13B PP Ignition breakup
#28
Exhaust Manifold Leak
Thread Starter
Idling on trailing plug only, somehow the Leading ign wont work when the engine is running, with ign on it works perfect if I pass a screwdriver by the pickup or if I turn the dizzy by hand, put the dizzy in and start, no spark on the leading
#29
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,805
Received 2,578 Likes
on
1,831 Posts
that car is really cool, i would street it here!
this is mine, Mr. Peepers | Facebook
i wonder if the same guy both of our housings? they both have that weird round flange
this is mine, Mr. Peepers | Facebook
i wonder if the same guy both of our housings? they both have that weird round flange
#30
Eats, Sleeps, Dreams Rotary
iTrader: (1)
RX3 13B PP idling - YouTube
Idling on trailing plug only, somehow the Leading ign wont work when the engine is running, with ign on it works perfect if I pass a screwdriver by the pickup or if I turn the dizzy by hand, put the dizzy in and start, no spark on the leading
Idling on trailing plug only, somehow the Leading ign wont work when the engine is running, with ign on it works perfect if I pass a screwdriver by the pickup or if I turn the dizzy by hand, put the dizzy in and start, no spark on the leading
#31
Exhaust Manifold Leak
Thread Starter
that car is really cool, i would street it here!
this is mine, Mr. Peepers | Facebook
i wonder if the same guy both of our housings? they both have that weird round flange
this is mine, Mr. Peepers | Facebook
i wonder if the same guy both of our housings? they both have that weird round flange
your def idles better, once ign is fixed I'll see what can be done on the carb.. these housings seem to be rx4 13B housings they don't have a round flange, but like a rotor shape with radiussed corners.. do yours have the blue paint as background of the mazda letters?
#32
Exhaust Manifold Leak
Thread Starter
Got it sorted!!!
FTW almost gave up after trying and checking everything.. in the end it were the stuped leading plug which crapped theirselves and had an internal shoftcut, measured only around 20 Ohm!!! replaced them with RX8 #9's and all problems went away, pulls strong with afrs of around 12.5 across the rpm range..
bad news: tacho (stack) died for unknown reason doesnt moce anymore and also doesnt go to zero when power is appllied, so I don know what rpm it was making, but from the sound pulls easy over 9k
FTW almost gave up after trying and checking everything.. in the end it were the stuped leading plug which crapped theirselves and had an internal shoftcut, measured only around 20 Ohm!!! replaced them with RX8 #9's and all problems went away, pulls strong with afrs of around 12.5 across the rpm range..
bad news: tacho (stack) died for unknown reason doesnt moce anymore and also doesnt go to zero when power is appllied, so I don know what rpm it was making, but from the sound pulls easy over 9k
#34
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,805
Received 2,578 Likes
on
1,831 Posts
mine are 74-75 Rx2/3 housings, round flange. i do have blue paint as a background, i did it, its electric blue mica from a 2007 Mazda 3, not that it matters that much.
#35
Exhaust Manifold Leak
Thread Starter
nope didnt do that, its connected to the negative terminal of the trailing coil.. I did same mig welding to the dizzy, but grounded the dizzy itself so doubt that could the cause..
used a scope altough on the leading coils, chargeing voltage isnt much more than 12v, negative spike just when it sparks is much more.. does triple spark only till just above idle
used a scope altough on the leading coils, chargeing voltage isnt much more than 12v, negative spike just when it sparks is much more.. does triple spark only till just above idle
#36
Old [Sch|F]ool
If you have an MSD, the coils will get over 400 volts. That is why nothing but the MSD gets connected to it.
If you connect a tach to the coil with an MSD, you will wreck the tach, assuming that the engine even runs. I've seen somebody connect an electric choke to the coil positive with an MSD once and the car would not even start. A tach is less of a current drain (really?) but they usually don't like 400v voltage spikes to them.
If you connect a tach to the coil with an MSD, you will wreck the tach, assuming that the engine even runs. I've seen somebody connect an electric choke to the coil positive with an MSD once and the car would not even start. A tach is less of a current drain (really?) but they usually don't like 400v voltage spikes to them.
#37
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,805
Received 2,578 Likes
on
1,831 Posts
since i'm running leading and trailing from the MSD (like PJ), i'm pretty sure the tach is running from the MSD's tach out. which works fine. i actually have trouble with the connector on the back of the cluster, it never works after the car's been on the trailer
#38
Exhaust Manifold Leak
Thread Starter
when exactly should there be 400v? during the carching of the coil or? I used a scope on it and the signal looks like around 12v when charging but at the moment of discharge there is a quite big negative voltage
#39
Old [Sch|F]ool
Are you using an MSD ignition box or just MSD coils?
