Author Topic: 2024 BMST  (Read 6107 times)

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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: 2024 BMST
« Reply #25 on: June 22, 2024, 12:00:02 am »
Dennis, I have no clue how you are supposed to set that thing up. I did some research on it when you first told me about it, but couldn't find much in the way of real details. From what I've found in the past, programmable advance systems tend to set the "static" timing at TDC, and then calculate the desired advance. What are the options for the advance curves? The stock timing at full advance is 35* BTDC at around 2500 RPM, but since you want to retard the timing by 5*, is there an available curve for that? Will this system produce a better spark than the Dyna, or is it more like the Dyna 2000 that had similar features, but produced the same spark as the standard Dyna S. The system Mike mentioned also seems to be an inductive type spark, judging from the coil's primary resistance.
The only thing you are gaining is a rev limiter, which won't make you faster. ;) Springs and weights can tailor the advance curve, but it's all-in well below the power band, so it's not really an issue.
Russ Collins said the Gerex CDI was one of the few ignitions that actually made more HP. ;D Jerry moved on to do ignitions for Maserati or Ferrari or some other exotic car company..

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As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Old Scrambler

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Re: 2024 BMST
« Reply #26 on: June 22, 2024, 11:47:56 am »
Scott..........Thanks ;)  CZ (Czech Republic) is the source for the Ignitech unit. It came with a downloadable set of instructions, schemematic, and the open-link set my lap-top up. I will set my new rotor at '0' on TDC and use the computer to plot the initial timing curve. I can store 3 additional curves or use the keyboard to modify the initial profile.......hopefully while on a dyno :)  BTW...the rotor design was shown on Youtube in a DOHC CB750 Cafe produce 'Auf Deutch"...........but a picture is still worth a 1000 words.....in any language :) :) :)
Dennis in Wisconsin
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CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
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Offline scottly

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Re: 2024 BMST
« Reply #27 on: June 22, 2024, 07:17:18 pm »
Hey Dennis, exactly which system are you trying to use? I didn't see any listing for a CB750. It is an inductive system, same as points or a Dyna. I saw a drawing that showed 4 separate coils, and 2 pickups arranged 90 degrees apart instead of 180 degrees, which leads me to think that maybe all four plugs fire at the same time? (wasted spark squared ;)) If so, the draw on you battery may be increased.
Did it come with a rotor, or do you have to make one from scratch? What about the pick-up plate? I got the impression it uses reluctance pick-up coils like the 650 and DOHC bikes, while the Dyna, Pamco, and Gerex use Hall-effect transistors.
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Offline Medyo Bastos

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Re: 2024 BMST
« Reply #28 on: June 22, 2024, 08:52:02 pm »
You just never know what lurks under my bed.. bwahaaaaaaa haaaaaa  ;D
You ought to see under my bed!


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Offline Old Scrambler

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Re: 2024 BMST
« Reply #29 on: June 23, 2024, 10:43:57 am »
Scotty...................Reluctance with magnets at 180-degees on a new plate that came with the unit. I had to figure out how to mount the rotor-wheel. The unit is adaptable to twin or indivdual coils of various resistance, and supposedly has the optional ability to regulate the dwell-time. Model is TCIP4. Hopefully I have wired it to allow the unit to measure and apply the optimal dwell-time by reading the dynamic current when I click on the auto-mode.

I admit I am WAY beyond myself for a farm-boy with less than 2-years of university experience and ZERO formal technical training. However, in 1991 I did all of the electrical installation to our new-construction home and no fires or circuit-breaker problems are known to date.
Dennis in Wisconsin
'64 Triumph Cub & '74 Honda CB750 Bonneville Salt Flats AMA Record Holder (6)
CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
'63 CL72 Project(s)
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'67 Triumph T100C
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: 2024 BMST
« Reply #30 on: June 23, 2024, 05:48:07 pm »
You just never know what lurks under my bed.. bwahaaaaaaa haaaaaa  ;D
You ought to see under my bed!


