is a .63 A/R too large for the turbine side

[chromejunks]

just got  a worn out 91 jetta n/a with 300k on it. i have the engine and tranny out completely rebuilding both. planning on converting to turbo i have already set the block up and machined it for the factory oil squirters etc.

now the first question you guys that are running the arp studs i understand that they are 5.400 long. how much of the stud comes through the washer and nut? I was wondering how much to long a 5.750 stud would be. if that is not too long or if i can machine the block threads deeper could run a stud from a cummins kit only difference is that you could get them in their custom age 625 material. that is what we have gone to on the dodges with o-ring holding 125 psi and 1050hp to the wheels diesel only. just thought it might be an option.

the real question is a .63 A/R too large lets say stage 1 wheel or would it be better to run a .48 A/R with a stage 2 or 3 wheel? looking at some sort of t3 or t3/4  ball bearing charger just trying to some hot side sizes that have worked for the street.


one more idea does anyone here have a contact with any of the replacement head manufactures. if so you might see if they could thicken up the deck of the head. that way when aftermarket studs are used and the clamping loads are increased we don't distort the deck if the head after all it is aluminum.

[andy2]

I would stick to a .48 turbine and the smallest t4 compressor (57 trim) when looking for a t3/t4 for a single turbo .Anything bigger and it will be useless for daily driving.You would likely be better off with a big T3 but I don't really know.Depends on what you will be using this car for?

You might be ok with the head when using a big single turbo as the torque will likely be kept lower and keep the head from flexing.

[Baixo]

i dont believe that a large t3 will be better then a small t3/t4.

i think a good quality ball bearing .48 a/r t3/t4 will work well.....

people will talk about lag and such, but there are ways to minmize....such as

a good head port and polish

2" ic piping

3" exhuast (or bigger) from the turbo back...

happy boosting

[AudiVWguy]

Try Top Line Automotive.
800-441-1400
404-699-6025    Atlanta, GA

http://www.toplineauto.com/index.asp

[chromejunks]

thanks guys for the info.
 
does anyone on the board have swirl numbers from a stock unported head? and how bad has the swirl dropped as the flow has increased?

still building the fixture to get mine on the flowbench and test i will post results when i get the head on the bench.