Need Advise For Drag Race Modification

Hi, Im a new member and was hoping that someone would share their expertise in regard to drag racing... I'm a race mechanic from Philippines and I feel a little awkward because here in PI, we usually use a single cylinder moped bikes for circuit and drag racing... I know that all forumers here are into big bikes like the massive ZX's, Gixxers and Hayabusas'... I hope that someone here from this forum can help me in creating a drag bike that can reach the quarter mile in 12secs... My 4 Stroke Yamaha T135 current time in 400m is 14.7secs... My total displacement is 168.7cc (Bore: 60.5mm Stroke: 58.7mm) and Im currently using %100 Methanol but planning to switch back to Petrol as Im having a hard time with Methanol because it attracts H20 and I have to drain the engine oil and fuel everyday... I hope someone can provide tips especially in regard to perfect carburetion and ignition timing tuning... Here's an link to the pics of mopeds/underbones that we use for drag racing: Yamaha T135 http://www.mocyc.com/modifyzone/view.php?category=YAMAHA& ;idmodify=266

http://www.mocyc.com/modifyzone/view.php?category=YAMAHA& ;idmodify=234

http://www.mocyc.com/modifyzone/view.php?category=YAMAHA& ;idmodify=265

Suzuki Raider R150 http://img99.imageshack.us/img99/8828/dddjjjmt9.jpg

http://images.google.com.ph/imgres?imgurl=http://mybikeshop. files.wordpress.com/2008/01/raiderr150_customfender_03.jpg&a mp;imgrefurl=http://mybikeshop.wordpress.com/2008/02/02/cust om-rear-fender-for-raider-r150/&h=374&w=500&sz=7 7&hl=en&start=10&usg=__tvtn9PuD0RKb243sD82wD7L4T TQ=&tbnid=09mVwnc5Og8KLM:&tbnh=97&tbnw=130&p rev=/images%3Fq%3Draider%2Br150%26gbv%3D2%26hl%3Den%26sa%3DG

 

I also own an '04 R6 but I got hooked up with underbone/moped modification as it is way to cheap than superbike modification... Quite frankly, I found it very challenging and exciting to modify a single cylinder 110cc-150cc four strokers and make it cross the 400m in less than 15-13secs at 150-165Kph from the starting line... In Thailand, they're able to cross 400m in just 9+secs using 100-125cc 2stroke engine and 11+secs for 4stoke engine under the same category... If you have any suggestions or any comments, please feel free to shoot me an email...

Best Regards,

Jade - X Project

Sure thing mate, the bike is modified for high rpm and high compression since it is being run with %100 Methanol... The lightening of the bike has been taken into consideration as well... Everything has been lightened but the problem right now is, the engine is making a weird knocking sound... Maybe because of the lightening of the counter-weight flywheel and the magneto... Im planning to have my crankshaft dynamically balanced... I have changed my stock tranny to close ratio racing tranny... I'm having issues right now with my top end... What would be the best  sprocket combination should I  install?  Currently, Im using  36T-14... Hope you guys can provide sprocket combination techniques or tips on how to find the right combi... If you guys have any suggestions or comments, please feel free to email or PM me...

Regards,
Jade - X Project


Edited by X Project - 08 October 2008 at 10:33am

Originally posted by Bikerphil Hi X It seems to me like your doing well already mate. As you are discovering already by big bore and stroking there is no substitute for CC's You will find the same challenge making any bike go faster, not just the small cc stuff. So why stop at 170cc or so? are there rules stating you must use stock cases and engines? How about putting a 500cc laydown speedway motor in there?

You got that right bro, I also am a believer of the saying " No replacement for displacement"... But of course, here in Southeast Asia, if you can make a 150cc - 200cc 4 strokers achieve 10 - 11.5secs at 155 - 170kph in 400m then you're one hell of a mechanic, and that's what I'm trying to achieve without the help of Nitrous, absolutely all motor engine...