on the tire or to shock it?

The way I think, I would have the N2O come on at the same time the transbrake is released at your min % to start with, and only the step retard for the nitrous shot taken out. Set it for say 30%-100% in say .8 to start with. To make it easy starting out, rely on the progressive to get it moving vs playing with the gear retard. If you find that it's spinning even at 30% starting ramp, then think about using the gear retard to pull some out where you need it out. You can watch the ACQ trace to see where it's spinning at. I think you'll find the progressive better at controlling the power then yanking timing - but yeah you can do it both ways, just a different way to skin the cat. I'd just use the MSD gear retard curve to trim wheel speed where you need it at specific points in the RPM/Time range.

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Re: Help with a 7531 and no2 progressive controller

#10 Post by supernova » Tue Jun 09, 2009 10:11 am

Oh I see what your saying. I was going to try I the other way. No I think your way will be better. Never thought about other ways to work it. I'm learning that the 7531 box and the programming. I like the fact that learning on his car will help me be a step ahead on my car.

I call and he doesn't have the gear retards wires yet so that is the chore tonight.

We probably are not going to use the n2o on the first outing unless it goes well with launching on motor alone. I also don't think if we do run the n2o it will be a 300 shot to start with. I want to start with half that and work up to 300.

You have given us a good starting point and some great tips and pointers, thanks. Looks like we have some things to try with the new toys.

I can tell you this, tuning with this box is a lot differant than the 7 al 2 or al 3 box'es I use to have.

Anything else to look out for?
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
572 C.I. BBC

Best to date: 1/8
et: 5.28
mph: 134
new wt. 3340 lbs

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Re: Help with a 7531 and no2 progressive controller

#11 Post by John_Heard » Tue Jun 09, 2009 10:37 am

You don't need to use the wire inputs on the gear retard feature, it can detect gear change when the RPM drops. You'll want those Step inputs to use for your nitrous instead.

You'll need to set it up in the software where it says "Shift-ShiftGr" and tell it how much to watch for at the drop (like 900 rpm). ALso you'll need to set the "Shift-LastGr" to 2 for your glide. Also use "SetGrOFF" so that it won't change gears when your step 1 input for the retard comes on. Remember if using gear retard for multiple gears, if you pedal it, it'll think you shifted. :mrgreen:

Start with using the minimal features of the box to get your feet wet.

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Re: Help with a 7531 and no2 progressive controller

#12 Post by supernova » Tue Jun 09, 2009 11:14 am

Wow I did not know it had that feature. Boy do I have a lot to learn. How come the instruction book doesn't tell about all this stuff? Or did I just miss it? I think when I get off of work today I will plug in the old lap top and spend some time just looking at all the stuff that scares me. I've been told you can screw up a bunch of stuff real quick if don't know what you doing. If I screw it up I will need help fixing it.

I think I now have enough info to mess it good so let us get to the track and try it out. I will print out this thread and takenit with me to the track for referance as I know I will forget it all.

Thanks for your help John. It's been very inlighting.
I will have more questions after this evening before we go to the track tomarrow.
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
572 C.I. BBC

Best to date: 1/8
et: 5.28
mph: 134
new wt. 3340 lbs

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Craig W.
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Re: Help with a 7531 and no2 progressive controller

#13 Post by Craig W. » Tue Jun 09, 2009 5:04 pm

I'll add my experience with riding the dots (rev limit curve). It can definitely save a run, but might lead to parts breakage. At a race last fall, I was a few runs past the end of the life of my slicks and having a hard time getting down the track. I added a rev curve and the 60' went back to normal. But it banged real hard a couple times and broke a rocker stud. Then it spit out the pushrod, the lifter came out of its bore and the pushrod wedged between the block and the cam. Wiped out two cam lobes, one pushrod and had to have two lifters rebuilt. But I won the race on 7 cylinders 8-)

I've used a lot of the other features on the 7531 and its a great box. I'm getting ready to go start using the Cometic progressive, so a lot of the 7531 features will no longer be used since I don't plan on ramping in the timing and ramping in the nitrous.

With moderate amounts of launch retard, getting up on the transbrake hasn't been a problem for me.

The gear curves can get you in trouble since they work off rpm. If you spin, the rpm will go up and so will your advance. The launch retard is based off time, so its a little easier for a new user to get a hang of.

Just work through all the options in the program and read the help notes. Before long you'll be comfortable with it.
Craig Watson
2QuickNovas Racing
5.23@131

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Re: Help with a 7531 and no2 progressive controller

#14 Post by John_Heard » Tue Jun 09, 2009 5:20 pm

I always love that comment "But I won the race..." lol Gotta love it..

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Re: Help with a 7531 and no2 progressive controller

#15 Post by Craig W. » Tue Jun 09, 2009 5:31 pm

Its a good thing the purse money paid for the repairs!
Craig Watson
2QuickNovas Racing
5.23@131

Sponsors:
AEM Electronics
Carnivore Performance
Rapp Racing
VFN Fiberglass
Fast Shafts

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