small turbo bad?
Thread Starter
TECH Resident
Joined: Jul 2010
Posts: 905
Likes: 0
From: VA
small turbo bad? if u run too small of a turbo is there any negitives minus performance? like can it damage anything but itself, mainly engine?
only reason i asked is im doing a custom rear mount set up and i got a turbo off a friend for $50, its only .50ar exhaust side and .63 comp side but for only making 3-4psi and being rear mount and till i get the system working and all and everythign hooked up right i figured it would do fine for now, and if its not big enough (which im assuming it wont or atleast for anything over 6-8psi which is my goal) all it will do is not give me the psi or hp im looking for right? or could it possibly damage (engine mainly) something cause its straining or something? thanks
only reason i asked is im doing a custom rear mount set up and i got a turbo off a friend for $50, its only .50ar exhaust side and .63 comp side but for only making 3-4psi and being rear mount and till i get the system working and all and everythign hooked up right i figured it would do fine for now, and if its not big enough (which im assuming it wont or atleast for anything over 6-8psi which is my goal) all it will do is not give me the psi or hp im looking for right? or could it possibly damage (engine mainly) something cause its straining or something? thanks
From what I have gathered you want a little smaller turbo on a rear mount setup then you would have on a front mount setup. This will reduce lag that comes with the exhaust piping That has to be run for the turbo. What kind of turbo is it whats it rated for is the motor stock or forged? It would help to know what you plan to run it on.
Thanks Derek
Thanks Derek
well if the turbo is only rated for 300, it will just be a restriction in the exhaust and probably cost you power, also would probably not even be able to sustain any boost. End up just over spinning the turbo and having it blow up. In that case, only real damage to the engine you can have if the turbo goes bye bye, is all of your oil pouring out.
On The Tree
Joined: Dec 2004
Posts: 187
Likes: 1
if u run too small of a turbo is there any negitives minus performance? like can it damage anything but itself, mainly engine?
only reason i asked is im doing a custom rear mount set up and i got a turbo off a friend for $50, its only .50ar exhaust side and .63 comp side but for only making 3-4psi and being rear mount and till i get the system working and all and everythign hooked up right i figured it would do fine for now, and if its not big enough (which im assuming it wont or atleast for anything over 6-8psi which is my goal) all it will do is not give me the psi or hp im looking for right? or could it possibly damage (engine mainly) something cause its straining or something? thanks
only reason i asked is im doing a custom rear mount set up and i got a turbo off a friend for $50, its only .50ar exhaust side and .63 comp side but for only making 3-4psi and being rear mount and till i get the system working and all and everythign hooked up right i figured it would do fine for now, and if its not big enough (which im assuming it wont or atleast for anything over 6-8psi which is my goal) all it will do is not give me the psi or hp im looking for right? or could it possibly damage (engine mainly) something cause its straining or something? thanks
TECH Enthusiast
Joined: May 2010
Posts: 558
Likes: 1
The A/R is only a ratio of the turbine inlet's area versus the size of the wheel. If you really want to know how much a turbo will choke your motor, you need to know the wheel size too.
A .96 A/R exhaust housing on a 60mm wheel will choke more than a .81 exhaust housing on a 88mm wheel. If it is a small turbo with a small A/R, that would be pretty bad. If it was a large turbo with a small A/R, then backpressure probably wouldn't be an issue.
A .96 A/R exhaust housing on a 60mm wheel will choke more than a .81 exhaust housing on a 88mm wheel. If it is a small turbo with a small A/R, that would be pretty bad. If it was a large turbo with a small A/R, then backpressure probably wouldn't be an issue.
Thread Starter
TECH Resident
Joined: Jul 2010
Posts: 905
Likes: 0
From: VA
Wheel size I'm not sure, and for hp rating I just guessed at 300 by looking at it and other turbos, I did find a kit though that uses same spec turbo and said its rated for 450, ls1 kit too
for compessor side the inlet is 3inchs and the exit is 2inchs, whole compersor housing might be 8inchs diameter give or take, the exhaust side is t3 inlet with 2inch exit and the whole housing is only like 4inchs toatal diameter but wider then my compressor, and my exhaust is .63 and comp is .50, well oppisite of what I said above.
