mark kibort

Scot was having some serious issues in the race. even though he ran near his best time at laguna , 1:41.6, he couldnt rev the car's engine over 5900 without it missing badly. (almost like a rev limiter) im thinking its voltage or bad alternator , or arcing from the coil terminals, etc.

any ideas?

on the way home, it started to reallly miss badly, but we know that was another issue, due to a bad fuel rail injector connection. the clips are all broken and one or two of them, even though they are seated, maybe do not have sound connections. he drove it to CT and it was running fine.


Has anyone heard of using an MSD box on a stock 928??? what the heck are these guys talking about. there is a new mechanic over at CT that suggested it. Im thinking that he doesnt know 928s very well, or can there be a way to use it to boost up the voltage on the ignition system?

thanks

MK
(for scot)

Jim bailey - 928 International

No simple way , problems include getting a proper tach signal as well as keeping the fuel relay energized when the factory ignition signal is no more ....Remember the NASCAR guys wire in TWO systems so they have a back up when one fails

RicerSchnitzzle

Not true. Though it may be for the newer sharks. I run MSD with no issues.

Since you can run the MSD off the stock coil wire, all other systems are still intact. ie factory ignition system is still used, you're just sandwiching the MSD inbetween the stock ignition and the original coil. You also have to remove the 2 resisters in the original coil line for better results. I have full spark all the way to redline.

Main cause of MSD's missing at high RPM, is the rotor. You have to bypass the resister with a solder bridge to the tip of the rotor.

Jim bailey - 928 International

Ah interesting the other applications they wanted to eliminate the factory TSZ ignition box since that was having " problems ".

RicerSchnitzzle

I've heard that before, I have no clue how well an MSD would do as the stand alone ignition.
I did how,ever hook mine up with quick disconnets. I can re-route the stock coil wires back to the coil in seconds, bypassing the MSD. that was my safety idea, though it sounds like it should be the other way around..as the stock ignition may be more prone to fail

dr bob

Hey Mark--

The weak alternator issue is easy to diagnose-- look at the voltmeter.

Clean up the known fuel system issues before you point the finger at ignition. You can (and probaby should) sub in safety wire for missing connector bails, for instance, and the connections need to be clean abd bright of course. The o-ring seals in the connectors do no good if they aren't seated.

After that, make sure all the original ignition stuff is in good shape. As much "fun" as it is putting any MSD or other aftermarket ignition on any car, the value is that you have all new stuff to replace the old stuff that you suspect is not reliable. --All New Stuff-- So be ready to do a complete re-engineer and replace with new if you want to gain reliability.

Coil tower arcing = new coil wire

Undervoltage issues in the ignition unfortunately have the same symptoms as low fuel flow. Just for grins, run the engine until the symptoms show up and kill the ignition while it shows the symptoms. Pull a couple plugs and see what they look like. Lean = white, ignition misfire = darker, generally.

toofast928

Look at Spark Plugs and wires first. Then the hard stuff..............

Lizard928

are standalone systems allowed in his sanctioning body?

mark kibort

Yes, its anything goes with SCCA ITE.

I think CT found some issues with the fuel injector wires. there was one that had the connector contact surfaces misaligned due to the wire backing out.

now, the next issue is the miss at high rpms. maybe its related to the injector wire, but probably not.

thanks!

MK

cdbtx

Oh don't bother with the high RPM issue.. I need every break I can get..

GregBBRD

You're kidding right, Mark?

Why would you want to change the reliable Porsche system for something else? I have an MSD box on my Nova....and never leave home without a spare. I had a customer with MSD boxes on a turbo....we had 3 spares of everything...and used them all!

Someone tell Mark what MSD stands for.

mark kibort

Hey, i have alwasys seen these things on some cars, but never really knew if there was any differences, other than someone building an ingition system because he was building it from scratch or somthing.

I told scot to just leave the system alone, as i agree, you cant beat the stock porsche stuff.


one of the guys here saw some big gains, but i wonder if it is due to a "hotter" spark.

what about this:

https://www.pulstarplug.com/howtobuy...engine=1376209

ever hear of a pulstar spark plug?

Mk

RicerSchnitzzle

^$200 for a set of plugs? Sounds like Moon Juice.. I love the Article in Popular Science like that gives them validity..no wait it's not an article it's just and add.

If your current plugs are igniting and burning all of your fuel, there could be no benefit. Their claims of 6-11% gains in torque would require at least 6-11% of fuel left unburned by stock plugs.


Mark, ask them for a free set to test on the track. Tell them you'll put a 6" sticker on your track car if they work..

mark kibort

I know, thats what im thinking.
But, how does the MSD differ? besides giving it a "better" spark, if its in line with the stock ecu, doesnt it just increase the spark intensity. If its timing, what does it change the timing to for making more power? cant i just pull a knock sensor and get a ton of hp at the higher rpm ranges?

Ive never played with this stuff, but it seemed Anderson tested the aftermarket ship or program, or piggie back computer and it ended up not doing very much.
Guess the stock stuff aint too bad, or we havent begun to learn how to do this spark stuff.

I do know that the BMW guys get a bunch of HP with an ecu change, but it plays with, not only spark and fuel, the VANOS system as wel.

mk

Charley B

With the fuel system such a mess, why are you concentrating on spark before you know the result of cleaning up your connections and assuring well seated seals?