Restrictor plate in BEGi exhaust
 

4 or so years ago BEGi installed my turbo and exhaust.
Today I find a 1.5" restrictor in my 2.5" exhaust just before the cat.
Why is this here?

https://drive.google.com/file/d/0B7N...ew?usp=sharing

https://drive.google.com/file/d/0B7N...ew?usp=sharing

:bowrofl:

it's the 1935 solution to boost creep

I was told to do this by FM in the year 2013. I got smart and researched this site instead.

Sweet jeebus, really? :facepalm:

iirc FM was suggesting 2.5" for people running 3" and creeping

1.5" is just ridiculous. why even run aftermarket exhaust in the 1st place?

Margaritaville wins again

This is incredible.

"Let's just place a superior, highly engineered band-aid at this"

Because Corky could decide if there was power to be lost or power to be found.

because injector pulsewidths :giggle:

A 2.375" pipe with a 1.5" flat plate restrictor in it will still have less restriction than a 1.5" pipe.

Sorry for interrupting the hate parade.

Does that make it less retarded?

Do I have to take a nasty shit right now because I ate last nights leftover taco meat straight out of a sandwich bag for lunch?

Yes, we know that just as well as you know how ridiculous the cost/benefit ratio of something like that is.

*edit: apparently I type too slow and G beat me to it lol

Don't expect to get that over with quickly if you are using a restrictor.

Leafy doesn't have a restrictor.

5" and he uses ALLOFIT

Insert baseball bat a few times and all of a sudden you're just plopping out flapjacks.

Oh, gee, thanks for that mental image.

Yes, but if you have a colon full of Taco Bells Finest and a 5" orifice to push it through, wouldn't you rather remove your buttplug first and get it over with?

I mean, unless you are into that, then who are we to judge?

More flow = less time to do the same work = more horsepower.


SHIT LIKE A HORSE.

I'm curious what pulsewidth Leafy runs after Del Taco at full tilt right past peak load

This is relevant to my new book, Maximum Leafy

I've found that if you strain hard enough, you get some weird spasms. Is this static?

POTFL.

Yes, but is your anus 0.63 A/R or 5.06 A/R? There is always a point of diminishing returns.

100 AR

he uses Taco Bell Ultra Spicy to help spool

:rofl:

I would imagine spool would be pretty poor at that point. I guess it all depends on if you are looking for faster spool or more top end?

It sounds like maybe he needs a double espresso, Its like an EBC for your digestive tract.

only p***ies use espresso

But its doesnt really matter now, does it? If the hose on Hustlers funnel mask is only 1.5" in diameter it does not matter how much espresso you put in the system. Sure you will get an increase in velocity, but that's not what we want here. We are looking for volume! You could have a 12" diameter funnel and like 3 dudes but its not going to help if you are restricted by the plumbing. It will never, ever reach peak efficiency unless you reduce the restriction. Period.

must upgrade to 6" and get a bigger funnel.

might need a custom made rubber fist too, for the porting

But where is the point of diminishing returns? There must be some golden ratio out there that we just are not aware of. We obviously need more research and testing. Data is the only way to unravel this mystery.

diminishing returns are when he starts to rip

You guys are thinking about it wrong. When you have a smaller outlet then you get more pressure, like covering up the end of a garden hose. So you can spray farther and get more thrust.

Basic physics guys, us EEs know how it works.

You engineers know nothing. Its all theory with no knowledge of the real world. Only through the rigors of testing and documentation following the scientific method can truths be revealed.

Testing shall commence immediately.

Attachment 233787

Is that book any good? I'm starting to think that it can't possibly be. Maybe it was ghostwritten by someone else, or constantly breathing in gas fumes has damaged the author's brain?

EDIT: Nevermind, looked up some excerpts, seems like its a good book.

I find it informative. Its not written in an overly technical way as you would get with, say, someones doctoral thesis. It takes a lot of complex concepts and boils them down so non technical people can understand them but still gives you the technical detail. I will continue to recommend it to noobs who are still trying to grasp the concepts. I find the writing style to be somewhat ...odd. Mostly due to the formatting maybe?

The author is a member of this forum and if you've read his posts, you'd be able to tell he wrote this book. :)

Until I actually looked for excerpts, I had assumed it was written in a more technical style. Looking through it now, there is no doubt in my mind that this book was written by the same person who posts here. I'll probably pick up a copy and bust out my highlighter. Might as well read all you can, right?