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Would make mine look bad  ;)
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline scottly

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Re: 2024 BMST
« Reply #31 on: June 23, 2024, 08:52:43 pm »
Dennis, this system is too complicated, and has no advantages that I can see. :(
Jerry, how much will it cost to pry the Gerex out from under your bed? ;D
Don't fix it if it ain't broke!
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Offline MRieck

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Re: 2024 BMST
« Reply #32 on: June 24, 2024, 09:51:47 am »
I can't help myself.  https://www.ebay.com/itm/255799758805
State of the art solid state components...pretty funny now. Don't like the mounting position of that box.....right over the exhaust primaries.
I installed this unit on my Hayabusa a number of years ago.  https://www.dynaonline.com/dyna-cdi-ignition-module-only-darc-2/
I picked up about 1.5 RWHP. Confident in that # as the bike had about 100 runs on the same dyno tuning testing various tunes.
« Last Edit: June 24, 2024, 02:40:13 pm by MRieck »
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: 2024 BMST
« Reply #33 on: June 24, 2024, 11:09:09 am »
I wonder what that $199.95 is worth now in today's dollars?  ;D ;)
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline MRieck

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Re: 2024 BMST
« Reply #34 on: June 24, 2024, 12:13:58 pm »
I wonder what that $199.95 is worth now in today's dollars?  ;D ;)
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Offline scottly

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Re: 2024 BMST
« Reply #35 on: June 24, 2024, 12:43:26 pm »
I wonder what that $199.95 is worth now in today's dollars?  ;D ;)
Helping Dennis set a new record: PRICELESS  ;D
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Offline Old Scrambler

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Re: 2024 BMST
« Reply #36 on: June 24, 2024, 03:16:10 pm »
Thanks guys.....new rotor should be installed by end of week................if it does not work, the Dyna S unit is ready.......
Dennis in Wisconsin
'64 Triumph Cub & '74 Honda CB750 Bonneville Salt Flats AMA Record Holder (6)
CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
'63 CL72 Project(s)
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Offline PeWe

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Re: 2024 BMST
« Reply #37 on: June 25, 2024, 12:57:08 am »
The ignition from https://www.ignitech.cz/en/info
has support for throttle sensor if I remember correctly, another tuning detail.

There are other threads about this ignition and how the CB750 setup was done.
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Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline dragracer

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Re: 2024 BMST
« Reply #38 on: June 25, 2024, 06:41:29 am »
Thanks guys.....new rotor should be installed by end of week................if it does not work, the Dyna S unit is ready.......

Dennis,
If the unit does not work out for you,  i have a solution that extends far beyond what you're attempting to use. Keep us posted.

Offline MRieck

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Re: 2024 BMST
« Reply #39 on: June 25, 2024, 03:26:03 pm »
The ignition from https://www.ignitech.cz/en/info
has support for throttle sensor if I remember correctly, another tuning detail.

There are other threads about this ignition and how the CB750 setup was done.
I've read many positive reviews on the unit .....starting from a number of years ago. The Sasche ignition I have for the CBX has 9 maps in it....I'll post pics of the curves. Only thing I do frown on is the rev limiter is set for either 9,300 or 10,000RPM. If you want something else you have to send the box back to Germany for "reprograming". Boy that sounds weird. ;D ;D ;D
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Offline Bill/BentON Racing

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Re: 2024 BMST
« Reply #40 on: June 25, 2024, 08:27:52 pm »
Dennis,that's all good, except about your daughter.... What about using a MC4 unit with a Race Pak added... it all works with a Dyna S. All programmable, can download each run
 to a file.....I know where one is that can be used and returned 🤔 or after you set the record, just keep em,and replace them....let me know if you're interested.  Good luck,
You can do it, bro, c'mon....
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Offline RAFster122s

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Re: 2024 BMST
« Reply #41 on: June 25, 2024, 08:52:30 pm »
Dennis, how is your daughter doing? Care to give us an update?
David- back in the desert SW!

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: 2024 BMST
« Reply #42 on: June 25, 2024, 11:28:18 pm »
I hope you will mount an Air/Fuel monitor of some sort.

Actual numbers on the Salt are better than old eyes haha.
« Last Edit: June 26, 2024, 11:08:52 am by Jerry Rxman Griffin aka MuthaF'er »
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Old Scrambler

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Re: 2024 BMST
« Reply #43 on: June 26, 2024, 08:59:08 am »
Thankyou to everyone for the offers of help and advice.........and especially your thoughts and prayers for our daughter ;) ;) Dr. A.J. is now walking and driving, but still doing PT 3 times a week planned into September when she will have the long screw going across her spine removed.

The Scottly dyno-test tells me the A/F is somewhat lean at high RPMs..........so I went up one jet size. That tends to show a rich condition on the plugs at a fast idle and mid-range. I have had several advisers tell me that a bung on the header is good for tuning but not for racing. Maybe I need a bung on a tuning header and another header (hanging on my shelf) for racing.........Hmmmmm ;)

8 weeks to Show Time ;D ;D ;D

Dennis in Wisconsin
'64 Triumph Cub & '74 Honda CB750 Bonneville Salt Flats AMA Record Holder (6)
CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
'63 CL72 Project(s)
'66 CL77 Red
'67 Triumph T100C
'73 750K3 Owned since New
'77 750F2 Cafe Project
2020 ROYAL ENFIELD Himalayan

