concerned about dyno hp

[deano_82]

Ok dudes i know i have some sort of issue with the car missing at around 4-5000rpm, which after much messin around we figure its gong to be coil packs.

We ran my car up on the dyno at my mates wshop on the weekend and ony made 134rwhp this was just over 4000 rpm

the car is r33 4door

rb25det

iridiums at 0.8

knn filter

full 3" although cat isn't hi-flowed

bleed valve standard boost ( we changed the boost in increments from 7-10psi and onlly made 2-7 hp difference

this was extremely concerning as it only put out about as much as my 900kg datto which is still pathetic.

any one else seen these types of figures.

I know there is nothing wrong with the dyno as it is the one from the recent summernats hp heroes the one that ran 1470rwhp on it, apparently most accurate in oz. i will have to tune next week but i wouldnt think that coil packs would make that much difference would they we should expect arount 200-210rwhp

comments thoughts

[skyr31]

With those mods your car should be putting out about 155rwkw or 210 rwhp (approximately) Correct me if i'm wrong guys!

[deano_82]

yeh i know would coil packs rob me of that much power, the air fuel ratio was cool, the curve looked ok then bang straight back down at around 4000-5000, which is where my misfiring is, hmmmmmm, i have found that it only seems to happen under heavy load, ieif i run the accelerator easing it on lightly all the way to redline, it seems to pull the right way, but if just plant my foot nothin after the 4ish you just get the missing,

[rb25]

today, mine put out 170rwhp on a Dyno Dynamics Dyno. I have an EBC (0.75bar) and exhaust and pod. Another 33 there put down 270rwhp with the same mods as me but with the addition of an apexi fmic and powerfc.

-rb25

[deano_82]

sounds like car has similar mods as mine not to sure if yours is full 3" is turbs back, butwe did notice that the standard cooler is crap as we were spraying water on it and was just drying so quickly, fmic would be handy, even yours to mine 134 to 170 is a big diff!!

[knore]

Ide say you made such low power because u were only able to go just over 4000rpm

[deano_82]

we could have taken it higher but it wasnt making any power past 4000rpm

[Munna]

we could have taken it higher but it wasnt making any power past 4000rpm

That power at those particular revs sounds about right. But you should continue to make power til about 6400, or even more with your mods eg exhaust. Peak power arrives t 6400 on a standard car. hopefully its just the coil packs.

[Clicks]

so how do you check the coil packs?

[rb25]

mine is making 135rwhp @ 4000rmp just like yours.....

and 170rwhp @ 6500rpm.

[MonstaS4]

I would think if a coil pack works ok at light load, it should also work ok at full load. Not 100% on this, but you could prolly use an Insulation Resistance tester (megga) on the 1000v scale to test it (know any sparkies?). The primary winding should have continuity from one end to the other and should not be shorted to earth. I think the secondary should also have continuity from the plug top to earth on the coil pack. Please correct me if i'm way off the mark!

[deano_82]

Yeh that sounds about right, i was thinking about testing the coil packs off a mates ca18, but not to sure if they are the same amp, voltage i'd say they would be if not very close.

[deano_82]

rb25 you would think that yours and mine should be making more power, they are around 180-190 standard from factory?

there is wear and tear but we had an older supra on there similar mods 4 years older no rebuild more kms and put out 200rwhp and they come out with 187kw factory same as skyzers i think?

[diduc]

similiar problem to my tuning at CRD. Mine's FMIC, unichip, full exhaust, EBC

made 163rwkw with a stuffed coil pack, replaced it and made 181rwkw on 7psi.

Jim @CRD suggested gapping the plugs from 0.8 to 0.75 if wanted to go on higher boost as the spark was breaking down with more than 7psi. Gapped it and had a test run on .8(11psi) and .9(13psi)bar, sweet.....

[deano_82]

hmm sounds promising, you guys know how much coil packs are, i know the splitfire for the rb series are around a g, should be able to them cheaper than that, how much are nissan coil packs?

[rb25]

The dyno used reads low apparently (around 20hp), maybe yours did too.

[deano_82]

nah its one of the mostaccurate in the country app, its the dyno dynamics from hp heroes at this yrs summernats, maybe but i doubt it, it seems accurate for the other cars on it?

[diduc]

used coil packs are around the $75-$100 mark each. $150 new.

[morlock]

I had this problem on my car....the engine was misfiring and spark was breaking down at high RPM (4000 or above). Had the workshop check it out and found that 2 of my coil packs were on the way out. I bought 2 second hand replacements from the for sale section on SAU replaced the old ones and now everything is sweet. In the meantime while running with the faulty coils the workshop regapped the corresponding spark plugs closer in order to try and reduce the misfiring. As more load is put on the coils, the spark breaks down more and arcs out causing the misfire. Check your plugs as well because there could be a lot of deposit on them which may be fouling them as well.

[deano_82]

cheers sounds like thats it