I've tried searching for some definative answers, and had no luck-- main question:
In my attempt to reach over 550whp, will my 38mm gate be too small? What are your reccomendations?

 

yes it can build backpressure an backpressure limits power output and my suggestion get a 44mm personal favorite an it works good at most levels sometime you can run dual gates but that a different animal

 

well think about it. a wg wastes unwanted pressure into the air, and out of the manifold to keep pressure down so you dont overboost. if you have a small turbo, and you are going to be using low boost, (which sucks btw) then it will be wasting a lot of air because of all the exhaust coming from your engine, it wont take much of it to spool that small turbo, especially at low boost. so maybe a bigger wg would help keep pressure steady. if your exhaust is small, then you have a lot of back pressure, youd want a bigger wg. (that sucks too) it really depends on the size of your turbo, and more so the boost pressure you will be running. but i guess to answer your question, no. at worst, the wrong size wastegate will not hold the boost that you want, and you will have creep, or overboost. (not good)

 

umm dart what is your diffinate answer not sure if we are agreeing here are you saying that WG size does NOT hinder HP or yes IT does hinder HP

 

WG size does not hinder HP

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony413 &raquo;</TD></TR><TR><TD CLASS="quote">umm dart what is your diffinate answer not sure if we are agreeing here are you saying that WG size does NOT hinder HP or yes IT does hinder HP </TD></TR></TABLE>He is saying that it doesn't<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Semnos &raquo;</TD></TR><TR><TD CLASS="quote">WG size does not hinder HP</TD></TR></TABLE>

 

The wastegate relieves extra pressure so it doesnt reach the turbo. It doesnt hinder HP.

Keep this in mind,If you have a large turbo that wants to make 40psi and you want to keep the boost at 8psi the wastegate has alot more work to do then if you have a large turbo and want the boost at 31 psi.

The more boost the turbo wants to make over your boost level the harder the wastegate has to work to remove that extra pressure in the manifold before it reaches your turbo.

If that pressure reaches your turbo you will have boostcreep, this will actually make more HP than a lower boost level if tuned properly but will cause issues with longevity and safety for your engine. In otherwords horsepower may help determine what wastegate you need but it is no a good driver for your decision.

I would ask the fabricator of the manifold what wastegate they recommend becausse manifolds work different at relieving pressure.

 

the wastegate will not hinder HP made.... but you will have problems with boost creep and spike though. If you have the funds I would recommend upgrading to a larger WG.

 

put it this way, i made 690 on a 38mm, single, and it was fine, the only downside was it has 6 pounds of boost creep. my 14 psi spring was boosting 20 psi without a boost controller. this was a gt4067. A cheap alternative is to add another 38mm.

 

no, the more boost you run, the smaller wastegate you need

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TiAL &raquo;</TD></TR><TR><TD CLASS="quote">no, the more boost you run, the smaller wastegate you need</TD></TR></TABLE>

yeah thats why everyone running more than 35psi is running atleast a single 44's or higher

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">yeah thats why everyone running more than 35psi is running atleast a single 44's or higher </TD></TR></TABLE>

then explain to me why we helped out a diesel tri-turbo tractor puller running 240PSI - not a typo - of boost and he is running ONE 38mm wastegate

 

because for one they run a solid block and only run for a very limited time to where a Honda runs a thiner sleeve and is also driven on the road and also cant handle more than 50psi on most after market sleeves

you are comparing watermelons to apples here

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostedEG6 &raquo;</TD></TR><TR><TD CLASS="quote">because for one they run a solid block and only run for a very limited time to where a Honda runs a thiner sleeve and is also driven on the road and also cant handle more than 50psi on most after market sleeves

you are comparing watermelons to apples here
</TD></TR></TABLE>

what does the wastegate have to do with the type of block or drivability? 10psi w/ 35mm gate is 10psi w/35mm gate, 240+psi is 240+ psi..., no matter what type of car or block or drivability...correct me if i'm wrong though...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">because for one they run a solid block and only run for a very limited time to where a Honda runs a thiner sleeve and is also driven on the road and also cant handle more than 50psi on most after market sleeves
you are comparing watermelons to apples here

