MODS

aem ems

aem uego elevation 4300ft reno nv

aem true boot

1680/550 setup

aeromotive fpr

bosch o44 fuel pump ran on a switched reley

nology coils and wires stock ignitor

gt3582r

tial 50 mm bov

tial 44 mm wastegate

large street port stage 2 engine

no omp strait pre-mix with motul double ester at 1 ounce 1 gal



so ive been running the car at 10 psi since ive went single and the car runs great to redline. i tried turning up the boost and tuning at 14psi it would start to break up around 6k rpm a/fs were at 10.9 and timing around 18-19 everything looked good so i figured it was ignition related especially since i was still running stock coils, so i just installed nology coils and wires (2 single post and 1 double post) the car started instantly and reved to redline with no problems did a pull in 2nd on 10 psi and it started breaking up bad around 5-5.5k rpm a/fs still look great and so does ignition so i tried adding fuel and taking away timing, this had no effect on the breakup so i slowly raised the rpm to red line while driving and it broke up from 5-6.5k rpm and then cleared right before i hit redline? i'm running ngk 9's all around and they were realy black when i pulled them out so i cleaned them whith our shops plug cleaner(sand blaster) hoping thats all it was but it still did the same thing when i put them back in. I ordered some ngk 10.5s today even though i dont think thats the problem. i think its a good idea since im shooting for the 500whp range.



Sorry so long im just trying to give as much info as possible

 

Try adding an HKS ignition amp...

 

ya i think these coils just suck. i was going to buy the twin power but my leading coil was cracked down the post, thats why i got the coils. What a waste of money so should i get a new leading coil and an amplifier or use some gm ls coils? is the stock ignition and an amp going to be enough for the 500hp range?

 

I also noticed that it was breaking up with very little load because i had never tuned that section of the map (never had to drive with very light throttle and high rpm)

 

so after hours talking with one of the nology engineers we found out that the nology hotwires and the profire coils do not mix (low ohm wires 500 ohms a foot). I made a set of wires at the shop for testing purposes and found out that the majority of the breakup was gone, but there was still a little bit that would show up around 6000-6500rpm. after doing some searches on the forum i found a great write on rf problems on certain types of wires (aftermarket,solid core) ,i dont know what style the wires are that we had at the shop but they say suppresed 7mm and the core looks like strands of fiber, im going to buy a set of ngk wires (supposed to be woven core) tommorow and cut them to fit since i mounted the coils where the battery used to sit and the nology coils have regular male style secondary post. also plan on re-routing the primary wires away from the secondary, they were pretty much touching each together.

 

I usually run stock NGK wires, or make my own MSD units. Depends on power levels. Stock coils can ohm out correctly and be shot. On the bigger powered cars I usually replace everything with msd parts.

 

Stock coils can ohm out correctly and be shot? you just mean ohms is a bad test because your not checking them loaded! do you still rum the stock ignitor with the msd setup?

 

what coil do u use for the leading? do u also run an ignition amp on the msd coils? i almost got rid of all the break up but there is still some at 6500rpm and im still not sure if its the coils? I fabed up a set of msd wires and it helped but there was still some breakup so i turned up the saturation time on the coils to see if it would help and it did, turning up the saturation time and it helping move the breakup 1k rpm up tells me the coils just arnt enough, but I'm just not convinced yet that these coils really do suck. I was doing some logging today and noticed that the injector duty was 128% and im getting 1v of knock when the breakup happens, i dont know if aem has a fail safe for inj duty? i know there is plenty fuel i just used resistors instead of the injector setup wizard!

 

so i made some progress on the problem, i put a msd 6a on the leading coil and it still had a couple studders at 6500rpm, at this point i didnt know what to think I was over trying to get rid of this issue and just started to turn up boost and tune, odley enough the higher the boost was getting the less i would notice the studder. by the time i was at 17 psi it was completley gone and i could make pulls to 7000 no problem by the end of the night i had i tunned out to 23psi and making full pulls with no mishaps what so ever! I'm confused what would cause a low load(140-150 kpa) /low boost breakup and go away when you have heavy load (200-220 kpa) and high boost? regardless im a little skeptical that its really gone!

 

Sounds like your tune is too rich at the lower load cells..