"Faster, faster, faster, until the thrill
of speed overcomes the fear of death."
- Hunter S. Thompson
Introduction:
Ok so what's with this Drag bike stuff. Well its hard to explain. It may help if you can get a spot on one of the Pit Crew Teams at the next Drag meet. This sport is in its infancy in India but is growing fast. What can I say Engines screaming, Riders edgy and tense. And then off they go. Men straddling Rockets. That blaze down a 1/4 Mile of Tarmac. Its enough to get you heart pounding and your hands shaking just watching, imagine what its like to actually take the ride. Its the most fun you can have with your pants on. In fact you don't even need a drag strip to enjoy the fun. Just find a good clean deserted road and enjoy.
The Sad part is our country has no Drag strips. We don't even have the equipment to time the bikes. Races are held on roads and we time them with video cameras or regular watches. But we make up for the shortage off faculties with our enthusiasm.
Building the 500$ Drag Bike (Yeah I know I'm way over Budget) :(. A work in progress. Target to beat the all India Drag record which stands at 12 seconds for the quarter mile. On Pump Gas. Stock Frame. Stock rubbers 3:50 18" (Some cheating allowed)
200$ on the Bike.
100$ on front Fork with Disc Brake
150$ on Chambers
175$ on the Lock up clutch with shipping
100$ On Misc. Parts.
150$ on the new CDI system without lighting RR etc.
120$ on the second fork and Mag rear wheel. (Dual disc conversion).
10$ on re-bore
90$ on New Pistons and Rings.
60$ on dual adjustable steering Dampers.
The Indian RD came in two versions the Original Japanese Engine with two restrictor plates held up with brass studs to the exhaust port roof, these plates reduced your exhaust duration by 2mm. The bikes with the restrictor pipe where faster than the ones without it because the plate could not be placed up against the rings. As a result the exhaust port opened sooner releasing power. Where as bike without the plate would not release the pressure till the port opened. Escorts claimed 31.5 BHP for this machine. This was known as the High Torque Model, and used an Exhaust duration off 175 degrees. From 85 onwards. When they started making their own barrels and sleeves. It came out as the Low Torque Model. Escorts claimed 27 BHP for this model and it used an Exhaust duration off 160 degrees. The transfers where also modified to suite each engine. Now keep in mind that the US RD350 had an exhaust duration off 183.6 and put out a claimed BHP off 39 BHP. Magazines off the day measured the Rear Wheel output at around 22 BHP at the rear wheel for the US RD.
Even the best maintained RDs in India only put out about 25 BHP. Because of the lack of quality mechanics and proper parts. Most don't Rev past 5500. The average top speed on the best maintained bike is around 140 Kmph. The single biggest contributing factor is our dishonest mechanics who love using used parts. I have seen freshly done motors with used pistons the wrong size rings and other glaring con's. And the best part is the Mech. has you sold on his ideas, that used pistons are somehow better than new ones. RD Dreams set the mark for both the LT and the HT with proving that a stock LT could touch a true speed off 140 and a HT a true speed off 160.
After reading and studying up on the RD and the work being done by Jade Racing and Ric Naylor, and Skalman Racing. All who have web sites. I decided to try building a Darg Bike. My RD is was running a set off US barrels sent to me by Bruce Mangles. With OEl ART pistons. I suspect the bike was making about 35 BHP it ran like stink and the prospect of doubling its output was too much to resist. If you guys haven't seen Ric Naylor's Drag Bike do the quarter in the low 10's you have missed something. That video has been a great inspiration for my self and a lot of guys in India. If it wasn't for these guys I would probably never have got into this project.
Why a Drag Bike and not just a good street bike. Well that's because of our Indian roads. We don't have the roads for speed. So if you really want to push the limits the only way you can do it down a drag strip or in a straight line. Besides a Drag bike is a drag bike. It has only one design objective to shoot you down a straight line at max acceleration. There are no corners, Midrange, nothing matters except all out power. The feeling off the rear wheel biting into the track, the motor hitting the power band and propelling you forward like you've been kicked in the rear by a horse is hard to put down on paper.
My search for building the monster of my dreams begins.
A friend buys a RD pictures below it has Proton chambers looks good and sounds good. But after taking the bike for a spin I inform my friend that he has been cheated. And he needs to look into the engine. When the engine is opened up we find it has sleeved barrels, used pistons and Indian made Power Pace rings (The worst rings you can buy). He re-bores the engine to .5 over and installs original Yamaha rings. Performance improves but the poorly made sleeves are a limiting factor. Anyway the bike looks cool.
