Topic: turboguzzi/Suzuki ignition mod.

[slikwilli420]

there has always been more racing here than anywhere else , not sure why . but because there were so many people racing in the 70`s and 80´s there are plenty who still want to race there old bikes .
i had thought that if you got rid of a few classes the other classes would improve . to be honest i had not considered that people like to win trophies to help with there low esteem problems !

Way to be an #$%* Simon! I knew you had it in you. Again, you can't beat those who don't race. I love racing, bigger grids are better, but unless you start dropping money into people's bank accounts and drum up interest, there isnt much that can be done. If you can't understand how people find pride in competing, no matter the level or competition, I can't help you or reason with you.

[Rocketman]

Sharing some additional information I have found regarding the built in rev limits of the Suzuki ignition unit/boxes.  I have been using 1988-1993 GSX1100 part 32900-48B10 which I now believe has a rev limiter set at 11,300 rpm.  I've obtained a copy of the factory manual for the 1993-1998 GSX-R1100W which lists the rev limit as 11,000 rpm for part 32900-46E10.  So there is an option if you are looking for a wee bit lower rev limit.  Probably best to stay away from the GSX-R750 and 600 boxes as I'm pretty sure they are in the 13,000 rpm range.

[seanbarney41]

there has always been more racing here than anywhere else , not sure why . but because there were so many people racing in the 70`s and 80´s there are plenty who still want to race there old bikes .
i had thought that if you got rid of a few classes the other classes would improve . to be honest i had not considered that people like to win trophies to help with there low esteem problems !

actually, as someone who is reluctant to race in ahrma, it is pompous, overly serious, overly competitive ex jocks like simon that make racing ahram unattractive.  Yeah, we already know road racing in the UK and Europe is more popular than in the U.S.  thanks to posts like this, not much encouragement to make any personal efforts to change the situation. 

[turboguzzi]

Sharing some additional information I have found regarding the built in rev limits of the Suzuki ignition unit/boxes.  I have been using 1988-1993 GSX1100 part 32900-48B10 which I now believe has a rev limiter set at 11,300 rpm.  I've obtained a copy of the factory manual for the 1993-1998 GSX-R1100W which lists the rev limit as 11,000 rpm for part 32900-46E10.  So there is an option if you are looking for a wee bit lower rev limit.  Probably best to stay away from the GSX-R750 and 600 boxes as I'm pretty sure they are in the 13,000 rpm range.

I surely seen my 500/4 revving into the 12K zone very often during a race..... So 13K limiter might be high, but i surely want to go over 11K.... Bandit variants might have different rvs limit, might be worht looking into that too

[bwaller]

Martin, my understanding was that GSX1100 ignitor box limiter was set to 11,200rpm, my Krober tach seems to show 11,000 at the cut-out point. However, Rick Stetson's dyno computer reads 10,800 when the limiter kicks in. 200rpm one way or the other is not a big deal.

So if it's only 10,800, another 1000 plus rpm would be helpful.

Now re low grids....I think it's really disappointing. When I started racing we had to work hard just to qualify. I agree with Simon here, there would be multiple heats of riders trying to make the final. Then when I returned to vintage race with four periods of multiple classes there were still 20 guys in my class, plus there were always multiple classes racing.

Numbers have dwindled here too. It's frustrating because the club has tried hard to keep racers and encourage new ones. At each event the only classes that race alone are the latest period, up to 1989. These guys race the fastest bikes and want more track time. Some of the earlier period bikes race four classes at the same time. I'm not sure how long we can maintain this.

I believe part of the issue is most newer bike riders are not mechanics and the thought of having to maintain an older bike is daunting to them. Of course the fact that older bikes are becoming more rare is another issue.

One thing about the last race of the year at Barber....it's quite dangerous. AHRMA cannot limit to only racers with experience participate, and as a result there can be a huge spread of talent on track at the same time. Everyone wants to race at Barber so the grids are large. In many cases this last race decides class championships. So you have large classes, with some guys racing on the edge to win a championship, and others who may have deep pockets and that are only there for the experience. Closing speeds on lapped riders becomes a huge issue.

 

[bwaller]

Martin, we are using the same ignition system, at what RPM does yours cut out?

