2800cc and 6262 turbo. Is a 39mm wastegate big enough?

[Jaswan]

Hi

So im getting close to building my turbo "manifold"

I have a precision 6262 ceramic bearing turbo. I bought the turbo, injectors (630 cc siemens deka), wastegate (39mm precision), bov (tial recerculating) and a couple of other bits used (low mileage) from a lad who was runniing them on a 24v vr6 golf. He was running 1bar boost and making 450 whp. I have asked him if there was any boost creep issues and he said it held boost fine.

Now, am i right in thinking that if the gate can hold 1 bar of boost perfectly well it can hold more boost even easier... Or .. Will the increased flow of gas mean the gate will need to dump even more gas relative to the boost pressure (if i am making sense here)

I am just a little paranoid that 39mm is relatively small for a wastegate. And my engine is 2.8L and the turbo is medium-sized at least.

Id rather get a bigger gate now before building my manifold. I was also thinking of getting a second matching gate to be safe. I can then provision for this on the manifold.

What are your thoughts on the set up as is? Will there be any problems holding/controlling more than 1 bar of boost?

Thanks for any input.

I would rather save a bit of reworking later if it needs to be changed

Cheers

Jason

[Jaswan]

Bump.

my basic Q is, if the wastegate holds 1 bar fine, , does it need to flow more or less gas to hold more boost without creep?

Jase.

[Thuppu]

The more boost you run, the less the wastegate needs to flow.

[speeding-g60]

people use larger wastegates on cars that need more control down low, dumping more pressure to maintain a lower boost level. low boost, big WG. high boost, small WG.

i use two 38mm on my 2008cc 20v 4 cylinder awd car with 67mm turbo, twin scroll manifold, with 47+ pounds of boost.

my new chassis car (same 2008cc 20v) i will be using one 46mm wastegate with 80mm turbo, twin scroll manifold (with ports from each side to WG) and run LOTS of boost.

Big turbo/low boost = bigger wastegate
Big turbo/high Boost = smaller wastegate
Small turbo/high boost = smaller wastegate
Small turbo/low boost = bigger wastegate

properly sizing blowoff valves and wastegates

[Jaswan]

thanks for the replies