: watch a noob build and race a turbocharged 250cc lsr bike


project89
02-23-2016, 06:06 PM
im going to say this now i have never modified a bike like this before

the inspiration 04 wr450f turned turbo lsr bike
http://i76.photobucket.com/albums/j39/lethalrides2k3/Turbo-Yamaha-Salt-Flat-Racer-by-Super-Rat_zps5xiwvkaz.jpg

im starting with a street legal 1986 honda xl250r
http://i76.photobucket.com/albums/j39/lethalrides2k3/IMAG0015_zpsi4wo9jfv.jpg

the turbo is a rhb31 good for 100 hp and is about perfectly sized for a 250cc engine
heres a small mockup before i decided to build a lsr bike
http://i76.photobucket.com/albums/j39/lethalrides2k3/IMAG0577_zpsoy3ftvzw.jpg

so far im still in the planning stages , and just today started to get serious about building this

http://i.imgur.com/hhT9Fy2.jpg

and from here im going to just copy and past my post from the other forum

ok so heres were were at as u can see above the rear suspension lowers beautifully
some how i missed the step in my forks tubes si i couldnt drop the clamps all that far but i may not have to

u can see the step here
http://i.imgur.com/tmYUsyu.jpg
i was able to drop the clamps one inch
http://i.imgur.com/ByJCUm2.jpg

i can bore out the top clamp to go over the first step though if needed for about another 2.75 inches of drop but i really need a wheel and tire to figure that out as a 17 inch wheel will drop the front an additional 2.125 inches


centerline of the rear axle
http://i.imgur.com/CfO9Q5G.jpg

centerline of the front axle with the 21 inch wheel
http://i.imgur.com/c1sgQEU.jpg

and from the rear footpeg mount ( lower craddle tube centerline ) is 7.25 inch from the ground
http://i.imgur.com/zlVK6Rs.jpg

the front centerline of the same tube is 8.75 inches from the ground so a 2 inch drop at the front axle centerline should even the lower craddle tubes to almost paralell to the ground
http://i.imgur.com/UfTe0W8.jpg

bike deff needs a bunch of stretch for me to get on it comfotably in a layed over position
http://i.imgur.com/4Nrf2qp.jpg

im thinking + 8 inches on the swingarm
http://i76.photobucket.com/albums/j39/lethalrides2k3/HD0060_zpsc3fhjoqd.jpg
and then cutting the rear subframe off tot he left of the right line and building my own , this will alow me to move the seat way back and let me lower the bike even more if i want to
http://i76.photobucket.com/albums/j39/lethalrides2k3/HD0060_zpscbz1zadc.jpg

Lead-Farmer
02-23-2016, 06:50 PM
Going to be a bitch making jumps with that much rake.

project89
02-23-2016, 07:23 PM
Going to be a bitch making jumps with that much rake.

lmao , bike will never see anything other then the salt, dragstrip or street again after this

project89
02-24-2016, 02:15 PM
front ends lowered ill post a bit more about it after i eat lunch
http://i.imgur.com/LjH4Roj.jpg

project89
02-25-2016, 08:55 PM
i had some time to mess with the bike , for my ideal seating position and to rear the bars i need to move the seat back 2-3 inches from were the rear of the stock xr seat is.
this will move a good percentage of my wieght above and behind the centerline of the rear axle , so it looks like im going to need atleast 8-9 inch extension on the rear swingarm

thoughts?

project89
02-25-2016, 09:08 PM
holy large pictures , reposting after i resize them

project89
02-25-2016, 09:16 PM
notice anything wrong with this clutch stack ? this is how i pulled it out of the basket , had just a lil bit of clutch slip all last year lol
http://i.imgur.com/4Q640Ut.jpg

side shot of the clutch side of the engine
http://i.imgur.com/IeTmnYn.jpg
how the clutch stack should be , im going to end up turning my own bottom plate for the clutch stack so i can run a few more clutch discs
http://i.imgur.com/AbU6wod.jpg
and the twin carbs im doing blow threw on , going to try running this on e85 , or methanol of i can get jets big enough
http://i.imgur.com/GtprFIp.jpg
piliot jet is removed from the primary carb already secondary carb only has a main jet
http://i.imgur.com/ZYXQE3V.jpg

