well i was just getting ready for our first test session of the year this wekend and my holley strip annilator ign. box took a dump. and guess what they have discontinued there ign. line .great customer support :mad: so I droped another $1100.00 today that I wasn't planning on and bought a crank trigger ,7530t digital 7 and hvc pro coil from MSD.I figgured If I'm gonna do it go all the way :D hell it's only money. Any way my question is that I would like to find out anyones experiances whith this system and possable advice on setups such as timing retards and gear retards to help maximize my potential and justify this investment. Any advice or tips are very much appreciated.
Thanks

What are you doing with it? Power adders?

The 7530/7531 boxes work great! There are a tonne of features if you have a laptop - launch control, rev limits, retards, datalogging etc.

Also controls a shifter if you want electric or air shifting.

Make sure to always download the latest software from msdignition.com as it changes often.

The datalogging is the best feature on the box.

No power adders here all motor :D . just want all of the tuning features and data that I can get. the only thing that I am unclear on or just havent figured out yet is the retard functions . I have ploted several variations to start doing some tuning at the track this weekend. but as far as I can tell the timing curves are only active after you leave on the launch rev limmiter.what if I want to footbrake race the car? Is there a way to set up a low rpm retard that is always active that would be nice to have for the street driving that is done.

Put the pink/purple/tan wires to toggle switches then to +12V and use them for street driving. I put a 1 deg on one toggle and a 2 deg on another so I could cruise on my base timing at 32, 31, 30, or 29 at the flip of a switch. I raced on 30 deg so cruising I could add a deg or two.

Why would you want a low RPM retard? Don't you want more timing for cruising/part throttle?

yes I was just not thinking and typing at the same time . I had thought of thyat and I guess it 's a great way of doing it. I have gotten a great deal of info from my playback tach. I am looking to be able to have info straight from the box it will be interesting to compair the accuracy of the tach memory now.

Ron,

I have an ultimate II tach also - the MSD is better, except for driveshaft RPM if you have that also. I use both if I remember to hit record. THe msd records automatically from either your line lock or transbrake activate switch.

It is nice because you can zoom in and display RPM slope rather than RPM so you can see your maximum acceleration before it spins (in my case) and then in the 7531 you can program in a max RPM per second acceleration rate for each gear separately. It knows what gear you are in by "rpm drop" which you also type in there.

The other way is to just type in an RPM profile with time and it will follow that curve. That's what some of the small tire racers do. I haven't had a chance to tune that myself.

I just took out 8 deg extra timing from transbrake release ramped up to 16 total degrees after 2 seconds. Didn't help me much, it lifted the front end and then killed the tires on 8 degrees anyways LOL.

alittle side note I just got a 7531 through the "Car Shop" in Moline IL (carshopinc.com) They were great to deal with and have good prices (summit was $860 Car shop $720 for the box). I just have to wire it and sell my progressive nitrous controller. never ends.....

I was thinking about using a on-off-on toggle switch to the box to trigger the gear retards I can wire one to the trans brake and one to the line lock for footbrake racing. I am looking forward to having the launch retard becouse I have been pushing my traction capibilitys to there limit w/ a 10.5" street tire and 3400lbs.
I am hoping to get into the 9.60's on motor and then I will think about using all of the other features and a little go juice to see just how fast we can go. ;)

Ron,

With my 632 knocking timing out of the launch didn't seem to take much away from the torque. I tried as much as 10 deg retard N/A and it didn't sound as happy off the brake but it still made gobs of torque.

I think if you have the 7531 box (or at least this feature) I think the best way they are doing it now is to leave wide open so that you flash the converter and plant the tire then drop the RPM limit vs time down slightly and then ramp it up gradually. You are essentially riding the rev limiter a bit until you are moving. That is what the msd curves looked like from an outlaw type 10.5 car I received. The rev limit started right where the rpm drops to after the converter flashes then tightens up and them ramped up slower for a second and a half.

I left with as little as 8 degrees total on the nitrous and the motor was still "happy." If I run a big inch nitrous combo ever again I will use the moving rev limit feature.

Originally posted by 66 283:
...then drop the RPM limit vs time down slightly and then ramp it up gradually...Is that the "slew rate" function? What units of time can you use to program this? We know from our Racepak data what the engine acceleration rate is on "good" launches... would you just match that acceleration rate as a starting point and then tweak it to see what you can squeeze out?

Ryan how does the nitrous like hitting the limiter on that slew rate function? Those drag radial guys are using it so I have to assume it won't hurt anything but??? Seems like there might be some potential for trouble if you're launching w/nitrous using the slew?

no, it is not the slew limit I'm talking about - it's the rev limit with time. It wasn't on the first version of the software but it appeared later. You just program in the RPM curve you want it to follow and how strictly you want to control it and it follows the curve.

I tried the slew limit on the street once and I could go full throttle (1000hp) and not spin. The engine didn't sound too unhappy - it only pulls a cylinder here and there to keep it on the curve.

I don't have a problem hitting the limiter on nitrous with the moving limit because it is not a hard rev limit like hitting 7500 and holding it there - you can set the sensitivity, and if you have a datalogged run you won't be hitting it very much.

This is exactly what Applied Nitrous Technology told me to do for nitrous traction control so I don't think it's unsafe...

Here is an example I received for my car from someone "in the know." I never got to try it because the email arrived a day late - after I hurt the motor largely due to blowing the tires off and hitting the rev limiter repeatedly. It really depends on the converter as to how quickly you bring in the RPM.

http://www.lumpracing.com/gallery/SNAG-00.jpg

I hope to be able to tune enough with the 7530t box I just bought to achive my goals n/a then I guess that I am going to have to upgrade to the 7531. so far I have been hooking pretty hard 1.38 60ft. and that is with 4 year old dot tires I have new rubber for this year.