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Turbos, BOV, IC, Wastegates, injectors etc


My name is Russell

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^ theres many a race car (le mans etc) that doesnt run a bov there not essential, actual compressor surge is never going to happen in normal conditions anyway.

agreed. altho best to have one in there. also sounds more gay without one when the air escapes back thru turbo

compressor surge is different again and a whole lot worse for turbo. when turbo supplys too much air for engine so compressor wheel tries to stall while the engines trying to spin the exhaust side the other way still. snap

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Some of you guys need a history lesson.

Anyway there's a book called "turbochargers" by Hugh McInnes. It's a must read book. It's got a few mistakes in it though but it covers everything.

A wastegate is only there to prevent overboost. It's only one of several ways to prevent it, the easiest but not always the best way.The original (old) turbos didn't have internal gates, newer ones usually do, they've been around since the mid 70s. Inbuilt gates are an upgrade. If an inbuilt gate won't work properly, it's not because it's inferior, it's because it needs modification.

Likewise you don't need a BOV either but it's an easy way to prevent compressor surge. If running low boost you don't need one , also if you're using the throttle before the turbo you don't need one either.If you're running highish boost with the throttle after the turbo you DO need one, factory ones work well though once you understand a bit about them.

The main problem with car enthusiasts these days is that there's lots of people trying to sell performance products, most of which are inferior to what car manufacturers fit on cars. These salesmen make false claims about their products (they don't even know themselves), helped along by wannabe car enthusiasts that don't really know FA about anything. No wonder so many modded cars blow up.

If you go back to the roots of hot rodding, afterall that's what it is, the cheap easy way is to get your upgraded parts from the dump, from a higher specced car than what you're upgrading.

Then it's back to "built or bought", and chequebook racers (which of course I've got zero respect for).

Sure if you've got lots of money you can buy a fast car. Some can build faster ones for a lot less money using the right parts but only if they know the basics.

edit, compressor surge WILL occur if you've upgraded the turbo to one which is "wrong" or too big for the motor. It will also happen when you launch it at high boost and the wastegate spring is too tight.

Oh and you haven't maxed out your turbo until you've wound up the boost so far that the wastegate never opens.

Boost creep is pretty common on 4G63Ts. The no brainer way to fix it is to fit an external. Redesigning the exhaust and boring out the internal will fix it cheaper. Boost spiking is caused by the boost rising quicker than the wastegate can open. That can be fixed by adjusting the spring, making the lines bigger and modifying the bleed mechanism/electronics.

Steve

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Oh and you haven't maxed out your turbo until you've wound up the boost so far that the wastegate never opens.

Boost creep is pretty common on 4G63Ts. The no brainer way to fix it is to fit an external. Redesigning the exhaust and boring out the internal will fix it cheaper. Boost spiking is caused by the boost rising quicker than the wastegate can open. That can be fixed by adjusting the spring, making the lines bigger and modifying the bleed mechanism/electronics.

Steve

turbo limits are based on shaft speed and compressor/turbine maps

boost spiking can also be cause by surging ....

perhaps learning the fundamentals before you start correcting books would be wise

it is wise to say nothing and look like a fool than to open ones mouth and remove all doubt

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turbo limits are based on shaft speed and compressor/turbine maps

boost spiking can also be cause by surging ....

perhaps learning the fundamentals before you start correcting books would be wise

it is wise to say nothing and look like a fool than to open ones mouth and remove all doubt

Choosing the turbo is chapter 4, Controls are chapter 9.

If it runs, spikes due to surging, you've failed in chapter 4.Maybe you need to do some reading too.

Steve

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mods please step in lol

as much as any ifno is good , its fucking useless if you dont put it into terms that us normal people can register .. so stop bickering and give us some good info or list of places we can get it

it like sitting in a class about quantuam physics when albert einstein and ernest rutherford are arguing ..you learn fucking nothing even though both have vast amounts of good knowledge

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Steve surely you could appreciate that some things could possibly have changed since 1980? And that the internet is the new TV, and almost the new library in many ways! Probably no one else on here other than you has read that book, but please don't dismiss other peoples opinions straight away because they haven't read it!

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Anyway there's a book called "turbochargers" by Hugh McInnes. It's a must read book. It's got a few mistakes in it though but it covers everything.

Just went through my books and realised I have this book. Haven't read it yet so will have a read of it, a quick skim suggests its aimed at turbo v8s though?

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Anyway there's a book called "turbochargers" by Hugh McInnes. It's a must read book. It's got a few mistakes in it though but it covers everything.

Just went through my books and realised I have this book. Haven't read it yet so will have a read of it, a quick skim suggests its aimed at turbo v8s though?

should at least lay some kind of groundwork in the terms of how to size up turbos for applications etc .

but yes a book that is older then me can only hold so much info

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You'll never get any sense from the internet.

Steve

as long as you keep posting, then never a truer word has been spoken.

you talk in circles, your "facts" are actually "opinions" or at best, ideas. you clearly demonstrate almost every time you open your mouth that you don't know what your talking about and everybody here (with possibly the exception of Fuel) is ignoring you.

ive said it before and ill say it again, post in a constructive, positive manor or fuck off.

sheepers.

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when the internal gate sucks basically. boost issues. unstable boost, boost creep, etc. although half the time is not the actual gate thats the problem. its usually bad boost control device that causes unstable boost. or actuator is faulty or not up to the task.

if none of the above is the problem. and boost is creeping up with revs. you can port the internal gate to get more flow. which may fix issues. getting an actuator with more travel to open the flapper futher can help also

external gate is the easy way out, but your pretty much guaranteed it will work. unless its undersized, or installed wrong of course.

possible small gains could be had by going to external gate. as your removing turbulence from around the exhaust wheel.

end of the day all your doing is bleeding off exhaust pressure, so turbo doesnt spin as fast.

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Someone has probably mentioned, but im way to lazy to check...

21st Century Performance, by Julian Edgar, ISBN-13: 978-0947216900.

Really good read, covers heaps of shit, highly reccommended.

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when the internal gate sucks basically.

So if im maxing out a turbo for what its capable of producing in my case a standard Rb25 turbo at 212kw, is it likely that the standard internal wastegate wont be up to it?

I only ask as the computer & engine i have now was dynod for that figure, the only difference was that he had an external wastegate of the exaust. Im keen on going back to internal wastegate to keep things simple and get a better turbo in with less play at the same time.

Cheers boe

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