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Discussion Starter · #1 ·
For a straight T4 60-1, a .96 "O-trim" turbine side AR is far to large correct? I'm seriously considering switching down to a .58 AR housing.

Any thoughts on this?

Thanks.
 

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seems a little too large for any usable power. A turbo of that size your going to need to run higher boost than what the stock pistons can handle to acually see any power and use it to it's potential.
 

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Discussion Starter · #3 ·
3GwithVOLKS said:
seems a little too large for any usable power. A turbo of that size your going to need to run higher boost than what the stock pistons can handle to acually see any power and use it to it's potential.
Ya thats what I figured. For 8-9 psi, I don't want to wait till 5000 rpm to hit boost.

Personally I'm ALL about small turbos. Though I don't want to go too small either. So a .58 AR T4 housing should be fine right? No back pressure issues such as those experienced by the .48 T3 guys?
 

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Never Too Much HP
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Jetblackness said:
Ya thats what I figured. For 8-9 psi, I don't want to wait till 5000 rpm to hit boost.

Personally I'm ALL about small turbos. Though I don't want to go too small either. So a .58 AR T4 housing should be fine right? No back pressure issues such as those experienced by the .48 T3 guys?
This is where i shut up because i cant read and make stupid comments sorry Jetblackness
 

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Discussion Starter · #5 · (Edited)
myrt said:
search bro... its all here. seams that .63 is gold if i remember right.
.63 for the T3 w/a stage 3 wheel (T31).

I'm assuming that is a far cry from a T4 w/ an "O-trim" wheel.

Also the .63 flavor is not availble for the paticular housing I need (o-trim wheel, w/undivided inlet flange, and an "on-center" discharge flange). Only choices are: .58 / .69 / .81 / .96 / 1.30

Trust me, I've searched a LOT. This information does not exist due to the simple fact that a vast majority of the turbo V6s are using the T3/T4 hybrid. The guys over at 3si have been seeing some good results with the T4 60-1, though they are unsure of what the specs on the turbine side are.

Really I just want to make sure that I dont end up with a turbine housing that wont boost for a while. See I have no idea how the smallest T4 wheel compares to the T31 wheel. If there anything simliar then I maybe able to go off the assumption that a .58 AR will be "just right".

myrt said:
This is where i shut up because i cant read and make stupid comments sorry Jetblackness
lol the way I phrased my first question makes me look like an utter noob (read: i'm only a partial noob, NOT utter). :lmfao:
 

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Kampfbereit
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We use T4s on our V6 kits. The legacy turbo vehicles are running T3/T4s.

Look into a full T4 setup, run yourself some compressor maps. You can't just take a turbo, throw it on and then see what happens. You need to map it out before you just go taking stabs in the dark.

Pick up a copy of Maximum Boost if your designing your own turbo kit. Anything I would tell you I would simply be repeating out of that book.
 

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REDLINE ALL GEARS
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Tearstone said:
Pick up a copy of Maximum Boost if your designing your own turbo kit. Anything I would tell you I would simply be repeating out of that book.
the most famous and important thing to say when boosting a car
 

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Kampfbereit
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thahnic1080 said:
the most famous and important thing to say when boosting a car
It's sort of like going to grade school. There are certain things you just have to know before entering into anything in life. If you engineer your own turbo kit you can't just take advice from other people on the forum because what's good enough for the gander won't be what is best for the goose. Properly selecting a turbo size is an aspect of tuning that can totally change how your car performs at a given boost level.
 

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Discussion Starter · #9 ·
Well i mean i have a fairly good grasp of how to read a compressor map (afaik), though my problem isn't with choosing the correct compressor so much as choosing the correct turbine housing, which garrett offers no maps for (well only for the BB turbos).

From what I've picked up, choosing turbine housing is a guess and test kind of thing. I mean thats what even Max Boost says.

Selecting what appears to be a logical starting point for an A/R is one thing, but actually getting the right one is yet another. Trial and error is usually necessary. A reasonable choice can be judged by the numbers, or to some extent by performance and response. Judging by the numbers requires measurement of exhaust manifold pressire, or turbine inlet pressure, and comparison with boost pressure.
And then he goes and discusses the pros/cons of divided-flange inlets. I will most definetly have my work cut out for me though. I'm going to have to delve a little deeper into this whole turbine aspect. Iirc, its not quite as easy as choosing a correct compressor since there are quite a few more variables to work with. Learning has never been more fun (rather learn about thermodynamics through having to choose the correct housing, than sit in class). :D
 