The engine management portions of the book are a bit dated, but the mechanical bits are still good.

--Ian

I'm delighted I can supply you buttheads with a source of mirth.

Assemble all your vast knowledge and tell me the secret to banishing the creep. After changing the A/R, altering WG springs 100 times, porting the wastegate, providing the gate its own vent tube, increasing the exit port size and then reducing the valve coverage, please tell me what to do next.

Also, would creep not suggest that the flow capability of everything else in the system is higher than the gate designer planned on for those operating conditions? Sounds like a compliment to me.

When nothing else works, the exhaust restricter is the best choice.

Creep was one of the reasons for cobbling up the A/O.

That silly book of 20 years ago has three glaring errors. Any of you jokers up to finding them? Don't count the one on the IC, that is too simple. Open to suggestions on any part of book, as second edition is nearly done.

Take a look for Jeff Hartman's turbo book. He did a great job, and it's only two years old.

The editor offered some interesting advice a long time back; for every equation in the book 100 fewer books will sell, and every picture will sell 1000 more books.

Thanks to anyone that bought a copy, the royalties are cool. And, yes, the royalties permitted a better brand of Tequila.

corky

Why is it that the same turbos on the engines they came on stock, like the sr20. The T25 turbine creep really seems to be a problem focused on mainly us and not so much on other cars. And its certainly not due to this motor being better than others. Are we like just better at tuning and running more spark advance than the other car?

And 3" exhausts?

My TD04 runs 5psi at red line and WOT, with the waste gate wired full open. And that must not be uncommon because Vlad told me it would. I don't know how it responds in a WRX.

I wonder if Corky will send me one of those?

I just wanted a fucking heat shield that fit or lacking that some stick on heat shield foil. In lieu of that I was offered a free A/O setup to make up for all the misery I went through with my S6 kit and it's boost creep issues.

Looks like the A/O is up for sale on the BEGi website. I haven't received the one I was promised, nor a phone call, nor an e-mail... not even a Christmas card.

Keith

The only solution to boost creep is simply to run all of it.

weld waste gate shut = no boost creep (actually it just keeps creeping forever)

BH2dKeith,

No A/O for you until the cast manifold is in my hands. The pattern has been at the foundry long enough to expect castings within a couple weeks.

Your turbo will need a few mods. You or me? If you do it, you will do it as I suggest.
I will be glad to fix it up, nc. What fuel system are you using? Need EGR?

Sorry about no Christmas card. It was just a bigger risk than I was willing to take.

Hang loose, you are at the top of the list. I'll need to figure out which list that was.

corky

Seriously, why do we give a fuck if we get 5psi of creep past peak torque?

because we understand how forces in engines work?

If its past peak torque then its not putting any more stress on any components than peak torque already did. Which is why its called -peak- torque.

Ebc on signal line to bov. Let it start trimming boost in the creep area.

Edit: peak wtq does not necessarily equal peak forces on components.

Not bad. Would need a vacuum pump though. BOV needs vacuum to open.

If the boost is removed from the signal line the charge will have enough pressure to open against the spring.

Hmmm. Would be interesting.

Wouldn't that make the turbo make a lot of hot air though? With an open intake line wouldn't it just spool through the roof, especially if it's already creeping?

I want a vac pump and a vac driven wastegate, mini cooper style. 0-allofit with no sweat.

What can be used more reliably than peak wtq?

Hope our fueling map is good enough to use ve?

Yes to both of your questions. High-flow, low pressure ratio regions of a compressor map typically correlate to shaft RPM of somewhere between "a lot" and "too much"

Is super high shaft speeds an issue because of centripetal force on the compressor and turbine wheels or is the issue overheating bearings..?

I honestly dont know.

"an issue because of centripetal force on the compressor and turbine wheels"

Having seen turbine blade passing through the housing and hood, yeah, the cf is probably the top speed issue for a sleeve brg.

Otherwise, I doubt a sleeve bearing gives shit. However, the ball bearing guys might find the balls spewed out into low earth orbit.

The centripetal acceleration of the wheels is reasonably high. For some impressive fun, calc the C A and then use that number to calc how long it would take to travel 283,000 miles.

corky

case and point.

:idea:

Perhaps. Peak *power* is peak fuel flow though, so boost creep has the potential to outrun your injectors.

--Ian

I thought it was clear that I was not including super basic reasons to hate creep past peak torque.

Come on then brain, explain it to me.