CG10 finetuning advice (Cams, Headers, Injectors, ECU?)

Hello Micramaniacs,
I have mine since 2017 and started to like it more and more the longer i have it. Not as a sportscar but as a small extraordinary comfortable (and reliable) car (especially for its size) that you can rev to the limit every now and then without worrying.

it's a preFL 1.0 from '97 with racing stripes! yes they give +5 HP :cool: (or minus 5)😅
20210721_203846edit.jpg 20210721_203936edit.jpg


it revs continously/steady to high revs on low speeds, without torquepeaks, but max speed seems really hard to reach. I barely get 145km/h in fifth gear. 4th gear seems to go easier towards 160km/h (Speedreadings on tachometer, gps might be ~10km/h less). Under the right circumstances the 4th even get's to the rev limiter = ~165km/h


now back to topic:
I already swapped the cams against 1.3 cams. didn't feel a difference. I try to use VMAX to determine powergains. With Both 1.3 cams it feels all the same.
Overall it feels like less torque down below.
I'm often testing full throttle in 2.gear on a closed place where i can go ~20-60km/h. without anyone bothering. Just a few pushes...
the 1.0 Cams seemed to pull better, they could surprisingly push me in the chair. Idunno how that makes sense 🤔

What else i tried:
GA16DE injectors. ->no big difference.
new exhaust (muffler) -> no big difference
as of now, i have a magnaflow M6 Muffler (which is surprisingly quiet an nice, despite it's big look) -> no big difference
GA16 Airbox ->get's a little louder. fit a K&N in it, gets a little more louder... but nothing serious, at least nothing that i notice from the inside.

latest: put on a 4-2-1 Header i found used. nothing written on it, no info about it. Has the oxygen sensor between cylinder 1&4. which i don't like an gonna fix sometime.
20210717_194433.jpg

put it on and it seems to gain a little more power, especially on higher speeds. felt like it get faster to VMAX. but not much.
found out later that it was a little leaky at the connecting Tubes to the cat.

I fixed that for now with some Exhaust paste. havent tried VMAX yet but 20-60pulls -> and there is a problem: It get's damn loud around 4000rpm like Motorcycleloud but it's coming from the front. Not sure if it was the header or just intake sounds.
as it's a dizzy model i tried playing with the Ignitiontiming -> retarding get's louder and pulls worse // advancing the timing gets faster and the rpm range where it's loud decreases

replaced the GA Aribox with the original CG airbox -> the sound is getting quieter.

checked spark plugs (NGK iridiums) they seem to get hot. the white ceramic seems reddish. running to lean?

20210721_192035edit.jpg

Of course the old ECU'S don't help much. figuring out the issue. It just shows an AF-Base of 100 (sometime ~105 or ~98) and O2Sensor seems to do fine jumping around like usual.

Idle is "coughing" a little. And not much adjustable since i swapped the cams. Too much vacuum maybe?:confused:


The Questions:
1.
Is it possible that a little CG10 micra makes loud intake noises after swapping the exhaust manifold? or coud the manifold have a serious leak?
Problem is: it's only loud under load. I can't listen closer while driving.:confused:

2. running lean: should i put in GA16 injectors or get a 1.3 ECU?

Or should i even put the CG10 cams back in or only the CG10 exhaust Cam?


As of now, after trying so many things, it seems to me that the ECU might be the best tuning even for stock engines.
3. how good would a CG13 ECU be? might work harmonically with the 1.3cams?
get a nistune or even a standalone ECU. Recommendations?

4. how high could a stock CG10 rev given a good ECU setup? when do Valves start bounce?


My Main Goal is not max power. But a little more spice. Higher efficiency on the way would be really really appreciated!

efficient at low revs an going very high revs if wanted:love: maybe i should've bought something with VTEC 😅
 
1.3 cams give a bit but not much.
Id start with checking the timing and put it at 17 degrees. Ive seen them at 10 degrees instead of the factory 15 due to worn chain/tentioners. Setting the timing and idle speed correctly can give alot of driveability
 

frank

Club Member
the cams should have made a noticeable difference, are your lobes set like this ?
and i deleted the road speed signal to the ecu on mine , to cure the lean burn on acceleration

 
The car is well maintained. timing was at raoundabout ~15° btdc. I tried different setting prior changing cams and the Exhaust manifold, and it felt like it would accelerate faster, but behave much worse if it goes uphill or if the car is loaded.

