# opinions on turbo sizing for my built ABA 2L



## Eganx (Apr 30, 2004)

I'll be buying turbo for my project here shortly. the engine is a fresh 2L bottom end(block is O-ringed) with a aba head(P&P, oversized valves etc.). I'll be running a 38mm external wastegate, a SRI, VR6 throttle body, 3" exhaust etc etc. so most everything is modified quite a bit. I'm looking at the T3/T4E 50 trim with a .48 AR and planning on running 10-15 psi through break in of the motor and street driving, and then running up to 30 psi at the track. the bottom end is balanced quite well, and with the top end I have I'm expecting to spin up to 7500RPM. so, with all this said, could I go a little larger to a 57 trim and up to a .63 AR, or will that be too much? any opinions on turbo size are welcome. thanks - Egan


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## Jay-Bee (Sep 22, 2007)

*FV-QR*

I think you are right on with the T3/T4e, might want to look at some compressor maps to see if 57 or 50 trim suits you better, also I would stick to the .48ar on a 2.0T that's what I am gonna be running, but that might not breathe the best up at 7500. 
57 trim .63ar sounds ideal.


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## 2pt. slo (Jan 4, 2004)

*Re: FV-QR (Jay-Bee)*


_Quote, originally posted by *Jay-Bee* »_
57 trim .63ar sounds ideal.


love mine. my motor might be a bit more built or if not the same motor almost with that turbo. check my sig.


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## bobsled (Aug 25, 2006)

*Re: FV-QR (2pt. slo)*

my 57 trim .48ar is wild. its a slug til 3500 then jumps to 7k in a heartbeat. traction is an issue haha. honestly kinda wish i went with something smaller for my dd


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## Eganx (Apr 30, 2004)

*Re: FV-QR (2pt. slo)*


_Quote, originally posted by *2pt. slo* »_

love mine. my motor might be a bit more built or if not the same motor almost with that turbo. check my sig.

what RPM are you seeing 10 psi at? 
about reading compressor maps, I'm gonna have to sit down and do the math for my motor to be able to apply it to a map. I just wanted to see what people with some experience thought


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## CTS Turbo (Oct 2, 2008)

*Re: FV-QR (Eganx)*

I'd go with a T3T4E 50trim 63ar, the 57trims tend to have some surging issues. Or if you wanted to go with something a bit more spendy a GT3076R with a 63ar.
http://****************.com/smile/emthup.gif


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## Daskoupe (Oct 9, 2006)

*Re: FV-QR (Clay @ CTS Turbo)*

t3/t04e here.
exhaust is .63 ar and the comp. is .60
I see full spool around 5k and rev all the way to 6700,
The larger housing is laggy but hell you can stay outta boost for the mpg


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## 2pt. slo (Jan 4, 2004)

*Re: FV-QR (Clay @ CTS Turbo)*


_Quote, originally posted by *Clay @ CTS Turbo* »_I'd go with a T3T4E 50trim 63ar, the 57trims tend to have some surging issues. Or if you wanted to go with something a bit more spendy a GT3076R with a 63ar.
http://****************.com/smile/emthup.gif 

mine has no surging issues. i also see full boost at 3500-3800


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## Jefnes3 (Aug 17, 2001)

*Re: FV-QR (2pt. slo)*

look at 46 Trim TO4e compressor. It can support 350whp
the 50 trim is VERY good wheel. (better that a 57 in my opinion)
But for ~30psi use consider the GT30. The newer wheel is better suited to this 'high' pressure.
for decent power up to 7500rpm def. use .63 housing. (even try an .82)
the .82 will give you a softer spool and superior top end. (reduction of transmission shock)
I hope you plan to run a 'big' cam, like 270-276, or the head won't breathe well beyond 6-6500.

Suggestion: pick a compressor that can support your power goals, don't oversize it for 'room to grow'. Properly sized compressor will allow you to go a bit bigger on the turbine side and give you great top end.

-Jeffrey Atwood



_Modified by Jefnes3 at 11:08 AM 11-17-2008_


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## 84_GLI_coupe (Apr 3, 2001)

*Re: FV-QR (2pt. slo)*


_Quote, originally posted by *2pt. slo* »_
mine has no surging issues. i also see full boost at 3500-3800

That only happens at the high boost region of the compressor map.
Clay, why a GT3076R and not a GT3071R? I thought I had it all figured out for a 3071R with T3 0.63 a/r turbine housing.


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## Jefnes3 (Aug 17, 2001)

*Re: FV-QR (84_GLI_coupe)*


_Quote, originally posted by *84_GLI_coupe* »_

Clay, why a GT3076R and not a GT3071R? ( 


Typical 3071 come with T25 turbine housing, not T3.
typical = as Garrett makes them.
-Jeff


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## RedDevil (Sep 21, 2001)

*Re: FV-QR (84_GLI_coupe)*


_Quote, originally posted by *84_GLI_coupe* »_
That only happens at the high boost region of the compressor map.
Clay, why a GT3076R and not a GT3071R? I thought I had it all figured out for a 3071R with T3 0.63 a/r turbine housing.









