HOW BIG ? Turbo size info needed....

[pommie02]

how big does a turbo have to be?
1000cc bike, running fuel injection, no intercooler.
im looking at a small turbo, from maybe a 1.8 ltr car
is there a formula for the right size

thanks gary

[Issues]

try here http://www.turbobygarrett.com/turbobygarrett/products/turbochargers.html
otherwise maybe here http://www.gcg.com.au/Technical%20Data/technicaldata.htm

I dont know much about them but you will have to match the exhaust flow rates to suit you riding style

[evad]

Gary, i believe that you need to deciede what boost you sre running and what is the max hp you are looking at and then get a turbo that will do that. As an example I have been told that a garrett T2 will run out of puff at around 140-150 hp. The bigger the turbo the later it comes on boost rpm wise.On the zrxoa.org sitehte t25 and t28 garretts are the ones they seem to go for with the ball bearing ones spooling up earlier than the older plain bearing ones. Did you get my email on how to get intouch with exuptorbo from the msefi.com. forum?

[pommie02]

got the email dave...
im just toying with this at the moment, i dont want big horsepower...just enough to scare the shit out of " sports bike riders".
i can just see myself on channel nine news...overtaking a pig car on the back wheel

[evad]

lol, sounds like fun, dean was asking eoday f you are still at volvo?
Let me know how you go :D:D:D

[EXBEN]

Pommie02 I would be looking for something off a 2L car. As a rough guide, a 1L bike reving to 11000-12000 rpm is going to need about the same amount of air as a 2L car reving to 5500-6000rpm, also if your not planing on running an intercooler I'd say go bigger with the turbo rather than smaller because compressing air heats it up & a smaller turbo is going to work harder & therefore heat the air more which is not good for detonation.
I like Garrett turbos & a GT28 (rollerbearing )is a good size for a 1000cc bike.
If you are looking for a second hand turbo, look for something of a nissan 200sx s15, or something like that.
Also don't listen to people that say this size turbo will have too much lag it won't & it's still nice to be able to cruise around off boost ie: you don't want boost from say 2000 revs because the bike would be too touchy to ride & will use a shit load of fuel for no reason. Im sure anyone that has ridden a turbo bike will agree.
Coming on boost at about 4000-5000 rpm is ideal.

[TurboKat]

Godzillas (Nissan GTRs) use twin Garrett M24 T25/28 snails with .42 turbine & .48 compressor housings (or it might be the other way around) built in wastegates & watercooled bearing housings. 1 of them is ideal for a street application on a 750 - 1100cc bike if you don't want more that 200 HP.
Tons of 'em on Ebay as well, cheap as chips - less than $250 for a good secondhand one.

[pommie02]

no i left the factory at xmas...im back at the job i left 12 months ago.
as for the turbo....its a secret, so dont tell the wife !
its something i have always wanted to do, i didnt want to strip my engine again...would i get away with 11:1 compression ratio.
and i have seen that some turbos can be fitted further back, not at the front of the engine.i have already got 120 hp at the back wheel, 170 with the gas....200hp is my target

[TurboKat]

quote:Originally posted by pommie02

would i get away with 11:1 compression ratio.

No way Jose, unless you want to run less than 5 psi boost, you'll hafta lower the compression ratio, there are many ways you can do it, dished/flat pistons is probly the best way, you can also enlarge the combustion chamber for more volume or use a thick (preferably copper) head gasket or a spacer/extra gaskets under the barrels.

[EXBEN]

Actually I disagree Turbokat, there are plenty of Busa stage 1 turbo kits on the market that run 6psi with no intercooler. early busas run 11:1 comp.
Depending on the motor & as long as it's tuned well you should be able to run that no prob.
What motor is it Pommie02 ?

[TurboKat]

Ben is right of course Pommie (he's always right & that's why I hate all his intestines ;)), as all the stage 1 type bolt on kits prove, it can be done but without an intercooler it's not a very efficient way of going about it & there's very little margin for error.
At 11-1, combustion chamber temps would get excessively high so you'd need to run 100+ octane fuel all the time or it'd detonate like a bastard on even 3 psi of boost & it'd be a pig to ride on a hot day.
The higher the static compression, the less flexible a turbocharged engine will be, with a smaller snail the boost would build so quickly you'd be going through the gearbox like a 125cc motocrosser & all the power will be too aggressive down low to use effectively (it would pull great power wheelies in every gear though :D) & with a bigger one you'd have all the power in a narrow rpm band at the top end (which is fine for a land speed record bike), neither makes for a practical real-world-rideable street/road bike.
Having said that, if you just want a turbo for the sake of having a turbo, almost any snail you bolt on will give you that boosty type thrill you just can't get from a n/a engine.
It maybe worth looking into water or water/alcohol injection if you don't want to lower the compression.

[latheboy]

If your going to have water/booze injection you had better have a good think about it first .. alcohol is heaps better than water at the job but unless your willing to carry a spare bottle in a back pack for long rides i would go the water .. if you run out of alcohol you'll be in trouble but you can get water anywhere to when you need a refill..

[Deano]

all this turbo sizing talk makes me think my T25 will be to small.

as they say 'water injection is a band aid fix for a poorly designed turbo system'

[Booster]

Had a good answer but lost from the hackers ...
I like using the smallest turbo that will do the job, less lag, some comprimise with inlet temps but not much of an issue with low boost levels , very roughly 15 psi will give ~100 deg temp rise or part thereof.
water is a good antidetonate but because of expansion as steam will usually not make more hp (if you turn the boost up because the water gives you a bigger safety margine you will make more power)
Good turbo info here too
http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/turbo_comparison_sheet.htm

[pommie02]

OK
I have priced up a decomp plate, im thinking 1.5 to 2mm thick. im not sure if that will lower my compession ratio to 9:1 ?
about $200... not bad, or i can have a copper head gasket.
as for a turbo..... a t25 or t28, the bigger t3/4 wont fit. i would have to move my front wheel!!!!!
there isnt a lot of room for a intercooler, but i have found someone who can cut one down for me.
the last problem is where to get the headers made....any ideas

[ozkat]

$200 is way too much for a decomp plate. See Abusa at www.cyanideracing.com.au he can get all that kind of stuff for you.

[Deano]

quote:Originally posted by pommie02

OK
I have priced up a decomp plate, im thinking 1.5 to 2mm thick. im not sure if that will lower my compession ratio to 9:1 ?
about $200... not bad, or i can have a copper head gasket.
as for a turbo..... a t25 or t28, the bigger t3/4 wont fit. i would have to move my front wheel!!!!!
there isnt a lot of room for a intercooler, but i have found someone who can cut one down for me.
the last problem is where to get the headers made....any ideas



what bike is it

[pommie02]

FZR1000...1988

[Booster]

I use copper cyl spacers on a few of mine, its not that expensive, cuts easily with a jigsaw, softens easily then vht coppercoat for a good seal.
1.5 mm would be a good starting point, there was a guy in Syd that turboed a FZR 1000 ,couple of years back, Rob someone , done a couple of other bikes too, harley and another cruiser i think, someone in Syd may know of him.