EL topmount mani with a gt3076r loooking for ~ 500whp.

Would a single 38mm wastegate work be sufficient vs the 44mm ?

Wastegate would probably have an 8lb spring in it...

I was thinking of using this...

http://www.dsmtuners.com/forums/vend...tes-stock.html

 

depends on the boost level(s) you will be running.

 

I'm making 450whp on a GT3076r with a 44mm on 23lbs, this is on a D-series so im sure if you running a B series it will make the 500whp no problem on lower boost levels. I would just go with the 44mm.

 

doesnt matter all that much about the motor as its mostly about physics. higher boost levels like bigger wastegates to excape out of. so if you planning on doing 20+ then go with a 44mm. if you plan on doing under 20 a 38mm will do fine. either way i think a 44mm wastegate will work just fine for low boost and high boost.

 

Big turbo + High boost = smaller wastegates (don't need to bleed as much)
Big Turbo + Low boost = Larger wastegate (to bleed off a lot of CFM)
Medium turbo, higher boost = 38mm-44mm wastegate. You can use it suffice that the spring is high enough for your needs.

You can use the new 38mm or 44mm. most use the 44mm for convenience.

 

explain your reasoning behind the bolded blue and the bolded black.


tothe OP: what type of mani are you using ? i think the tial MS-V will work just fine for you.

 

well i thought that if you have a lot of exhaust pressure going one direction, (out the downpipe) its gonna tend to want to go that way, if you have a small wastegate or small area you want all the pressure to escape out of, its gonna take a lot of convincing for it to do that. if you have a big wastegate, an easier way for it to go out of, then itll like that better. from what ive read, it seems like design is a factor too, like placement of wastegate on the collector.

that also explains how i see using the 44mm with higher boost levels.

now, seems to me a 38mm will work fine for lower boost levels since...well its not all that much pressure...and its what im running and it works just fine.

am i seeing this wrong?


and yea, i read tial is getting rid of there 38mm and going with the vband ms-v wastegate! sounds cool.

 

if your trying to run high boost on most sized turbos you want the gate to stay shut so you can build the wanted boost, a smaller gate on a mid-large size turbo is going to make higher boost with a smaller gate because its not losing its flow from a larger gate opening. having a large gate is easier to open because of the surface area of the valve. big valve face = less force required to open = less boost, the opposite applies for a smaller valve face.

you also gotta think about how turbine A/R helps reduce backpressure

 

yea but wont a large turbo with a small gate want to creep? no matter what the boost level?

 

if you have horrible backpressure ratios any turbo will creep. besides you can tune to compensate for the extra psi. usually bad creeping comes from WG placement.

 

This is on an a stock AP2 (05 S2K).

Manifold is a pfab EL top mount coupled with a 3076R.

I am not planning on pushing big boost, not thinking more than 20psi.

I need to know what w/g flange I need to have built with it.

 

buy the new tial ms-v and see if you like it! i think it comes with the vband flanges to weld on too.

 

I'm not building the manifold...and I don't want to have to do it 15 times, wanting to do it right the first time.

But, I want to be informed as to why it won't work, other then people telling me get a 44mm b/c it's "baller" or some stupid b.s. like that.

 

i think a 38mm should do you fine. im going to say get a 44mm Vband flange BUT buy an adapter to use the tial MS-V wg, that way if it isnt working for you, you can switch to a to a 44mm without any harm done to the manifold.

 

perfectly said.

 

Great idea, but I haven't seen these "adapters"

 

you will need to have one made, all you gotta do is use one of the extra flanges from the MS-V kits and weld a junction that can be V-banded to the 44mm flange

 

couldnt say it any better master!

personally i run a 38mm on that very same turbo with that very same power. click sig, i have a dyno graph there complete with pressure log vs rpm you can see, no log. it tapers down a bit though.

 

I'ma gonna give it a shot..

Worst case scenario, it would only creep in the lower boost range..but I don't see that happening.

 

just make sure you have a good merge between the WG and the collector

 

 

After talking to a well known tuner on here, I believe I am going back to the 44mm setup.

He stated from his experience s2k's tend to creep sometimes even with a 44mm gate...

 

i thats due to manifold design because of space requirements

 

yep, a 38 will hold it just fine with proper placement...especially at 20psi

 

38mm will hold just fine. but make sure you have 15lb spring in it!