Thread: advice

I appoligize if my post wasnt clear to someone who didnt understand the characteristics behind it. Ill give you that much.

Again i plainly said the creep most likely had to do with my wastegate placement more than wastegate size.

Most manifolds use a 90 deg angle placement of the wastegate which is probably the same to be said about this guys manifold that posted this thread. So in that case knowing that info, I said if you dont want creep, go with the 44mm or larger gate. 38mm gate with that turbo at a 90 deg angle is going to creep without a doubt, not questions in my mind as because mine did with both a smaller turbo and a larger turbo than the 6262.

If the guys wastegate placment is at a 45 point in the same direction as the collector then he would probably have no issues running a 38mm gate which some on here have pointed out already can be done with proper placement. Im just giving out info on what i know and have tried myself. That is all.

I am going to have to agree with Ashton here.

If you are going to be running a ramhorn with a larger turbo, you are going to have to go with a 44mm or larger wastegate. Especially if you want to be able to run a lower pressure (below 20psi).

I have tuned plenty of cars that have tried to get away with a 38mm gate with a better flowing turbo setup and have had nothing but problems with trying to control boost pressure.

When I say better flowing, I am referring to a tubular manifold and 30R and greater turbo size. If you have a 6262 on a log manifold and a 38mm gate.. then sure, you probably could run a 38mm gate. Switch that log out for a tubular manifold and you most certainly will have an issue.

Sure, *some* of it has to do with wastegate placement, but that isn't everything in the equation.

Moral of the story, if you plan on making a tubular manifold and have the space, throw on a tial 44 mvs or something similar and call it a day!

BTW, if you guys need or want to see any comparisons between a 38mm gate and a 44mm gate on the SAME setup.. I would be happy to post some plots.

Yep, that also has to do with backpressures. A log manifold and smaller turbine housing on the turbo is going to create more backpressure, so when the gate opens that backpressure is gonna force exhaust out the gate quicker.

When you are dealing with tubular manifolds that flow well and larger tubine housings that help keep backpressure down and are very efficient setups you are almost always gonna have issues running the smaller gate because backpressures are not there helping force exhaust gasses out.

Again positioning of the gate can help in those situations as well like it was said already. Also the style of the gate. Your old tial 38mm gates are a straight 90 deg angle as well out the valve to the dump tube. Whereas the tial 44 and Tial MVS 38, 44, 46, and so on gates have an angle to them from the valve to the dump tube. Also helping increase flow.

It all depends on setup.

As mentioned before JK, I am not disagreeing with Ashton at all. I am just wanting some clarity to the information being issued. Simple.


"Wastegate sizing is inversely proportionate to the desired level of boost and is somewhat independent of the size or power of the engine"

big turbo/low boost = bigger wastegate
big turbo/high boost = smaller wastegate
small turbo/low boost = bigger wastegate
small turbo/high boost = smaller wastegate

I have also seen this posted by SR20GTi-R (Jamie) on here as well. I will have to dig up flow diagrams if you interested as well (which will agree with what JK and Ashton are saying)

And in order to help explain the big turbo/low boost, etc "table" posted above, this may help a bit



I hope that helps

Cheers

The 50mm JGS gate also fits the same flange as the tial 44mm ...all are good choices , I like the Vband flange gates the best my self

Absolutely. It is such a pain to try to get to the two bolts on some cars when everything is all bolted together and on the car. Even more so after a few dyno pulls and everything is crazy hot!

thank you gentleman i appreciate it very much