I recently purchased a sheepey built turbo kit for my b series an it came with turbo smart wastegate/blow off valve. I'm aiming to get 600+ horse power and was curious to know if I need to change the wastegate springs in it to hit that power number I'm getting tuned tomorrow an I know the waste gate came witha 7 psi spring which is not alot, is that gonna keep me from hitting my numbers? This is my first turbo build thanks

 

a 7psi spring isnt alot, but you have electronic boost control according to that pic. It looks like a 3port solenoid maybe. So you can go roughly 3x what spring is in the gate. However, youll start to lose resolution. Hitting you power goal really comes down is your engine and turbo setup make and handle that goal. You didnt really give any details.

i have a 8psi spring in mvs gate on a 4port solenoid btw

 

It's fully built sleeved block portflow head with full valve train bc stage 2 turbo cams built transmission sheepy built turbo kit precision 5858 ball bearing an yeah I have a 4 port hondata boost solenoid I'm Hopi g to hit some where around 600 to 650 is my goal

 

Well, the 5858 is going to be close to its maximum efficiency by about 600whp (depending upon dyno, but from my experience, 500-580whp is the sweet spot for that turbocharger), So you'll definitely need the larger 14psi spring even with a 3 port solenoid . So, you'd get best resolution at about 17.5 -20psi of boost pressure. But that won't make 600-650whp on that spring with that turbocharger.

If you have a Gen 4 wastegate (something older on their shelves) then finding a new additional spring might be tough to get, but luckily the W38/40/45 gates use the same springs. you can find the 10psi inner spring (TS-0505-2012) , but that would replace your 10psi. Since I believe the 7psi spring is an inner spring you want to see if you can add a larger outer spring. But the best I've seen is the TS-0505-2013 which is the 25psi Outer spring.

Again these are choices, but, again, I think you have the 7psi Gen 4 inner spring. So, it's best for you to find the Gen 4 10psi Outeri spring, to put you at about 17psi. (not the best for BBG, but you want 600-650whp, so, meh... )

So, part number for the Gen 4 10psi outer spring (which is what I believe you need, but you'll have to confirm for yourself, is TS-0505-2005, which is a brown/blue spring.

I hope that helps. But you'll need to confirm before you decide.

 

Awesome thanks man yeah see I have a garret gt3586r with the bigger turbine housing option and it wouldnt build boost till about 6k rpms so i was kinda looking for that mid range more like 35 to 4500 rpm range ima definatly do some more research on all this you broke it down pretty well I was kinda getting confused on inner spring outer spring an all that ill keep an up date on how it does I'm getting tuned tomorrow so hope for the best thanks for the knowledge an input my man

 

You don't need to go that large. A good GTX3576R, Predator, GT(X)3582R, GTW3476 or if you must stay Precision, a 6262 would do the trick.

 

Yeah man its a big *** turbo it came with a full race kit that I bought from a buddy an it takes forever for it to build even tho my car redline is 9500 but still yeah id like to stick with precision I havent had any problems out of them yet I'm trying to sell this full race kit if I can I'm gonna buy that 62/62 for sure

 

actually, your turbocharger is not that large in comparison to a gtx3076r. You are simply looking at the compressor and turbine housings to extrapolate overall size and capability of the turbocharger.

the reason for the additional lag is due to the design structure of your exhaust manifold, that is design for top-end power only, not for mid-range or low-end Torque.

you will find that there is a debatable discussion regarding precision's reliability issues, ETC. Although you may not have experienced any problems currently, many others in both domestic and Sport compact drag racing world have. That does not mean that they do not make Power, simply that they are a bit more sensitive to higher rotational speeds than other major brands that use the OEM, as their infrastructure such as Garrett or Borg Warner.

whichever turbocharger you decide, Please be aware that a larger compressor and exhaust wheel & shaft are required in order to get the higher horsepower expaectations that you're looking for, regardless of how high an RPM is reached.

 

Shodan makes mention of the GTW3476 and that's what I am using. Begins building boost for me at 3300 and I'm at 25psi by 5500. I'm running it on a single cam, D16Z6, and I would be willing to bet this would be even better on a B-series, especially a GSR.