bigsnorlax

Plan on boosting the f22a sometime soon. What do you guys think would be a better STREET turbo.

T3/T4 50 trim .63AR
or
T3/T4 60 trim .48AR

They both offer the .48AR and 63AR so would a different combination be better?

How will a smaller trim with a larger AR spool and perform up top as compared to a larger trim with a smaller AR?

I dont want something too small that starts too fall way before my redline (8k) but still be very streetable and perform well lower in my RPM range. Is that going to be possible with either? These two options just kind of confuse me as to how they would compare to eachother.

Goal i guess would be around 350hp. This is going into a sleeved and built block. I understand i could always go larger and make more and more power but for me... even 350 would be satisfying and probly damn UNstreetable :D

bigsnorlax

meh? Iv seen this post a few times on VW forums and it always ends in some dumb debate and never seems to get a good answer. Any boost experts/gurus lurking nearby?

W!d3b0dYr3X

The larger the trim paired with smaller a/r will spool faster and vice versa. People sling the word trim around like it determines the size of the turbo or the size of the wheels when in fact it has nothing to do with either. Trim is found by taking the inducer and dividing it by the exducer then multiply by 100. So theoretically the turbo could have multiple trims. One for the compressor wheel and one for the exhaust. Usually it only refers to the compressor wheel tho. The inducer is the small part of the wheel where air enters and the exducer is the largest part of the wheel where the air enters the compredsor housing. Therefore trim is the angle of the blades themselves. As trim or the angle increases the wheel can support more mass flow. With that said the two turbos u list would prob be pretty close to the same except the curve of power on the 50 trim would be lower than the 60 since it will flow more uptop. I would say it would be better to look into a. 63ar 60 trim for your goals

ashb82

both those turbos will fall off fast on a f22a. I know i have used a 57trim with ar.62 exhaust on my f22a. i stop making power at 6500 rpms and it fell off fast. i use a hx35/40 and make power all the way to redline of 8000rpm.I have full boost by 4000rpms with 12cm exhaust. with a 18cm housing i have full boost by 5500rpms. I have learned from trial and error a f22 falls off fast when you choke up the exaust.

bigsnorlax

Oh wow. Very informative. I guess iv been reading wrong or there is just a lot of misinformation on the internet (go figure).

But thanks! i guess i will go the 60 trim with the .63ar. I was just worried it would be too large for my goals.

W!d3b0dYr3X

It depends on where u look for ur info. And it will also depend on the size of your wheels the larger the wheel the more airflow it will support. For example my friend has a to4e which is 60 trim and 61mm wheel I think? And it can handle up to 600 hp. I had a small t3t4 that was 60 trim with a 50 mm wheel and was only good for around 275 to 300

bigsnorlax

can you tell me more about this turbo? Thanks for the info again guys. I just want to make sure i do this right and build something satisfying