Hi,
I have narrowed my turbo size options down to a few but I am haveing trouble deciding between them. Im going to go with a garrett T3/T4 but i can decide between:

57 trim .63 A/R
57 trim .48 A/R
46 trim .48 A/R

My motor is all stock and im looking at running 10psi boost. I would like fairly fast spool up but enough top end to not be too disappointed. I don't plan on reving past 7500 rpm regularly anyway and im looking to make around 250 to 300 whp.

Thanks for the help

 

from my understanding / research etc etc... i am new at this whole turbo thing myself so for whatever this is worth but 90% of people say no matter what get the .63ar with any trim....

just my 2 cents from what I've read (not experienced myself) 57trim .63ar would be the way to go for an LS.

my motor will spin to 8000-8500rpms so ill be going with a Garrett 60trim .63ar on 10lbs shooting for 275-325whp (lsvtec gsr girdle etc/arp rod bolts & shot peened rods)

don't flame people.. im just jumpin in the conversation.. that's why i made it clear i have no personal experience with turbo applications

 

Yea after reading a bit I am leaning that way as well. Most of the setups I have see are also running .63 A/R. Maybe i should look at 60 trim as well..
Is it the higher the trim the faster the spool but lower top end? Should I be looking at a 60 trim since I am not reving past 7500 rpm. or will 57 trim do the job?

 

50 trim t3t4 .48 if you want quick spool .63 if you want more up top

 

run the 57 or 60 trim

 

agreed this seems to be the near ideal unless you get into custom turbo sizing.

 

Get a simple 57 trim .63ar for now. You need to do more research...it's fairly obvious judging by your post. I'm not going to go into details on that, but one little thing you need to realize is that you dont have to limit yourself to running 10psi or whichever arbitrary number you choose. As long as your turbo is efficient at that pressure, your fuel can support the power and the engine can handle that power, you can run as much boost as you want. It's power that kills engines...

 

I have been reading for a year now and this is my second turbo setup. First one worked for a bit but I have learned a little more and im going to fix th things i failed on before. The problem is i read some things and its easy to understand the theory but when you try to think about it practically it gets confusing.

Anyway from what you have said about making sure my turbo is efficient at a pressure. Is this what helps determine my trim. So since I am looking for efficiency at low boost pressure and high flow...i am looking for a lower trim. I may be completly wrong about this in which case I will just stick to what you said.

I understnad what you are saying about boost just being boost but I am trying to use it to gauge how much power my car can handle in its condition and I have heard from experience that it is safe at around 10 psi. I know no other way of figuring this out until i dyno it though.

I have found a 54 trim .63 A/R...what do you think about that..can you give me an idea of what the characteristics of this will be like.

MY last question is do you think i should use a thicker than stock head gasket to lower my CR. what will this do for driving while not boosting? lower my power?

I know this is alot but i appreciate your help. I am learning alot for this.

thanks

 

x2

 

the 54 trim would work pretty decently if it was cheap and in good shape id say go for it it can flow enough for high 400whp at high boost

you guys got something against the 50 trim?
it has a much better compressor map than the 57 trim

 

i also have a b18b.. would you say a t3/t4 .57 with .48 a/r would be any good JUST for street use? or is it way to big? mid range power?

sorry to hijack.. just its related to your topic

 

with the .48 it would be ideal for daily driving type of street use it would spool by 4000-4500 max with that smaller hotside so it would have good midrange and hold it through the topend
if you mean the other type of street use as in racing no it wouldn't be ideal

 

so it would be fully spooled up by 4500 max you think? i've been seeing lots of .63 or .60 hotsides.

would it hold through up to redline? *stock* or would it feel weak?
daily driving use as in having fun around corners and on ramps. not street racing at all never

 

Okay I have decided to look at some compressor maps and I think your right the 50 trim looks better even the 45 trim. Im just worried that there is a reason people dont commonly use them. What do you guys think?

