Iginition box comparo, got this from the other site, pretty lengthy

[sids]

Some guy posted this infor on the other DSM board, I decided to copy paste it so that there will be additional info to help me on my query down there.


" I'm looking to make a comparison between the MSD DIS-2-HO, and the Crane HI-6DI2 ignition boxes. Here are some relevant specs from the manufacturer's sites (I deleted useless things like dimensions and operating voltage):

MSD:
- Spark Energy: 170 milliJoules Per Spark
- Primary Voltage: 470 Volts
- Output Voltage: 43,000 Volts (Stock Coil)
- Current Draw: DIS-2 HO, 5.3 amps@10,000 rpm
- RPM Range: 12,500 rpm w/14.4 Volt Supply

Crane:
- Current draw: 3.0 amps max at 10,000 RPM
- RPM operating range: 20,000+ RPM (with rev limiter disabled)
- RPM limiter range: 500 to 9,900 RPM in 100 RPM increments for each stage
- RPM limiter accuracy: ±30 RPM
- Multiple Spark Duration: Approximately 20° crankshaft rotation below 3,600 RPM. Maximum 12 sparks per seq. with 1 millisecond interval between sparks.
- Primary voltage output: 450 volts
- Primary energy output: 1200 millijoules/sequence
- Trigger inputs: Module trigger (12 volt square wave)

Now this is where it gets interesting. My observations from comapring these specs:

- Energy output: Crane is 1200 mJ/sequence, MSD is 170 mJ/spark. I need to find out how many sparks are in a "sequence" to be able to compare these specs. Dammit.

- The MSD draws more current at 10k RPM (5.3 amps vs. <2.0 amps). Makes me wonder if the MSD is putting out more spark than the Crane, or if there's just more waste in the MSD circuitry.

- Primary output voltage: MSD 470 volts, Crane 450.

- Although not listed in the MSD's short rundown of specs, the Capacitive Discharge is also for 20° of crank rotation. MSD does not specify an RPM at which it goes to single spark... Crane uses CD under 3600 RPM, and single spark over 3600.

- Crane rev limit and stage limit is adjustable in 100 RPM increments to 9,900. MSD is adjustable in 250 RPM increments to as high as the unit will fire (12.5k). Advantage to Crane for the smaller increment, I'm not revving higher than 9900.

Any other ideas anyone has about these two boxes are welcome, as well as hands on experiences with them. Thanks for any input..

The DIS-2 (not HO) gives 105-115 mJ per spark, 1540 mJ per sequence. Compare to 1200 mJ per sequence on the Crane.

MSD goes to 3000 RPM with multiple sparks, and >3000 is single spark. On the Crane the switchover is at 3600 RPM. Not sure which is better or if it matters.. the multiple spark is jsut to improve idle and low RPM throttle response. Both ignitions do multiple sparks for 20 degrees of crank rotation.

The Crane will require an electronic trigger adapter, while the MSD will not require anything (90s need a tach adapter). This is because the Crane uses + coil triggers, and the MSD uses - coil triggers (our stock system is - trigger). Advantage to MSD. "


I have a crane cams hi6, well ok the only reason I got it is becuase I got the ignition module at a good price, around $200, but had to spend for the tach adapter and it doesn't fit the stock coil pack so I had to use accel coil packs.

anyway, there are knobs on the side of the ignition box, i think it says something like 1st stage rpm limit, 2nd stage rpm or something like that, 4 in all.

I haven't touched the thing since I got it and have no idea how to adjut it? what are the knobs for? my primary goal in getting the ignition module is to increase mileage, any idea what setting do i have to dial it?

 

[brads]

I was tempted to answer this one on the other site, but realized that was an old post that someone brought back from the dead, so the guy probably already bought something.

Anyhow, for you, what makes you think you need an ignition amplifier? I run stock plugs, stock wires, stock ignitor, stock coils and it runs quite well at 24 PSI. I tested the stock stuff, its actually pretty damn good.

Brad

 

[sids]

hehe, the clincher reason is because of that one line in their ad


"Increase fuel mileage"

and I got the box kinda cheap, increase fuel mileage without sacrificing power sounds good to everyone

 

[rdrkt]

Trust me there is no good reason to go with an aftermarket igntion. I think its a waste of money on 11 sec cars its even more pointless on slower cars.

 

[brads]

Increased fuel mileage would only be applicable if you were having severe misfiring/ignition problems before the install.

BUT for arguments sake, lets say it increased fuel mileage enough to save you one gallon a week(probably much higher than you could really expect). At saving $2/week, it would take you over 3 years to just break even. Even longer before you actually started realizing a savings benefit from your mod. From the number of complaints I have seen, if your aftermarket ignition box lasted the 3 years it took to break even $$ wise, you would be the exception to the rule.

You want to optimize your ignition? new plugs (stock recommended) and wires (anything but Nology). You want to get fooled into thinking you are improving gas mileage? http://www.tornadoair.com/ is a much cheaper complete waste of money.

Brad

Originally posted by sids
hehe, the clincher reason is because of that one line in their ad


"Increase fuel mileage"

and I got the box kinda cheap, increase fuel mileage without sacrificing power sounds good to everyone

 

[sids]

one look at the tornado air shit is enough to know that its BS, anyway, thanks for the input, so I just leave all the knobs alone?

 

[brads]

The settings are just for the multi stage rev limits. So if you dont want to hook them up, turn the knobs to all 0, this will disable them.

Brad

Originally posted by sids
one look at the tornado air shit is enough to know that its BS, anyway, thanks for the input, so I just leave all the knobs alone?

 

[sids]

OKi doki, just set everything to zero.

Just what are the multi stage rev limits for? from my understanding, it allows you to set say 3000 as the rev limit for drag launches by shutting down the ignition, forcing you to shift to 2nd then when your in second, the next rev limit comes at say 6000 rpm? is this what the rev limit means?

 

[brads]

You dont use the limit to shift to second. When you are about to launch, you hold the gas to the floor, and it sits on the limit. Then when you go, you just have to feed the clutch out, and leave the gas floored. You wire the limiter in so that it shuts off when the clutch is fully out. So as soon as the clutch is out, and presumably engaged, then the limiter shuts off, and you can keep accelerating through first gear. Without this, you have to work the clutch and the gas coming off the launch, this just makes it easier to get consistent launches.

The extra limiter they have there is for burnouts to heat the tires up. You hook it to a switch on your dash, and then you can hold the car on the limit, while doing big burnouts.

I still think you'd be better off selling it, and using the money to get something useful. No point in hacking into your wiring to put this on. It will make just as much of a difference in your mileage and performance, if you leave it in the box.

Brad

Originally posted by sids
OKi doki, just set everything to zero.

Just what are the multi stage rev limits for? from my understanding, it allows you to set say 3000 as the rev limit for drag launches by shutting down the ignition, forcing you to shift to 2nd then when your in second, the next rev limit comes at say 6000 rpm? is this what the rev limit means?

 

[latvianrkey]

I want a rev limiter so I can lauch better at the track. Is there an aftermarket rev limiter available at all, or is it not even possible?