Offline scottly

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Re: 2024 BMST
« Reply #44 on: June 26, 2024, 09:47:46 am »
It's normal for the AF to dip into the rich zone below the torque peak RPM; it's just the nature of the beast. Even with the too lean 120 jets, it dropped into the rich zone around 6K. The run from 2015 with 125 jets showed the mixture at the higher RPMs was dead-on at 13:1. :)
« Last Edit: June 26, 2024, 09:51:55 am by scottly »
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: 2024 BMST
« Reply #45 on: June 26, 2024, 10:55:41 am »
Thankyou to everyone for the offers of help and advice.........and especially your thoughts and prayers for our daughter ;) ;) Dr. A.J. is now walking and driving, but still doing PT 3 times a week planned into September when she will have the long screw going across her spine removed.

The Scottly dyno-test tells me the A/F is somewhat lean at high RPMs..........so I went up one jet size. That tends to show a rich condition on the plugs at a fast idle and mid-range. I have had several advisers tell me that a bung on the header is good for tuning but not for racing. Maybe I need a bung on a tuning header and another header (hanging on my shelf) for racing.........Hmmmmm ;)

8 weeks to Show Time ;D ;D ;D

Tuning = racing
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline dragracer

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Re: 2024 BMST
« Reply #46 on: June 26, 2024, 11:51:31 am »
Not trying to create controversy here but constantly monitoring AFR through a full run seems to be a practical tool to have when making an attempt at a record.  The realtime data would be invaluable to get an optimum tune from one emd of the track to the next. Since you aren't using fuel injection with a ton of sensors to make constant  electroniclly controlled adjustments to AFR or timing,  the logging capabilities of a Wego3 or similar are much-needed for mechanical  changes back in the pit area to make the bike as efficient as possible throughout the run. While its true race fuel tends to shorten the life of the sensor, its not like you're racing everyday to degrade the function in quick fashion. The tools are available to help aid in the quest for a new record. We're all living vicariously through you and very much know you're capable of exceeding the current record in grand fashion. The idea is ban together to help, not criticize, judge, or hinder

Offline Old Scrambler

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Re: 2024 BMST
« Reply #47 on: June 26, 2024, 04:24:48 pm »
Yes, the 125 jets are in but actual size may change at the salt because I have VP110 oxygenated gas and the track gas is Sonoco NON-oxy. I may try the equivalent Sonoco that best matches VP MR-12......I think its EX02 with 25% Ethonal that may need larger jets???

Thanks, Frank..............I have a complete AFR unit in my parts-bin.........had it since before I owned a lap-top, which is why I did not bother with it on the original build.......I'll hunt it down and install it since my header needs minor welding......discovered a small hole.......and maybe its time to make use of the back-up unit since its barely been used. More chores for a good cause ;D
Dennis in Wisconsin
'64 Triumph Cub & '74 Honda CB750 Bonneville Salt Flats AMA Record Holder (6)
CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
'63 CL72 Project(s)
'66 CL77 Red
'67 Triumph T100C
'73 750K3 Owned since New
'77 750F2 Cafe Project
2020 ROYAL ENFIELD Himalayan

Offline BomberMann650

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Re: 2024 BMST
« Reply #48 on: July 01, 2024, 08:40:55 am »
Visited the test n tune over the weekend.
Ran into a couple of bmst people.
Had a drink at carmens, ate at the cafe.  It was a good time.

There was a little rain on Thursday - so the salt was a bit sticky.  One team managed a 227mph pass with their liner.  Some motorbikes made 150 club status.  There was a 7 mile course with potential to keep going.

Tourists are becoming a problem at the speedway.  Some like to do donuts while they visit, others have bonfires and leave the remnants.  A more innocent tourist parked the family van in the racers staging lane.  Another followed the blue line clear out to tower.  Bypassing the wall of "no spectators past this point" signage.

If its like this at the end of August - red shirts are gonna have to be on constant alert

Offline Old Scrambler

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Re: 2024 BMST
« Reply #49 on: July 01, 2024, 09:08:43 am »
No spark........so I missed out on the test & tune......................When is the BLM going to post a sign about requiring a permit to be on this area of the salt....and no campfires >:( >:(  This portion of the salt flats is designated as a National Monument and should be regulated like others.
Dennis in Wisconsin
'64 Triumph Cub & '74 Honda CB750 Bonneville Salt Flats AMA Record Holder (6)
CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
'63 CL72 Project(s)
'66 CL77 Red
'67 Triumph T100C
'73 750K3 Owned since New
'77 750F2 Cafe Project
2020 ROYAL ENFIELD Himalayan