and does anyone know what this lil knob on the side of the carb is for ?? i played with it all last year made no difference in the bikes idle or how it ran
http://i.imgur.com/mci9Nxh.jpg

project89
02-27-2016, 02:27 PM
gentelmen we have extension , or atleast a temporay one for mockup ( also swapped my stock 17inch rear wheel for an 18 inch wheel off an xr200r i had laying around )
http://i.imgur.com/RZWLUhu.jpg
http://i.imgur.com/niNpIRn.jpg

lol couple changes to the suspension and i can do lsr/drag, and hill climbs lol

project89
02-27-2016, 05:35 PM
so heres how im thinking about dong the rear section of the bike , red lines are what im adding , and blue line at the back is just an extension of whats already there so i can move the seat and fender back
tieing all in to the swingarm should take all the flex out of the frame since im doing a rigid rear suspension

http://i.imgur.com/PPCyJvr.jpg

project89
02-29-2016, 02:48 PM
mocked up some more stuff today
http://i.imgur.com/vaOddrt.jpg

http://i.imgur.com/XoIN2mp.jpg

im going to possibly slide the battery forward and that leaves me enough room infront of the rear tire to build the fuel tank instead of putting the tank uptop on the top tube , not sure were im going to put it yet though

http://i.imgur.com/O6TwZtl.jpg

http://i.imgur.com/OykDRpZ.jpg

chrischabre
02-29-2016, 09:39 PM
Just remember...width is wind resistance just as height is...You planning on running it with fairings or naked? I miss land speed racing. If you want to get really inspired and depressed at the same time..Look up Hass/Serafini racing. Good friends of mine chasing the 300 mph record in 1.5 miles. Looking forward to more man. Ive often thought about throwing a bike together to race but I have other stuff on my plate

project89
02-29-2016, 10:20 PM
Just remember...width is wind resistance just as height is...You planning on running it with fairings or naked? I miss land speed racing. If you want to get really inspired and depressed at the same time..Look up Hass/Serafini racing. Good friends of mine chasing the 300 mph record in 1.5 miles. Looking forward to more man. Ive often thought about throwing a bike together to race but I have other stuff on my plate
probably naked this year , maybe a lil windscreen or something to get my head/helmet behind , gota read the rule book again and see what all i can do

chrischabre
02-29-2016, 10:51 PM
cool deal man. Cant wait to see more..it already looks better, longer, and without the seat and tank haha

project89
02-29-2016, 11:02 PM
cool deal man. Cant wait to see more..it already looks better, longer, and without the seat and tank haha

just mocking everythign up till i have the bike just about done so i can make sure everything is good before i weld up the frame/swingarm , turbo kit etc etc incase i need to change anything , once its all mocked up and together and i know its how i want it ill do all the final fab and welding

stock seat and tank are deffinatly getting tossed , part of me wants to pick up 2 2.5 pound nitrous bottles and make the fuel tank out of them

chrischabre
03-02-2016, 11:24 PM
Just like in Off roading, keep weight low, and balanced. the nitrous bottles isnt a bad idea, depending on how much you plan to ride it, I think one would be sufficient, we ran a 5 gallon moon tank on one of the cars I was racing and with a healthy small block, we burned maybe a gallon with warm up, and the run (short or long course) on the salt... While weight isnt a penalty per say on the salt, with a small displacement like your bike, it will be in my opinion. Remember the racing mottos

"Every ounce counts" "nothings lighter than a hole" and "is it breaks, make it stronger, if not...make it lighter"

haha. Im pretty stoked on this project man...Its gonna be fun, different enough to be noticed and you wont be into it a bunch initially....until the bug bites hard and you go insane

project89
03-03-2016, 12:01 AM
....until the bug bites hard and you go insane

oh im already eyeballing the almost 50hp motor off the kx250f i just bought , the only problem is its 13.5-1 cr stock , a 10-1cr piston and the turbo and that thing would be a screamer . but i just bought the bike so its not going to happen the kx didnt come cheap lol

there is however is a 440cc snowmobile engine laying around lmfao

GLHS60
03-03-2016, 06:28 AM
Old Turbo 2 cyl bikes needed a "surge tank", curious if one will be required here.

