project89

iTrader: (1)

picture of a bunch of parts



i already cutup the rear swingarm to start building a new wider swingarm out of it i didnt grab any pics today but ill grab some tommorow

project89

iTrader: (1)

trying to get a feel for were im going to stick the turbo and leave room for the plenum , battery, fuel pump and regulator.

customblackbird

iTrader: (15)

I mounted the plenum to my carbs and ran the BOV under the seat and relocated the battery to the back rear cowl. I used the shoria lithium battery bc of its stupid small size and low weight. I mounted the turbo under the seat and ran up to 12psi with no intercooler on 87 pump gas. But this was on a 90 Suzuki 600 oil cooled bike.

project89

iTrader: (1)

im not sure im going to do a blow off valve but just incase i do what one did u use ?

customblackbird

iTrader: (15)

The BOV was a cheap one off eBay. They are all the same basically. You need one for when you boost and let off the throttle so the surge doesn't stop the compressor dead in its tracks and possibly break the turbo turbine. What your going to need is a decent waste gate. I used one off eBay by a seller called wyntom and they are the best eBay quality and well worth the price which is still really cheap around 60-70$.

I don't know what carbs your going to use but using slide carbs was fun to work correctly with boost. My plenum I welded from steel and used pilot tubes to help equalize the carb pressures esp with fueling off idle and transition. Pilot tubes need to be in the center of the pressure stream and their DIA plays a big roll in how they work.

The other fun part is your fuel pressure must be higher than boost pressure. I ran an external universal electric fuel pump with a return line back to the tank. Base Fuel pressure should be 2-3psi and then fuel pressure should raise at a 1:1 ratio with boost so fuel pressure will always be 2-3psi over boost. I ran a aeromotive bypass regulator that was boost referenced and bypass style. I drained turbo oil back through the crankcase oil fill and tapped oil from a plugged pressure port. Remember to use an oil restrictor in the turbo feed line so you don't push too much oil to the turbo and past the seals.

project89

iTrader: (1)

im using the stock carbs with pitot tubes , the secondary carb only has a main jet in it so im hopipng it doesnt make this to hard for me

i have a bypass regulator on the way , not sure what pump im going to use yet the staor on my bike is very small i only have 6.5 amps to run the fuel pump , lighting and ignition

i may buy the hotshot stator which will give me 16.5 amps of useable power
for the fuel pump im looking at a honda trx/rancher fuel pump it does 50 psi but its expsensive at 100$ but it is a low draw pump and has a bult in surge tank , other option is a bosch 044 or something similar

will a single pitot tube be enough to feed presure to both carbs fuel bowl's ?
im thinking about putting a single one right on the compressor outlet pre plenum
if not ill put 2 sperate tubes after the plenum before the carbs

i supposedly have a box comming full of megasquirt 1 v2.2's headed my way been thinking about just doing efi with one of those

project89

iTrader: (1)

i think i found a small enough bov my main concern is the bike wont make enough vacum to pull it open so ill be sure to get a piston type one i can change/modify the spring on

the turbo has an internal wastegate that im going to try first , if it over boosts ill port the housing and see what happens if that still doesnt work then ill goto an external

customblackbird

iTrader: (15)

Hmmm thats not a lot of juice. How much boost are you going to run? Only because 12psi was stupid fast and actually caused me to total the bike lol… didn't realize It lifted the front wheel at 100mph at 12psi on the highway = ouch.

50psi seems like a lot, I doubt your going to run 18psi so anything that will put out 20psi fuel pressure is good for you. THis is the pump I ran http://www.summitracing.com/parts/sum-g3138/overview/

My pitot setup was for 4 miniki slide style carbs, I used two 3/8" steel hard fuel line to my carb vents. Remember all carb ports have to be plugged or pressurized otherwise fuel will push out or the carbs won't operate correctly. People thought the slides wouldn't operate correctly… ha mine ran better than most of these old bikes on the road and throttle response was perfect and boost went from 0 - 12psi at 8K like a flip of a switch.

