Testing the HiRev 7500
- Thread starter Newbomb Turk
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Dave999
Well-Known Member
i can't see what you can do to eliminate slew rate.....
you can choose more expensive components to reduce it
but every switch..
points,
or trigger,
optical, hall effect, magnetic, and the associated electronics to make them work to do the job we want
have a switching time
the light in your timing light and on the test machine, also have a switching time
they can all Patent what they like, you can't eliminate slew rate.
you can strive to make it as insignificant as possible
you can strive to mask the effect with your timing curve
but you can't eliminate it,
In the same way you can't travel faster than the speed of light.......
to eliminate slew rate would break the laws of physics
on top of that any dwell control will change the timing slightly
when its acting there are more transistors with their associated slew rate in the mix
when its not acting the little RC time constant circuits that switch those transistors are not doing that job anymore
In the realm where your trigger is a tiny magnet and coil, your relustor is stuck on a vibrating shaft driven off a gear that is pulsing with every pump of you oil pump
you are making the spark jump off the rotor to the contact and the rotor is whizzing around on an armature that can be pulled back and forth by engine vacuum.....of all things....
does it matter...
if it does
cam position sensor
crank trigger
and either wasted spark or coil on plug set up is the way to go
megajolt Lite/Jnr and Ford EDIS 36-1 trigger 2 coils off a ford fiesta for those with no cash
just stop messing with a distributor that is still based on a 1912 delco design....
some delco designs are alright.....
Dave
you can choose more expensive components to reduce it
but every switch..
points,
or trigger,
optical, hall effect, magnetic, and the associated electronics to make them work to do the job we want
have a switching time
the light in your timing light and on the test machine, also have a switching time
they can all Patent what they like, you can't eliminate slew rate.
you can strive to make it as insignificant as possible
you can strive to mask the effect with your timing curve
but you can't eliminate it,
In the same way you can't travel faster than the speed of light.......
to eliminate slew rate would break the laws of physics
on top of that any dwell control will change the timing slightly
when its acting there are more transistors with their associated slew rate in the mix
when its not acting the little RC time constant circuits that switch those transistors are not doing that job anymore
In the realm where your trigger is a tiny magnet and coil, your relustor is stuck on a vibrating shaft driven off a gear that is pulsing with every pump of you oil pump
you are making the spark jump off the rotor to the contact and the rotor is whizzing around on an armature that can be pulled back and forth by engine vacuum.....of all things....
does it matter...
if it does
cam position sensor
crank trigger
and either wasted spark or coil on plug set up is the way to go
megajolt Lite/Jnr and Ford EDIS 36-1 trigger 2 coils off a ford fiesta for those with no cash
just stop messing with a distributor that is still based on a 1912 delco design....
some delco designs are alright.....
Dave
And that is exactly why distributors are adjustable, to make up for the "slew rate". You could call it tolerance stacking of the ignition system if you wish.i can't see what you can do to eliminate slew rate.....
you can choose more expensive components to reduce it
but every switch..
points,
or trigger,
optical, hall effect, magnetic, and the associated electronics to make them work to do the job we want
have a switching time
the light in your timing light and on the test machine, also have a switching time
they can all Patent what they like, you can't eliminate slew rate.
you can strive to make it as insignificant as possible
you can strive to mask the effect with your timing curve
but you can't eliminate it,
In the same way you can't travel faster than the speed of light.......
to eliminate slew rate would break the laws of physics
on top of that any dwell control will change the timing slightly
when its acting there are more transistors with their associated slew rate in the mix
when its not acting the little RC time constant circuits that switch those transistors are not doing that job anymore
In the realm where your trigger is a tiny magnet and coil, your relustor is stuck on a vibrating shaft driven off a gear that is pulsing with every pump of you oil pump
you are making the spark jump off the rotor to the contact and the rotor is whizzing around on an armature that can be pulled back and forth by engine vacuum.....of all things....
does it matter...
if it does
cam position sensor
crank trigger
and either wasted spark or coil on plug set up is the way to go
megajolt Lite/Jnr and Ford EDIS 36-1 trigger 2 coils off a ford fiesta for those with no cash
just stop messing with a distributor that is still based on a 1912 delco design....
some delco designs are alright.....
