Landracing Forum
Bonneville Salt Flats Discussion => Build Diaries => Topic started by: Rchop on March 31, 2008, 07:54:19 PM
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Well, here it is, start of another season of racing for us old farts!
Last year all of my tools had already been moved when I decided to build the Bonneville Bomber. That bike was put together with a 4 inch grinder, a 120 volt Lincoln mig welder, a 10 inch disc grinder and a benchtop drill press. Any special tools I had to make, buy or borrow to complete the job. SJBMW did my heads and everything else was done in my shop. With the help of my friends at AirTech, MDR, and Bob's Garage, including help from Scott, we got the job done
A lot of things were put together, knowing they would be changed this year as more time was found for construction. Here we are again, getting ready to race while I still have more on my plate than I have time to complete. I have the house and shop nearing completion and vines just delivered, ready to plant. Whew...what did I do when I had a full time job!!
Most of the tools are still packed, so I'm still working on a shoestring for the Maxton race on April 5-7. I do have more tools available than last year, so it will go a little quicker.
My goals are this year:
1. Add engine and gearbox oil breather/recovery tanks. Last year, after each run I had oil dripping from the engine breather tube onto the salt and the 90 degree gearbox was overflowing from the breather vent.
2. Add reverse cone to exhaust megaphone to reduce exhaust reversion.
3. Add Air/Fuel, RPM data logging system to record info from each run Last year I couldn't remember "or see" the indications for this info on each run.
4. Add an airbox and ram air tube for the carburetors
5. Try to stream line the bike more than last year
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Item # 1 is complete...
(http://www.frsengineering.com/mx1.jpg)
(http://www.frsengineering.com/mx4.jpg)
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Item #2 is complete...
(http://www.frsengineering.com/mx3.jpg)
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Item #3 is complete including all new wiring needed for the data loging system...
(http://www.frsengineering.com/mx5.jpg)
(http://www.frsengineering.com/mx6.jpg)
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Item #5 is underway. I want to build a completely new airbox and intake system when I get the new Lectron Carbs. For the first Maxton race, I have set up a stock R100 airbox with an open filter body (removed the filter material). I opened the air intake tubes and fitted 1 1/2 inch stainless tubes in each side that are sealed with liquid plastic. I will attach 1 1/2 inch tubes on each side that lead to the front of the fairing.
(http://www.frsengineering.com/mx2.jpg)
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For the first race this season, I will be using an old set of 38mm Mikuni VM round slide carbs. The TM flat slides I used in Bonneville and El Mirage were garbage. I had nothing but problems with them and one of them had already failed when I started the bike this year. I don't know where they are made now, but it must be some third world factory that has been sourced because of the low price and quality!!
The Lectrons and new airbox will be on by Bonneville.
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Right side ram air tube has been installed...
(http://www.frsengineering.com/7.jpg)
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Front ram air "Y" has been fabricated and installed...
(http://www.frsengineering.com/8.jpg)
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Front view of the intake "Y" ...
(http://www.frsengineering.com/9.jpg)
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The bike is ready to go. It's been lowered, air intake has been modified and new electronics have been installed. I modified the seat and moved the footpegs forward a couple of inches. It has new Mikuni carbs for this race, I will be looking forward to mounting the new Lectrons when I get them.
(http://www.frsengineering.com/mx7.jpg)
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The front suspension bottoms out a couple of millimeters before the fender and fairing touch...
(http://www.frsengineering.com/mx9.jpg)
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Here's a "wind's eye view" of the frontal area...
(http://www.frsengineering.com/mx10.jpg)
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I really like the lowered stance of the bike now...
(http://www.frsengineering.com/mx12.jpg)
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New brackets were made for the GPS speedometer and the data logging system...
(http://www.frsengineering.com/mx8.jpg)
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cool ! I am not a bike guy but like any thing that is fast
terry
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This is a "rider's eye view" of the all the onboard information...
(http://www.frsengineering.com/mx13.jpg)
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cool ! I am not a bike guy but like any thing that is fast
terry
Thanks Terry, it may not be as fast as a modern bike, but this old 1970 R75 can go!!
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Rchop:
Really nice job.
Is it possible to streamline around the cylinders, then allow a limited amount of air in through a small opening and duct it around the cylinders and heads similar to a small airplane?
