nitrous in mud racing

68formalGT wrote:Karl, you weren't using a start and step(msd 8987) or some other timing module?

I use the old MSD Start retard with my old early 7al-2 since it's basically a repackeged original 7al. I think the replacement is the MSD 8987.

havent had any issues with that im assuming??

The reason for a plug change is for your tuning so you will know if its good or going south on you. Once you get it where you want you won't have to change them as often.

Ok good I was sort of thinking that but wanted to be sure. I know I gotta read plugs while I try and tune

bigben wrote:havent had any issues with that im assuming??

Nope works like a champ. Over the winter I plan to make some changes though. Looking to go air shifter and 2 step, so the nitrous side will have to be re-done some since cuttently it's wired to a wot switch.

Ok cool. What the reason for the two step adding more spray?

So I can set the launch rpm, hold the pedal to the floor and let it eat. There will be a relay wired in so the nitrous doesn't start until after I launch

kjett wrote:So I can set the launch rpm, hold the pedal to the floor and let it eat. There will be a relay wired in so the nitrous doesn't start until after I launch

Did you T off the transbrake power to a relay to turn power off to the carb micro switch when on the brake?

Haven't done it yet. That's the plan for this winter when i also change the shifter to a cheetah air setup.

How hard do you think it's going to hit when you release both the brake and the extra horsepower from the nitrous all at once?

Karl what you going to for an ignition if ur switching? As for those of you running controllers do u just use a dial retard and let the controller do rest or do u have a msd digital 7 that ramps the timing out to

68formalGT wrote:How hard do you think it's going to hit when you release both the brake and the extra horsepower from the nitrous all at once?

Dunno, but I'm hoping to make some nice wheel stands in the mud truck

bigben wrote:Karl what you going to for an ignition if ur switching? As for those of you running controllers do u just use a dial retard and let the controller do rest or do u have a msd digital 7 that ramps the timing out to

Haven't thought that far in advance. Trying to get through this season 1st. I am thinking more of the newer digital stuff so I can do individual cylinder timing and prevent the typical fat/lean cylinders when running a cast intake and single carb.

kjett wrote:Dunno, but I'm hoping to make some nice wheel stands in the mud truck

I want to see that!!!!!


Haven't thought that far in advance. Trying to get through this season 1st. I am thinking more of the newer digital stuff so I can do individual cylinder timing and prevent the typical fat/lean cylinders when running a cast intake and single carb.

Is there a horsepower level where the fat/lean cylinder mix becomes a problem or is it always there even at say 300 horse and below? I've read that you can tune the cylinder by changing the plugs to a different temperature depending on what each cylinder needs. How about distance/time, we're racing 100 to 200 feet and 2 to 4 seconds, does it make it more difficult or less then in drag racing?

I would say it's always there. I have seen #4 and #8 a little leaner than #3 and #7, and that was back when I was only spraying a 175 tune. Any way you look at it, be it 1/4 mile or 150', a bad tune is a bad tune. I burnt a hole in #8 piston and cracked a cylinder wall on a 275 tune on that 466 in a 150' track simply by not pulling the correct timing. The other cylinders weren't too bad compared to the outer 4 cylinders.

let me know on the digital box im just gathering parts so id like to hear youre input ! heck may even be intrested in buying youre old ignition when time comes if youre going to part with it