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Honda b18c turbo tuning issue

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Hello everyone!

I just finished an Honda Civic Ek for a costumer.

The engine is a b18c with 9.1:0 cr, gsc T1 cams, link g4x plug-in ecu, and ngk tfsi coils.

While tuning and monitoring for knock with my headphones with the link knock block, I hear a clear knock spot at 0.3 bar of boost and 4500/5000 rpm. I am at 20 degree of advance.

if I go lower at 17 I still can hear knock. I have to go as low as 10 degree just in two map cells to have no knock noise. This will cause a hole in my timing map and climbing egts. After this spot even at more boost or higher rpm all is normal.

does it ever happened to anyone?

to better understand if I am crazy and I need a vacation, I plugged in the knock into the g4x ecu just to see if logging I can see that spike and tomorrow I’ll try again.

thanks for the support


If that hole is near peak torque rpm try to add more fuel there as that's what usually happens in that rpm range- lean air fuel mixture causes the knock although it's no different afr to adjacent areas of RPM...

Is that at the point your VTEC solenoid engages? Does moving the VTEC switch point 500RPM higher or lower change anything? Is it still using the distributor for the trigger? - check timing is stable around that problem RPM with a timing light - you can get significant spark scatter with a cam trigger at specific RPM ranges due to valve train resonance.

Hi Adam, yes it still use the oem distributor for triggers.That’s another issue, I checked with a timing light ad is a little bit too advanced at that rpm range. But I also tried to align timing with timing light and is doing the same, and I still need to lower timing causing a big hole in the timing map. The Vtec crossover is at 5500rpm so is not in that point.

I still need to try again the car, I will do it tomorrow, but I have another question.

I have the engine that shakes a bit too much at very light throttle. I tried with tps scaling, play with ignition and afr, overrun fuel cutoff but nothing works. I have this exact probem on a 4g63 with link ecu too. I’m sure that I’m missing something here but cannot find what’s wrong. I cannot see this behaviour on both cars from logs. The Evo has a drivebywire setup and the civic a cable tb.

Would need to see a log. Possibly idle ign timing or overrun fuel cut. On road cars I typically use quite large retard and a long torque introduction time to smooth out the transition from/to ORFC.

Hello everyone,

here are the attached logs. I think I have a trigger issue regarding the b18 engine

Attached Files

I solved that, using inner sensors from another oem distributor. Rpm signal was super noisy as you can see from previous logs, and cylinder 2 was so loud that I can hear detonation with audio as well.

does anyone tried a cam/ cranck trigger wheel on b series engine ? I saw that I can use a b20 oil pump that has a specific space for the sensor but I don’t understand which cranck trigger wheel I have to use. And I don’t know if I can keep the cam sensor on the distributor too.

thanks for help

Most of the USDM OBD2 honda B series had the 12T crank trigger. You could use one of those with the stock distributor as the cam sensor.

If the car is no longer using power steering, and it’s in the customers budget, you can look into the t1 cam trigger kit. It replaces the exhaust cam gear and has a much more reliable signal (hall sensor) than the oem distributor. You can also completely remove the distributor as well. It’s a 12 “tooth” plus home. This is what I use on my haltech elite

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