Article 1: Coils ain't Coils - Coil Pack Comparison
Author: 5-0 IGNITE
Currently, the most popular coil pack upgrade for Nissan SR and RB engines are in the following order;
· GM LQ9/LS2 D585 ‘truck’ ignition coils
· Toyota Yaris ignition coils
· Audi R8 ignition coils
· Nissan R35 GTR ignition coils
From the list above, the D585 coils are the only ones that requires modification to the stalk in order to actually make them coil-on-plug (bar the SR20 engine). Appearance of how these coils are mounted to your engine are debatable and depends on individual choice or preference. There are a few enthusiasts who would like to run ignition leads and remote mount the coils whilst some will dislike that choice for taking away the clean look ‘build’ on a modern engine.
If you live in the land of V8s (Australia, New Zealand, Canada and United States) then lucky you! Second hand LQ9/LS2 coils are abundant from your local wrecker, otherwise, brand new ones go for about $120 AUD retail each for AC Delco replacement. If you are in the market for these, using all brand-new genuine parts and to be 100% plug and play, an expected figure is around $1110 AUD (6 AC Delco coils = $720, mounting plate = $150 and conversion harness = $240).
“But bro, what about Yaris coil packs?” These are the cheapest and proven upgrade under $500 - or are they? The Toyota part number 90919-02240, replaced by Bosch 90919-02265 at about $120 AUD each with shipping, has been discontinued. There are also many counterfeits going around. We had that kit on our R33 GTR project vehicle, at about 450whp and 20psi on the dyno, spark blow-out occurred. We stopped the dyno session for 30 minutes to let it cool down a little before removing the spark plugs and gapping them down to 0.50mm. Until then, we only sticked to the 98 RON tune and abandoned the high boost E85 tune until later date as a 0.50mm plug gap is not acceptable. If you are in the market for these, using all brand-new genuine parts and to be 100% plug and play, an expected figure is around $1000 AUD (6 genuine coils = $660, mounting plate = $100 and conversion harness = $240).
What? Audi R8? Yes, these are gaining traction being a bang for buck kit. There are many OEM and aftermarket manufacturers for these VAG coils such as Bremi, Delphi, Eldor, Beru, Bosch, NGK and Denso etc. Brand new can be found at few stores at around $70 AUD retail each. Our preferred source is Denso because we know we can trust the Japanese brand and the specific coils are manufactured in Italy. We continued the tuning with our R33 GTR test vehicle and yielded 603whp (dyno dynamic roller) @ 27 psi whilst running 0.9mm spark plug gap on NGK BKR7E. At that power level, we have maximised the 5/16” stock fuel lines, we will be back shortly to achieve the 650whp mark after bigger fuel line is installed. There were no signs of spark break down and appears to be capable for plenty more, world-wide, there have been many claims of over 200hp per cylinder on these coils. Check out our range!
R 3 5 G T R coils. These are the bee’s knees and overkill for most sub 1000hp application. No need for further explanation so we’ll get straight to the pricing. Brand new OEM Hitachi coils can be had for about $130 AUD each with shipping. These use the same coil pack connectors on some RB engines (with swapping wire position) but you’ll definitely want to replace all or any crispy ones. If you are in the market for these, using all brand-new genuine parts, an expected figure is around $1210 AUD (6 genuine coils = $780, mounting plate = $350 and replacement connectors = $80). In addition, if you have OEM igniters, you have to do the wiring work to bypass it.
Other common direct replacement coil pack prices:
· OEM Nissan RBs set of 6 ~ $810 AUD + shipping
· Split fire RBs set of 6 ~ $570 AUD + shipping
· Okada Project RBs set of 6 ~ $1600 AUD + shipping
Whilst being powerful, the GM LQ9/LS2 D585 ignition coils have a risk of self-discharge and timing drift. To maximise its’ performance, tuners has been pushing its’ dwell time between 5ms to 6ms towards it over-charged current limit. There have been reports of engines being blown as a result; a safer dwell time lies in the range of 4ms so they don’t have to pick up bits of the engine on the dyno room floor but then, you are not getting the most out it, are you? There are many reports of counterfeit products that has proliferated the market worldwide. There are reports of AC Delco coils not faring well with its quality either, hence, most sellers opted to supply 2nd hand OEM coils that were in good working order.
There are many ways that a counterfeit product can ruin your engine (or your life) so it doesn’t need to be discussed. There have been no other reported faults with the OEM Denso coil 90912-02240 other than cracks found on the rubber stalk due to age causing spark jump. It pays to check the 2nd hand coils you bought.
VAG has a troubled past with its never-ending recalls on their OEM ignition coils. Fortunately, there were no reported recalls or faults with the Audi R8 models, therefore, many VW and Audi owners have opted to use the R8 coils for a replacement and an upgrade. The Japanese brand aftermarket replacement of the Audi R8 coils are popular among performance enthusiasts.
No reports of OEM R35 GTR ignition coils being faulty, unless it is a counterfeit.
Aside from spark duration and spark voltage, the performance of ignition coils is determined by the spark energy it produces. The dwell ‘charge’ time is also important for high RPM engines where ignition coils that require longer dwell time may suffer from heat or may not be up to the task. In short, it is ideal for an ignition coil to have a dwell time that is as short as possible whilst giving the required spark energy in order to give the coils enough time to cool down when not firing.
The spark energy calculation below is theoretical. It does not account for core and winding losses.
Stored Energy in a magnetic field (inductor);
(Curtin University 2013)
LQ9/LS2 D585 ignition coil
Figure 1 - LS truck coil primary current and dwell (V8bait 2017)
Dwell time = 4.5ms (absolute safe point)
Primary current = 6.8 A
Primary voltage = 13.9 V
Yaris 90919-02240/90919-02265 ignition coil
Figure 2 - Yaris Denso coil primary current and dwell (Laine 2012)
Dwell time = 2.4ms (saturation point)
Primary current = 11.4 A
Primary voltage = 13.5 V
Audi R8 ignition coil