^This. My turbo is of comparable size to a GT2560r, with a 3" downpipe, and a Tial 38mm dumped to atmosphere. I can hit a rock solid 4 psi if I want.

 

Yup. I will be modifying my downpipe and the wastegate outlet tube to switch to a "dump to atmosphere" configuration.

Keith

 

Good to hear that it is on its way. Not sure how your view can dispute math. Engineering relies on math, not on opinion.

You know from your own experience with divorced wastegate downpipe designs that a dump tube that returns to the downpipe at the turbine outlet is not much if any better than an internal wastegate, so I am unclear why you designed a system like the S4 with external wastegate with the dump return so close to the turbine outlet.

Keith

 

Not completely wrong, but, in my view, you've got one point quite wrong. SOP/404.

The heat energy increases rapidly with greater boost and greater flow. Exhaust gas velocity increases also. Not only does the faster velocity offer up more molecule hits per time, they also hit with more kinetic energy. Therefore energy in the exhaust, not even counting the heat, will be an exponential function I don't know the real number, but it is going to greater than squared.

Hence, more boost, gobs more energy, gobs squared (+), to vent. All of which would suggest to me that the higher the boost, the bigger the wastegate.

Please don't suggest some gate maker says otherwise. Many probably do.

Do you really need to vent more energy at lower boost when the energy hasn't been generated yet?

I would have agreed with you a few years back, but have changed my view.

A remote gate has more merit than just the opportunity to use a long vent tube.

Corky

 

The higher the boost, the less you actually need to bleed off, so you don't need as much flow. I don't understand why we're still discussing this in the year 2014.

By "Some gate maker," i'm saying that ALL "gate makers" suggest exactly what i quoted from Turbosmart's website.

This is beside the point, however. The 38mm is plenty big enough for Keith's application. I run a much bigger turbo than his on my DD with a 38mm and i can hold any boost pressure i want from 5psi to 30psi depending on springs used with no spikes.

 

+1

 

-2

I suppose you are correct. As long as it works, which the remote gate seems to always do.

Understanding how it works and even it's limitations doesn't really matter.

It got cast in stone moons ago that only one wastegate maker understood the things, and set about making them work better. He succeeded. No one copied him.

Perhaps sometime in 2015 we can set about making them work a little better.

corky

 

Wait... Why are we arguing about external wastegate sizing? Isn't this really, REALLY simple?

Corky you're reminding me vaguely of Hyper right now.

"It's OK that you don't understand it, this is PROGRESS."

 

What in the world?

 

Haven't any of you guys read "Maximum Boost"?

 

I've read it more times than all of you guys put together, and it has several errors.

The idea of a smaller gate being adequate at very high boost pressures is one of them.

You fellow don't let much get by you if it's not correct. While I might be wrong, don't I get the same privilege?

Yes, it's easy to make them work.


corky

 

You know what would solve this? Hard data. So who is willing to pony up for 4 different wastegate sizes and a good data aq setup?

 

You'd be surprised what qualifies as hard data.

 

Someone missed their calling in life to rival Stephen King for best fiction.

 

All I know is you mt.net guys(at least the ones that know what you are talking about ) scare the crap out of me! Thus why I am more of a bystander/reader/spectator instead of a participant. (well that and I gots no churbo...yet)

With that said I too applaud Corky for staying active on this forum because it is a hard crown indeed and he has always answered(from what I have seen) with as much tact as you would expect from a business owner. I was really excited about the new kit and had several correspondences(over the past 10+months) with Corky but the last one that I sent him on m.net showed a "confirmed" message that it had been received/read but never heard back and after many stories of lack/bad customer service and a few of my own as far as poor communication when trying to gather information on their kits, I was done and moving on. The kit itself seems fantastic and looks to have been well thought but the price tag in the end still would have turned me off since I was told that the price wasn't going to be much more than the kits now and maybe I didn't clarify what kit they were comparing it too.(S4,S5,S6?)

Customer service seems to be the one big complaint about BEGI and what the root of the problem is exactly I cannot say but I hope it is resolved because that is one aspect that I believe FM holds over them easily. On the other hand the products/options offered by BEGI is superior IMO, I mean why does a aftermarket supplier like FM still use anything but rigid(metal) intercooler piping? Mind boggling IMO but even so I think FM makes great products and supports the Miata community, just as BEGI does. Not trying to turn this into a BEGI vs FM thread just pointing out that IMO they both have pros and cons of doing business with them.

I really do wish Corky and BEGI success with their new product line and hope the issues that have become a tarnish on their reputation can be resolved in time, hopefully sooner than later.

 

FM actually moved FROM metal piping kits to the silicone.

The silicone 1 piece hoses are superior in some views. Including mine, for a street car using an off-the-shelf kit.

I know i'd rather have that than the steel rusting pipes i have now.

 

Well FM is a well established company that is not going to thwart just because of my insignificant opinion and I am sure they have their reasons and probably sound ones at that.

My biased opinion is based on my experience with my '04 SRT4 and the lousy factory rubber intercooler hoses, I know its not all that fair to compare those to silicone hoses but seeing how much people want to say, "oh silicone hoses aren't that much superior than rubber counterparts" then I automatically figure that in time they will suffer the same issues as those rubber intercooler hoses of the SRT4. My concern/issue with the FM offerings is probably unfounded but thus the IMO cope out.

 

Nobody actually says that unreinforced ballooning rubber hoses are anywhere close to triple ply reinforced silicone hoses.

 

I've had both types and, by far, prefer the silicon hose option. The steel ones are finicky to install and align properly and present far more points of failure. Until you've been forced to crawl under your car on a filthy side street and burn yourself attempting to reconnect a recalcitrant coupling, you won't understand what a luxury a one-piece, preformed hose is.

 

Props awarded for use of the word "recalcitrant."