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Discussion Starter · #10 · (Edited)
Ok I think I've found my answer:
Unfortunately there is no easy scientific method for selecting the proper A/R ratio. Seat-of-the-pants feel is important: If boost rise is sluggish, the ratio is too large. In extreme cases, the ratio gets so big the turbo can't turn fast enough to produce the required boost. But if the ratio is too small, the turbo gets into boost so quickly that the vehicle becomes almost undriveable--and on top, it will feel like a choked-up normally aspirated engine that's under-carbureted. Also, what equates to a low or high A/R ratio varies by turbine series and engine displacement. Assuming the ubiquitous TO4-style turbo on a typical 350ci engine, Innovative offers these A/R guidelines as a starting point, based on where you want the turbo to work best:

Operating Range; A/R Ratio
Low-end; 0.58
Midrange; 0.69-0.81
High-rpm; 0.96

The accompanying Turbonetics table lists its baseline recommendations for a variety of engine displacements.



Given an equivalent turbine trim and A/R ratio, as engine displacement increases, the operating rpm range characteristics of the turbine decrease. Then there's also the heat the unit will see from the engine and exhaust gases, which change the unit's efficiency curve. Wastegate location and design also affects the turbine's performance. The interrelationship of all these factors is extremely complex, so there are no simple selection maps for turbines like those available for compressors. Even for experienced turbo installers, it often boils down to trial-and-error--kind of like trying several different size carbs on a normally aspirated motor. About the best advice we can give is that once you've settled on the compressor, consult your favorite turbo dealer for advice on mating it to a turbine housing that's best suited for your application's needs.
.58 it is.
 

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Kampfbereit
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Jetblackness said:
Thanks.
I swear, one of these days I'm going to get a tat with the words GOOGLE4EVA! across chest. :twothumb:
If it is not on Google, it does not exist.

But yeah, turbo design is a lot of trial and error. The prototype V6 kit that is on LunarEclipses car really is not anything like the production V6 kit that you see Ryu raping faces with today. A lot of money was put into this stuff and I still get a lot of people asking for turbo specifications on the kits that I sell.
 

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Discussion Starter · #14 ·
Tearstone said:
If it is not on Google, it does not exist.

But yeah, turbo design is a lot of trial and error. The prototype V6 kit that is on LunarEclipses car really is not anything like the production V6 kit that you see Ryu raping faces with today. A lot of money was put into this stuff and I still get a lot of people asking for turbo specifications on the kits that I sell.
Very true. It seems like there are no two kits that exactly alike. Which makes sense since everyone has diffrent goals. Where as Rulez/OrlandoGT are both looking to make Ferrari owners weep like little Russian Ballerinas trying to perform to Rostropovich's 5th Symphony wearing high heels, I'm looking to pick on Saturns, and Geos (my current competition doesn't even involve mobile vehicles).
 

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Kampfbereit
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Jetblackness said:
Very true. It seems like there are no two kits that exactly alike. Which makes sense since everyone has diffrent goals. Where as Rulez/OrlandoGT are both looking to make Ferrari owners weep like little Russian Ballerinas trying to perform to Rostropovich's 5th Symphony wearing high heels, I'm looking to pick on Saturns, and Geos (my current competition doesn't even involve mobile vehicles).
I think all of us Turbocharged cars here in Orlando are looking to make Ferrari owners weep. Let's see we got... Tearstone, Rulez, OrlandoGT, Dave, Jayhawk785, Warsheep. We are all running nearly the same xtech kits. I'm building up a block as soon as we are done with Mike's car.

Also, can't forget about the fastest N/A 4cyl 3G, 3GwithVolks, working on his turbo setup as well.

Then over in Tampa, we have Donny's RS & Galant ES, DFAGod's GS and Ryu all boostin'. As soon as Ryu's car is done this next time around we are expecting some pretty decent numbers on the dyno and the track. Keep on the lookout for that.
 

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Discussion Starter · #16 ·
Tearstone said:
I think all of us Turbocharged cars here in Orlando are looking to make Ferrari owners weep. Let's see we got... Tearstone, Rulez, OrlandoGT, Dave, Jayhawk785, Warsheep. We are all running nearly the same xtech kits. I'm building up a block as soon as we are done with Mike's car.

Also, can't forget about the fastest N/A 4cyl 3G, 3GwithVolks, working on his turbo setup as well.

Then over in Tampa, we have Donny's RS & Galant ES, DFAGod's GS and Ryu all boostin'. As soon as Ryu's car is done this next time around we are expecting some pretty decent numbers on the dyno and the track. Keep on the lookout for that.

