Drag Race bike project, gen II

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Yes, the Cat definitely is a boat anchor.
Losing 20 lbs and adding 10+ HP is an awesome first moification! :eusa_dance:
 
Just a little constructive criticism if that's Ok. With the wide wheel you've added weight and reduced HP. And, the Akra pipe makes great power and is light but the Brocks/Hindle 4-2-1 is lighter yet and makes more power.

That's not to say you can't go fast with the parts you've chosen because people have, but there are better choices for a VMax built for Drag Racing. This is not my opinion, it's well documented at this point.

Again, I'm excited about your project, and don't want to appear negative. Just thought I would pass on some of my experience.
 
Just a little constructive criticism if that's Ok. With the wide wheel you've added weight and reduced HP. And, the Akra pipe makes great power and is light but the Brocks/Hindle 4-2-1 is lighter yet and makes more power.

Of course a constructive critism is ok.
The wide wheel weights 18.6kg vs. stock wheel 14.8kg (w/o a brake disc and damber).
I know it is not good, but looks better:biglaugh:

I want to use stock slip ons, that's why the Ackra collector.

Any experience about VMax rear end w/o suspension at race track?
 
I think you loose 7 to 8 HP with the 240 tire over the 200 tire :ummm: but yes it does look better I also run the 240
 
To correct you have NOT lost any horse power by adding the heavier tire setup. You added more inertia force which requires more power to turn the wheels. So hence no loss , just more power used to turn that heavier mass.

Todd
 
Its lost to the rear wheels hence slower. You can free it up by switching back. I thought the point here was a drag race bike?
 
To correct you have NOT lost any horse power by adding the heavier tire setup. You added more inertia force which requires more power to turn the wheels. So hence no loss , just more power used to turn that heavier mass.

Todd

Well, yes the ENGINE hasn't "lost" 8 HP. But the bike has lost 8 HP at the rear wheel.
 
To correct you have NOT lost any horse power by adding the heavier tire setup. You added more inertia force which requires more power to turn the wheels. So hence no loss , just more power used to turn that heavier mass.

Todd

Put It On A Dyno With A 200 Then Dyno With The The 240 And See If You Don't Lose 7 To 8 HP
To The Back Tire Which Is What counts...So Hence You Loose HP By Running The Wider tire
 
I'm not loosing any crank or wheel HP because of a wide tire. A cheap (Dynojet) inertia dyno only shows less rwhp when a heavier wheel.
Bigger weight and wheel inertia of a wide tyre is not good at a drag strip, but a better friction is.
 
IMHO...

Fist if this is to be a race bike, pull the rear shock and replace it with an alum strut. In shaft bikes I raced in the past, I used a strut length that gave me a horzonal shaft. I know most people drop the rear way down but because a shaft bike tries to "climb the gear", I always felt it was best to put that power down. May not make any difference but one always has opinions. building for E85 is the way to go, but you really have to pull the heads to make that work for you. The reason E85 is so good is that it lets you run more compression and more advance. If you build an E85 engine with stock compression you are not really getting any real boost.

I know Sean did some work looking at the the cams and pistons and I think he said there was not much room for much bigger cams. You deck the block and cut the head and you have even less. If I were building a drag bike out of the gen 2, that engine would be up on the bench and I would being doing a lot of measuring and testing with modeling clay to get the valve pockets cut right and hopefully get a bit more cam. Of course bumping the compression and extending the valve timing is what you DON'T want to do if you put a blower on it.

Tuning pipes is a matter of length and size, and length of megaphone. Its really had to do for a V4. Most pre made pipes are made to function over a wide RPM range. You only need a lot of performance over a very short RPM range in a drag bike. The old school experimenter in me says I might try making up a 4 pipe setup and spend some time on the dyno. "ram tuning" is all about timing when certain presser waves arrive at the valve. But that means nothing if you supercharge it.

I guess what I'm saying is you should build a normally aspired motor OR an supercharged motor. Building us an e85 normally aspired motor then just dropping a supercharger on it is NOT a good way to go. I would go with NO2 OR supercharging. It really makes a difference in the way you should build your motor.

But then I'm just a real old racer and don't know anything about all these fancy new things...

Craig
 
As far as weight, If this is going to be a drag bike, get different forks. If you want to do it on the cheap, go to a junk yard and look for older dirt bikes . You don't want the zillion inch travel, but they will be MUCH lighter and you can mod them to limit the travel. Back in the day the hot ticket was Ceriani ultra light forks. thats what I ran on all my drag bikes. Have no idea if there are any still around, but I'm sure you can find some forks that are much lighter.
 
I will split the front fork tomorow and weight all the parts. Most probably I'm saving the stock fork, but making it 60mm shorter. I want the bike looks as stock as possible.
 

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