Cool project!!

project89
03-03-2016, 09:52 AM
Old Turbo 2 cyl bikes needed a "surge tank", curious if one will be required here.

Cool project!!
thanks

are u talking about the oversized plenum before the carbs? if so i have made mine a lil to big , but ive seen some videos of what happens when when its to small or not there at all so i purposly made it a lil bigger

project89
03-03-2016, 04:23 PM
turns out my 1mm oversized forged piston puts me out of the 250cc class and into the 350cc class , so i need to see if i can press the pin out of my stock piston without damaging my piston but i have a feeling its not going to work out , if i get stuck using my oversized piston , ill use the stroker crank as well and push the motor to 273cc and run it in the 350cc class for fun

looks like im going to be in m/pbg or m/pbf if i run methanol possibly could fit into m/vbg(f)

chrischabre
03-03-2016, 09:12 PM
oh im already eyeballing the almost 50hp motor off the kx250f i just bought , the only problem is its 13.5-1 cr stock , a 10-1cr piston and the turbo and that thing would be a screamer . but i just bought the bike so its not going to happen the kx didnt come cheap lol

there is however is a 440cc snowmobile engine laying around lmfao


turbo sled motor sounds fun....imagine the linear with the clutch set up properly...and being a bunch lighter than the sled will help...only downfall is the width

project89
03-03-2016, 09:56 PM
turbo sled motor sounds fun....imagine the linear with the clutch set up properly...and being a bunch lighter than the sled will help...only downfall is the width


have sawzall / grinders , torch , and welder , Will build for fun !!!!!!!!!!!!!!!!!

lol

Geerbangr
03-04-2016, 12:57 AM
Once you got the bike mocked up where you're "happy" with the look/stance and or whatever else you're after have you checked the R&T? You don't want a high speed tank slapper starting causing salt in the wound(pun intended).

project89
03-04-2016, 01:02 AM
Once you got the bike mocked up where you're "happy" with the look/stance and or whatever else you're after have you checked the R&T? You don't want a high speed tank slapper starting causing salt in the wound(pun intended).

im waiting on a 17 inch front wheel , and a set of lowering springs for the front forks so i can mount them back properly and double check , i do belive i will have enough rake to be fine , i was told the stock rake of the bike was fine , and now that it is lowered it has even more

Geerbangr
03-04-2016, 03:22 PM
im waiting on a 17 inch front wheel , and a set of lowering springs for the front forks so i can mount them back properly and double check , i do belive i will have enough rake to be fine , i was told the stock rake of the bike was fine , and now that it is lowered it has even more

Make sure to check the trail once you get it mocked up. 5-7" comes to mind. We don't wanna read about you going 432 mph across the salt and that bitch started tank slappin and kicked you off the top of it.

project89
03-06-2016, 12:44 PM
no progress lately , been busy working on the car and working on machinery around the farm, i did however get some tubing ordered for the rear swingarm and subframe so that should be here this week.
one of the guys on the camaro forums may be getting rid of his megasquirt ecm , im thinking about buying it and ditching the carbs and going fuel injection ,the main issue i see with that is were in the world can i get a small enough single thottle body with a tps sensor

chrischabre
03-06-2016, 08:08 PM
have sawzall / grinders , torch , and welder , Will build for fun !!!!!!!!!!!!!!!!!