What you are describing sounds like a standard ignition scope pattern.
Assuming that you don't still have 12v+ tied into the coil.
What you are describing sounds like a standard ignition scope pattern.
Assuming that you don't still have 12v+ tied into the coil.
#40
Exhaust Manifold Leak
Thread Starter
#41
Exhaust Manifold Leak
Thread Starter
In the end the cause where the plugs, somehow they had like 3 ohm or so, just shorting the energy from the coil.
Engine is running quite well now and last weekend it did is first race (histroic cars pre 76, only NA and parts from that era allowed), which went really well, we were 3rd in the clase (sub 2500cc class) and 7th overall.
here is are the pictures of the day, so one can see the rest of the field in this race series mettet4mei | Bravo Racing
after the 30 min race session, there was maybe 1 minute of driving towards the trailer and the car was shut off. somehow both leading plugs where wet. I then changed the 2 leading coils for a single FC leading coil, did some driving on the street and found the plugs to be at least dry. could it be they are too cold? (#9 rx8 trailings in all 4 holes)
overal the engine is really going well, but after 8500 rpm torque is dripping rapidely. probaly the cause if the longer than optimal intake length and maybe port timing is conservative.
I bought a second engine made out of rx8 rotors and RB housings which will need to make at least 300 hp at the flywheel, hopefully more so we can aim for the #1 in the class next season. thefastest cars in the race are opel kadett togehter with the 911 rsr. also in our class there is a ford escort. the kadett for sure has around 300hp as its a 2.5l CIH engine spinning 8k rpm, and the ford is probaly running a cosworth engine, also easily producing around 300hp. for the overal class there is a porsche 911 rsr, and then these muscle cars which are with over 500 bhp slightly behind in in term of lap times as compared to the kadett and the 911 rsr
Engine is running quite well now and last weekend it did is first race (histroic cars pre 76, only NA and parts from that era allowed), which went really well, we were 3rd in the clase (sub 2500cc class) and 7th overall.
here is are the pictures of the day, so one can see the rest of the field in this race series mettet4mei | Bravo Racing
after the 30 min race session, there was maybe 1 minute of driving towards the trailer and the car was shut off. somehow both leading plugs where wet. I then changed the 2 leading coils for a single FC leading coil, did some driving on the street and found the plugs to be at least dry. could it be they are too cold? (#9 rx8 trailings in all 4 holes)
overal the engine is really going well, but after 8500 rpm torque is dripping rapidely. probaly the cause if the longer than optimal intake length and maybe port timing is conservative.
I bought a second engine made out of rx8 rotors and RB housings which will need to make at least 300 hp at the flywheel, hopefully more so we can aim for the #1 in the class next season. thefastest cars in the race are opel kadett togehter with the 911 rsr. also in our class there is a ford escort. the kadett for sure has around 300hp as its a 2.5l CIH engine spinning 8k rpm, and the ford is probaly running a cosworth engine, also easily producing around 300hp. for the overal class there is a porsche 911 rsr, and then these muscle cars which are with over 500 bhp slightly behind in in term of lap times as compared to the kadett and the 911 rsr
#42
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,805
Received 2,578 Likes
on
1,831 Posts
awesome, i'd love to go do that with mine! a P port Rx3 should be really competitive with anything pre76...
#43
Exhaust Manifold Leak
Thread Starter
it should be yep, but there is missing about 40-50hp, once we found those sleeping ponies I think we can easily compete with the top of the field
#44
Blood, Sweat and Rotors
iTrader: (1)
Great car! I think the 9 heat range is too hot for track use, with a peripheral port race only car you should run 11's after the car warms up. I warm up my 12a J Bridge on br8eq14. Fires up first time.
.
.
I have an ignition question. Running a 6AL wired wasted spark to MSD Blaster 2 coils, should I wire the coils in series or parallel?
.
.
I have an ignition question. Running a 6AL wired wasted spark to MSD Blaster 2 coils, should I wire the coils in series or parallel?
#45
Exhaust Manifold Leak
Thread Starter
I wired mine in parallel.. maybe you can try both and let me know what works best.. I ditched the dual coils and went for a FC leading coil.
