95gsrturbo

Im looking into different size wastegates for my rebuild

Im looking to get an inline pro mani, with an SC44 and probably run 10psi street and 17-20 track, (bottom end built already)

my main Q is I know the 35mm should be enough and for a fact the 38mm is sufficient, but if i can get a 40mm Tial cheap should i go for it-- or will it me over sized on lower boost levels?

J337_UNIT

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 95gsrturbo &raquo;</TD></TR><TR><TD CLASS="quote">Im looking into different size wastegates for my rebuild

Im looking to get an inline pro mani, with an SC44 and probably run 10psi street and 17-20 track, (bottom end built already)

my main Q is I know the 35mm should be enough and for a fact the 38mm is sufficient, but if i can get a 40mm Tial cheap should i go for it-- or will it me over sized on lower boost levels? </TD></TR></TABLE>

actually.. for lower boost levels TIAL reccomends u use larger wastegates because at low boost, you have more exhaust needing to go thru the wastegate.. if u have a small wastegate and low boost, its going to be more restricting if anything and you could potentially have boost creep.. check out http://www.tialsport.com and click technical information for yourself if u have time they explain it.. its very logical.

actually here it is..

"Flow capacity. Contrary to popular belief, larger higher HP applications do not necessarily require the largest wastegate available. The lower the boost pressure you are gunning for the larger your wastegate needs to be. An engine/turbo combination that is set to 25+psi has a smaller wastegate flow requirement than the same application set to 7 psi. This is because the wastegate is used to lower the boost not raise it, the lower the boost pressure is set the more flow the wastegate must allow."

95gsrturbo

anyone else have experience to provide first hand? thanks by the way

_entropy

I am running a TiAL 44mm gate and it holds boost fine at 6 psi. You can't go too big on wastegate.

Mighty Mintos

im running an hks GT wastegate 60mm, works great for 10 psi of boost no boost creep at all. from what i have seen, the small TiAl wastegates can't hold low boost too well. most of the time if you want to boost 10 psi, it will spike to 14 or 15 lbs.

Chip

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HKSGSR &raquo;</TD></TR><TR><TD CLASS="quote">im running an hks GT wastegate 60mm, works great for 10 psi of boost no boost creep at all. from what i have seen, the small TiAl wastegates can't hold low boost too well. most of the time if you want to boost 10 psi, it will spike to 14 or 15 lbs.</TD></TR></TABLE>

You say that probably because you have never owned a car with a tial. My car with a T3/60-1 and a tial 38mm has no problems controlling boost as low as 8 psi.

Johnyquest

The only reason I tend to disagree with that school of thought is because at higher boost levels, the overall flow generated is much much higher... henceforth needing a bigger gate... I feel as though you can easily overwhelm a 35mm gate, per say, regardless of boost... because exaust flow volume should roughly be proportional to power output... if that makes sense to anyone but me.

Matt

95gsrturbo

this is the info i was looking for- thanks - so ill probably go with the 38 or 40mm depending on what price i find them at. looking for a used one preferably andy info on someone selling somehting

thanks

Mighty Mintos

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chip &raquo;</TD></TR><TR><TD CLASS="quote">

You say that probably because you have never owned a car with a tial. My car with a T3/60-1 and a tial 38mm has no problems controlling boost as low as 8 psi.</TD></TR></TABLE>
no actually i have ran a 35mm tial wastegate and it couldnt hold 10 psi at all, it just spiked to 15. hey im just telling you what ive seen, you make your own judgements.

DIRep972

iTrader: (1)

You can never go too big, but alot of times you don't need to go bigger. Sometimes you are just wasting money by going bigger. You should be fine w/ the 35mm.

Rain_man

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Johnyquest &raquo;</TD></TR><TR><TD CLASS="quote">The only reason I tend to disagree with that school of thought is because at higher boost levels, the overall flow generated is much much higher... henceforth needing a bigger gate... I feel as though you can easily overwhelm a 35mm gate, per say, regardless of boost... because exaust flow volume should roughly be proportional to power output... if that makes sense to anyone but me.

Matt</TD></TR></TABLE>

Not exactly correct I'm afraid. Flow and boost (pressure) are related but one does not necessarily determine the other.

For instance, a small T25 at 25psi will flow significantly less than a T4 at the same boost. Hence the need for a bigger WG w/ a bigger turbo.

In this instance, the turbo being used however does not need a bigger WG. If the WG can bleed off enough pressure to hold the lower PSI, then it will not have problems bleeding off pressure at higher boost levels.

Rain_man

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HKSGSR &raquo;</TD></TR><TR><TD CLASS="quote">
no actually i have ran a 35mm tial wastegate and it couldnt hold 10 psi at all, it just spiked to 15. hey im just telling you what ive seen, you make your own judgements.</TD></TR></TABLE>

There are other factors besides the WG that determine how well boost will hold.

thelate1

i'm curious about this too. gonna be running a t3 .42/.48 on my b18a. i picked up a tial 35mm cause i always thought it helps stop spiking not create it. i'm planning on running about 8psi. should i sell the 35mm and get a 44mm?



thanx

Rain_man

Save your money and keep the 35mm. If your manifold's WG port is in a good location you're fine.

thelate1

alright, thanx!

Johnyquest

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rain_man &raquo;</TD></TR><TR><TD CLASS="quote">

Not exactly correct I'm afraid. Flow and boost (pressure) are related but one does not necessarily determine the other.

For instance, a small T25 at 25psi will flow significantly less than a T4 at the same boost. Hence the need for a bigger WG w/ a bigger turbo.

In this instance, the turbo being used however does not need a bigger WG. If the WG can bleed off enough pressure to hold the lower PSI, then it will not have problems bleeding off pressure at higher boost levels.</TD></TR></TABLE>

Well I think we're sort of agreeing. That's what I meant. The wastegate size needs to be proportional to horsepower output... in a sense.

Matt