Ok first off i would like to ask what size wastegate should be used on a precision 6262 turbo charger? It is a t3 non divided housing manifold and turbo... What Wastegates are working or should work for this turbo charger? (people with real world experience only please)

Please check back after answering b/c after i get a few answers i have few more ?s to ask i just wanna go step by step... here is a picture of manifold

 

That flange is 44mm, it should work fine

 

thats what i thought... but its NOT working fine.... on the dyno (dynojet) the car held boost fine 15.5 psi on pump and 24.5 on race gas... it keeps pegging 18 psi on the street ive tried smaller spring i had a 9 psi spring in it on tune... went to a 6 psi spring and same thing.. i havent tried a bigger spring yet 14lb but i figured i would just try it and see.... im tired of hitting boost cut at 7500 rpms.... it holds boost perfectly all the way to 7 then at 7200 - 7500 bam 18 psi

 

what are you using to conrtol boost pressure just the spring and no controller? I had the same problem with my set-up it would hold boost steady on dyno but on the street it would creep, I got the nlr-ams boost controller and now it holds steady +/- 1 psi where i want it in every gear.

 

I get same issue on s256ETT, 7500 and i get 24psi on tial 44mm. I run a 3 inch side exit exhaust and i think i have so little back pressure, the gasses prefer to use the turbo and exhaust as opposed to more restrictive wastegate outlet. Thats my opinion anyway. Gonna fot a restictor in exhaust tailpipe to see if that helps stop it.

 

i have a side exit too ..... it just boggles my mind

 

you either need another wastegate or you need to modify the manifold. You have a 90 and a 45 bend before your wastegate.

 

I bet adding a second 44mm to the underside would take care of it. This seems to happen with the "large" turbos, even though the WG placement looks pretty good on your manifold.

On anything over 400 hp, I put two 38mm MVS gates, or two 44s ... Don't buy into that "larger turbos = smaller gates" stuff. The more power you're making with your 4 cyl, the more gate you need, period.

 

I buddy of mine was having the same issue on his sidewinder K-series manifold. With a 8psi spring in his 44mm gate he was boosting 12psi before vtec and after vtec it would go straight to boost cut at 17psi. We added another 44mm with a 8psi spring and it would slowly creep from 10 to 12 and to redline. The issue is that for low psi on a larger turbo you need more gate.

 

poor priority of the wastegate, do a pull with no wategate on the car at all and see what boost level you make, my guess is 8-10psi

 

i will do that! whats funny is that the car holds 10 psi fine all the way to 8k then it just lays over to 18 instantly

 

have a nice day

 

its full size