In the stiff or soft sidewall thread there was some comments about using a launch retard to help with the issues.

Anyway, I got a pm asking about how I use the launch retard. I figured I would start a thread about it.

I have use my Holley EFI software for a launch retard & it sounds like the grid is similar or identical on how it works.

The PM explained how they use it to help with consistency. I replied with I mainly use it to help with wheelie control. I also use it to slow my ET. I used it once in May for tire shake then spin. I've never really used it for 60' to 330' consistency.

I did try it in one time hit this past weekend. The curve was a little different than I normally use & the car did not like it! I plan on revisiting this in the near future.

I hope to post up a picture of the curve soon.

I would like to hear about how our members use or don't use the launch retard.

2BKING

Using the Grid, I am actually using step 1 triggered by the K&R delay box Timer 1 to slow down from 5.20 in the heat to 5.80 for index racing. I like using step 1 and the timer that way I can make last minute changes in the lanes.
With Ron's MFI I also use timer 3 set the same as timer 1 to trigger a electronic lean out to pull fuel while the timing is pulled, thats helps a bunch.
Timer 2 use used for shifting on time.

I have found this to be really consistent and predictable. Now if I can only hit the pro tree as consistent I would be okay

Last year running a gas carb trying to slow to 5.80 using a combo of Launch retard and step 1 it was very inconsistent and it was .200 slower to start with with the gas carb

MSD Grid 7730 is a very powerful moderately priced ignition control. Many ways to activate the retard feature (like Big Steves method) to include Launch Retard programming. Holley ecu can do everything (almost) Grid can do. Because of the “almost”, my Holley EFI ignition control is divorced and Grid controls ignition exclusively. Hence the dual crank trigger pickups.

It has been my experience that controlling wheelies with Grid is better served when retard is programmed to start the moment the TB solenoid is energized, starting line launch retarded. This allows more launch consistency, and the delay box can fix anything RT related. For no-box, starting the delay 0.30 after TB release will keep your rt closer to no retard.

With an ecu one can use a height sensor to control the front wheel maximum height if desired. Mad Racing Parts offers a height sensor that is compatible with Grid that will activate a Step function to retard ignition and prevent excessive wheelies also.

I recently watched a racer replace their engine with one close to 100 hp more. The prior 6” wheelie turned into standing the vehicle on the rear bumper the first test run. When it came down, it bent the front motor plate slightly and the rear transmission brace was bowed down 2”. He ended up programming 14* timing retard the moment the TB was energized and left the retard in for a full 1.60 seconds and then ramped it to full ignition at 1.90. Still did a 12” wheelie that carried 40’ out.

As for the recent stiff or soft sidewall thread, the OP is convinced spending more money changing equipment will achieve the desired results he wants. imho, a few key strokes in Grid would do more for consistency and probably loose little to nothing in present performance with what he’s using now.

quote:

Originally posted by Big Steve:
Using the Grid, I am actually using step 1 triggered by the K&R delay box Timer 1 to slow down from 5.20 in the heat to 5.80 for index racing. I like using step 1 and the timer that way I can make last minute changes in the lanes.
With Ron's MFI I also use timer 3 set the same as timer 1 to trigger a electronic lean out to pull fuel while the timing is pulled, thats helps a bunch.
Timer 2 use used for shifting on time.

There may well be more to it but, based on what is written here, why not just land the wires for both timing retard and fuel lean-out on Timer 1? Then you only need to change one timer and they’ll always be synced.

Could of I guess but just wanted to keep them separate incase I wanted to turn the lean out on or off at different times. never been a big deal making the changes to both timers. On time is always the same, only change is off time

This message has been edited. Last edited by: Big Steve,

quote:

Originally posted by Big Steve:With Ron's MFI I also use timer 3 set the same as timer 1 to trigger a electronic lean out to pull fuel while the timing is pulled, thats helps a bunch.

Steve, if you have AFR data, how much does it change the ratio during the lean out period?

