I am debating going to a lower a/r housing on my pte 5862 or going with a twin scroll and quick spool valve. Does lowering the a/r really kill power potential? I can only think of one guy on here that runs the QSV and hopefully he chimes in.

Basic question: if I lower my a/r could I still hit 600 horse with better spool?

 

I got an idea make your own mind up

 

I don't know enough about a/r to make a decision right now. I don't wanna spend $1000 on a new twin scroll housing and QSV and come to find out I could still hit my goal with a lower a\r

 

what aspect ratio is the current turbo

 

I wanna say .63 because I remember there were 3 choices and I chose the middle one. It's a t4 flange

 

They were just talking about this in ARM's group. You'd have better luck posting in there.

 

Keeping the 5862? Just a larger AR with qsv?

 

you need to get everything lined out before you make knee jerk decisions your not even close to having the car 100% that could change things with the current snail setup

 

agree. do you have a 3" downpipe yet nick?

 

Your lower a/r will help spool but i wouldnt go lower than a .63 on that turbo. Too much backpressure going to put too much stress on the seals. If you are trying to make 600whp i dont know if youre gonna do that on a 58mm wheel. Sure the larger turbine will help but i dont know if it will help that much. Although i dont know the comp map (because there isnt one) of said wheel. If you want quicker spool i would switch to a 58mm turbine with the .63 housing. But that definitely wont get you 600whp. Really 500whp is that line where you have to sacrifice spool time for the desired power level as most "stg3" turbine wheels are 57-58mm and wont support much over 500 and going to a "stg5" turbine wheel which is usually in the 62mm range is going to add about 400-600rpm to spool time

I honestly didnt know much about the qsv until i read what paul wrote on arm's page. Im definitely gonna look more into it and may size up myself and run a qsv.

 

Too many changes to your build will delay finish, I would get it up and running first, if spool is awesome and making the power you need then I wouldnt invest in the qsv.

once you come around to wanting a bigger turbo then I would look at qsv

 

Thanks for the advice all. I'm going to continue hunting this spool issue. Has to be a bug somewhere because on 15psi everything was dandy. Full 3" fab pipe came in today so time to get busy