Sure, I can.
I'll make some few tweaks to the bracket since I've seen what went right & wrong.
Datsun 240z with L28 & 3x 40 DCOE, MJLJ w/ TPS
Moderators: JeffC, rdoherty, stieg, brentp
I came back from my first trip with MJLJ system running.
The car was very nice to drive with map above.
I've made some adjustments on carbs to increase idle at 800rpm, increase timing by 3-4° everywhere. Car feels very good, it is smooth but there's still power to get at max rpm but also in the 2500-4500 range.
I've experienced some "pop" from the exhaust when going uphill with TPS at 40%, rpm at 3500, it shows timing is not correct yet but it is getting there.
After this first run, it is obvious on the map where some timing adjustments would make sense.
While cruising, you clearly see the cells that would need to be changed.
Since I've made many others changes besides MJLJ (valvetrain, gas tank, e-fans, etc.), I've only made 30km (20 miles). I'll check everything first prior to run the car for a longer period of time.
The car is smoother than before, some "raspyness"at mid rpm is gone versus dizzy setup but it still scream at WOT
The car was very nice to drive with map above.
I've made some adjustments on carbs to increase idle at 800rpm, increase timing by 3-4° everywhere. Car feels very good, it is smooth but there's still power to get at max rpm but also in the 2500-4500 range.
I've experienced some "pop" from the exhaust when going uphill with TPS at 40%, rpm at 3500, it shows timing is not correct yet but it is getting there.
After this first run, it is obvious on the map where some timing adjustments would make sense.
While cruising, you clearly see the cells that would need to be changed.
Since I've made many others changes besides MJLJ (valvetrain, gas tank, e-fans, etc.), I've only made 30km (20 miles). I'll check everything first prior to run the car for a longer period of time.
The car is smoother than before, some "raspyness"at mid rpm is gone versus dizzy setup but it still scream at WOT
Mathieu
Here are the files to make the bracket for VR sensor.
You'll find Igs & Stp files with 3D models inside.
pdf files for drawing of each part.
You need also to source 2 bolts with washers & nuts (locknut): M5 & M6 with the appropriate length.
If you ever need something else, do not hesitate. Those CAD files are made with Catia.
You'll find Igs & Stp files with 3D models inside.
pdf files for drawing of each part.
You need also to source 2 bolts with washers & nuts (locknut): M5 & M6 with the appropriate length.
If you ever need something else, do not hesitate. Those CAD files are made with Catia.
- Attachments
-
- VR Sensor Bracket - Datsun 240z.zip
- (86.15 KiB) Downloaded 901 times
Mathieu
I've driven the car today. It still feels very nice.
However going at WOT, I experienced a loud BANG from the exhaust. First reflex was to release throttle so I did not check if I could go further in revs.
Soft rev limiter is set at 5000rpm for now (still breaking in the engine that should see 7000rpm in the future). Could have I hit rev limit? I did not look at rpm at that time - I was passing somebody on a small forest road.
Soft rev limiter is turning down timing to 0°, isn't it? Could that cause exhaust bang?
However going at WOT, I experienced a loud BANG from the exhaust. First reflex was to release throttle so I did not check if I could go further in revs.
Soft rev limiter is set at 5000rpm for now (still breaking in the engine that should see 7000rpm in the future). Could have I hit rev limit? I did not look at rpm at that time - I was passing somebody on a small forest road.
Soft rev limiter is turning down timing to 0°, isn't it? Could that cause exhaust bang?
Mathieu
I had a lot of fun today!
3 hours driving the Z in forest roads was fun. Especially when the car runs great! No issue at all!
First, I was able to reproduce the BANG, it is coming for sure from the soft rev limiter. So there isn't any worries there anymore
Then, I had plenty of time to play with timing. To support my tuning, I had my nose, my butt & a DIY detcan that works great.
I'm sure I can go further in tuning but I start to be close from the limit of the engine. Each change has produced positive results with no downfall.
Coolant temp while engine is running is good.
Here are the progress I've made. You can see difference between maps to check what I've made.
Load is TPS%.
Since 1st map & no knock heard, I've ramped up a little max timing. From idle to 3500rpm, slope is linear. I've used Excel to better see the shape of the map (even if MJLJ software allow us to visualize in 3D the map)
Still, no TPS tuning involved.
Car feels great, better than with Mallory dizzy. Power & torque are definitely above previous setup.
Still no knock of whatsoever to spot even when going up-hill in high gears.
I started to play with TPS with next map.
First attempt was really to check impact with TPS, so I've only modified one small area of the map while cruising at 50kph in villages & 100kph on roads. I've put the cell modified in blue.