Pete
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I have thought about that Pete. I think streamlining the cylinders would just add more drag than leaving them hanging out there. They are pretty well streamlined in the original state. We are only talking about 50-60 hp and top speed in the 130's if I'm lucky this year. My top speed was 123+ last year without all the changes I'm making this year.
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Very nice, I'd change one small thing though. Cut those cylinders/heads off and put them straight up and down inside the fairing 8-). Honestly though it looks like you thought things out and did a good job.
If you are only using one battery have you tried having the LM-1 sensor warmed up and data logging and then starting the motor?? Ours would drop out with the low cranking voltage. I put a second small battery just for the data logging to take care of that and it has worked fine. It is the pits if you are on the line ready to go and the engine dies or something and you have to restart it and wait for the sensor to warm and push the record button while they are wanting you to go. I put a separate battery on the lakester also just for data logging as a result of all of that.
Good luck with the bike,
Sum
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Maybe a smooth bell mouth on your intake and a bit farther forward would be better---put tube ahead of body turbulence and sharp edges break up flow,bell mouth would smooth it out.
Maybe some of the others here with more experience and expertise can chime in.
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The air intake tubes look corrugated, maybe that's an optical illusion because of the stripes, but I'd think that smooth tubes would flow better, but I'm prepared to be wrong.
roy
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Great idea Sum, I will see if my LM1 drops out on starting. As far as moving those cylinders, I would love have an XR750 motor in this bike...if I could find one :-D
I'm not sure about the bell mouth. I have seen quite a few intake tubes at El Mirage and Bonneville on cars and bikes...most without a bell mouth.
The intake tube is corrugated on the outside, but smooth inside. The tubes are way bigger than this engine will ever need, so I won't have to worry about any restriction. I set it up this way to give the carbs intakes undisturbed air and maybe...maybe a slight pressure increase if I can go fast enough!! I am not an expert by any means on high speed airflow (advantages/disadvantages), so any input is appreciated.
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Nicely done. Difficult bike to streamline. Love the ram air. I think there is something to be gained by pulling the clipons in and forming blisters around the open fairing sides to enclose the riders upper torso. Yes it will be wider, but I believe less drag. Good Luck. Larry
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Nicely done. Difficult bike to streamline. Love the ram air. I think there is something to be gained by pulling the clipons in and forming blisters around the open fairing sides to enclose the riders upper torso. Yes it will be wider, but I believe less drag. Good Luck. Larry
That is on my list for Bonneville Larry. I tried to just turn in the clip-ons this week and they contacted the fairing. Kent had a set of bars on his side car rig at Bonneville that put your hands in position similar to a boardtrack racer. I'm gonna try to build something like that and then fair in the side openings.
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Cool! Really like them boxer twins vorsprung durch techique.
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That is one nice beemer. Good luck in NC and see you at SW. Fred
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take a look at http://www.profblairandassociates.com/pdfs/RET_Bellmouth_Sept.pdf
roy
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Thanks for the comments guys, I look forward seeing all of you at the time trials.
take a look at http://www.profblairandassociates.com/pdfs/RET_Bellmouth_Sept.pdf
roy
Interesting reading Roy, thanks. The question is...will I get a measureable benefit from a bellmouth? I will try to find one to fit my intake before I go to Bonneville and try it. I have found that every little bit helps in LSR.
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Thanks for the comments guys, I look forward seeing all of you at the time trials.
take a look at http://www.profblairandassociates.com/pdfs/RET_Bellmouth_Sept.pdf
roy
Interesting reading Roy, thanks. The question is...will I get a measurable benefit from a bellmouth? I will try to find one to fit my intake before I go to Bonneville and try it. I have found that every little bit helps in LSR.
It was interesting and as you pointed out maybe not worth a lot, but some. One thing to keep in mind is that the article is concerned with the air that goes into the bell-mouth. We are also concerned with the air that goes around it and is the reason we try and size the opening as close to right as possible to avoid air stacking up in front of it and reducing the aero in that area. We have tried to round the opening.....
(http://purplesagetradingpost.com/sumner/temp-pictures/hood-18.jpg)
........... edges so we are more in the middle between the straight and bell mouth. I think the bell mouth, like they show, without finishing off the sharp outer edges would be bad aero and you might need more HP to overcome that than what you are picking up with the bell mouth. They also criticized the rectangular opening we have on this car and I do see the point there. Mine on the lakester will be round like on Rick's red streamliner.
