Nasty looking dyno charts - Mechanical Issue?

Graybeard · Post by **Graybeard** » Thu Mar 15, 2012 1:13 pm

We're a lot happier with the knock sensor off, but I still don't like the noise in the curves, and we were expecting to hit around 280 and hoping for closer to 300hp with our setup. Since the noisy curves make us suspect ignition problems, we're going to replace the coil and igniter in the aftermarket (Distributor King) distributor with OEM units. We'll replace the aftermarket plug wires with OEM and replace the plugs too. Our AFR is at 11.8 and our spark advance is at 24.5*. We added a degree more advance and didn't see any more power so we dropped it back to 24.5*. I'm afraid to go any leaner than 11.8 for fear of detonation, so I'm hoping a better ignition setup will give us a little more. Also, our intake cam is advanced 3* and the exhaust cam is retarded 1*. How much impact could changing cam timing have , and what cam timing should we try next? Thanks in advance.

Post by **Gaskleppie** » Sat Mar 17, 2012 8:38 am

Do you see any indication of knock on the plugs? 24* is pretty much timing for a charger at 13psi. Try to lower the ignition a few degrees and see if the graph looks better.

Graybeard · Post by **Graybeard** » Thu Mar 22, 2012 9:49 pm

We looked at the plugs, even under a magnifying glass and saw no evidence of detonation. We ordered and received a Honda igniter and coil and dropped it into the distributor. It seems it cleaned up the dyno noise a bit, but it is still there. I dropped the spark back to 18* and richened the AFR to about 11.5, and worked my way back up again. This time we didn't see power increase after about 21.5*, so I dropped it back to 20.25* for a bit of safety. At that point, my son wondered out loud if out stock intake (required for the CARB sticker here in CA) was causing us trouble, so we unhooked the air pipe frome the air box and ran it again. The results jumped up to 165/198. I think we are figuring it out...

He's got a 60mm JDM B16A TB, with a B81A1 air pipe going into a CRX air box. The LHT modified TB port was opened up to 68mm I think, so it looks like we need to find an aftermarket TB and a CAI setup that will work in the CRX. Any suggestions for a new TB and CAI? Here's the final results for the day on the dyno:

David974 · Post by **David974** » Fri Mar 23, 2012 2:24 am

for a 2liter the stock TB hurt you can go for Skunk 2 alpha series TB they look like stock ones, very affordable and available in 66 an 70 mm size, go for the 70mm a good 3\"CAI will help a lot if you can find one CARB

Graybeard · Post by **Graybeard** » Fri Mar 23, 2012 2:34 am

Thanks for the TB recommendation. We have had good luck with Skunk2 products in the past. We have the BAR sticker, but the CARB legal stuff kind of went out the window with the LHT headers.

We can swap back to stock exhaust manifold, stock TB, stock air pipe & air box for the smog test every two years, so we are not too concerned about CARB stickers anymore. It's a \"nice to have\", but not necessary. I've also been searching tonight for a decent CAI that will fit the CRX form factor. I took data on my Volant CAI vs stock on my Cobra when I put it on and it had a consistent 8-10* IAT improvement (pre-blower), so I know they work. And it is clear that a larger diameter pipe would be a good thing....

Graybeard · Post by **Graybeard** » Sat Mar 24, 2012 1:07 am

I was just studying my datalog for that last run on the blown car, and the eCtune log of the RPM is showing the same noise that the dyno curves are showing. It is interesting to note that the jitter in the RPM log is as much as 300 RPM over a 30mS period. What causes so much noise on the RPM plot? Is this a typical looking RPM log? I would have expected a much smoother graph...

David974 · Post by **David974** » Sat Mar 24, 2012 10:25 am

Hi I 've just tune a car this morning and the rpm curve seems like yours I've never noticed that it was so wavy when you zoom on it or use only one graph in the screen

Graybeard · Post by **Graybeard** » Sat Mar 24, 2012 12:27 pm

Thanks for the input. I went digging through eCtune forum archives looking for other RPM graphs, and I found a few. They all have the noisy RPM plots, so that seems normal. I wonder why the RPM logs are so noisy. Does the PCM think the RPMs are actually that jittery? Or is that an artifact of Calvin's datalogging code? It still leaves me wondering why our HP and torque curves are so noisy... These kinds of questions drive me nuts till I figure them out.

Spawne32 · Post by **Spawne32** » Mon Apr 09, 2012 2:22 am

CA is always going to give you trouble with performance mods no matter what. I run a 3\" intake with a blox velocity stack on the end and that really opens up the blower to breath alot right off the bat. Granted im only an M45 unit on 8psi with the stock pulley system on a ported and polished b18b1 with all the bolt on's. But i run roughly 27 degrees of timing in the top end @ 8psi on pump gas 93 @ about 12.5afr. One thing we did recently just for shits and giggles, not really thinking it would improve much at all but wound up making all the difference in the god damn world was we took my oem 60mm throttle body, and venturi'ed it to the max on my buddys lathe. We went from 62mm at the inlet down to the 60mm plate all the way up to 67mm at the inlet and down to the 60mm plate, and I really didnt think it would have any effect at all but it was almost a nice and day difference in low end throttle response and really helped that supercharger breath immensely by apparently increasing air velocity through the stube.