Results were good, engine feels a little more responsive at cruising speed. Nothing crazy however; if somebody would have changed the map without telling me, not sure I would have noticed it immediately.
Since it was going towards the right path, still without knock, I went further. I've forgot one cell in the following map (TPS@50, rpm@2500). I'll have to adjust it next time.
For this last map, I've changed load impact on entire rev' range (engine can go only up to 4800rpm for now with soft rev limiter)
I've noticed a good impact on engine output this time. Still no knock to report.
I still believe I can further but I'm getting close to the limits, a dyno could truly become useful now but I need a load controlled unit - not so common in France & expensive...
Progress are also during acceleration, car pulls faster while pressing down the pedal, I can feel more torque during throttle progression. It goes better from steady speed to full acceleration.
I can also literally smell AFR change, I need also to control AFR with my wide-band next time, something I haven't done yet. I did not change anything on carbs yet but they run flawlessly with no hesitation.
3 hours driving the Z in forest roads was fun. Especially when the car runs great! No issue at all!
First, I was able to reproduce the BANG, it is coming for sure from the soft rev limiter. So there isn't any worries there anymore
Then, I had plenty of time to play with timing. To support my tuning, I had my nose, my butt & a DIY detcan that works great.
I'm sure I can go further in tuning but I start to be close from the limit of the engine. Each change has produced positive results with no downfall.
Coolant temp while engine is running is good.
Here are the progress I've made. You can see difference between maps to check what I've made.
Load is TPS%.
Since 1st map & no knock heard, I've ramped up a little max timing. From idle to 3500rpm, slope is linear. I've used Excel to better see the shape of the map (even if MJLJ software allow us to visualize in 3D the map)
Still, no TPS tuning involved.
Car feels great, better than with Mallory dizzy. Power & torque are definitely above previous setup.
Still no knock of whatsoever to spot even when going up-hill in high gears.
I started to play with TPS with next map.
First attempt was really to check impact with TPS, so I've only modified one small area of the map while cruising at 50kph in villages & 100kph on roads. I've put the cell modified in blue.
Results were good, engine feels a little more responsive at cruising speed. Nothing crazy however; if somebody would have changed the map without telling me, not sure I would have noticed it immediately.
Since it was going towards the right path, still without knock, I went further. I've forgot one cell in the following map (TPS@50, rpm@2500). I'll have to adjust it next time.
For this last map, I've changed load impact on entire rev' range (engine can go only up to 4800rpm for now with soft rev limiter)
I've noticed a good impact on engine output this time. Still no knock to report.
I still believe I can further but I'm getting close to the limits, a dyno could truly become useful now but I need a load controlled unit - not so common in France & expensive...
Progress are also during acceleration, car pulls faster while pressing down the pedal, I can feel more torque during throttle progression. It goes better from steady speed to full acceleration.
I can also literally smell AFR change, I need also to control AFR with my wide-band next time, something I haven't done yet. I did not change anything on carbs yet but they run flawlessly with no hesitation.
Mathieu
Thanks! 
Weather was very nice, I've been able to play more with MJLJ today.
I've increased max timing as well as timing under load. Car is much more powerful than when I started. It is becoming too fast to check everything properly on open roads, even with rev limiter set at 5000rpm
So far, everything turn out great, including carbs, they respond very well with no issue or what so ever. They will just run out of air above 5000rpm, I will need bigger chokes.
here's the map so far. No knock detected with the following map.
I've detected some conditions that could be improved where power/torque comes suddently. It shows some power/torque could be gain before torque increase event happens. So I've made another map that should address that but I haven't tested it yet.
Weather was very nice, I've been able to play more with MJLJ today.
I've increased max timing as well as timing under load. Car is much more powerful than when I started. It is becoming too fast to check everything properly on open roads, even with rev limiter set at 5000rpm
So far, everything turn out great, including carbs, they respond very well with no issue or what so ever. They will just run out of air above 5000rpm, I will need bigger chokes.
here's the map so far. No knock detected with the following map.
I've detected some conditions that could be improved where power/torque comes suddently. It shows some power/torque could be gain before torque increase event happens. So I've made another map that should address that but I haven't tested it yet.
Mathieu
I need to check that and see if I can increase timing at low load.
On a side note, I've checked AFR and I need to address some very lean conditions at WOT before messing up with high rpm if I don't want to make my engine explode.
I don't know what makes this situation: carb tuning, chokes too small, fuel pump, timing... I've got many things to try.
On a side note, I've checked AFR and I need to address some very lean conditions at WOT before messing up with high rpm if I don't want to make my engine explode.
I don't know what makes this situation: carb tuning, chokes too small, fuel pump, timing... I've got many things to try.
Mathieu