i need help choosing a WASTEGATE!
 

hey guys i need help choosing a wastegate size. the turbo ill be using is a Borg Warner s362. the specs for the turbo are as follows:
-Compressor wheel Ind. 63mm extended tip
-Turbine wheel 71mm
-.88 turbine a/r
-Flows upto 67lbs/min
-Supports upto 675-700hp
-included: T4 mounting gasket and oil drain gasket
-SINGLE ENTRY INLET T4 FLANGE
-Supports up to 675-700hp

I only want around 350-380rwhp and was told that i could achieve those numbers at around 12-14psi when tuned on a microtech and stock port...

with that said; what TiAL wastegate would you guys recommend?

ive tried to read and understand a bit on how a wastegate works and what i hear is that if your running a big turbo with low boost than u need a big wg... im just not sure if my turbo is considered BIG or SMALL and if 12-14psi is low for this turbo.

I run a 44mm Tial on my 35r setup.

44

Is there no way for you to run a divided turbo manifold and twin scroll turbine housing? You're basically giving up free spool. Rotaries love twin scroll. There's a reason why Mazda used a fully divided twin scroll setup from the factory for 89-91 turbo models.

TiAL 44 will be fine if routed properly. If his turbo is not running a divided housing he can still run a divided manifold with minimal loss. Ideal? No. Noticeable? A little bit. The plus side is it will have the potential to make a bit more power with the slightly larger (in volume) A/r than the divided housing of equal size, Noticeable? Again, a little bit and not worth choosing a divided housing IMO. As a example, We compared two 20B cars we did here once one with a divided housing one without. we were surprised how little difference there was overall. On that comparison we thought for sure the divided housing was going to be a noticeable hinderance and it proved to be only a minor difference.

I ask cause the manifold I have is undivided and has a flange for a 38mm wg. It seems that a 44mm is most recommended here and by my mechanic. I vaugly understand how to choose a proper wg but wanted to know if I could get by with a 38mm since I won't have to modify the flange. I can also buy a 38mm to 44mm conversion flange but wouldn't that still "choke" it a bit? Or would a 44mm still act like a 44mm regardless of the smaller flange?

38mm is too small. Cut off the flange and weld on a 44mm,a adapter flange is pointless.

my mechanic is selling SS divided manifolds with 44mm TiAL flanges for 750... i didnt want to but looks like i will be buying it if thats the case. i guess i would benefit from having a 44mm... did you also mention that theres benefits to be had for running a divided manifold even if the turbo isnt? i guess thats another plus right?

or if anyone knows someone sellinga t4 manifold with a 44mm or bigger flange let me know lol

Why not just do this??

cause the whole arm leading up to the flange is smaller than the opening to a TiAL 44mm. in that case, wouldnt i have to get the whole arm cut off to replace it with an arm with a bigger radios and 44mm flange just so it can flow the way it should?

take a look. i feel like theres no easy way to do it. :scratch:
http://img.photobucket.com/albums/v3...0/IMG_1122.jpg
http://img.photobucket.com/albums/v3...0/IMG_1124.jpg
http://img.photobucket.com/albums/v3...0/IMG_1126.jpg
http://img.photobucket.com/albums/v3...0/IMG_1127.jpg

That, is a poorly designed manifold. With the wastegate runner at 90 degrees to the primary runners, you're going to have boost control issues regardless of the size of wastegate.

f*ck sh*t d*mn b*lls... uhhh looks like im going to be shelling out 750 for my mechanic's manifolds than :(

aaron, the one i have is considered a short runner? if my mechanic's is a long runner, are there positives and negatives to either? can anyone elaborate? since my search on that answer in other threads usually seem to turn into arguments between two sides ;/

There is arguments because neither answer is the wrong answer. There isn't a wrong answer. They each have pros and cons, same as equal and unequal.

well im looking for a "streetable" car and im more into autocross than dragging so response is definitely priority.

i read that short runners like the one i have are typically more responsive where long runners can net you higher power levels. i know my mechanic's long runner is divided so maybe it can still help spool? wouldnt you think so? sorry for noob questions lol

Being divided will help and it's more complicated than just short will do X and long will do Y, there is number and type bends involved along with tube diameter, size of turbine and turbine housing etc. Usually on here people are comparing their apples with your oranges and it gives you a peach for a result.

the new tial MVs gates are awesome, so small physically

and as stated the gate priority on that manifold is less than ideal

i did end up dropping the doe for my mechanic's manifold.. but im still curious to why the one i have isnt ideal? cause i may still want to put it on another less serious set up or is it not a manifold you would recommend using at all? thanks

Did you not see my post? The wastegate runner exists at 90 degrees to the runners. This does not encourage flow into the wastegate, making boost control poor.