Damn you FL guys really push the envelope. Man the day a kill story is posted up on the DSM boards with the title "OMFGBBQ I jsut got PWNED by a 3G" is the day I break out the champagne glasses. :D

BTW I can't really explain how anxious I am to see the results of such a built bottom end. Its like the VR4 6g72 on a steroid binge that would make Barry Bonds jealous. 400, 500 whp? Bah, try 700+ with a proper head setup (no need for modesty, you know its true). :D
 

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Jetblackness said:
Damn you FL guys really push the envelope. Man the day a kill story is posted up on the DSM boards with the title "OMFGBBQ I jsut got PWNED by a 3G" is the day I break out the champagne glasses. :D

BTW I can't really explain how anxious I am to see the results of such a built bottom end. Its like the VR4 6g72 on a steroid binge that would make Barry Bonds jealous. 400, 500 whp? Bah, try 700+ with a proper head setup (no need for modesty, you know its true). :D
Believe me, I've pwn3d plenty of DSMs myself, no way in hell would they post that up but we do get a shitload of respect from them here in Orlando. Actually those guys always hang out with us on the corner.

We are hoping to see 600whp, but if it makes 700whp then that will be awesome :)
 

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10 Turbo Traits

Provided by http://www.conleyracing.com

1. COKING of turbo bearings

Coking does happen but can be easily avoided. Idling the engine a few minutes before turning it off reduces turbo housing temperature which in-turn reduces oil temperature. Also using a good synthetic oil significantly reduces the coking potential.



2. THE BIGGER THE COMPRESSOR WHEEL

· Produces more air to the engine per engine rpm

· Provides more horsepower potential but less low end torque

· Results in slower spool-up and increased turbo lag

· Requires a higher stall converter



3. THE SMALLER THE COMPRESSOR WHEEL

· Produces less air to the engine per engine rpm

· Provides less horsepower potential but provides more low end torque

· Results in faster spool-up and decreased turbo lag

· Requires a lower stall converter

4. THE BIGGER THE TURBINE WHEEL

· Produces less air to the engine per engine rpm

· Provides more horsepower potential due to reduced back pressure but provides less low end torque

· Results in slower spool-up and increased turbo lag

· Requires a higher stall converter

5. THE SMALLER THE TURBINE WHEEL

· Produces less air to the engine per engine rpm

· Provides less horsepower potential but provides more low end torque

· Results in faster spool-up and decreased turbo lag

· Requires a lower stall converter

6. THE BIGGER THE TURBINE WHEEL

· Produces less air to the engine per engine rpm

· Provides more horsepower potential due to reduced back pressure but provides less low end torque

· Results in slower spool-up and increased turbo lag

· Requires a higher stall converter



7. THE BIGGER THE COMPRESSOR HOUSING A/R

· Produces more air to the engine per engine rpm

· Provides more horsepower potential but less low end torque

· Results in slower spool-up and increased turbo lag

· Requires a higher stall converter



8. THE SMALLER THE COMPRESSOR HOUSING A/R

· Produces less air to the engine per engine rpm

· Provides less horsepower potential but more low end torque

· Results in faster spool-up and decreased turbo lag

· Requires a lower stall converter

9. THE BIGGER THE TURBINE HOUSING A/R

· Produces more air to the engine per engine rpm

· Provides more horsepower potential but less low end torque

· Results in slower spool-up and increased turbo lag

· Requires a higher stall converter

10. THE SMALLER THE TURBINE HOUSING A/R

· Produces less air to the engine per engine rpm

· Provides less horsepower potential but more low end torque

· Results in faster spool-up and decreased turbo lag

· Requires a lower stall converter
 

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My luvly manly lump!
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Ohhh crap. You guys rock! That's an excellent catch of info, Jetblackness. Thinking about turbo upgrade options myself, I sometimes think that the .48 I have is sufficient for what I'm doing. But after months of driving it rather untuned, I notice that I spool at a very low RPM of about 2400-2700 on a stock engine in 3rd. No joke! That's hardly nothing, and IMO, we really don't need as much wheelspin from premature boost anyway. Not something pretty nor useful on a FWD car since we really can only dream of launching on twos :p

Not to mention our stock differentials and axles.

Anyhow, I've got a lightened flywheel, and I'm extremely pleased at how the RPMs shoot up so quickly (I'd assess a 50% reduction in response time/lag from stock). The .63A/R turbine wheel that Russ offers seems to provide more than enough cushion for the amount of displacement we can safely bore out to. However, given the amount of airflow that could be had from upgrading to a 65mm+ T/B (bored-out 6G74 or aftermarket with modified intake mani plenum) and something like a MAF-T makes me wonder.

Thinking about it, Russ... dude, I've been waiting way too long for this engine to be put in. I've taken care of absolutely EVERYTHING I need to set this swap up way beforehand. I'll let you know how it went, or give you a call if we encounter any issues :D

Oh... and for everyone's pleasure, I'll see if I can dismantle the turbo this weekend too, to see if I really need to rebuild the sucker.
 
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