 

alright, ive had the 57 trim with both .63 and .48 exhaust a/r's on ls motors on 10 psi making 250whp.


get the .48 a/r which is very contrary to whats being said. the .48 hit full spool around 3800 and had no problems pulling nicely to 7000rpms. it was instant on and always there. loved it. ( actually ive got that turbo on my built gsr temporarily. boost is right there it feels like a stock motor with that power)


when i had the .63 ar it wouldnt see 10 psi until around 4500-4800, but didnt really feel like it took off until 5000 rpms. this setup only lost around 10ft/lbs from peak tq to redline of 7400.


i feel the .48 and its associated powerband very well fit a car that gets driven wherever i go and the ls transmission that i had bolted in it.

 

Although i normally disagree with running a .48ar turbine on a honda, it should work well on an LS. If you ever plan to swap a VTEC head, i would suggest running a .63ar immediately. The .48ar tends to run out of breath on a better breathing VTEC engine

 

Thanks guys that helps alot! Having you describe your experiences really helps in deciding what kind of experience i want to have on my setup.

what do you guys think about trim? how does that seem to affect the ride?

 

agreed.

the .48 feels bitchin at 5000 rpms on my 2.0L vtec, and it feels like a stock single cam at 7500 rpms lol.

 

For the power you're hoping to make, i would still suggest a 57 trim, but in a .48ar if you're primarily concerned with spool time. If you want to get a little fancy and the best of both worlds, PM TheShodan about the GT3251e. It's a good mix of the best characteristics of the 57 trim and the fast spooling ability of a smaller unit...plus it's more efficient at lower pressures. It is a bit more expensive, but IMO it's totally worth it.

Another option would be a T3/T04e 50 trim .63ar. It would still be a quick spooler, but with the .63ar turbine housing, it should give you power through redline. With this turbo, you're going to need an aftermarket MAP sensor to make the power you want. You'll probably need to push it to ~12-14psi on an LS to get 300whp out of it; however, you'll have an awesome street setup

 

Actually i was just looking at a compressor map for that setup and was trying to figure out what it means on my car. Sounds like something im interested in. Are you saying that I would need to push more psi compared to the 57 trim .63 A/R? If so, Why? beacuse it flows less? or do you jsut mean in general for those power goals i will need to run that much?

last question is do you think this is a safe reliable setup: t3/t04e 50trim .63 A/R, ~300whp, ~12-14 psi, STOCK LS?

Thanks guys you really helped out alot and I feel like i understand alot more (weather i do or not)...really appreciate it!

 

going out to buy my turbo tomorrow. just wanted to make sure what I think is along the right lines..

 

Yes, the 50 trim flows less than the 57 at the same pressure ratio given the same conditions. The important thing to know about turbo setups is that power creation and gross air flow are the two things that wreck engines. The PR (pressure ratio aka boost pressure) don't have an impact. As long as your turbo is efficient at 12-14psi (which it is) and you have sufficient fuel to support your power goal, you'll be fine.

I wouldnt rush the turbo choice. If you still have questions, hold off on buying a turbo for a few days. There are great options out there that you may be overlooking. Give it a few more day's worth of thought and then buy something with confidence

 

Okay fair enough. I would like to do some more research. What things do you think I have overlooked that I should look into that may help me make a good decision?

 

I just hate to see people make hasty decisions. What is your price range for this turbo? Which characteristics are MOST important to you? Honestly, i'm not sure which is the best one to suggest for you and i want to make sure we're giving you the right answers

 

from what i have read I think were on the right track. What is most important to me is making use of my power band that I have right now with my stock ls. That means I would like to have "fairly" fast spool up as I cannot handle too much past redline. But at the same time I beleive something like a .48 A/R will spool way too fast and I will be wasting alot of fuel at times that I don't intend on boosting. I feel the .63 A/R will give me what I am looking for and with the 50 trim it will start flowing a bit sooner.

I guess I am looking for a street car that has good power and is fun to drive and can haul *** when I want it to. (Im not going to be flooring it on the regular but in the case that I do I want it to pull and hold). Reliability is very important to me as well.

Hopefully this makes sense but thats the best explanation of what im going to be doing with it.

Appreciate your time bro