Here is a picture below.
The chambers he is using on his bike are made by Proton. These pipes where actually made for the Suzuki Shogun 135 cc engine. Hence they really don't work well for the RD350. There have also been incidents of the chambers exploding if used on a RD. They use the original bend pipe of the bike. As do most proton chambers.
Even though they sound cool look good and are cheap due to the poor
performance I decide to pass on them.
Next stage is an exhaustive search and study on chamber design. How they work. How they are designed. All the software programs that help you design pipes where tried. I discussed the chamber design with lots of people I meet on the net. One of the guys I meet was Rickard who races in Sweden. He has one of the most powerful RZ350s ever to be put on a Dyno check it out at Click here . Rickard agreed to design a set of pipes for me. Which would give the bike 65 BHP on the rear wheel. My request to him was to build a set of pipes that had a very wide power band. With a good kick at 7000 RPM. The pipes should also work on a stock RD350. As soon as I received the design work on building the pipes began. First we cut the stencil in KG Cardboard. After the measurements where confirmed we put the stencils on a steel plate and cut the plate. The steel pieces where then turned and welded to form the cones.
The Cones where then joined together. To form the pipe shown below. Lastly we set the pipes in to be chromed. he final product shown on the left.
While designing the pipes we thought it would be interesting to do something different. i.e. lets see if we could make them look as stock as possible while allowing us to keep the side stand and main stand. Which we where able to do. The Kicker had to be reshaped to clear the chambers. We finally mounted up the chambers on the bike and took some pictures. At this stage the engine is still stock. With mild porting. Can you spot one key important difference between these pipes and the other pipes.
Ok Ill share the secret. Its in the header. We have started our cones at the header. And not using the stock bend pipe. This double the amount off work that needs to be done. But its worth it. An honest confession. We had pipes designed for us by many different software program's and different tuners. The specs Rickardo sent us went against everything we had worked out. Or considered building. The tuned length calculations where all wrong. The diameter sections where all wrong. Everybody kept saying the RD hates large belly sections. So we had serious reservations about going with his design. But as you will read we did a wise thing. Moral off the story the best pipes are 80% experience and 20% the math.
Stock Engine with Chambers:
Time came to take the bike for its first trial run. I take the bike out for a spin. Am initially disappointed because I cant notice any change in the performance. On the way home I decide to blast the engine. Now normally on the RDs I have ridden in the past I keep the RPMs below 7000 which is quite high considering that most Indian RDs don't rev past 6K. I am in second open up the throttle the RPM starts to build 4-5-6-7- and then suddenly the bike just shoots out from under me my arms are wrenched hard the front wheel goes vertical. I'm doing about 50-60 clicks now. The complete experience was like an explosion. I look at the RPM meter and its off the redline. The complete experience was quite a shock it caught me completely off guard. As a reflex action just shut the throttle and pulled in the clutch and brought the front wheel down with a dab of the rear brakes. Took the bike out onto the highway and kept sampling the redline. It was great and felt great. My hands where shaking, I could hear my heart pounding man this was great. I was hooked.
But there was a problem here it was close to impossible to keep the front wheel on the road. It would work fine till 7-8K then bang and the front wheel would shoot right up. On the first and second gears it was really hard keeping the bike from flipping. The only way to control this was by cutting off on the throttle or pulling in the clutch. I even tried sitting on the tank or moving as much of my body weight up front nothing worked. Bike would behave till the power band kicked in and then bang the front wheel would shoot up. Something had to be done about this.
The pipes pictured above where welded together by a friend of mine. They are on sale for 90$ each. Plus shipping. Of this Rickard will get a fee for his design. But we haven't figured out to ship such large items so we haven't been able to send any out off the country. I strongly recommend getting in touch with Rickard Directly and buying a design or set of pipes from him.
END PIPE STORY
In an effort to keep the wheel down. The best option was to try and shift my weight onto the front wheel and change the weight distribution and shift as mush as my body weight onto the front wheel. One option was to sit on the tank but that didn't seem practical. So I started trying out various handle bars that would allow me to shift my body weight front. I tried the U shaped one like the ones on the blue bike above. Also tried a straight pipe design. Neither worked. Then I found these adjustable clipons where the angle of the handle could be adjusted to any setting you wanted. They fit the bill so I stuck to them but even with these the front wheel wasn't sticking to the road. So I dropped the front end of the bike by an inch this allowed most of my body weight to be transferred onto the front end I weigh over 100 Kgs so this got the bike to a stage where the front wheel was floating but not flipping the bike over when I opened up the engine. The Clipons where later transferred under the Triple Clamps.
