View Thread: Whats a wastegate?


SLP Addict
You guys have said i couldnt do a real tech article, this is one i have written, from studying about it, this is what i have come up with.


Almost all turbos have a wastegate, this allows you to use a smaller turbo to reduce lag, and keeps it from spinning to fast at high engine speeds, its a valve that lets the exhaust skip the turbo's blades, it senses your boost pressure. if the boost pressure gets to high, its prolly means the turbo is spinning to fast, when this happens the wastegate sends some of the exhaust around the turbo's blade letting the turbo slow down.

SLP Addict
This is pretty much what i have learned from Howstuffworks.com

Sia Bani
Originally posted by SLP Addict
This is pretty much what i have learned from Howstuffworks.com

the greatest website.

A-Tech
it works more like a fuel pressure regulator.

SLP Addict
GOD DAMN!, i cant even get a fucking wastegate right, fuck it, i dont even wanna be a mechanical engineer now!

A-Tech
mechanical engineering has nothing to do with that kinda shit, usually most of em just sit around designing a small piece of an engine or something.

SLP Addict
Yea, but i want to be a tuner, and if im gonna be some shitty tuner, then im not gona do it at all, theres no way im gonna be another saleen, or roush, no that these are bad tuners, just there are already enough of them. i wanna be like lingenfelter or RUF

SLP Addict
But i no its Never gonna happen

Felix Leiter
A wastegate is a pressure relief valve. For reference, there is one on your hot water tank. If for some reason the hot water tank builds too much pressure up inside of it (due to the water getting too hot or some other malfunction) this valve will open and spew hot water out all over the floor (which may sound bad, but is much better than a pressure vessel exploding-- think of metal shrapnel and other hot-water-tank parts hurtling at you). This valve will be set to open at a certain pressure, or KPa.

A turbo (which is a turbine-fed super charger) will continually build pressure. For conversation's sake, a low pressure turbo will operate at between 7-9 psi (think Volvo) and a high pressure turbo will operate at 12-14 psi (think Talon). Now, a turbo works like an air compressor... imagine you took your bike down to the local garage to fill your tires with air from their big air compressor. What will happen to the tire if you leave it on the compressor too long? Too much air, and hence too much pressure, will build up inside the rubber tube and it will explode!

To solidify this point many people die every year from trying to seat a new car/truck tire in the bead by overfilling the tire (usually to 3x the tire's recommended pressure) in hopes that the tire bead will "pop" into the slot in the rim. This should be done with the tire in a cage, so that if it explodes you are not killed by pieces of rubber and metal from the rim.

Anyway, the tube in your bike tire exploded because you put too much pressure on it by overfilling it with air! The same thing will happend in an engine if the turbo overfills it with air. Therefore you need some sort of a pressure relief valve, or pop-off valve, or wastegate. This is the "pop then whistle" sound you hear coming from a turbo-car upon upshift.

On a side note, the more air you stuff into an engine with a turbo the more power you will have. Unfortunately too much air will wreck the engine-- hence aftermarket pistons, cylinders, etc. I've heard of Skyline GTR's running up to 2 Bar (30psi) without much in the way of engine modifications but I think that most top out around 20psi (talk to one of the Talon guys around here).

A-Tech
like I said, just like a fuel pressure regulator.

SLP Addict
I hate you felix..............

911GT2
The wastegate goes off whenever you lift off the gas or the boost is too high. Listen to Getaway from Stockholm II and you'll hear the Escort's blow off valve (another name) go off like mad.

SLP Addict
Yea, such a great sound

911GT2
You'd also hear it quite well on some of the cars on this board running high boost (Ck, maybe DominicanS4 as well as pretty well every Talon owner on AF).

Rotary Boy
ummm slp, do you have any idea what you get yourself into as a tuner? I have 11 people who work for me, and while our sign out front may say "specializing in import parts, service and repair" you might as well call us a tuner because as of the last fiscal quarter 71% of our profit was comming from somthing dealing with the performance aftermarket. sure that seems cool, but what it also means is I deal with the absolute dumbest richest most spoiled kids you can find, and this is what you have to do before you can become the next lingenfelter. you have to go through years of putting up with kids getting money from momy and dady and having you put H22's in their civics or having your turbo their 89 caprice, or having to fix parts that stupid kids have broken(like the stock integra that had been hooked up to a 150Hp N20 canister). I do a shitload of work at my job, I don't even need the paycheck I just do it becuase I like it, and I even considering all the work I do it is nothing compared to the amount of work that goes into each car LPE puts out, forget ruf they are not a tuner they are a liscenced manufacturer.

