hey!
as part of a project Im working on, I need an extremely cheap turbocharger.
I need an extremely cheap turbocharger because i am on a very small budget and I only need to run it at 1-2 psi of boost.
I need a small turbocharger because i want it to spool up fast.
my original plan was to buy something like the garrett GT25 and then modify the wastegate to go at 2 psi,
but GT25's are pretty expensive, and built to handle around 10 psi which is much more than I need
EDIT
So after some more research, I figured out my idea isnt my idea and has been done before so,

Im building a nissan s13 engine with motorcycle carbs.
I was thinking about taking 4 cheap little turbos and doing a quad blow through turbo setup,
meaning each cylinder had a turbo which blew through a single carb.
I was thinking this would be good because I would have 0 lag, since the turbos were small, and only
had to spool to 2 or 3 psi, and would be able to hold high RPM'sbetter since each turbo's small airflow,
while being weak for the whole engine, would be sufficient for filling a single cylinder.

thats the idea.

so now that I wrote that, I can expand this post to a greater critique of the idea.
here are some preliminary questions I have:

1) IF EACH TURBO IS PUSHING 2 PSI OF BOOST INTO EACH CYLINDER (8 PSI TOTAL), WILL I NEED AN INTERCOOLER?

2) WOULD I HAVE TO ENLARGE THE WASTEGATES ON THE TURBOS TO ACCOMODATE THEIR NEED TO RELEASE MORE PRESSURE?

3) HOW DO I CALCULATE HOW MUCH HP I GAIN FROM THIS?

here is a helpful diagram I made.

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Thanks!

 

Re: looking for the smallest cheapest turbo ever (for good reason)

Leaf blower. Not to troll but an integral power plant may be easier depending on design and you could probably get about 1 PSI pressure. Check around for Probe turbos or k-car turbos. I have pulled K-car turbos for $25 each at the JY. Pain in the ass to do but hey if you're lookin for a head unit not a bad deal.

 

Re: looking for the smallest cheapest turbo ever (for good reason)

thanks Drac0nic. I hadn't thought about junkyard turbos,
Im adding some more info to the first post because the idea has already been done,
and I dont need to keep it somewhat secret anymore..

 

Re: looking for the smallest cheapest turbo ever (for good reason)

some help to make youself a decision
the size of your engine is important.
the turbo will only make boost, if it flows MORE air than what the motor can 'consume"
eg:
if u have a 302 sb,
302 x 5000rpm / 3456 = 437cfm of air per minute- ( just remember , the engine is an 'air pump' and flows air in cubic feet per minute.)

boost is measured in lbs/ minute, since it has density, and that is not measured in CFM any more.
p2/p1 is a ratio used , to determine, the ratio over and above the atmosphere conditions .
@ sea level, the atmosphereic conditions = 14.7 psi
therefore,
2 psi boost is...
14.7 + 2 / 14.7 = 1.14 p2/p1 ratio

now,
437 cfm x 1.14 = 496 'turbocharged CFM"
converted to LB's per minute, due to the air now having density , from getting compressed...

.0691 x 496 "turbo cfm" = 34.27 lbs
which equals approx 342.7 hp

choose / find a turbo that flows 35- 50 lbs / minute
or ..it will be a waste of time

hope this helps.

 

sorry, u edited ur original post..

 

Re: looking for the smallest cheapest turbo ever (for good reason)

That was great info!
I just edited the first post, with the full idea.
inreality there are 4 turbos, one for each cylinder, so the full boost would be around 8 pounds instead of 2.
should have explained, my b.

 

Re: looking for the smallest cheapest turbo ever (for good reason)

aahhhh
but
unless you compound the turbos, the boost is not added together...
if all turbos blow into the same carby / throttle body, it still is 2 psi , IF the the turbos are wasted gated at that level...

 

Im using quad carbs as well, so each cylinder also has its own carb.
The carbs Im using are off the Yamaha R1 bikes.
sorry, I should have made that more clear as well.
basically, each turbo hits its own carb which hits a single cylinder.
4 cylinders, each with a carb and turbo exclusively its own.

 

ok,
still it will only have 2 psi, not 8psi

 

oh. wow. I feel stupid.
somehow I convinced myself that 2 psi in each cylinder = 8 total,
which is completely false.
2 psi in each cylinder = 2 psi.
8 psi in each cylinder = 8 psi.

so I would need to limit the wastegates to 8 instead of 2
and pretty much NEED an intercooler,
as Im assuming heat will accumulate from 4 turbos even if boost wont?

 

dont feel stupid... we are only human
limit the gates to what u want to run...
nah, no intercooler needed.. not for under 5-8 psi
just send it ..

 

thanks for the lenient advice man!
I have found alot of cynical car people, so its nice to find dudes who patiently talk me through stuff.

Im still looking for cheap small turbos so anyone who has any ideas keep em coming!
if Im in the junkyard, what cars will have small turbos as stock?
never hurts to have too much info!

 

to bring this discussion to a close, the turbo Im going to go with is the IHI RHB31 3T-505.
I would be using american made clones, as legit IHI's are around $800-$900 each.
The clones are built more or less to the same standards and run for $250 each.
http://www.ebay.com/itm/MOTORCYCLE-...es&vxp=mtr&hash=item19c5f471a9#ht_1276wt_1155

the other reason I like this turbo is its the same one that was used on a mitsubishi 1.6 in the same way
that I want to use mine. They put 4 of the RH31's on an evo4 engine with EFI and they say they spooled at 3 MPH.
not bad if you ask me

for now Im shelving the idea, since i need to get the engine finished and running before i can think about boosting it
but it will happen eventually.

thanks for the help!

 

So... $1100+ just for the 4 turbos, since the entire reason for going this direction is limited budget, how is that helping? Why not just a single with stage3 T3 and 50-57mm compressor? I'm confused.

 

your confusion is completely valid,
Im on a limited budget but Im set on doing the quad turbo configuration.
I wasnt planning to turbo the car at all before I had this idea, so I wont be doing anything besides
the quad idea, and this is an inexpensive way to do it compared to buying 4 IHI or Garrett turbos.

 

i think what cat herder is trying to say is why spend 4 times the money to not really gain much in performance. trying to spool four turbos with a four cylinder sounds pretty hard in its self i know your set on a goal of four turbos but from a performance aspect and budget go get a internally gated ebay turbo for under 200 and have something that will for sure perform rather than something that may end up being just for show and wont run for shit

 

hmmmm , i do agree
i think the OP is looking for the 'wow ' factor
yes, a single turbo would be easier , cheaper , and problay make more power

 

damn..
so the consensus is that 4 turbos wouldnt spool quickly because the engine wouldnt be able to supply them with power?
I see the logic there. I felt that since the turbos were essentially the smallest in the world, it wouldnt matter
but you guys are the ones who understand this stuff, not me.
I really would like to try this out, but if it wont do anything it isnt worth the time..

 

for the wow factor def go for it and see what happens but if your looking for performance def stick to one. id hate to see you drop a ton of money into it and not be able to spool them at all

 

go back and use the formular i gave you, and see if the smallest turbo will flow enough ?
get some data on the turbos... list it here
wheel sizes etc
list ur rpm range of motor...
do give up yet.