I'm now able to really exploit the complete power of the engine without worrying about the bike flipping. The bike is now producing at least 45 BHP on the rear wheel with the mild porting. Bored out stock carbs. She is really moving. But getting her stop was a problem with the old drum brakes up front and rear. I need to upgrade the braking system. On a high speed run I was able to take her up to 165 after which she became very unstable. So the next thing I need to sort out is better brakes and larger front forks to stabilize the bike.
The stock RD forks are 34mm. I decided to try the fury conversion this upgrades my fork dia. to 35mm and gives me disc brakes up front.
FORK Transplant & Disc Brakes.
Post transplant the bikes stopping power is improved and she is more stable. I take her for another high speed run. She goes fine till 165 but the wobbles start again. I decide to add another disc brake to the front end and install a set of steering dampers.
Post the dual disc installation the bike is now stopping on a dime. It can also do some really cool stopies. Braking is no longer a problem. The brakes are off a German 175cc Zandap which uses a Brembo caliper and master.
CHOOSING A FARING:
I need to chose a faring. My two present options are listed below. I'm also thinking of using a TZR style faring. But the Honda CBZ faring with the inbuilt head lamp looks really neat maybe that's the one I will go with. As its the most aero dynamic of the lot.
NEW TEAM RIDER:
In the middle of all this we have a new team rider. Heavy is out light is in. Her training starts soon.
Ok everything is looking good. But you know us RD riders we are never happy. We are all the time on the look out for more power. Rickard informs me that with my present setup the bottle neck is my stock reeds and 28mm carbs.
A quick fix for this would be to use RZ350 reeds. I receive a case full of RZ reeds both stock and with dual stage fiber reeds from Chaz. Chaz I owe you big time for the parts. Also in order to get serious with an RD engine you need the right tools a Hand drill is simply the worst tool to be using. So I save money for a year and buy a Dremel Tool with Flexi shaft. Yes it took me a complete year to save up for it :(
The first job I tackle is installing the RZ reeds onto the RD. This involves removing a lot of metal from the barrels as the stock RD reed block is tiny when compared to the RZ reeds.
I also find that the 76 bits I got with my Dremel kit is really too small to tackle this job. So I came up with a modified bit that at 30,000 RPM cuts thru the metal like butter. The bigger bit also gives a better finish. If your interested in customized bits for your Dremel drop me an e-mail. The bit on the left is the Dremel bit. The one on the right is the one I came up with.
If you cant afford a RZ350 reed block and Manifold pair. You can improve your top end by porting your stock reeds. I tried this before I switched to RZ reeds and porting the reed block does help. Only thing is dont cut back as far as I did. Leave 1-2mm of the rubber. I also found that instead of a square cut you could cut a half moon shape this helps flow.
If you want to exploit the reed mods to the max you can remove the central rib and switch to single stage reeds like the ones pictured above.
The carbs where also bored out to 29.5 mm. The bike was running strong. And revving hard. Rickard recommends widening the exhaust port to 46mm and raising it to 27mm which I do. At this stage I suspect I had the bike close to 55-60 BHP. But I wanted more to take it to the limit.
The Reed Story in Stages
This is what the stock reed blocks look like note Tiny and really small.
The next step up is to hole out the Intake enough to take the RZ reed block. Easy peasy. These RZ reeds should be good enough for 65 BHP or even more. After all they flow enoughf for the 63 BHP RZ350.
Now you want to get cooking when you know the air flow cant keep up with the motor. You need more intake area as well as better control over the frequency at which the reeds are going to vibrate. This is where you ditch the steel plated reeds. In favor of something that more at home when your doing 13,000 RPM. These babies will flow more air than your RDs ever going to need. Good for 80 BHP. A friend of mine says we race the stuff we sell. Well here it is in action for you mate. India's fastest RD getting ready.
He he he sorry I cant show you the prep to fit these guys. If I did you would see my bridged Intake Ports ala TZ style.
But what's the use of all this if you don't have carbs to match. So here are some nice big 34mm Mikuni's bored out to 35mm. Note the angled spacer narrow at the top and thick at the bottom this helps direct the flow down thru the extra 8th port cut into the sleeve.
Oh well thats that for the Intakes side of things. On the drag strip Ill be running it without an air filter.