This is something you could look into as it would be perfectly legal in CA.

Spawne32 · Post by **Spawne32** » Mon Apr 09, 2012 2:26 am

I see your blower is ported, you wouldnt happen to have any pics of it? Also I see your running a #7 plug, have you tried running #8 plugs at all? Also A personal recommendation, rather then the standard copper tips, try running a fine wire iridium plug as well, i find that the fine wire plugs have much better ignitability then the standard style.

Graybeard · Post by **Graybeard** » Mon Apr 09, 2012 2:53 am

I am digging for the pictures, but can't find them. I'll email my son to see if he has any. I have always run copper plugs on the blown Mustangs I have worked on, including my own KB Cobra. Copper is strongly recommended for FI engines across the Mustang community. I'll have to give the fine wire irridium plugs a try. Do you have a brand you like better than the others? We also haven't tried #8 plugs yet either. But I am beginning to suspect the distributor may be what is causing our noisy dyno graphs. If we are getting a little wobble in the shaft, it could explain the jitter in the graph. We have a second stock ditributor to try vs the Distributor King unit we are currently running. I did upgrade the ditributor King unit with a stock ignitor and coil, but if it has a mechanical problem, it could explain the torque and HP noise on the graph. Thanks for the suggestion on porting the TB. I think it is a good idea for us emissions challenged left-coasters.

But we already bought a Skunk2 Alpha series 70mm TB, which looks very stock. The cops will have to look close to see that it isn't stock. They won't have to look that close st the LHT headers and AEM CAI though. But my son decided he would run the risk. It's his car... We did get back on the dyno with the new intake setup, and were able to get 262HP 197 tq (SAE corrected on a Dynojet Dyno). We were at 19* at an AFR of 11.8 at 13 PSI of boost on 91 octane pump gas. You are a lot more aggressive than I am at 27* and 12.5 AFR...

Spawne32 · Post by **Spawne32** » Mon Apr 09, 2012 3:04 am

I ran the NGK gpower on my car in the 6 heat range for quite a while however I am not nearly as heavily modded as you, and I am a non vtec car which I believe, makes all the difference in the world with the plug type's. Non vtec's come factory with a 5 heat range where as the vtec motors come with a 6, and they use a completely difference NGK part number although visually they appear to be identical. Gapping was a major problem for me as I wasnt exactly certain what to run given the fact that all the plugs I was getting were coming pregapped to 1.1mm or .040. When I gapped them down to .035 alot of the pinging i was experiencing went away drastically. With some part number experimentation I found that you can actually get them pregapped .031 which seems to work much better, so currently ive been playing with the ZFR7F, however the new motor I will probably run the iridium version BKR7EIX. Only reason I am not running a Gpower platinum plug is because I just couldnt find it in the appropriate heat range, but the ones I did run held up fine to the drag racing torment I put them through. They just started showing signs of being a tadddddd to hot on cylinders 3 and 4. I think you would be ok running NGK (2668) BKR8EIX as they come pregapped very small, just check the plug after some runs to see how the temp looks. If it's too cold you will definitely know right off the bat, but given how hard you are pushing that blower, I think it warrants it with the IAT's your probably seeing.

Graybeard · Post by **Graybeard** » Mon Apr 09, 2012 3:14 am

Thanks for the suggestions. FYI, our IATs were 110. Not too bad. We're running an 03 Cobra pump and heat exchanger. We do have a slight kink in the intercooler line that we still need to fix. It may make it run even a bit cooler, but probably not too much. FYI, we gapped our copper plugs at 0.032\". We have been very lucky relative to detonation during the tuning process. The only time we have had any detectable detonation was at the beginning of one run with a lean tip-in. We're using a det can and have been checking the plugs with a magnifying glass.

Spawne32 · Post by **Spawne32** » Mon Apr 09, 2012 3:20 am

Graybeard wrote:Thanks for the suggestions. FYI, our IATs were 110. Not too bad. We're running an 03 Cobra pump and heat exchanger. We do have a slight kink in the intercooler line that we still need to fix. It may make it run even a bit cooler, but probably not too much. FYI, we gapped our copper plugs at 0.032". We have been very lucky relative to detonation during the tuning process. The only time we have had any detectable detonation was at the beginning of one run with a lean tip-in. We're using a det can and have been checking the plugs with a magnifying glass.

Ah ok, those are insanely good IAT's even with the intercooler setup, you are measuring the IAT's in the manifold I assume as well? I think the fine wire plugs really shine at the small gaps thats why I use them. The closer together you get between the ground strap and the tip on the standard plugs the less exposed the spark is to the mixture in the chamber, so the fine wire plugs really open that area up without compromising spark power. I think your also right about the distributor as well as really on the OBD1 cars that distributor controls basically 90% of the cars functions. You have your 3 mechanical position sensors inside and then the coil and the igniter, and when one has a problem your kinda left in the dark as to what to do next. The simplicity of the system is a double edged sword.

Spawne32 · Post by **Spawne32** » Mon Apr 09, 2012 3:26 am

http://www.youtube.com/watch?v=HikB3eXBb78 not really a perfect science test but you get the idea, i love this kind of stuff when it comes to fine tuning.