granitemonkey

I know right now the biggest I have seen on the websites is 106mm. But I could have sworn I have read something about a 114mm turbo. Is there anything bigger? Any companies working on anything bigger? Just a little bit of discussion

mongse

iTrader: (2)

Garrett has a 106 advertised, but they do make bigger.

granitemonkey

Hmmm, things that make you go hmm How big we talking?

goober35

iTrader: (1)

I wander what size turbo is on the big rigs. I know they double compress the air.

John Wilde

There are 120MM and bigger!

gator's 99TA

iTrader: (2)

double compress? what are you talking about? you mean 2 atmospheres?

granitemonkey

goober35

iTrader: (1)

No. What i have been told. There is one exhaust houstin and 2 cold housings. It will compress the air once and then send it to the other compresor and compress it again.

John Wilde

I don't think that is totally true.
They just run turbos in series.

stangkillin99ss

your correct its not one turbo alone, its 2.

Spin

my parents own a few big rigs and as far as i know there is no such thing but who knows... people are willing to try anything these days... but i dont see how running one compressor right into another on the same turbo will do anything at all different than one compressor. that is unless it had a seperate before turbo intake for each compressor, but why not just run twins if you were gonna do that...

but to answer the original question, rig turbo's get way up there in size... i dunno what the biggest you can get is but i know its well over 106mm. and the sad thing is, some of those big rigs are running 4 of those massive turbo's and putting over 250-300 PSI into the engine (no joke, but obviously thats race and show trucks only... you cant haul a load with 3000 HP and 9000 lbft), and i dunno if any of you have ever seen the intake on a big rig, but they arent small by any means, it takes a ton of air to get a boost reading that high in a semi.

goober35

iTrader: (1)

They double compress the air. If you compress,compressed air it will go from 12psi to 40psi very quickly. So i have been told.

Spin

yes but the air going through the 1st compressor cant just magically double... only so much air gets through and thats it, no matter how many times you compress it after that its still the same amount of air

all im sayin is i dont see how double compressing it will make any difference in the amount of air going through the intake unless it was 2 seperate turbos and even then it wont be double compressing the air... and like i said, my family owns rigs, i see them every day of my life and ive even been to rig shows where i have seen rigs that would completely blow your mind, as they did mine, but i have yet to see anything even similar to double compressing the air.

Spin

and if you have 12 PSI and you compress it again, it will still come out the other end of the second compressor as 12 PSI and the same amount of air because your not compressing more air into a smaller area, you are compressing the same amount of air into the same area as the 1st compressor , or at least on any combustion engine you are. and to make the area after the second compresser smaller, you will have to make the intake tubing smaler, and you wont change anything other than causing restriction to the same amount of air as before and that will get you even less power than you started with, the boost may go up in the last situation but power will still be less because you are still pushing the same amount of air, however, through a smaller area.

i dunno if all that made any sense because i cant think of another way to explain it, but if you dont understand what i said let me know and ill try to make it clearer

stangkillin99ss

the reason they are used is not to double compress the air. Its to allow the HUGE turbo to spool up much faster. What is done is they put a smaller turbo first in line, this small turbo can feed the larger one causing it to spool up much faster than if the larger one were trying to spool on its own. Its not meant to "double compress" but more to help that big *** turbo spool up.

gator's 99TA

iTrader: (2)

i agree with spin. lets remember boost is measured in psi, which is a measurement of restriction, not total cfm. double compresing makes little sense to me if you are trying to accomplish the goal of making more air available into the motor. doubling the restriction in terms of psi isnt going to make more power.

stangkillin99ss

12 psi is 12 psi any way you look at it

mzoomora

iTrader: (36)

It is similar to a 2 stage air compressor in you garage. The first compresses a larger volume of air and compress it under low pressure, then the second large compressor takes that and compress it to the final psi. The second compressor is fed air rather than having to scavenge air, so it spools faster. Like said before, the second compressor could be designed to do it by itself, but much slower, and less efficiently.
You could probably find a diagram of how a 2 stage compressor works on the web, it is the same principal.

Spin

i agree with stangkillin and mzoomora (keep in mind there are other ways to set up the turbo's tho that make them work differently than you explained), but the arguement isnt about how the twins work on them, its about double compressing the air. i understand some people might look at how one turbo runs into the other and think thats whats happeneing, but im just trying to clear it up, its not double compressing, stang and mzoom already explained it good enough so im not gonna waste time saying what they have already said. but anyway lets try to jump back on subject here, i dont know exactly how big you can get them for rigs, i know the get absolutly enourmous tho, probably as much as or more than double the dimensions and output as anything you could get for a car, but i believe this forum was originally asking about car turbo's, but i still dont know how big they go either

mzoomora

iTrader: (36)

The ones that are one our fire engines are about the size of a small round office trash can. I dont know how to better describe it, but they are pretty big.