You need to calculate pitot tube DIA. I would go larger than you need and then use inserts that you can drill out for fine tuning if you need to go smaller. With that being said I used two 3/8 OD tubes for 4 carbs so one 3/8" should be more than enough. My bike also put out 80hp stock and was 600cc 4 piston oil cooled. My pitot tubes both centered at the entrance of the plenum and looped up and out which then connected to both vents to all 4 carbs.

Internal waste gates are known to be poop. It also depends on what its set at and doesn't really allow adjustability. I think my GT15 had a 15psi internal wastegate. Instead of messing with it I made a bracket to block it off without welding it shut so I could run a 38mm external wastage. BUt for packaging they do the job without having to work in an external.


here are some pics of the bike when it was finished and started tuning (WB02 sensor) sticking out by the seat lol. Loved that bike. I actually still got it and fixed most of the damage but my wife won't let me ride it.

shows the 2 pitot tubes int he entrance of the plenum

project89

iTrader: (1)

thanx man that helps alot , ill update as i get more done, going to try to build the plenum today if i have enough sheetmetal laying around

project89

iTrader: (1)

started the rough mockup of the plenum

AlkyIROC

I've always wanted to throw a small turbo onto my Harley but never got around to doing it.

project89

iTrader: (1)

that might be a good thing , once u turbo something it becomes an adiction , nothing is off limits when it comes to turbos after u do ur first setup on something

AlkyIROC

I saw a conversion in a bike magazine years ago. I think they used a turbo off an old corvair but there are much better options now. Wouldn't be hard to do since it all hangs off the side of the bike. They key is finding a turbo that isn't liquid cooled because my Harley is air cooled. Not sure if something off a 1 liter pontiac firefly would work or not.

There would be other changes required also. My carb is gravity fed so increasing fuel pressure as boost increases would need a small fuel pump and regulator. Not sure how the Super E carb would like pressure on the inlet port.

project89

iTrader: (1)

should be the same setup im using on my bike or customblackbird used on his

project89

iTrader: (1)

mocked up the cr250 forks , need to buy conversion bearing for the bottom bearing , the top bearing is a direct fit but requires a small spacer under the nut since the bearings are slightly closer together on the xr vs the cr

Street Lethal

iTrader: (16)

The older Kawasaki GPZ Turbo's were sweet as hell, should give you a pretty good idea as to where to mount the turbo on the dirt bike like in the video which is up front (see below). That Suzuki GSX a few posts up came out awesome, looks really good, gotta admit. AlkyIROC you should go for it, turbo Harley would be killer on the street...

project89

iTrader: (1)

mounting the turbo up front on a dirtbike would not be good to much mud and dirt not tp mention stones come flying off the front wheel . not to mention u would loose all ur clearnce inthe front when going over logs tree stumps rocks etc

project89

iTrader: (1)

mocking stuff up to figure out my layout for everything

project89

iTrader: (1)

back to working on it








going to get the head ported and probably do a bore and stroke kit


my clutch may have had excessive play in it lol

project89

iTrader: (1)

well i found out today that the wristpin is siezed to my rod , cant even press it out , so im buying a stroker crank ( nothing more then a latemodel xr250 crank that has a +3mm stroke )ive got a 76mm wiesco forged piston being delivered for it tommorow
this project is going to be put on slow down for a lil while as i just bought an 05 KX250f


its my buddies bike , ive been trying to get him to sell me the thing for almost 3 years now , hes in the middle of reassembling the engine now as it wiped out the titainum valves , so its getting brand new rings, new moose racing stainless valves ,moose racing hd valve springs ,moose racing ti retianers , so i wont have to do a darn thing to it for a while

project89

iTrader: (1)

forged piston arrived for the bike today


wiesco 10.5-1 cr 1mm oversized

project89

iTrader: (1)

my cr250 front wheel was delivered yesterday , took a minute to bolt it up today , going to have to wait till i pick up an 18 inch rear wheel to replace the 17, but im pretty sure im going to have to raise the rear a lil bit or lower the front , id rather raise the rear then lower the front so hopefully it wont be to much of a pain in the ***

