Calling all MSD DIS 2 users ?????

[44pirate]

I installed one. I notice smoother Idle. I little bit more punch at lower Rpms. The only thing I noticed is bac fire when shifting out of 1 to 2nd.
Do you guys notice anything li e that.
Do I have to gap my plugs different lean it out more?

I did a bunch of searches couldn't find anything that answered these ??

Can you help a brother out.

 

[HyperGSX]

I don't have that problem with my car

 

[44pirate]

Did you notice anything different from previous setup.
How do you have the studder box setup.
What plug wores do you use?

 

[EROK81]

LIke 44pirate said, how did you hook up the stutterbox? I know on mine it will sometimes sound like a backfire when you shift/engage the sutterbox.

**Edit, it didn't realize you were the one that started the thread. But still read that anyway.

 

[44pirate]

I have my studder box rpm set at 5250 so when I shift into 2nd I'm not near that. I get a bacfire. Just wondering if anyone else gets that. How bout spar gap. I have mine at .028.

 

[4TireFire]

Not sure on DSM,s but i know on all other cars that ive installed MSD the gap on the plug is increased as recommended by the manufacturer of the ignition. Call MSD and they will tell you exactely where to set your gap.

 

[44pirate]

If anyone cares. I regapped my plugs to .030. I get less popping. No bacfire yet. I have my studder set at 5250. I build 7psi of boost. Haven't launched it yet. Saving it for the Trac thursday.

 

[44pirate]

I just got a email back from a MSD tech. He says that I should try a .035 gap and check my ground to make sure I have a good ground. So as soon as the enging cools down I'll try the gap change.

 

[44pirate]

Still got the backfire. Anyone else got any ideas

 

[Dyre]

Whats your stutter box trigger? The clutch?

It sounds like your stutter box (second rev limiter basically) is kicking in when you shit and cutting ignition. The fuel is still there, but gets thrown out of the exhuast ports and is igniting on a hot part of the exhuast...

That would cause the backfires easy...

 

[44pirate]

I have it set at 4250.
Also for some reason my spark plug wire keeps popping off at the plug.
I have my stutter set with the clutch at the bottom of the pedal. I think it's happens when the plug wire comes off.

 

[Dyre]

Well, if your trigger is your clutch (best way to do it IMHO) then thats the route of the problem.
When you go to shift, you're engaging the 2-step which cuts the spark- This means the last little fuel in the injectors isn't burned in the chamber. Instead it is ejected out of the chamber and collects in the manifold/turbo where something hot ignites the raw fuel and cuases a little backfire/pop.

If its not too loud (and not shooting vissable flames out the tail pipe) I wouldn't worry about it. There isn't much you can do without a fully programable ECU to stop this type of thing.

If you have an AFC you might be able to lean out the very top RPMS very slighty and see if it helps the poping.

 

[P8ntBalla]

kind of a vague questions about stutter boxes in general:

if you have your stutter box triggered by the clutch, and youre making a pass at the track(redlining the gears and thus engaging the clutch at 7-7.5k rpm) wont the box kick in and drop your rpms? or is it hooked up to the speed sensor or something like that to where it wont do that?

 

[brads]

It depends on how the box was made. Some like the MSD dont sense speed at all, only clutch position, so they would stick you on the launch limiter as you shifted gears. Which would allow you to use it for WOT shifting if you wanted to.
The TMO senses speed, but uses that to select between the your launch limit, or a fixed RPM for shifting(6000 I think). End result is the same, WOT shifting. It just means that you dont have to worry about a change in your launch limiter affecting your shifting down the track.

Brad

Originally posted by P8ntBalla
kind of a vague questions about stutter boxes in general:

if you have your stutter box triggered by the clutch, and youre making a pass at the track(redlining the gears and thus engaging the clutch at 7-7.5k rpm) wont the box kick in and drop your rpms? or is it hooked up to the speed sensor or something like that to where it wont do that?

 

[Dyre]

Originally posted by P8ntBalla

if you have your stutter box triggered by the clutch, and youre making a pass at the track(redlining the gears and thus engaging the clutch at 7-7.5k rpm) wont the box kick in and drop your rpms? or is it hooked up to the speed sensor or something like that to where it wont do that?

When you shift it will engage the rev limiter, but all that does is cut spark. When you pull your foot off the gas normally you do the same thing anyways, so it doesnt matter.

Its not like the MSD is going to pull the car from 8krpms to 4krpms instantly when you shift... The car just acts likes normal, just no spark while shifting.

Your RPMS drop anyways when you shift becuase you arent applying more gas. Its like a mechanical over rev (when you miss a WOT shift going from 3-4, but go 3-2 on accident.... The motor revs up, even though the stock rev limiter cut spark long ago) but not bad, becuase the 'over-rev' is the normal operational revs of the motor.

hope that makes sense...

 

[P8ntBalla]

so if i got this thing i could still rev past the launch-limiter and shift with the clutch without it sounding like im standing on the limiter?

 

[44pirate]

Originally posted by P8ntBalla
so if i got this thing i could still rev past the launch-limiter and shift with the clutch without it sounding like im standing on the limiter?

When your racing you shift so fast that you really don't hear hit the launch limiter. What's nice about it is, you can shift without lifting off the gas pedal caause your rpms will drop to what you set the launch-limeter at. For instance, I have it set at 4250, I build 7psi of boost at the line, as soon as I lift off of the clutch it will go to WOT but because of the clutch engaging I start at 4250, with my tires spinning of course, when I hit 7000 rpm I shift into 2nd without lifting off of the gas pedal. When the clutch pedal reaches the floor the launch-limiter takes my rpms to 4250 for how long I have the clutch to the floor. This is pretty fast so as soon as I let out the clutch it will try to go to WOT. The launch-limiter only kicks in when the pedal hits the floor. Hope this helps.

 

[Dyre]

Depending on how fast you shit too you won't be coming near your 2-step rpm limit.

It wont sound like your bouncing off the limiter until the revs have droped to the 2-step range on thier own.

 

[P8ntBalla]

o i c

 

[44pirate]

Well Dyre you the man.
I set my launch rev limiter to 6750 and no more backfire.
4250 was real close to my normal driving shift points. SO when I would shift it would cut spark and leave alot of unburnt gas go out the exhaust and pop.
Thanks for your help
George

Now if you can tell me why my plug wire pops off of my spark plug.
MSD 8.5mm wires. Only one does. I've changed the plug. It goes on real tight but it seems to pop off any way.

 

[Dyre]

My friends CRX blows one wire off the coil pack all the damn time. We don't know why.
Its his POS beater car, so we don't really care to try to fix it, but we checked all the easy stuff and couldn't figure it out...


Make sure theres no moisture trapped in the boot, and that the boot is clipping all the way on. Maybe try to close the little clip in the boot down a little more. (make it tighter)

 

[44pirate]

The funny thing is that it started with one. Then that stopped and then it moved to another. Moisture I think is the answer. I'll see if that might be the problem. Thanks again