Personally I think GT3071R is too big for 2L motor unless you're shooting for 30PSI and getting full boost at 6K RPM.
I have quickly plotted how that would look on GT3071R map.
Far right points are your MAX RPM which I estimated to be 6500
left are half way to the redline about 3250RPM, which is arbitrary point which depends on the A/R selected. VE = 0.8 
This should give you a rough idea how it looks. 












_Modified by RedDevil at 11:09 PM 11-18-2008_


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## Jay-Bee (Sep 22, 2007)

*Re: FV-QR (Clay @ CTS Turbo)*


_Quote, originally posted by *Clay @ CTS Turbo* »_the 57trims tend to have some surging issues.

I have spoke with 2 different people running this turbo w/ int. wastegate on MK4 AEG 2.0s and reported no surging issues. Vdubbugman is close to 300whp too.
http://****************.com/smile/emthup.gif
But all in all I think a T3Super60 is more suited for me right now.


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## 84_GLI_coupe (Apr 3, 2001)

*Re: FV-QR (Jefnes3)*


_Quote, originally posted by *Jefnes3* »_
Typical 3071 come with T25 turbine housing, not T3.
typical = as Garrett makes them.
-Jeff

Only the internal gated ones from what I've seen.


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## Eganx (Apr 30, 2004)

*Re: FV-QR (RedDevil)*


_Quote, originally posted by *RedDevil* »_
Personally I think GT3071R is too big for 2L motor unless you're shooting for 30PSI and getting full boost at 6K RPM.
I have quickly plotted how that would look on GT3071R map.
Far right points are your MAX RPM which I estimated to be 6500
left are half way to the redline about 3250RPM, which is arbitrary point which depends on the A/R selected. VE = 0.8 
This should give you a rough idea how it looks. 










RedDevil, your IMG didn't work for me, I'd like to see it though
I looked at the maps after doing the math for my motor, and a 50 trim looks like it would work well, but the GT3071R looked perfect(assuming I am using the correct info to plot with). but I don't have the $$$ to spend on it








so if I run a T3/T4 50 trim with a .63 AR turbine housing will I be able to reach around 30 PSI at 6000RPMs?


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## 84_GLI_coupe (Apr 3, 2001)

*Re: FV-QR (RedDevil)*


_Quote, originally posted by *RedDevil* »_
Personally I think GT3071R is too big for 2L motor unless you're shooting for 30PSI and getting full boost at 6K RPM.
I have quickly plotted how that would look on GT3071R map.
Far right points are your MAX RPM which I estimated to be 6500
left are half way to the redline about 3250RPM, which is arbitrary point which depends on the A/R selected. VE = 0.8 
This should give you a rough idea how it looks. 









Stock head and cam, and you'd still be spooling well before 4000rpm on a 0.63 a/r T3 sized turbine. A 0.48 a/r T3 turbine housing, on a bushing turbo, is building boost by ~2500rpm. 0.63 a/r isn't that much later, especially with a ball bearing center cartridge.
I've looked at maps too, and helped with GT2860RS and GT2871R builds on 1.8L Honda/Nissan engines. Very nice and smooth turbos, but the turbines are too small for my tastes and my goals. A GT28* would just work against everything else that I'm doing to my engine.
I'm not convinced that the curves on your map are correct. Ever gone to the turbo calculator at Squirrel Performance? It's been reasonably accurate when comparing to real cars on the dyno here.


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## 84_GLI_coupe (Apr 3, 2001)

*Re: FV-QR (Eganx)*


_Quote, originally posted by *Eganx* »_
so if I run a T3/T4 50 trim with a .63 AR turbine housing will I be able to reach around 30 PSI at 6000RPMs? 

If you have to ask that question, your engine will pop if you try.
The T04E compressor (as found on said 50 trim T3/T4) isn't really made for that high of boost at the relatively low airflows that our engines can consume. At 20-ish psi, it's just fine, but much more than that and it may try to surge.


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## Eganx (Apr 30, 2004)

*Re: FV-QR (84_GLI_coupe)*


_Quote, originally posted by *84_GLI_coupe* »_
If you have to ask that question, your engine will pop if you try.
The T04E compressor (as found on said 50 trim T3/T4) isn't really made for that high of boost at the relatively low airflows that our engines can consume. At 20-ish psi, it's just fine, but much more than that and it may try to surge.

why would me engine "pop"? so 30psi is not attainable with this compressor???? when I applied my info to the map it looked like it would work for my goals... I might not be calculating my info correctly. 