Started reading up about Time Area calculations. I get most of my info from www.macdizzy.com and I bounce some figures around with the various software packages available. RD Jeff was a big help in this department. Credit for my first engine or cut should go to him. Though now Ive moved on and feel the new engine will produce much more power. I would never have started cutting if it wasn't for his help and guidance thanks a ton RD Jeff I owe you.
The drawing below shows the porting specs of a base RD350B from where we started.
The Picture below shows the extent to which the ports have to have their width opened up. The barrels pictured below will put out 80 BHP on the crank as per TSR. Note the flat roofs. A common mistake done by nearly every Indian mechanic is that the roofs are never done flat and in a line. This kills the engine.
After porting is completed you need to map the ports flow angle. The barrel on the left shows a stock engine the one on the right shows a ported barrel. Also note that the metal between the ports has been removed to increase flow.
So with all these inputs and help from Jeff I began porting my motor. The topic of porting is so detailed that I feel it deserves another page on the site which I am presently working on.
You may wonder why people are so secretive about what they do to their engine. Well the truth be told Im so confident that there is no one in India who can do a decent job of porting an engine that I am willing to share my formula. This whole business of keeping everything under your hat sucks and is only done by engine builders who don't know what they are doing or are too scared to let others know what they are doing because then their work could be questioned.
So armed with all this I took the Dremel bit to the barrels. The porting came out quite well considering this was my fist attempt.
Once the barrels where done I installed them with a set of STD size Dyke Rings. These have L shaped rings that expand on compression and are the best design for race and drag bikes.
I jetted the carbs at 240 mains and needle in richest position. Initial test show the bike to rev freely upto 13,000 RPM. The last step in this Journey for me is to get a set of 36mm carbs. Once that is done the bike will be ready for the Drag Strip. But until then I fell I can safely say I have the most powerful RD in India.
Some of the local guys have been taunting me to race with them. I don't feel its worth the bother. Because after you beat them its always the same old story. i.e. Oh my bike doesn't have chambers, my timing is out, the clutch is slipping etc.
If there is anybody else out there working on setting any records speed or time with RD drop me a line. As I have got more and more engrossed into TA values and flow angles my desire to ride the bike has been taken over my desire to perfect the engine.
Stuff Im working on
a. Rebore the barrels and put in a new set of pistons and rings to up the compression.
b. A half seat
c. Rear sets to move the foot controls back.
d. Faring for front and back
Ok the lockup clutch RD400 Con rod, DT175 Pistons, RD400 barrels should be with me in 48 hours.
Both the sets of barrels have been re-bored. The ported barrels to .25 over and the radically ported barrels to .5 Over. Both have new pistons and rings.
The old crank was taken out and replaced with a freshly rest crank with imported Yamaha Bearings from Thorsten in Canada. The big ends of the crank where cut to improve oil circulation.
The Fury rear Mag wheel is being fitted as I write this.
The bike is running the ported barrels with the stock carbs bored out to 29.4mm and ported stock reeds. The jeting has been completed I landed up with 40 Pilots and 280 mains.
My plans for the bike has changed a bit. I plan on now building two drag bikes. One will be for the class B and one for Class C. In class B you can modify your bike with only locally available parts from Indian bikes which means I have to stay with the stock carbs and stock reeds.
In class C or open class you can modify your bike as much as you want and use what ever parts you want. For this class I will use the radically ported barrels, 34 mm Mikuni VM Power jet carbs, RZ reed blocks with TDR dual stage fiber reeds. Lockup clutch, Air shifter, RD400 Con rod, DT175 pistons. RD400 barrels etc.
The fury Mag wheel should be done soon. The bike is running well and the next drag meet is around the corner. I have blown a Crank seal gasket and will need to strip and rebuild the engine fast. Lets hope I can do this on time. I have also ordered two adjustable steering dampers for the bike. She is running smooth and powerful. Lifting the wheel rather flipping the bike in the power band.
Stuff I need to get done fast.
a. Install a single solo seat.
b. Drop the clipons even further down.
c. Sort out the special Drag CDI system which is in the process of getting ready.
d. Take some more pictures of the bike to share how it has evolved.
e. Fabricate some RD400 like head gaskets.
f. Install a digital Speedo so I can get an accurate idea of top speed.
Ok one more piece falls into place the lock up clutch has arrived all the way from MRE Racing in the US.
This is what it looks like.
Once this is installed I hope the clutch slipping problem is resolved or reduced. Though the clutch would get stiffer and may require an air shifter. Anybody know of a used air shifter going cheap.