If you want to work on cars for a living become an ASE certified mechanic, get a degree in mechanical and automotive engineering, buy a garage and pray to superman that it doesn't flop.

911GT2
I'm going for automotive engineering as well, but i'm looking more towards design.

SLP Addict
Originally posted by Rotary Boy
ummm slp, do you have any idea what you get yourself into as a tuner? I have 11 people who work for me, and while our sign out front may say "specializing in import parts, service and repair" you might as well call us a tuner because as of the last fiscal quarter 71% of our profit was comming from somthing dealing with the performance aftermarket. sure that seems cool, but what it also means is I deal with the absolute dumbest richest most spoiled kids you can find, and this is what you have to do before you can become the next lingenfelter. you have to go through years of putting up with kids getting money from momy and dady and having you put H22's in their civics or having your turbo their 89 caprice, or having to fix parts that stupid kids have broken(like the stock integra that had been hooked up to a 150Hp N20 canister). I do a shitload of work at my job, I don't even need the paycheck I just do it becuase I like it, and I even considering all the work I do it is nothing compared to the amount of work that goes into each car LPE puts out, forget ruf they are not a tuner they are a liscenced manufacturer.

If you want to work on cars for a living become an ASE certified mechanic, get a degree in mechanical and automotive engineering, buy a garage and pray to superman that it doesn't flop.


Yea i dont even think im gonna make it, but you never no until it happens, and i dont have to worry about my(hopefully)buisness going bankrupt

Brother=Programmer
Dad=Networks Operations manager for Sprint PCS
Other brother=Drug dealer
so if it were to flop im sure they would try to help me stay upand going.

1 yr ago, i wouldnt of even had the money to buy a book for school, i lived in a TRUE ghetto, and right now, im almost completly away from all of that, (except brother) and i think if i try hard enough i can make it.

A-Tech
I pray to superman every night.

Rotary, I graduate with an associates in auto mechanics in a year, any jobs on colorado? =\

Felix Leiter
Hey Rotary, how big is your business? Any room for someone with a B.Mgt, major in Marketing and minor in Strategy?

I too started mechanical engineering hoping to eventually be on the next design team for some big manufacturer. 2 years in I decided that in all likelyhood I'd spend the rest of my life hunched over an Apple staring listfully at an autocad program, designing a seat-bracket for a John Deere tractor...that is when I switched to business. I'm not sure if I made the right decision and I hope it works out for all of you dreaming of mechanical engineering.

Rotary Boy
it's me and 11 other people. i would love to bring you guys in for jobs since it seems that you will soon have sklls that would be appreaciated, however in the past month we just got three new things, a new lift and two new workers. The lift was expensive and I have to pay my two new guys, so the place doesn't have the capital to bring on any more employies right now, hopefully though the busniess will continue to grow as it has for the past few years. as for how big is the place, we have alittle office connected to a warehouse, the office isn't very big two rooms, a bathroom and a closet, but the warehouse is massive: 140feet long and 70 feet wide with a 40 foot ceiling, we also have a small parking lot (fits about 12 cars). since our warehouse is massive and has a gigantic door we just store customer cars inside while being worked on or awaiting pickup. The place also has a small basment which is meant to be used for storage, we don't really use it for anything though becuase it is too small to be productive, good place for our fridge and a few file cabinets but thats about it.

A-Tech
I really want to get into the field, and your place sounds pretty kick ass, if things change, I am serious about you notifiying me =\

SLP Addict
My dad has said he will let me get ASE certified, and he said somthing about a new car, if i get every certifacation, it would prolly take me till im 18 to get them all, but even if he would pay half its great!

A-Tech
ase..... is hard. takes some serious mechanics training.

SLP Addict
Well, i guess i better get working then

raska
Originally posted by A-Tech
mechanical engineering has nothing to do with that kinda shit, usually most of em just sit around designing a small piece of an engine or something.

Yeah, but you also write very extensive tech reports. And the punishments and preventative measures against plagerism are throught he roof. We have to sumit most stuff in hard copy and online.

A-Tech
hmmmm, sucks for those balls.

SLP Addict
Yea, im trying to get my self to learn how to write LONG report's, im not so good at that, thats why this article on teh wastegates was so short