[Rocketman]

Based on my tach 11,200 to 11,300 seems correct.

AHRMA did institute new requirements for Barber this year. Entrants must have participated in 4 days of racing in the current season and finished a minimum number of laps/races. A limit was also placed on the total number of entries, 650 I think. A small step in the right direction.

No doubt the 70’s and 80’s were the golden era for motorcycle racing in the US.  Participation in most sports including racing is down. Lots of options for our entertainment dollars.

[scottly]

Martin, my understanding was that GSX1100 ignitor box limiter was set to 11,200rpm, my Krober tach seems to show 11,000 at the cut-out point. However, Rick Stetson's dyno computer reads 10,800 when the limiter kicks in. 200rpm one way or the other is not a big deal.

So if it's only 10,800, another 1000 plus rpm would be helpful.
 

The dyno is making instantaneous measurements of RPM based on the ignition signal. When the rev limiter kicks in, there are suddenly less ignition pulses, even though the crank speed has not decreased near as much, if at all. Your tachs may have some inherent damping, and don't react as quickly, so are probably more accurate than the dyno.

[turboguzzi]

we are stepping away from the original subject, but interesting discussion....

FIM has a 107% rule to qualify for motogp/wsbk level events, i.e. if top qualifier does a 1:40 lap, last qualifier should be faster than 1:47.

In national grade racing it goes to 110% i think, in our vintage racing it's 112%. In practice over a typical 10-12 lap race, slowest riders get lapped once and towards the end of the race.

If AHRMA follows FIM normatives, it's really odd that a minimum % of best quali time rule is not applied.

For people that just want to lap around, there's regularity racing.
BTW, it is more fun than you'd think, you still need to lap fast to get any consistency in your times, just the red mist, stuff-you-in-the-next-corner attittude is taken away.

[Rocketman]

While getting ready for my first track day of the year, I put the timing wheel on my 550 to check the timing as I had installed an ignition box off a 93-98 GSX-R1100W.  The results shocked me!   My ignition was timed statically for the old box at 28 degrees BTDC.  With the "new" box the timing advanced an additional 7 degrees between 5K and 7K to 35 degrees BTDC.  It also was not holding the timing steady as it was moving around even when the RPMs were steady.  Decided to go back and check all my ignition boxes. Put the old box on (88-93 GSX1100) and found it was full advance from idle to 9K.  Had an NOS box (88-93 GSX1100) as a spare and put it on.  Could immediately tell the bike was running better, better idle, RPM picked up smoother.  The timing light showed it advanced smoothly from idle to full advance around 5K.  Took it to 9K just to be sure.  So, when dealing with used ignition boxes I guess when the seller says they came off a running bike, it is still buyer beware!

[cb550fcafe]

Had an NOS box (88-93 GSX1100) as a spare and put it on.  Could immediately tell the bike was running better, better idle, RPM picked up smoother.  The timing light showed it advanced smoothly from idle to full advance around 5K.  Took it to 9K just to be sure.  So, when dealing with used ignition boxes I guess when the seller says they came off a running bike, it is still buyer beware!

Any chance you have a part number from that new box? I'd like to source a spare also.

[seanbarney41]

Hmmm?, I wonder if that's what's wrong with my gixxer

[Rocketman]

The part number is 32900-48B10 from the 88 to 93 GSX1100.

[turboguzzi]

interesting, just makes me want to build now a test rig outside of the bike to "map" boxes, been on my mind for a while.... shouldnt be that complicated.

[scottly]

Here you go, TG...

[turboguzzi]

nice! but was going to make it even simpler by simply mounting everthing on my lathe....

how do you read rpm?

[scottly]

I was using a laser tach, but any electronic tach would work, same as with the stock ignition on the bike. Best would be to use an engine analyzer scope, so the rev-limiter could be monitored. How fast does your lathe turn? This unit will exceed 11,500 RPM. The motor is from an electric scooter, the timing belt, pulleys, and orange bearing block are from a DIY CNC plasma cutter that was retired after 8 years of service, and the rest was bits and pieces laying around the shop, so my out-of-pocket cost was $0.   

[turboguzzi]

good info, tnxs, now need to remember where i put the electric motor of a scooter i took apart thinking that one day it could be put to good use. Any ideas?