lol


do it...you wont haha

project89
03-06-2016, 08:22 PM
do it...you wont haha

i may when this bike is done , theres a junk bike pile on the farm , theres atleast 8 different frames and motors laying in that pile and a bunch of complete bikes some quad frames as well

project89
03-13-2016, 09:06 PM
no updates , been trying to track down a good stock stroke crank for this thing , may weld up the rear swingarm and rea subframe this week though while i keep searching

project89
03-25-2016, 09:12 PM
well after a couple of weeks of searching for a good crank and rod , i finally gave up and decided to replace the rod myself , cranks out of the engine just need to press it apart and replace the rod myself , ill throw up some pics tonight

project89
04-10-2016, 01:12 PM
as luck would have it i get the crank out and get ready to press it apart and i come across a good bottom end on ebay.
so i bought it , now i have a extra motor or atleast a spare bottom end


can anyone recomend an elctric pump that would be good to use as an oil pump for the turbo, after studying the oiling system of the 250 rfvc motor i no longer want to tap into the engines oiling system , my 2 options were to tap into the trans feed or the camshaft feed , and pulling oil from either one will result in a burnt up cam or trans more then likley

since the motor is a wet sump motor im thinking i can use a electric pump and hook the feed line to the sump drian in the bottom of the engine case and then return it nexto the case vent , i would then put a mini tank in the return line that would hold a lil extra oil in it to help with oil capacity and cooling .

think of the mini tank as a square tank witht he line feeding back to the engine 1-2 inches up the side wall of the tank so the extra oil would remain in the bottom of the tank instead of draining right back into the engine causing it to be over filled

Lead-Farmer
04-10-2016, 01:58 PM
as luck would have it i get the crank out and get ready to press it apart and i come across a good bottom end on ebay.
so i bought it , now i have a extra motor or atleast a spare bottom end


can anyone recomend an elctric pump that would be good to use as an oil pump for the turbo, after studying the oiling system of the 250 rfvc motor i no longer want to tap into the engines oiling system , my 2 options were to tap into the trans feed or the camshaft feed , and pulling oil from either one will result in a burnt up cam or trans more then likley

since the motor is a wet sump motor im thinking i can use a electric pump and hook the feed line to the sump drian in the bottom of the engine case and then return it nexto the case vent , i would then put a mini tank in the return line that would hold a lil extra oil in it to help with oil capacity and cooling .

think of the mini tank as a square tank witht he line feeding back to the engine 1-2 inches up the side wall of the tank so the extra oil would remain in the bottom of the tank instead of draining right back into the engine causing it to be over filled Ive seen guys using tiltons but i have heard from a few people that the rbracing pumps are the best out there.

project89
04-10-2016, 02:29 PM
Ive seen guys using tiltons but i have heard from a few people that the rbracing pumps are the best out there.

those are return only pumps arent they ? i need a pump to presure feed the turbo , not return the oil


i know theres a few ppl using theese on go carts and mini bikes
http://www.ecotrons.com/pictures/detail-picture-of-oil-pump/

not sure it would hold up for what im doing, and id hate to take out a 300$ turbo because of an 59$ pump

im going to look into the pumps the diy turbine guys use , as in those apps the oil temps are way higher then what they would normally be using a turbo in the normal manner

Lead-Farmer
04-10-2016, 02:39 PM
those are return only pumps arent they ? i need a pump to presure feed the turbo , not return the oil


i know theres a few ppl using theese on go carts and mini bikes
http://www.ecotrons.com/pictures/detail-picture-of-oil-pump/

not sure it would hold up for what im doing, and id hate to take out a 300$ turbo because of an 59$ pump

im going to look into the pumps the diy turbine guys use , as in those apps the oil temps are way higher then what they would normally be using a turbo in the normal manner Im pretty sure those rbpumps can be used for pressure not just return.

project89
04-10-2016, 02:42 PM
Im pretty sure those rbpumps can be used for pressure not just return.
thanks ill take a look , one consideration i need to make is power draw . bike has a small stator, and im trying to keep the battery small to keep as much wieght off the bike as i can, might need to look into some lith ion batterys though they sure are spendy

project89
04-30-2016, 12:41 AM
finally got around to working in it a lil bit and got the crank out
http://i.imgur.com/rg5jqiR.jpg
http://i.imgur.com/J3g6mhA.jpg

ive got another new engine on the way as well , tommorow im going to press the crank apart and swap out the rod , the wrist pin is siezed to the rod
along with that ive got a set of street bike forks now that will bolt on it