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

Not really, my point is for high boost apps, a 38mm is all you need, now perhaps people do not choose the correct spring pressure they should, or the manifold placement is less than ideal, or even the vac line is too small and delays response. there are a million things that can cause problems. running race gas on a non race gas valve is my favorite.

my personal car with a 3582 and a single 38 wastegate running ~32 psi and holding rock steady should be a better example

 

rude....to answer your question, yes

it wont let me use the IM feature (and i'm a paid advertiser at that)

 

i switched to the 44 cause its a little bigger and a lot nicer, i got tired of fighting with those mounting bolts on the 38

 

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

Not really, my point is for high boost apps, a 38mm is all you need, now perhaps people do not choose the correct spring pressure they should, or the manifold placement is less than ideal, or even the vac line is too small and delays response. there are a million things that can cause problems. running race gas on a non race gas valve is my favorite.

my personal car with a 3582 and a single 38 wastegate running ~32 psi and holding rock steady should be a better example</TD></TR></TABLE>


what do u mean a race gas valve?

 

Pretty simple guys. Doesn't take much wastegate at all to run a lot of boost, because the wastegate doesn't need to bypass much, it all goes through the turbo. Now, the reason you see big gates, or even 2 gates, is to have the ability to run low boost with a big turbo. You have to bypass a lot of exhaust around the turbo to keep the boost low. A big turbo and a 35mm gate, and you won't be able to get the boost low enough for street driving or even for track racing. Most FWD cars can't use 20+psi in first gear!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">what do u mean a race gas valve?</TD></TR></TABLE>

the 38mm has a black valve or a silver valve...the silver valve is for race gas use, the black valve is not, if you use race gas on a black valve it will corrode and stick open/shut

tony, you are 100% correct, that is why you see 60mm gates on the drag cars cars, to control low boost in first gear to high boost in 5th gear

 

tony's soo smaaaaaarrrtt

 

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

the 38mm has a black valve or a silver valve...the silver valve is for race gas use, the black valve is not, if you use race gas on a black valve it will corrode and stick open/shut

tony, you are 100% correct, that is why you see 60mm gates on the drag cars cars, to control low boost in first gear to high boost in 5th gear</TD></TR></TABLE>

Wow, I had no idea those existed. So, if I already have a manifold flanged for the 38mm, and wanted to run the t3/67h.o. do you think I would have issues with creep?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">Pretty simple guys.</TD></TR></TABLE>

To put it another way, it limits HP CONTROL, not HP itself.

The only time it would actually limit power is if you're shooting for the turbo's maximum efficient psi, say 35psi, and your wastegate creaps insanely up another 10-15psi and just can't push air at those tip speeds. I can't see that happening on the large turbos Hondas use though ...going beyond max efficient pressure that is.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TiAL &raquo;</TD></TR><TR><TD CLASS="quote">no, the more boost you run, the smaller wastegate you need</TD></TR></TABLE>
x2...
it depends on the turbine size and wg placement mainly.
If you want to run 8psi on......say a gt42r with a d16, it's going to take you a looong *** time to make pressure. by the time you reach it, hardly any of your exhaust gas will need to be redirected to hold that boost. there wouldn't be any need to run a 44mm or larger wg b/c a 38mm would be fine.

the reverse is also true. if you want to run low boost on a small turbo, lets say a 14b on a gsr, you'll need to redirect alot of exhaust gas and a larger wg will be needed.

also you need to take into consideration if this will be open or closed loop wg setup? If your running a small wg and a small turbo, you'd either need a big dp and exhaust or run open loop. if your running closed loop, the additional exhaust gas that was reverted from the wg now back into your exhuast can/will cause extra backpressure which =lag=shorter powerband and can hold back peak power

 

You will make the most power with no waste gate at all.....