Ok the Lockup clutch is done. Man this kit rocks Im in love with it and would recommend it even for a street bike. I did a complete write up on the Lock-up Clutch. Which you can read about here.
The Rear wheel Mag conversion is through.
The RD400 Barrels are finally here. As are the Blaster 66mm Pistons and RD400 Con Rods.
Kevin Bayron sent me some Jets so my jetting is finally sorted. Im using 380 Mains, 50 Pilots, Y Tube Wire Mesh air filter.
Have decided to build an open class Drag bike and keep the RD350 Drag Bike as it is. So I can run it against the other RD350s.
The bike is running good. and the only things still pending is the Rear Sets and the Faring. Pictures and How-To coming soon.
Well its been months since I've updated this page. A lot of water has flown under the bridge since then. The 12 second record has been broken wide open.
I have received a lot of helpful information from TZ racers and present day GP racers. The database has grown to include ignition timing curves, porting specs and chamber designs off nearly every TZ racer ever produced. Id share this info with you except that the people who gave it to me did so on the condition I would not pass it on. :(. Anyway the timing maps where a big help. And Ive got a much better understanding of the relation ship between timing, detonation, RPM and power. The porting specs have also helped in understanding the latest trends in flow and chamber scavenging.
One thing became obvious pretty fast. The RZ reeds would have to go. I needed something bigger so since then I've upgraded to really huge 6 petal fiber reeds. The new larger Mikuni Round slides are also on. 34mm;s rebored to 35mm. The porting setup has been totally revamped. Using the more modern TZ shaped ports. I've moved to using sleeved barrels this allows me to use really large pistons. I can also play with stuff like bridged exhausts and redo the transfers layout.
The stock RD350 heads could not be reshaped to give the desired squish and comp ratio so I have gone with a new set of heads. Custom designed squish ration and dome volume. The chambers are also being changed to take advantage of the increased power.
I think its safe to say the bike is making much more power than the older chambers and TSR porting specs. Wont be too long before my quarter mile timings fall below the 11 second mark.
The biggest improvement to the bike was made when I got the racing system CDI sorted. This uses two source coils and two pulsars. For one really hot spark. There is no lighting or charging coils all the power is feed to the HT Coils. The low weight on the crank end really helps the engine rev more freely.
The bike handles much better now. The most noticeable difference is the improvement in the power bellow the Power band. On the old setup the bike felt like a weak RD below 8000 RPM. Now the bike feels really strong from 2000-8000 RPM after which it hits the power band and shoots out like a rocket. The jump from 8000 to 11000 RPM happens in under 2 seconds. My top speed has gone from 160 to 194 Im sure it will cross 220 with a decent faring and a lighter rider. And the right gearing setup.
The only area which we are still working on are the gears. The bike is getting a primary gear setup with straight cut gears off a TZ350. The change in the Primary setup will cascade down to all the other gears and the figures say I should cross even 240. But the figures are always a bit on the optimistic side. Id be happy if I can get it to 220.Note: We use Kms. Not MPH.
I am in the process of ordering the G-Pro and an Air Shifter from MRE. This will allow me to change gears while holding the bike at the redline. The G-Pro will help in measuring the quarter mile times down to an accuracy of 1/10th of a second. And I hope will give some credibility to the low 11'sthe bike is running. Ill also finally have an accurate HP figure that people cant argue with.
Here is a slightly dated picture of the bike.
Stuff that's been changed since these pics where taken.
New rear tire with sticky compound. If you look closely the rear tire on the bike sidewalls is new but the centre is flat. That's what wheel spin does to tires it eats them.
Dropped the rear Mudguard.
Installed the solo seat.
New Chambers much shorter and larger Dia.
Stuff that Im working on now.
Front faring to help me cross over the 220 mark.
Rear Disc Brake.
Air Shifter
I know she's Ugly but then again the only thing most guys see of her on the road is.
Ugly never lost a race.
Only downer in all this joy. She eats pistons and rings. I get about 50-60 Kms of life out off her at the redline which is presently over 13,000 RPM. If I keep it below 9000 RPM the wear and tear isn't so bad. But that's what you get for using an exhaust port that's 75% of bore width and speeds way over 4000 fpm on the piston.
Im working on sharing my porting setup. As it isn't based on any one TZ or GP design the guys shouldn't mind. As soon as I can enter it up into my AutoCAD database.
Keep it smoking and ride safe.