eCtune

My son and I have built an 88 CRX HF with the following mods: Engine - OBD2 B18C1 block - 84mm Darton M.I.D. Sleeves - Cometic head gasket - LS Crank (stroked & bored to 2.0L) - 84mm Forged CP Pistons (9.7:1 CR) - Forged Manley Rods - Balanced rotating assembly - ARP main and head studs - Self ported and polished, CC’d B16a head - AEM cam gears - GSR Intake(3*Adv)/CTR Exhaust(1* Ret) cams - Ported Eaton M62 JRSC blower - Pulleys: 3.8� blower, MVM stepper, CRV crank - LHT aftercooled intake manifold - 03 Cobra IC pump and heat exchanger - NGK BKR7E plugs gapped to 0.028� - Precision 680cc Low impedance injectors - Walbro 255LPH in-tank fuel pump - LHT 3� Headers - Thermal R&D 3� catback - PLX M300 Wideband - Innovative motor mounts - ACT aluminum flywheel Transmission - Rebuilt 93 GSR YS1 5 speed transmission - Quaife LSD - Competition Clutch Stage 4 We are running a USDM P30 with Hulog and Ostrich 2, tuning with eCtune. Idle and part throttle is pretty well dialed in and we are now working on WOT tuning. We're seeing around 13PSI of boost at the top of the WOT runs, and our IATs are running right around 100*F. We have run a dry compression test and see (1-4): 220, 220, 225, 222 We didn't bother with a wet test because the numbers are good and we are not burning any oil. We have about 1K miles on the engine. We are running an aftermarket distributor with about 15K miles on it. Plugs and plug wires are new. VTEC was set to 3K RPM and was on. But our dyno graphs are looking very nasty and we are only seeing about 208HP and about 160 ft-lbs of torque. I am speculating that these issues are ignition related. Please take a look at the attached dyno sheet and give me your opinion on the funky looking HP and torque curves. Thanks in advance.

I should add that the log I recorded from an earlier run (forgot to on this run) showed that something is pulling about 5* of spark atvance at 3K RPM (table: 12*, final: 6.75*) up to about 11* of spark at about 5K RPM (table: 16*, final: 5.25*). I do have the stock knock sensor enabled. On my twin screw blown 4V Mustang, I turned the KS off because the blower noise sounds like knock to the 96 Cobra ECU. Does the same issue occur with Hondas with JRSC kits? I can see where the retarded spark could give me the low HP, but the spark curve is nice and flat, so I can't see how that could cause the nasty noise in the HP and torque curves.

Check your ECT/IAT correction tables to see if it's set-up to pull spark at those temps.

forged pistons, supercharger and knock sensor just can't work together. You need to disable knock sensor! and 13psi is too much for eaton blower. The highes boost which works ok on this supercharer is 10psi but still need some cooling like methanol injection or similar...LHT does not work like it should at that boost (13psi) Timing at 13 psi should be around 18 degrees, not 5 you mentioned.

Thanks for the help. IATs are set to pull 0* at 68*F and 122*F, and 2.5* at 134*F. With the LHT aftercooler, were running very steady at 100-110*F. Just out of curiousity, I looked at the IAT fuel corrections too. Why is it the fuel corrections are negative numbers at high temps? I would have expected the opposite. The ECT table is set to pull 0* at 200*F and 3* at 209*F. We were at 202*F at the top of the run we logged, so it should have been pulling about 1* of advance due to ECTs. I have the fan set to turn on at 195. I think I'll drop that down to 185 based on this feedback. But that still doesn't explain the nasty looking curves nor account for all the spark getting pulled. Perplexing.

EITCP wrote:forged pistons, supercharger and knock sensor just can't work together. You need to disable knock sensor! and 13psi is too much for eaton blower. The highes boost which works ok on this supercharer is 10psi but still need some cooling like methanol injection or similar...LHT does not work like it should at that boost (13psi) Timing at 13 psi should be around 18 degrees, not 5 you mentioned.

Thanks for the input. I was afraid that the knock sensor would not work with all the blower noise. I hadn't thought about the pistons. I would have assumed they would be noisier when cold, but not when warm, although we could be getting a little piston slap at the bottom of the stroke due to the longer stroke of the LS crank. I'll turn off the knock sensor and lower the fan setting and try that. The local shop who's dyno I use has the dyno booked up fo rthe next few days. I'm not sure when I'll get a chance to get back on it. Hopefully soon. I forgot to add that the Eaton blower was ported. Not sure that makes a difference. Are there any other symptoms of too high boost for the Eaton other than high IATs? We were a little conservative with the spark as a part of the tuning process, so we are only at 15* of advance. We stopped tuning when we saw so much noise on the dyno graphs. I immediately suspected ignition issues of some kind, so I figured we should fix that first before continuing. We noticed that the spark was being pulled by something else after looking at the log later. The final spark advance is a nice smooth line, so I don't see how that causes the noise in the dyno graph. Perplexing...

Get rid of the knock sensor +1

I will disable the knock sensor. Now I need to get some dyno time. The dynos seem to be booked up all over the area. I hate WOT tuning on the street...

Sorry, finger slip.

your funny curve can be related to too conservative timing, wich can be related to many things, like high IAT, too much boost etc.. try to give 3-4 degrees just for one dyno run and you will see if the curve is any better. When i am looking at your curve i see nice line untill 4500rpm, then it goes to nasty one.

post some logs. Then we can say more.

I will post a log after the next dyno session Friday. I forgot to record the log on the last few runs (getting rushed to free up the dyno), so I don't have logs of the later WOT runs. The economy must be picking up. Dyno time is pretty scarce around here these days...

We turned off the knock sensor and got a few dyno runs in this afternoon. We had to spend a lot of time screwing around swapping belts because we destroyed the blower belt. But finally, we were able to do a little tuning. We were running with some pretty aggressive AFRs and timing, but didn't have a lot of trouble with detonation. Our best run of the day yielded 249/193. Boost was at 12PSI, AFR was 11.5 and the spark was 23*. Here's the dyno chart and I've attached the eCtune log. It's still a pretty nasty looking curve. We have ordered an OEM igniter and an OEM coil to try to beef up the distributor to see if that will help. I've also attached the eCtune calibration file for reference. [/img]

it looks like ignition issue to me if you fixed the knock thing. Spark Plugs can do that too.

almost every one of my customer has come to me with something like a turbo LS/V and NGK 5's... but you usually hit a brick wall when it comes to that, you seemed to get a decent pull.