First time on the dragstrip!

[slayer61]

patrino, what is the db limit where you race? I have done some vintage bike racing & was allowed (aloud!) 100 db due to class rules while "modern" bikes were limited to 93 or some such thing. Keep it up & good luck!

[patrino]

My 'home track' is Portland International Raceway. It's only ~15 minutes from my house, and is actually a city park. Hard to get more convenient! The noise limit for the night drags is 103 dB. I got popped at 106 dB on the 131 mph pass. We dug into my spares, looking for a way to quiet it down on the spot, so we wouldn't have to quit. We wound up rotating the 'muffler' 90 degrees, so that it pointed down towards the ground (thinking that it might take some of the energy out of the exhaust). That got us down to 105 dB!

Heading up to the shop this afternoon to take some measurements & inspections, see what I can work out. I'll keep folks posted!

[patrino]

Photos up soon ... I fit a baffled muffler last week. It worked great, and I ran last night without any problems. Best pass was a 10.392 @ 132 mph.

[patrino]

One of the many interesting things is that my top speed last Friday was only a mile or two per hour faster than my former previous top speed, but my ET was down by ~0.4 seconds. The main difference between my best runs and my former best runs were better 60' times. I've heard that a tenth quicker in a 60' time means three to four tenths quicker on the quarter ... wasn't sure if that was B.S. or not but my time slips suggest that's the case.

A friend who has come out to the track multiple times is good with a TIG. If he's willing, I'll ask him to add some mounting points on the frame and swingarm, to fit some additional struts, to stiffen the rear end. I'm running a strut now, but with the long swingarm and stackup in slop of various bushings and fasteners, there's still a noteable amount of flex in the rear of the bike. I know that stiffer isn't always better when it comes to motorcycle racing, but it's not too much work (figure a half day to make and weld the brackets, and a half day to fashion some additional struts) and can be undone pretty easily if it doesn't help (just undo the new struts).

[storm 64]

10.32 @ 132 is pretty respectable👍 Maybe have your buddy weld you up a set of wheelie bars. That would help with your consistancy and put you deep into the 10's. Keep up the good work and thanks for keeping us posted.

[patrino]

Here are some exhaust photos. Not pretty or light, but it did the job.

IMG_0361.jpg

[patrino]

Another one:

IMG_0362.jpg

[patrino]

And a final one. The second hanger bracket was necessary, due to the flex of the first hanger bracket (it's pretty long) and the flex at the header-to-muffler joint (it's flex pipe). One bracket would've almost certainly work but I felt better without the pipe wobbling with only a single bracket.

IMG_0363.jpg

[bobgroger]

Last time I was at PIR they ran 1/8 mile. Weekly brackets are 1/4 now?

[patrino]

@bobgroger, I've only run there three times, always on a Friday or Saturday night, and it has always been 1/4-mile. I believe the bracket racing's run on Wednesdays over the 1/8 mile.

I've been only going to the quarters because I've been focusing on getting the bike and myself dialed in. It's easier for me to do both of those, without at the same time trying to compete against someone. That said, I finally feel like I've got the bike (and me) set up OK, so planning to hit a Wednesday night soon!

[patrino]

Got the wheelie bars mounted this week. With the longer swingarm, the old upper mounting points didn't work. I wound up welding a couple 3/8" coupler nuts to the underside of the frame. I don't weld often; one looked good but on the other side I blew a hole in the frame tube. A buddy of mine with a lot more experience patched the hole with his tig. Should be good to go!

Hoping to do some shakedown runs this Saturday.

[storm 64]

Got the wheelie bars mounted this week. With the longer swingarm, the old upper mounting points didn't work. I wound up welding a couple 3/8" coupler nuts to the underside of the frame. I don't weld often; one looked good but on the other side I blew a hole in the frame tube. A buddy of mine with a lot more experience patched the hole with his tig. Should be good to go!

Hoping to do some shakedown runs this Saturday.

Sounds great! The wheelie bars should be good for about a .5 of a second. Plus it will help with your consistancy.👍

[patrino]

Progress last night ... did a handful of passes in the 10.1xxs, with a best of 10.150. The sixty-foot time for that run was 1.613. The wheelie bars definitely helped. If nothing else they let you think less about clutch control.

The engine's running well, though I'm going to probably lean out the needles a clip, and the main jets a size, depending on what the plugs look like.

The big challenge / unknown is chassis tuning. My friends / pit helpers say the frame's flexing a lot, like it's hinged in the middle (and that's what it feels like). The rear tire is lighting up during some passes, not in others. I played around a bit with tire pressure and wheelie bar height, but still thinking on what's working and what's not.

[bobgroger]

Progress last night ... did a handful of passes in the 10.1xxs, with a best of 10.150. The sixty-foot time for that run was 1.613. The wheelie bars definitely helped. If nothing else they let you think less about clutch control.

The engine's running well, though I'm going to probably lean out the needles a clip, and the main jets a size, depending on what the plugs look like.

The big challenge / unknown is chassis tuning. My friends / pit helpers say the frame's flexing a lot, like it's hinged in the middle (and that's what it feels like). The rear tire is lighting up during some passes, not in others. I played around a bit with tire pressure and wheelie bar height, but still thinking on what's working and what's not.

You are doing great! Way better than me, I am scared to launch decently with a stock wheelbase no bar bike. I am going out a week from Wednesday, hoping I do better. I have also lost 60+ pounds since last time I was out pre-Pandemic. Should be good for a couple tenths. And my leathers fit now. Actually, that was the whole reason for the diet. I was too cheap to buy bigger leathers

[Rob S.]

I've just read the whole thread, and I didn't see where you mentioned what bike it is, or was. For some reason I'm under the impression it's an 1150. Whatever it is, 10.15 is damn impressive. What mph did it do?

I've read that even if a bike has a slower E.T., if it reaches a higher mph, it means it's a more powerful engine, and would probably win in a longer race.

Some pics of the entire bike would be nice. Are the wheelie bars removable? Could it still be street legal?