_Modified by Eganx at 9:47 PM 11-18-2008_


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## Eganx (Apr 30, 2004)

*Re: FV-QR (84_GLI_coupe)*

_Modified by Eganx at 8:32 PM 11-19-2008_


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## VdubyaVR6 (Mar 8, 2004)

*Re: FV-QR (Eganx)*

well i've never actually completely build a turbo motor but i'm in the process of building an aba16vt and i've been doing alot of researching so I could size my turbo properly for my goals and I like math (engineer..







). So here is a quick map I made for what your goals are.
I took my cfm's off of my 16vt so they might actually be a little high (I think I assumed a 90% VE to be safe though) and your PR should be right around 3.
My lowest cfm is at 5000 rpm or 2/3 of your max rpm which I think is where you want to be close to full boost if you have a properly sized turbo. And the upper end should be close to what you would flow if you assumed 85% VE like you said at 7500 rpm. So according to my compressor map you would be able to accomplish your goals. The only thing I see is that if you are able to get full boost around where my point is its in the least efficent part of the graph which would be harsh on the turbo.
Hopefully i've been of some kind of help for you... http://****************.com/smile/emthup.gif 
Here is my map...











_Modified by VdubyaVR6 at 11:04 PM 11-18-2008_


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## steve12345 (Jan 8, 2006)

Awesome tool here:
http://www.turbofast.com.au/turbomap.html
Just be realistic with your VE's and you can see exactly what compressor is best.


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## RedDevil (Sep 21, 2001)

*Re: FV-QR (Eganx)*


_Quote, originally posted by *Eganx* »_

RedDevil, your IMG didn't work for me, I'd like to see it though
I looked at the maps after doing the math for my motor, and a 50 trim looks like it would work well, but the GT3071R looked perfect(assuming I am using the correct info to plot with). but I don't have the $$$ to spend on it








so if I run a T3/T4 50 trim with a .63 AR turbine housing will I be able to reach around 30 PSI at 6000RPMs? 

Yes, with GT3071R You will be in the sweet spot at max boost but only close to your redline. But trying to run 30 psi with that turbo you will be hitting the surge almost all the way up to 6000RPM.


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## Jay-Bee (Sep 22, 2007)

*Re: FV-QR (Eganx)*


_Quote, originally posted by *Eganx* »_Will I be able to reach around 30 PSI at 6000RPMs?

Eganx, why don't you set yourself more of a power goal than just an expected PSI, as different PSI levels on different sized turbos can yield various power gains.


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## Eganx (Apr 30, 2004)

*Re: FV-QR (Jay-Bee)*


_Quote, originally posted by *Jay-Bee* »_
Eganx, why don't you set yourself more of a power goal than just an expected PSI, as different PSI levels on different sized turbos can yield various power gains.

if you put it that way, I'm shooting for over 300HP, maybe 325ish. this motor is built to handle the power and boost, so I'm trying to take advantage of it.


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## Jay-Bee (Sep 22, 2007)

*Re: FV-QR (Eganx)*


_Quote, originally posted by *Eganx* »_
if you put it that way, I'm shooting for over 300HP, maybe 325ish. this motor is built to handle the power and boost, so I'm trying to take advantage of it. 

You should be able to hit that with 23-25psi on a properly tuned setup with a nice turbo and everything else needed to support it.
http://****************.com/smile/emthup.gif


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## Eganx (Apr 30, 2004)

*Re: FV-QR (Jay-Bee)*

so a T3/T4 50 trim with a .63 AR should work for my goals then


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## GTijoejoe (Oct 6, 2001)

*Re: FV-QR (Eganx)*


_Quote, originally posted by *Eganx* »_so a T3/T4 50 trim with a .63 AR should work for my goals then

Yes!
.48 is just silly for hp and boost ratings so high for an ABA, it would hold you back.
My 57trim .63 gets 17-19psi by 42-4400.
Plus my 50trim .48 made MAD peak torque at 3.6k, no traction is NO FUN.


_Modified by GTijoejoe at 9:50 PM 11-20-2008_


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## bobsled (Aug 25, 2006)

*Re: FV-QR (GTijoejoe)*


_Quote, originally posted by *GTijoejoe* »_
Plus my 50trim .48 made MAD peak torque at 3.6k, no traction is NO FUN.

_Modified by GTijoejoe at 9:50 PM 11-20-2008_

im in the same situation right now... 1st and 2nd are pretty much a joke i have to creep through them even at only 7psi.


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## 20B_envy (Mar 16, 2006)

I'm building a 16vABAT and now I'm having doubts about the turbo I've got (t3/t04b "super s" .63). I'm looking for about 300whp...
I would imagine I wouldn't have any surge issues being that it's not that big of a turbo, but looking at the maps I'm teetering close to the surge line... maybe I'm inputting some of the wrong values .
plus I've never seen the super s trims anywhere... anybody got any ideas of what the compressor map would look like?


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