the kx250f i bought has kept me pretty distracted from working on this thing , hopefully i get moving on it again now

project89
05-04-2016, 02:25 PM
aparently when i do manage to blow somethng up which isnt often , i do manage to blow it up good
http://i76.photobucket.com/albums/j39/lethalrides2k3/IMAG07941_zpsrgvo864y.jpg
http://i76.photobucket.com/albums/j39/lethalrides2k3/IMAG07951_zpsdpdxjwcz.jpg

wristpin broken perfectly in the middle , i bet u i rode the bike around for a good 6 months like that , the motor would knock at high rpms so i just never reved it up high

Lead-Farmer
05-04-2016, 02:36 PM
Its fine, rub some marvel mystery oil on it.

project89
05-04-2016, 03:14 PM
Its fine, rub some marvel mystery oil on it.

ive got a stroker crank and big bore piston for it now , need to bore the top of the case to accept the new cyl , so im not to worried about it anymore , but atleast now i know why the motor used to knock at like 7K+ rpms , i just always short shifted it and it ran fine so i never expected to find a broken wrsitpin

GLHS60
05-04-2016, 07:31 PM
aparently when i do manage to blow somethng up which isnt often , i do manage to blow it up good
http://i76.photobucket.com/albums/j39/lethalrides2k3/IMAG07941_zpsrgvo864y.jpg
http://i76.photobucket.com/albums/j39/lethalrides2k3/IMAG07951_zpsdpdxjwcz.jpg

wristpin broken perfectly in the middle , i bet u i rode the bike around for a good 6 months like that , the motor would knock at high rpms so i just never reved it up high

Wow, piston must have good pin retainers!!

project89
05-04-2016, 11:17 PM
Wow, piston must have good pin retainers!!
the retianers were just thin wire spiro locks but they were in there good

project89
05-04-2016, 11:26 PM
hoping the wiesco wristpin wont do the same when i add 15-20+ pounds of boost to the motor

project89
05-09-2016, 10:31 PM
so this weekend im going to machine the flywheel , not sure what it weighs stock but its a heavy sob , think im going to try to knock about 4 pounds out of it

http://i.imgur.com/EassUjL.jpg


http://i.imgur.com/0n7VHib.jpg

project89
05-10-2016, 04:48 PM
flywheel wieghs in at 4.73 pounds im going to try to knock atleast a pound out of it which i think will be very easy to do but going to try real hard to get close to 2 pounds out of it , if i really wanted to i think i could knock it down 2.5-2.75 pounds

project89
06-01-2016, 08:40 PM
heres an update , and a phrase i thought id never say

#1 i like my honda to much to cut it up

so i was given a ching chong 250cc motorcycle and decided to cut it up instead and im going to put my honda back street/trail legal
http://i.imgur.com/xmAramp.jpg

the question now is do i have the balls to try to go 150mph on a Chinese built frame
going to mount up the turbo tommrow , and then i need to a decent looking rear fender and gas tank for it , not the plastic crap that came on it

project89
07-03-2016, 12:52 AM
http://i76.photobucket.com/albums/j39/lethalrides2k3/IMAG0864_zpsyl5rtpwy.jpg
http://i76.photobucket.com/albums/j39/lethalrides2k3/IMAG0865_zpsizwmdila.jpg
http://i76.photobucket.com/albums/j39/lethalrides2k3/IMAG0863_zps0w59we4h.jpg



used a bunch of old header tubing to build the hotside , i also used new tubing to make up the turbo to intake port pipe but didnt grab a picture with it on .
the carb bolts on the inlet of the turbo*
i need to fab up the oil tank , battery box, extend the swingarm and rear frame of the bike 12 inches *, and finally build a set of handle bars*


*thats not the downpipe im running its going to get cutoff and run parallel to the swing arm , that was the pip i was going to use on my other bike , i just bolted it on to see how i would need to modify it
ive decided to build this as cheap as possible out of parts and junk i have laying around as for the xl250r im putting it back together for an around town/part time trail bike