Single Vs. Twin Turbo

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Originally posted by E_SolSi+May 28 2003, 03:38 PM-->
@May 28 2003, 03:09 PM
i dont really know how it compares but I am guessing the sequential setup would cause the smaller turbo to spin slower or something b/c of the compressed air coming from larger turbo.

:huh: ??????
they arent connected at all

there is a "door" that switches what turbo is getting the exhaust gas and providing the boost for whatever RPM/load/speed/whatever
so the small turbo spools up very fast and provides boost at low RPMs then when more boost is needed for more power than the smaller turbo can provide the door switches and the larger turbo now takes over
and there is usually something that pre loads the larger turbo before the switch so there is no secondary lag

this twin turbo setup is very good
but it takes up a lot of space.... so if you want a larger turbo chances are you cant get 2 of them in the space available so people swap to one
and its heavy.... twice the turbos means more piping and all that shit so it is lighter to go with one larger turbo

ok i see. sort of like a check valve. I was thinking it was like how compound superchargers work.
 
:blink: Weird.. I always thought the TT stood for twin turbo thus meaing the turbos were the exact same.. maybe i thought wrong.. anyway, from how i understand it; for sequential turbos, at low rpms only one of the turbines spool and provide boost while the other one is at idle.. then give throttle position, rpm, load, etc... (much like vtec) the other turbo starts to spool and provide boost also.. and for V configurations, its much like a "regular" setup, where both the turbo spools at the same time.. correct me if im wrong.. i dont know for sure.. :blink:
 
problem is it's hard to get 2 turbos to be efficient without larger displacement. I'd say they would only be a worthwhile option for at least the 2.0s
 
Weird.. I always thought the TT stood for twin turbo thus meaing the turbos were the exact same

If i were a supra owner, i wouldn't want a turbo as big as a t88, way too big, way too laggy. You won't make any power until after 5500 rpms, and even then it's just in short bursts.
When TT setups on supras are done correctly with bigger sequential turbos they make the power they want, and they make it alot quicker than a big laggy t-88.
Know only because a friend of mine just made 900 whp on the bottle off of a t-78 and he's moving onto a TT setup now.
First off, the turbos aren;t sequential, each gets its exhaust flow from 3 of the six cylinders. Second off, most of the twin tubo kits for the supra are (a) way too expensive for most people and (B) many of them have more spool up time (lag) than a bigger single turbo upgrade (t78).

I know this beacuse my dad and i worked on a twin turbo supra back in 98, I was 12 at the time. He had one of the first 600hp supras.
 
Originally posted by boostdGS@May 27 2003, 10:28 AM
If i were a supra owner, i wouldn't want a turbo as big as a t88, way too big, way too laggy. You won't make any power until after 5500 rpms, and even then it's just in short bursts.

Thats why most supra owners who switch to a huge turbo they also hook up some n20 to help it spool quicker
 
uh Inifinte I think you don't know what you're talking about.. Not to be rude or say you're a "baka," but I did a little research and I was right. There are two types of twin turbos; parallel and sequential. Parallel turbos work like regular turbos, usually for V configuration and boxer engines, where each turbo serves a bank. For sequential turbos, the two turbos are in tandam and "sequential." At low rpms and engine speeds, only one turbo is spooling and exhaust energy is flowing to it. When higher rpms or speeds, the second turbo intervines and "aids" the first one in power. And the Supra is sequential along with the FD3S, R32-34, and Porshce 959. Second, a single big T-88 provides lots of power and faster spool than two big/mid-size turbos (say GT-28). But two small turbos do provide better power delivery and spool up time than a single on the streets.. If single turbos are so laggy, why is the fastest "street-legal" Supra running a T-88? You can always kill the lag with anyway. Also, lag is sometimes a good thing to give you traction..
 
Originally posted by endlesszeal@Jun 4 2003, 04:52 AM
Second, a single big T-88 provides lots of power and faster spool than two big/mid-size turbos (say GT-28). But two small turbos do provide better power delivery and spool up time than a single on the streets..

i don't buy that at all
 
This is all assumptions given that I can't even afford an exhaust system for a Supra.. Speculations and stuff can be made, but it's from what I've read and heard. Anyway to explain, say there are two Supras.. One has a single T-78 and another has twin gt-2835s. I've heard that the single spools relatively faster than the twins because the single turbo has less pipping and all the exhaust energy is driven towards only one turbo..Also, the dyno numbers are bigger (if you care about that). then again, two smaller turbos, *smaller than the gt-28*, say a bit bigger than stock, spools faster than either one, but doesnt make as much power.. Either way, I cant say this and this is for sure because I havent experimented with any setup.. In contrast, I do know that the JGTC Supras use the 3SGTE motor, and the a good portion of the fastest (drag) Supras, Skylines, etc. convert to a fat single..
If someone can make sense of this blabbing or knows a little bit more, feel free to correct me or add to it.. "learning is a never ending process." :worthy:
 
Originally posted by endlesszeal@Jun 4 2003, 04:52 AM
There are two types of twin turbos; parallel and sequential.

actually there are three. TTs can be arranged in series, where one turbo blows into another turbo. the concept is also being used in Garrett's hydracharger (two turbos in one housing)(if you have the June 2002 issue of SCC there's a pic on pg.18)
 
:huh: I think that doesnt really count because its not a well developed design and hasnt even seen the day of light on a automobile.. Also, its not a "real' tubrocharged because its not longer driven by exhaust energy.. or was it? didnt really read that part all to much.. Anyway, you can look at either way.. i.e. is a rx7 engine really 1.3 litre or 2.6? there are two rotors, but only one is counted for displacemnt and its widely accepted, however some object.
 
Originally posted by endlesszeal@Jun 4 2003, 05:03 PM
:huh: I think that doesnt really count because its not a well developed design and hasnt even seen the day of light on a automobile.. Also, its not a "real' tubrocharged because its not longer driven by exhaust energy.. or was it?

it is used in some diesel trucks. the reason why its not used in cars is because of size, but garrett is trying to overcome that with the hydracharger, by putting two compressors in one housing(one compressor blows into the other). it still uses exaust energy.
 
Actually, I do have that issue and I just re-read it. It breifly mentions the Hydracharger and it's NOT drive by exhaust energy. And it's not a "true twin turbo" because the turbos are not indentical because one is the size of a quarter and the other one is a "regular" sized one. One of the turbine is turned by a some kinda liquid that is plumbed and runned by the crank pulley. The article than mentions Low Drag Turbo for Garrett or something.. Anyway, Im way to lazy to quote it, but you want me to, I'll do it..
 
yeah i know it runs off water but turbos arranged in series is the same thing, but ran off exaust. the main thing in series is one turbo pumps into another one. if you dont want to include turbos that arent the same size then you shouldnt have said sequiential turbos, which uses different turbo sizes. series can still use the same turbos sizes though.
 
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