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No worries, you'll sort it out, coil pack is well worth it, there will be no need for using a CDI system, even if someone runs a setup in excess of 1200hp, GTRs run 1600hp+ on stock coils, as long as one uses genuine oem coils.
Marios
At this point, all the details are sorted. Pretty much all the issues and resolutions are discussed here, and the info has been passed onto Spoolinup who has integrated it into his kit.
At this point, all the details are sorted. Pretty much all the issues and resolutions are discussed here, and the info has been passed onto Spoolinup who has integrated it into his kit.
Good to hear. On a side note, the smallest gap I've run on the plugs with the bosch coils was 0.50mm, and that was when I was mapping the car at 46psi, and the system gave no trouble at all, consistent also. I do strongly believe that if I used the gtr coils on my current setup , at the specific boost, the gap on the plugs would be at 0.55 at least if not 0.6. In the future if I am able and decide to up the power even further I will switch to the gtr coils again.
Marios
Last edited by Evo8cy; Jul 5, 2020 at 10:47 PM.
Reason: typo
Matt@Spoolinup and I were discussing the limitations of the stock harness, so I decided to measure dwell to saturation using the stock coil power harness. The image below (coil current measured using a current clamp) shows that it takes 5.3 ms to reach saturation, and the coils are only at 11 amps at saturation. With the Spoolinup harness, its 3.8 ms to saturation, and the primary circuit is at 14 amps. I drove my Evo around like this, and it ran fine, but without a doubt, the coils will be producing lower spark energy than with the Spoolinup power harness. Also, 5.3 ms of dwell at 8000 rpm is 70% of the available time to charge the coils.
-In regards to the boot issue. R35 hitachi coil part number is IGC0079. The same coil is used in the Infiniti, Maxima, 350z, Juke, part number for the Infiniti FX50 ignition coil is IGC0078, same coil longer boot.
-Yeah the stock harness and oem can bus routes in general,do suffer, lots of bottlenecks.
Very interesting read. I'm glad I didn't dive head first into a R35 gtr cop setup before reading this. In terms of the issues of internal resistance on stock harness, if I use an aftermarket ECU will the resistance still be an issue, or is there an intrinsic issue with the wiring harness itself? Also is it still an issue if I run sequential ignition instead of wasted spark with my aftermarket ecu.
Matt@Spoolinup and I were discussing the limitations of the stock harness, so I decided to measure dwell to saturation using the stock coil power harness. The image below (coil current measured using a current clamp) shows that it takes 5.3 ms to reach saturation, and the coils are only at 11 amps at saturation. With the Spoolinup harness, its 3.8 ms to saturation, and the primary circuit is at 14 amps. I drove my Evo around like this, and it ran fine, but without a doubt, the coils will be producing lower spark energy than with the Spoolinup power harness. Also, 5.3 ms of dwell at 8000 rpm is 70% of the available time to charge the coils.
Thanks for all the testing. Quick one, you said on page 1 that the GTR coils draw 14A during the dwell period, but here you say the coils are at 11A when saturated. I'm a bit confused by the expression here. Isn't saturation a point at which maximal magnetic field strength has been formed in the coil, and when it collapses it triggers the maximal spark energy output? Saturation may take longer based on the incoming voltage/current fed to the coil from the power supply (ie: lower = longer dwell time required) but saturation is saturation, right?
The most telling detail is the voltage sag to 9.3v that you observed during the dwell period. Even with stock or Yaris coils, especially in wasted spark configuration, the stock power feed is inadequate. 16AWG wire is really only good for 10A constant in free air and it's really surprising to me that Mitsubishi undersized the feed to such an extent. Engine bay temps are high, and the circuit is fused at 10A - upgrading the ignition circuit fuse to 15A is really exceeding the wire rating and I'd suggest isn't a great idea. Was this test you performed where you obesrved the 9.3v at the end of the dwell period in wasted spark mode, or were you isolating a single coil only on the harness with no others connected and measuring it in situ while triggering it manually? I assumed this was in wasted spark mode, and you had all coils in place and the engine running but you were taking measurements from one coil. This would influence the results as you would have 2 coils in their dwell periods simultaneously. Similarly, did you perform the above current draw test in wasted spark mode with all the coils connected and running together?
I have almost finished converting my ignition system to sequential spark configuration, and I am debating the need to run a relay for a dedicated power supply for the ignition coils. I assume the spoolinup power harness is simply a relay with a fused power feed that uses the stock feed as the 12v relay on trigger signal (ie switched 12v trigger).
Seems this thread died in the ***. Anyway, completed the installation of the GTR coils in sequntial spark mode. Ended up making a bespoke power supply with 14 gauge Raychem #44 wire to the harness plug, dedicated 14 gauge ground strap to the cylinder head, 30A sealed relay with a 15A sealed fuse holder. Built my own coils harness from 18 guage tefzel, spliced power and ground wires sealed with Raychem SCL and everything is then covered with raychem DR25. The harness is terminated into a 6-way Deutsch DT connector. Turned out really nice, fired up today for the first time and it ran well. I elected not to use the stock feed for the relay trigger, as this feed is on its own circuit with the ignition relay, lots of wire and the 10A fuse feeding it. Too many parts to fail that could take out the new system, so I am triggering it with an ECU switched 12v power signal that was previously used to power the narrowband o2 sensor.
I spoke to PRP in australia about the power feed situation and they advised that they don't really consider it a big deal. There's a 1000kw R34 GTR with 18 guage feed and ground apparently and that's doing just fine, so I guess the coil output must be pretty insensitive to dwell time with the GTR coils (or dwell voltage, as the case may be).
Last edited by EvocentriK; Nov 1, 2020 at 06:48 AM.