Dave
I like that . It Includes the entire system.
bee1971
Well-Known Member
Let’s see.
I test everything with 13 volts.
The trigger doesn’t matter although you will argue that from stupidity.
The distributor would be locked otherwise what the **** would you learn?
The coil doesn’t affect retard and one of the boxes I’ve tested only works with ONE COIL.
The gap is .060 or .100 depending on what spark rack I use.
Until I see you test something you can get fucked.
bee1971
Well-Known Member
7 minute mark on the FBO Box
However Don claims to use ONLY a certain Pertronix ignition coil with no ballast with his FBO Box
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It is you who are ignorant. Show me an HEI firing ANYTHING of consequence.
Not the junk **** Pontiac garbage you build.
No one uses an HEI with ANY serious power adder. Unless you have a hard on for doing the ridiculous.
As for the magneto, how much power do you think a fuel engine was making in say 1990? They ALL had Mallory mags.
ALL OF THEM.
Then when NHRA fucked everyone with the nonsense rear axle rule, they had to have a way to limit rpm.
A magneto without a points box is very difficult to control with rev limiters and such.
Being the ignition guru surely you grasp that.
At any rate, you can’t prove an HEI is any better than the HiRev 7500 or any other ignition because it’s not.
Case closed.
I said it earlier but I’ll say it again.
Other people are watching this thread. Guys with far more knowledge and experience than I have and light years ahead of Bewy.
I can say the consensus is two fold.
One he’s making an *** of himself.
And two, he’s a book reader that has no practical experience.
At some point maybe he’ll turn it around.
bee1971
Well-Known Member
Only box I DO NOT have
Those pictures are on his website
He has changed the build of his box numerous times over the years as you can see
Damn expensive for what gain - Rev Limiter feature might bee nice
Mattax
Just the facts, ma'am
If I wrote 'eliminate the slew' then I mispoke. Or mistyped to be more precise.
These are techniques so the output works around the delays.
One has something to do with working off of the previous spark signal. Another which @KitCarlson described picks up a signal inside the logic board, bypassing a lot of the switching. I suspect another way is knowing the slew of a system, then that can be used for a predictive adding of advance. Maybe it can even be firmware programable into aneprom or something. Then the next trick is to protect it from heat and vibration. Or maybe these things need to be cooled, so its more than just protecting from heat - its getting rid of it too.
Mattax
Just the facts, ma'am
Easy buddy.
He's asking a lot of questions.
I get it. I know it can be taken as question the person, but it doesn't have to be.
That's coming from a kid who always had questions. And could be annoying.
I still ask questions (and it still annoys some people, they think I'm questioning them 'cause I'm na old guy now. LOL)
He's asking a lot of questions.
I get it. I know it can be taken as question the person, but it doesn't have to be.
That's coming from a kid who always had questions. And could be annoying.
I still ask questions (and it still annoys some people, they think I'm questioning them 'cause I'm na old guy now. LOL)
Are you using a power supply?
Rather than introduce another potential varible if you could just tell me what distributor you will be using I will try to duplicate it.
Are we only testing timing and not the point where the ignition gets sketchy? If so If you could be so kind as to let me know which coil you are using.
It sounds like there are different versions of the FABO box so it would be best to use the same box.
Seems to me all those boxes were a few HP and TQ away from each other. Flip a coin.