The chain is not worn. i chainged it a few years ago. The old chain was very slacky.
are your lobes set like this ?
Would it run at all, if the cams were installed wrong? 🤔

The timing is adjustable perfectly as it needs to be. Checked it with a timing light. And as the Distributor is connected to the Exhaust cam, it should be positioned right, shouldn't it be?

i deleted the road speed signal to the ecu on mine , to cure the lean burn on acceleration
That's interesting, read it somewhere before. Was it done by just unscrewing one screw from the dashboard?
Any sideeffects i should be aware of? I mean, there must be a good reason the fine Engineers at Nissan did this.


And how is the difference between 1.3 intake & 1.0 exhaust cams combined versus both cams 1.0 or 1.3 ?

I would consider "downgrading" to the 1.0 exhaust cam if it gets less "loud". Although i have to admit, that the engine overall seemed quieter with both 1.3 cams compared to 1.0.
 

frank

Club Member
Would it run at all, if the cams were installed wrong? 🤔




That's interesting, read it somewhere before. Was it done by just unscrewing one screw from the dashboard?
Any sideeffects i should be aware of? I mean, there must be a good reason the fine Engineers at Nissan did this.
yes plenty of threads on here with lumpy idle and low power after a cam change, try a search on lobes in my username
and the forced closed looping at lower speeds is there to protect the cat on long steep hills imo
 
the forced closed looping at lower speeds is there to protect the cat on long steep hills imo
is that the reason the car might feel slower once the engine is hot as well?
Open loop on cold engine?
It feels snappier when it's cold. But of course the idle speed while it's cold is higher too.

Could be a dirty mod to put in a switch that shows the ecu a colder temperature value 😅 should only be used for short periods.

i'll try to check the cams in the next time... would it be worth going back to the 1.0 exhaust cam while at it?
 

Craig

Unofficial Member (Gold)
Club Member
1.0 to 1.3 cams should give a noticeable bump beyond 4k or so (were the lobe profiles clearly different between the two sets), what mileage is on the engine?

Sounds like you've an exhaust leak too which won't help things.

Craig
 
were the lobe profiles clearly different between the two sets
yes, definitely. Measured they have about 1,5mm more lift. They must be the 1.3 Cams.

The engine has ~170k km (~100k miles), always starts without hesitation, even with the old battery and starter.
never measured compression tho...

i had a switch on the coolant temp sensor, and did some back to back dyno runs
whatever i can think of, you already tried :D👍
 

frank

Club Member
yes, definitely. Measured they have about 1,5mm more lift. They must be the 1.3 Cams.

The engine has ~170k km (~100k miles), always starts without hesitation, even with the old battery and starter.
never measured compression tho...


whatever i can think of, you already tried :D👍
here,s the dyno printout, went mega rich then held at 13ish afr
you can see the erratic closed looping on the other 2 runs

 
tried to check the lobes... it's actually really hard to tell by looking at the lobes.
Checking the timing marks is easier and it's set right:
20210725_202408.jpg

the lobes:
20210725_200939.jpg

20210725_201044.jpg


The exhaust sound:

the coughing is hearable, though it's a very low tone and my mobiles Camera/Mic isn't suited ideally for the job. It might be misfiring. Can't tell for sure.
you can hear it best at the end:
https://streamable.com/i0jthf

it's much louder at the front under the engine bay:
https://streamable.com/1uovn8


i can barely set the idle rpm lower than ~700. (Idle adjusterscrew fully in; TPS unplugged for adjustment mode, ign. timing set to ~15°btdc):
Screenshot_20210725-211550_NDSI Lite v153.jpg

turning on the light lowers it:
Screenshot_20210725-211553_NDSI Lite v153.jpg

i don't think it's a vacuum leak.🤔
faulty IACV/AACV maybe?
 
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