hi took me ages to build (3 years almost sigh) but have 2k aprilia rs 250 complete front end fitted to my 3ln ( showa race forks, disks, callipers, wheel (120 tyre) and speedo set up, also have the swingarm, shock and wheel (150 tyre) of the same bike running custom made sprockets and carrier, spacers and chain, it runs a 3ln power plant bored to 290cc, JE forged pistons and rings gas flowed and ported by Jack Knight (mini specialist) lightend and balanced cams and rods with 400rrsp cylinder head (all re-valved and seated,valves from fzr 600) and carb's, carb's re-jetted and dyno'd, k&n pod air filters currently running at about 58bhp although bigger jets are needed and trying to develop a better exhaust without the exup, modified gaskets and manifold as will be running renault uno turbo when i get round to it, its fitted with k1 1000 gsxr seat unit and under tray on original 3ln sub frame with a couple of mods to brackets, billet home made catch tank and matching resiv's, 400rrsp radiator and petrol tank, all electrics are under the tank with custom battery box and loom, carbon race clip ons with hairy rs quick action throttle, Oberon bar end mirrors, carbon zzr 600 stubby can, remote igniton, on daylight mot so no lights (cant find any i like) just waiting to get paint back from house of kolor and were ready to rock and roll!!!! will be posting pics of the full build as soon as poss, i will also show all measurements, cuts and welds also i have a shed load of 3ln parts and some very tasty one of parts like polished cases and yokes, swingarm, and rims i will sort through it all photo it an post it on the site.. also have a nearly complete 3ln that i wont break £400 for the engine and you can have the rest of the bike for free just in case your wondering how quick this bike is it runs at 58bh at 12500 and dose a 1/4 mile in low 10's but not been thrashed as still breaking in, its slow thats why im adding the turbo asap
no videos as yet...loads of pics though just going through them as scattered around a bit and mixed with another build, i said the engine was done by jack knight however only the gear box and manifold have been done by these, the engine was built by stan stevens and i highly recommend anyone in uk to have their bike tuned here, they can do amazing things they can produce 70bh from a standard aprilia 125cc....if i get the right amount of cash from the parts left over i will be putting their Rd250 bored to 292cc producing 120bh into another 3ln.....watch this space!.. off to go work on my gsxr srad fighter now....triples to press stem into grrrrrrr
low 10's is not accurate to the dot as there is no track near us for testing but we have a long strip of road which is roughly 1/4 mile and timed with stop watches...and it uses the 400rrsp cdi
been advised by a few people that adding the turbo is a no no coz of the lag ect ect.....love to hear some feed back...on turbo or noz mods
For turbos on small bikes, take a look at these clowns - funny page, interesting thoughts: http://feralinjection.com/cbr/Turbo2.html The turbo can be found on ebay, or in various wreckers (you'll probably have a better time in England than I will over here).
<!-- s:-? --><img src="{SMILIES_PATH}/icon_Eyecrazy.gif" alt=":-?" title="Eye Crazy" /><!-- s:-? --> This bike sounds AMAAAAAAAZING!! Please post some pics up asap <!-- s --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt="" title="Very Happy" /><!-- s --> Can you tell us anything more about the big-bore and head? Im in the process of building my engine and the 400rrsp head idea hadnt even occurred to me, let alone some big-bore pistons!!??!
yes that link is very funny and points out some things like distance of turbo from the exhaust ports, i own a mazda 626 turbo 1988 and thats where i'm learning turbo systems - i rebuilt the turbo myself and the car goes surprisingly fast for 286,000 kms. about distance of turbo from the exhaust ports - i've seen v8 cars use the turbo mounted at the rear of the car - i guess thats just for v8's cos their displacement is huge compared to a 250cc lol, but i dunno heaps about that, the link says heat=energy but i think thats wrong, it only works good cos there is more pressure when the exhaust manifold pipes are short thus spinning up the turbine bigger and faster. just my 2 cents.
Think of exhaust gas being hot and therefore expanded and thinner. The gas flow is extremely fast. As it cools it contracts, and the velocity decreases. The further your exhaust gas travels the more it cools. The turbine works on gas flow, not pressure. You want the gas flowing as fast as possible through your "hair dryer" to give you maximum boost.
cheers <!-- s --><img src="{SMILIES_PATH}/icon_smile.gif" alt="" title="Smile" /><!-- s --> i like to learn things, whats your thoughts on a v8 running turbos at the rear of the exhaust system? sounds like a dud setup to me.
It does not sound promising, will have a talk to my workmate, (turbo guru). He races a RB31 3 Litre 2 door Skyline and runs a 340kw (dyno tested) at the rear wheels. Did all the turbo work himself.
a turbo for v8 will not work. the turbo is meant for engines that produces power in the range of 100s of hp.. more hp = more air is combusted, more air being combusted means higher volumetric flow rate. if you have the same pressure boundaries at entrance and exit of turbo pump, you would get a very slow air velocity through the turbine, since the volumetric flow rate is smaller. turbine efficiency is highly dependent on the air velocity due to the angle of attack of the turbine blades, if you are out of the operation zone, you will get very bad efficiency. hence the twin turbo for cars, to stay in the optimal turbine operation range as the volumetric flow rate out of exhaust varies (increasing power = increasing volumetric flow rate).. and hence variable turbo (variable angle of attack) on your Porche <!-- s --><img src="{SMILIES_PATH}/icon_cool.gif" alt="" title="Cool" /><!-- s --> if you really want to learn... go hug your physics teacher if you are in high school.. if you are already working, i guess you can always go back to school and get an engineering education... I've heard that back in the 90's there had been turbo charged 4 cylinders 250s in FSAE competition.... its alot of very intensive engineering work, to size turbo properly is one thing, and to avoid destructive damping is another. you really have to know your **** when there are no after market bolt on turbos designed for you.
if you google it theres a guide that some people did a turbo fzr250. but they have a lot of trouble doing it and it didnt add much to the power.
thanks i'm 31 and i weld aluminium for bread, yeah trying to figure out a turbo setup for a car with no bolt on kit is deffinatly a challenge, i might put one on my zetec (ford focus) motor one day - lucky for me they make a kit for those motors <!-- s --><img src="{SMILIES_PATH}/icon_smile.gif" alt="" title="Smile" /><!-- s -->
Having subscribed to STREET MACHINE magazine, they have featured turbo V8s producing enormous power. Have a look at this HT Monaro below. Generally twin turbos are used for bigger engines to get rid of the turbo lag (large turbos take longer to get up speed). For drag racing superchargers are preferred because the throttle response is instant.