project89

iTrader: (1)

picked up a stroker crank + the counterbalance shaft for 60$ shipped , cant get a direct answer if the stroker crank fits my older engine so i said **** it for 60$ ill just order the damn thing
its not that much difference between the stock crank and the stroker crank displacement wise , with the crank it pushes my motor to 270cc on the nose

not much of an increase but the increased stroke and displacement will help with the low end tq before the turbo spools up

project89

iTrader: (1)

this is officially a new thread starting form here , i dont want to start a whole new thread

copy n paste from my other forum were i have a couple lsr bike guys helping me build this

im going to say this now i have never modified a bike like this before

the inspiration 04 wr450f turned turbo lsr bike


im starting with a street legal 1986 honda xl250r
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


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



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

i was able to drop the clamps one inch


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


centerline of the front axle with the 21 inch wheel


and from the rear footpeg mount ( lower craddle tube centerline ) is 7.25 inch from the ground


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


bike deff needs a bunch of stretch for me to get on it comfotably in a layed over position


im thinking + 8 inches on the swingarm

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


the record for the class i am building for is currently 123.xx mph , something this engine combo should be capable of

project89

iTrader: (1)

front ends lowered ill post a bit more about it after i eat lunch

project89

iTrader: (1)

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


side shot of the clutch side of the engine

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

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

piliot jet is removed from the primary carb already secondary carb only has a main jet


and does anyone know what this lil **** 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

project89

iTrader: (1)

gentelmen we have extension , or atleast a temporay one for mockup



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

project89

iTrader: (1)

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

WTR388

Ya know, that fiber-fiber connection in the clutch must be a secret, a friend of mine is a top Canadian pro MXer, his dad is a former Canadian superbike pro, and has always wrenched for his kids (both are top pros, so he knows his stuff), I was watching him do a clutch in the pit one day, and he did this by accident, and started throwing the pressure plate on, he was in auto pilot I guess, didn't believe me when I said he messed up lol.

Do you guys usually run the forks that low in the triple clamps going these speeds? I change mine just a few centimeters or millimeters from track to track, on higher speed or deep sand tracks I extend them out for stability/lighter pressure, on the hard pack and tighter tracks I suck them up a bit for the nimbleness and front pressure for grip. Doing 120s with them dropped in so much would make me nervous and worried about headshake/speed wobbles... my FZ6 would do it a bit at 140, just had to keep the throttle wide open to ride past the resonance and it would smooth out.

project89

iTrader: (1)

i only dropped the forks in the clamps to lower the bike so i could take measurements and all that for mock up .
the forks will actually be sent out and cut down so they are much shorter. though thats a good set of cr250 forks that i really dont want to cut up so i am looking for street bike forks that will fit my trees , or a complete street bike front end that will fit on my bike .
if u notice the front of the bike is still a bit high i left it like that because the new 17 inch front wheel will lower it some more and bring the bike to about the perfect level, my only concern about this is it may tighten up the rake to much , and make the bike unstable at speed , but i will have a steering damper on it for sure , dont need any speedwoobles on a very light bike that will be seeing high rates of speed

my bars will actually be a set of clipon's right above the lower tree just to give u an idea how ill be sitting/laying on the bike , rear pegs are right infront of the rear tire

the stock seat and tank u see in the pictures arent actaully going on the bike , i will have to fab an all new tank that sits much lower and the new seat will prolly be about an inch thick with the padding


tommorow i think im going to just throw the cyl back on the motor and the head so i can get back to redesigning the turbo kit there a whole lot more room now on the bike so theres a bunch of improvements i can make to my original layout

project89

iTrader: (1)

mocked up some more stuff today




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

project89

iTrader: (1)

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

my bore limit is 75.508mm , so trying to come up with a stock piston for this thing as im sure the one on my rod is toast due to the pin being siezed in the rod

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

project89

iTrader: (1)

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


the question now is do i have the ***** 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