yeah ebay is were I'm gunna probably get another turbo at, I was looking at the on3 turbos, they had a 76mm .96 ar I think ceramic ball bearings for like $600 ish I think, when I'm not on my phone ill find it and link it. Also had non ball bearing one for like $300 ish
Again I paid $50 for it, if it dosnt work it worked well for a mock up, then ill just switch flanges and get a good/decent t4 turbo probably if everything else works out for me, ill upload pics of my build in another thread when I get more and I'm on my actual comp
Thanks guys!
for compessor side the inlet is 3inchs and the exit is 2inchs, whole compersor housing might be 8inchs diameter give or take, the exhaust side is t3 inlet with 2inch exit and the whole housing is only like 4inchs toatal diameter but wider then my compressor, and my exhaust is .63 and comp is .50, well oppisite of what I said above.
yeah ebay is were I'm gunna probably get another turbo at, I was looking at the on3 turbos, they had a 76mm .96 ar I think ceramic ball bearings for like $600 ish I think, when I'm not on my phone ill find it and link it. Also had non ball bearing one for like $300 ish
Again I paid $50 for it, if it dosnt work it worked well for a mock up, then ill just switch flanges and get a good/decent t4 turbo probably if everything else works out for me, ill upload pics of my build in another thread when I get more and I'm on my actual comp
Thanks guys!
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Just putting in my 2 cents the sts upgrade 76mm turbo on my remote mount has a .96 A/R starts to spool around 2500 and usually sees 9 psi by 3600. Also alot more than the length of hot side goes into how fast it will spool, size of engine, timing in the tune, and a good turbo cam ( my grind 560/560 lift, 234/230 duration lope sep is 117), wrapping the exhuast, and keeping the stock manifolds all help a remote mount start spinning.
Also I agree with 3800SII that little turbo will probably will be a nasty choke point. But for only paying 50 dollars you are almost guaranteed to get you money out of it, and it shouldn't hurt to try it, let us know what you find out.
Also I agree with 3800SII that little turbo will probably will be a nasty choke point. But for only paying 50 dollars you are almost guaranteed to get you money out of it, and it shouldn't hurt to try it, let us know what you find out.
Thread Starter
TECH Resident
Joined: Jul 2010
Posts: 905
Likes: 0
From: VA
these are 2 turbos i was lookin at, would etehr one be a good size to go up to 8-10psi?
http://cgi.ebay.com/ebaymotors/3-Per...item20bb2eab71
http://cgi.ebay.com/ebaymotors/On3-P...item20bb2eaed1
on is for mustangs but i figured its still a 76mm turbo and should work for what ever correct? let me knwo what u guys think, thanks!
Nice 
TECH Enthusiast
Joined: May 2010
Posts: 558
Likes: 1
I bought one of those On3 performance 76mm ceramic ball bearing turbos to use for a rear mount on my V, I'm going to post a full review when I get everything up and running. It seems like a nice unit, I can tell it is actually a ball bearing unit by how it stays spinning even without oil. How long it lasts is another thing, but rear mounted turbos don't seem to experience the same EGTs as a front mounts, so it may last for a good while. Also, I plan on running the water lines for reliability since it is going to get a restricted oil supply.
Thread Starter
TECH Resident
Joined: Jul 2010
Posts: 905
Likes: 0
From: VA
dont see were there claiming 750hp on 8 psi but
and i heard there decent from mustang owners who got there turbo kits said both were decent for what they are
and does any one have any idea about how much an STS 76mm upgraded turbo would run about? was gunna call cause i dont see it on there site or anything
and i heard there decent from mustang owners who got there turbo kits said both were decent for what they are
and does any one have any idea about how much an STS 76mm upgraded turbo would run about? was gunna call cause i dont see it on there site or anything
Thread Starter
TECH Resident
Joined: Jul 2010
Posts: 905
Likes: 0
From: VA
well finally i got my kit up and operational, the turbo actually puts out 4psi with out a problem and before the engine went into limp mode (need tune this was just trial runs) i could feel it hit and pull harder, being said though im in the market for a new turbo anyway cause ether it being smaller or just shitty it leaks oil everywere after shut down, and i have check valves installed to stop it from leaking, car dostn smoke AT all but just leaks nasty oil out the DP and into intercooler piping : \ , but it did work and spool decently the few times i took it out, hit boost at about 3.5k in 2nd and 2.5k when i went into 3rd from 2nd, rest of my kit is perfect and sounds awesome, hopefully will have new turbo on and be done and tuned and i will let yall know what it puts down