There are a couple of other things you can do to help hook the tires starting with a launch retard (Grid) system. Start with a small amount (6*) and go from there.

Additionally if you have a Dedenbear powerglide case there is an adjustment bolt at the back of the case than can be used to soften, or increase, the release of a trans brake. ATI and Dedenbear have web sites that explain the process.

Bob

As I posted on here before I use my delay box timers to pull timing with a MSD Start and Step retard box. I can pull at the hit, or down track any amount up to 15 degrees I think.

Only thing doing it that way is you can't pull different amounts on a pass. You are stuck with whatever the box is set at.

But it works great pulling some at the hit if the track is bad.

quote:

Originally posted by B KING:
I used it once in May for tire shake then spin.

I did try it in one time hit this past weekend. The curve was a little different than I normally use & the car did not like it! I plan on revisiting this in the near future.

The curve below is what I used in May to cure the tire shake, then spin. The next 2 elimination runs were identical 60' times to the thousands & I lost on the 2nd run.

I need to get the launch retard curve loaded up & posted that I tried this past weekend.

2BKING

quote:

As I posted on here before I use my delay box timers to pull timing with a MSD Start and Step retard box. I can pull at the hit, or down track any amount up to 15 degrees I think. Only thing doing it that way is you can't pull different amounts on a pass. You are stuck with whatever the box is set at.

For twice the price you could have chosen Grid 7730 and had multiple different options for timing retard while still on the starting line or changing during the run, not to mention a host of other great features.

Mark, when you have the dealy box and step retard already in the car, it is pretty much free to try it lol. Just hook up 1 wire and your pulling timing. A lot of cars have a delay box and start step already in them.

This is the launch retard I tried on my 1st time hit this past weekend. The radials did not like it & hopped mildly about 3 times at the hit. Radials like to be planted pretty hard (within reason) & dead hooked at the hit.

Most of my launch retards look similar to the 1st one I posted in this thread but with more timing pulled & further out.

2BKING

quote:

Originally posted by moparacer:
Mark, when you have the dealy box and step retard already in the car, it is pretty much free to try it lol. Just hook up 1 wire and your pulling timing. A lot of cars have a delay box and start step already in them.

Agree completely, but I’m writing to the mass of non-posters that visit

quote:

Originally posted by markemark:

quote:

Originally posted by Big Steve:With Ron's MFI I also use timer 3 set the same as timer 1 to trigger a electronic lean out to pull fuel while the timing is pulled, thats helps a bunch.

Steve, if you have AFR data, how much does it change the ratio during the lean out period?

I do not. I just knew from all my years experience from running MFI that I knew that I needed to pull some fuel since I am pulling 15* for about 4 seconds depending on conditions , if I didnt I would load the cylinders with fuel and drop cylinders. I did some simple math and a wild guess and came up with a total area of circle that leaned it out about 10 pill numbers while the lean out is activated. Timing is pulled a .300 from TB release and trans shifts at .400. When the timing comes back in down track, I ramp it all in at .500 it acts and feels like a T stop turning off. I an running 5.80 @ 128 mph where everyone else is running 115 ish

This is a very interesting topic.

I manage my timing map, throttle stop events, shift point a bit different based on track (concrete for about 90 feet) and the need to reduce the top end speed to less than 120 due to a short shut off area and mph/parachute requirement. Packing the chute after every run is a PITA.

From what I've read it seems a radial tire timing map would be different than a bias ply tire.

Bob

This message has been edited. Last edited by: RPROGAS,

quote:

Originally posted by RPROGAS:
Additionally if you have a Dedenbear powerglide case there is an adjustment bolt at the back of the case than can be used to soften, or increase, the release of a trans brake. ATI and Dedenbear have web sites that explain the process.

I ask about that adjustment bolt when I picked up my trans from Hughes many moons ago. I was told to leave that shyt alone & that's what I have done. LOL!

2BKING