I also have been told 9 should be warmest one should run, but after 30 min of track use the leading plugs where wet, and the trailing also dont look like they are too hot.. I then switched to the FC leading coil, after some WOT street driving I shut the engine down and coasted on the driveway, plugs still look cold but at least they were dry so I am a bit puzzled..
I also have been told 9 should be warmest one should run, but after 30 min of track use the leading plugs where wet, and the trailing also dont look like they are too hot.. I then switched to the FC leading coil, after some WOT street driving I shut the engine down and coasted on the driveway, plugs still look cold but at least they were dry so I am a bit puzzled..
#46
Exhaust Manifold Leak
Thread Starter
Damn, no edit possible..
what I still wanted to say, if you measure the resistance of the coils you can get and idea what will work best. I think for CDI ign, like the dynatek and probaly also the 6A, they write it will work best with low resistance (0.5 Ohm) coils. so if your coils measure 1 Ohm, and you put them in parallel, they will have 0.5Ohm. if yours already measure 0.5 Ohm, it will be 0.25 Ohm and this might be too low for the CDI (altough I am not sure if this really is an issue for the CDI)
what I still wanted to say, if you measure the resistance of the coils you can get and idea what will work best. I think for CDI ign, like the dynatek and probaly also the 6A, they write it will work best with low resistance (0.5 Ohm) coils. so if your coils measure 1 Ohm, and you put them in parallel, they will have 0.5Ohm. if yours already measure 0.5 Ohm, it will be 0.25 Ohm and this might be too low for the CDI (altough I am not sure if this really is an issue for the CDI)
#47
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,805
Received 2,578 Likes
on
1,831 Posts
the FC coil is pretty beefy! https://www.rx7club.com/haltech-foru...e-log-1019239/
#48
Exhaust Manifold Leak
Thread Starter
yep, it has only 0.5 Ohm primary resistance, so basicly I am just using the coil with the MSD, I might try using the FC ignitor without MSD to see if that makes a difference
#49
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,805
Received 2,578 Likes
on
1,831 Posts
#50
Rotary Enthusiast
iTrader: (1)
Join Date: Jul 2004
Location: Rocket City, Alabama
Posts: 1,035
Likes: 0
Received 2 Likes
on
2 Posts
I have been running PP road racing engines since 1997.
Do you have Mazda Factory Racing PP housings, or do you have street housings that have been made into racing PP housings?
For MFR PP housings, they are made for 20 Deg BTDC timing, both leading and trailing. These housings have the spark plugs located slightly differently than street roatary housings, so their timing requirements are slightly different.
For street housings that have been made into PP housings, I run leading 24 BTDC and trailing 18 BTDC.
I use an '81 - '83 stock distributor, and I dyno at 320 rwhp.
I warm up with 7 or 8 heat range NGKs, and then I use the 11.5 plugs for road racing. The 9 and 10 heat range plug will overheat the tip, which will cause detonation when running on straights longer than 3/8 mile. The hotter plugs will run okay for short bursts, but they engine will break up when running longer, sustained runs. For example, the 10 will run okay for one 1/4 mile pass, but if you turned around and ran 3 back to back 1/4 mile runs with no cool down in between, then the 10 heat range plugs will cause the engine to misfire. I fought this problem for awhile until an experience racer gave me a set of old 11.5 plugs, and that cured most tuning problems with my PP motor.
Also, your spark plug gap is much too wide. For a high rpm PP motor, you should be running 0.65mm gap.
Do you have Mazda Factory Racing PP housings, or do you have street housings that have been made into racing PP housings?
For MFR PP housings, they are made for 20 Deg BTDC timing, both leading and trailing. These housings have the spark plugs located slightly differently than street roatary housings, so their timing requirements are slightly different.
For street housings that have been made into PP housings, I run leading 24 BTDC and trailing 18 BTDC.
I use an '81 - '83 stock distributor, and I dyno at 320 rwhp.
I warm up with 7 or 8 heat range NGKs, and then I use the 11.5 plugs for road racing. The 9 and 10 heat range plug will overheat the tip, which will cause detonation when running on straights longer than 3/8 mile. The hotter plugs will run okay for short bursts, but they engine will break up when running longer, sustained runs. For example, the 10 will run okay for one 1/4 mile pass, but if you turned around and ran 3 back to back 1/4 mile runs with no cool down in between, then the 10 heat range plugs will cause the engine to misfire. I fought this problem for awhile until an experience racer gave me a set of old 11.5 plugs, and that cured most tuning problems with my PP motor.
Also, your spark plug gap is much too wide. For a high rpm PP motor, you should be running 0.65mm gap.