(http://purplesagetradingpost.com/sumner/bville-cars-2/357-1-07.jpg)
While we are on this, I feel openings like on the car in the picture (and is one that goes with us) is a disaster. It might have the right amount of square inches of inlet, but it is so narrow top to bottom that I feel a lot of the inlet area is ineffective and not contributing to the air the motor needs. The flat leading edges of the opening probably cause air to pile up there and effect both the air going into the scoop and around it. Neither good. Now saying this the car has set records. I still think it would do better with a more oval shaped opening that could probably be smaller.
c ya,
Sum
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(http://purplesagetradingpost.com/sumner/bville-cars-2/357-1-07.jpg)
While we are on this, I feel openings like on the car in the picture (and is one that goes with us) is a disaster. It might have the right amount of square inches of inlet, but it is so narrow top to bottom that I feel a lot of the inlet area is ineffective and not contributing to the air the motor needs. The flat leading edges of the opening probably cause air to pile up there and effect both the air going into the scoop and around it. Neither good. Now saying this the car has set records. I still think it would do better with a more oval shaped opening that could probably be smaller.
c ya,
Sum
Sum, we were trying to come up with a good intake configuration for the new motor in the lakester, was thinking of just using a bugcatcher... :roll:
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............................Sum, we were trying to come up with a good intake configuration for the new motor in the lakester, was thinking of just using a bugcatcher... :roll:
Hey is that one of those V-8 'busas?? I like it, who is going to get to drive first :evil:,
Sum
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First, sorry for the hijack, nice Beemer....
Sum, its the Kieth Black Hayabusa 8, I mentioned we were going to the blown class... 8-)
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Rchop
Looking very nice. You've probably thought of it, but, have you looked for a velocity stack that would fit your intake tube. It would take care of the bellmouth as well. There ought to be a lot of them back there, if you can get to them before they rust away... :roll:
Larry
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I think the thing to take away from Prof. Blair's article is: "The fundamental message is that there is a considerable benefit in either CD (27%) or mass flow rate (16%) by the addition of even a simple radius at a pipe end to make a bellmouth, but the gain in CD above that simplicity to an optimum may be only 4% more."
You REALLY need that radius on the edge at the open end, belling it out gets you a little more, but that radiused edge gets you the most.
roy
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Stainless,
You have got to be kidding!! Who loaned you their blown hemi for the pictures?? That thing has more frontal area than your whole car!!Looks like the Bockcar is getting a steriod injection. I love it!!!!
Rex
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Stainless,
You have got to be kidding!! Who loaned you their blown hemi for the pictures?? That thing has more frontal area than your whole car!!Looks like the Bockcar is getting a steriod injection. I love it!!!!
Rex
Rex, it's the motor out of the MSA Blown Alcohol Dragster, fits nice except for the aero thing.... :roll: The frame rails are 24 inches across, so we didn't even need motor mounts. Picture is several years old, there are still dark hairs on my head.... 8-)
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Well, here I am. We have wi-fi in the motel, so I will be able to update in the evening. Today was nice, partly cloudy with nice comfortable temps. We breezed thru tech inspection and joined in the rookie orientation at 5pm. I ran the course this morning on the Triumph about 4 times to try to pick a good line. I took pics on the last run and will post them when I get back. Lots of Hyabusas and some really fast cars and trucks. This weekend is the HotRod magazine speed challenge which drew quite a few participants. There are 2 new full race Ford GT's that have got to be my favorite cars of all time! The guy that pitted beside me is running a new Dodge pickup with the Viper V-10 and some other special race gear...sure sounds fast! Also, quite a few cars running AA class engines (over 500ci)...lots of muscle!!
Unfortunately, it's supposed to rain all day tomorrow :( Clear is the forecast for Sunday, so that may be the only day we run. I will have lots of pics to post including some interesting road snacks and a pic of the Grand Ol' Opry and the adjacent Bass Pro Shop as we drove thru Nashville...git-ur-done!!
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Good luck. May the speed be with you!
Larry :-D
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Good luck. May the speed be with you!
Larry :-D
Thanks Larry, Rain Rain Rain...all day today! No racing, lets hope it dries out by tomorrow!