Dave999
Well-Known Member
no probs.... wasn't having a dig....
which is why i got onto ECU the more you stuff you cram in, the more it becomes a control unit, making decisions based on more inputs than 1 trigger signal and the current flowing, etc.
coil per plug and an ECU which know which coil goes next leaves a nice long time to get each coil ready....
mind 82-92 Jaguar UK used ah HEI module to fire off the V12 with a readline of 6500 rpm
Lucas CE1 ignition module.... (delco 4 pin as we know it).
apart from the £200 cost of replacing it if it went wrong i don't think ignition issues overburdened jaguar's warranty claims department, mind sales didn't overburden their sales department either..... for the XJS
poor fit and finish, rust and disintegrating suspension bushes yes... but their v12 wasn't falling on its *** at 3500 rpm..
to get them to work to a specific rpm limit the trigger coil resistance and no. of windings needs to be very closely matched to, or catered for by, specific resistors in the module... and the magnetic part needs an appropriate level of magnetism.
of course none of us do that..... so we could suffer diminished performance and less then spectacular rpm range .
later of course FI and combined ECU...
the chip in the HEI
https://www.futurlec.com/Datasheet/Motorola/MC3334.pdf
build your own and custom fit it to your mopar trigger by tweaking RL, and rev yer v12 to 6500.
They'ed toned them down from an 8000 rpm redline by this stage.
One interesting looking distributor cap.......
Dave
Oh looks a bit like the FBO one
warning labels!!!!...health and safety in 1982.... would you believeObviously nobody would go racing with ah HEI
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It would be interesting to see the average of the two individual runs combined and layed over each box along with the timing curves. It was interesting that he chose to increase the timing on the second pull of the fbo box.
Yeah, while he chose not to on the others. It still was not a night and day difference.
I pull power right off a battery.
If I’m testing a Chrysler ignition I always use a Chrysler distributor. I do that because 95% of the time it’s what distributor guys use with that ignition.
I use a basic canister coil most of the time because that’s what most guys use. Unless the ignition requires a particular coil then I use what is called for.
I used to have a Blaster II coil that I kept right by the machine but I’m not sure where it went because I haven’t seen it in a while. I probably should look for it.
If you are wanting to test and compare results then I’m 100% down for the cause.
If you are of the mind, you can development the testing protocol on your end and I’ll duplicate that on my end.
Or, I can test a distributor, box and coil on my bench and I can send you the exact parts and you can test them on your machine and we can compare the results.
If that’s what you want I’m definitely down for the time and effort to make that work as that would be much more interesting and educational than just me testing stuff on my bench.
Along with the averages I wished he would have spent more time showing the peak torque numbers.
I’d think outside of the increasing blow by issue most of the power changes were from slew rate changing the timing curve.
He didn’t say exactly what the curve was but he did say it was a MP distributor and curve IIRC. So it was in pretty quick if that’s what he said,
no probs.... wasn't having a dig....
which is why i got onto ECU the more you stuff you cram in, the more it becomes a control unit, making decisions based on more inputs than 1 trigger signal and the current flowing, etc.
coil per plug and an ECU which know which coil goes next leaves a nice long time to get each coil ready....
mind 82-92 Jaguar UK used ah HEI module to fire off the V12 with a readline of 6500 rpm
Lucas CE1 ignition module.... (delco 4 pin as we know it).
apart from the £200 cost of replacing it if it went wrong i don't think ignition issues overburdened jaguar's warranty claims department, mind sales didn't overburden their sales department either..... for the XJS
poor fit and finish, rust and disintegrating suspension bushes yes... but their v12 wasn't falling on its *** at 3500 rpm..
to get them to work to a specific rpm limit the trigger coil resistance and no. of windings needs to be very closely matched to, or catered for by, specific resistors in the module... and the magnetic part needs an appropriate level of magnetism.
of course none of us do that..... so we could suffer diminished performance and less then spectacular rpm range .
later of course FI and combined ECU...
the chip in the HEI
https://www.futurlec.com/Datasheet/Motorola/MC3334.pdf
build your own and custom fit it to your mopar trigger by tweaking RL, and rev yer v12 to 6500.
They'ed toned them down from an 8000 rpm redline by this stage.
One interesting looking distributor cap.......
Dave
Oh looks a bit like the FBO one
Obviously nobody would go racing with ah HEI
View attachment 1716386852
That link is way too hard to read on my phone. I’ll read it later tonight on my iPad.
Edit: the driver is on the wrong side of the car. No wonder they got away with the HEI.
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I kept wishing something was gonna come outta the side of that block.
lol not me. I hate the carnage but I was waiting for the big crapola moment. It had to be close.
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