Go Back   DTMPower BMW Forum > Technical Discussions > Forced Induction

View Poll Results: Twin Turbo or Single Turbo?
Single Large Turbo 7 63.64%
Twin Turbo 3 27.27%
Turbo and Supercharger 1 9.09%
Twin Screw Supercharger 0 0%
Voters: 11. You may not vote on this poll

Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 12-18-2007, 06:44 PM
Master License
 
Join Date: May 2007
Location: RI
Rides:Turboed 98 ///M3/ 93 turbo 240sx/ 2007 X5
Region: USA - New England
Posts: 52
DC47A is a New Registered Member
Twin Turbo vs. Single Turbo?

Let me Know what everyone thinks, about the ever popular debate single turbo or twin turbo. Especially these days with the new ball bearing turbos pretty much eliminating that dreaded twin turbo lag of the past.
Reply With Quote
  #2 (permalink)  
Old 12-18-2007, 07:53 PM
Andrew's Avatar
mooseoftoose
 
Join Date: Mar 2005
Location: Canton CT
Rides:1984 Euro 320i
Region: USA - New England
Posts: 1,790
Andrew has achieved their Master LicenseAndrew has achieved their Master LicenseAndrew has achieved their Master LicenseAndrew has achieved their Master LicenseAndrew has achieved their Master LicenseAndrew has achieved their Master LicenseAndrew has achieved their Master LicenseAndrew has achieved their Master LicenseAndrew has achieved their Master LicenseAndrew has achieved their Master LicenseAndrew has achieved their Master License
Well the point of a twin turbo setup is to reduce lag, which it does. The "dreaded turbo lag of the past" would be form a single turbo. Twin typically solves solves this problem.
Reply With Quote
  #3 (permalink)  
Old 12-18-2007, 10:55 PM
Master License
 
Join Date: May 2007
Location: RI
Rides:Turboed 98 ///M3/ 93 turbo 240sx/ 2007 X5
Region: USA - New England
Posts: 52
DC47A is a New Registered Member
See i thought it was the total opposite. You have to spool both turbo witch takes more time and emission hence the lag. I guess you learn something new everyday!
Reply With Quote
  #4 (permalink)  
Old 12-19-2007, 02:54 PM
Master License
 
Join Date: Feb 2002
Location: Naperville, IL
Rides:Turbo 332is, 86 535i
Region: USA - Great Lakes
Posts: 377
LDORADO325 is a New Registered Member
With all the extra work in fabrication and parts cost for twin turbo, the single turbo is the way to go. Most high hp cars use a single turbo setup.

-Mike
Reply With Quote
  #5 (permalink)  
Old 12-19-2007, 03:18 PM
RacerJames666's Avatar
 
Join Date: Feb 2005
Location: Sitka, AK-Lake View, IA
Rides:BMW 633csi 84'....BMW M3 99'-RIP : (....
Region: Other
Posts: 1,004
RacerJames666 is a New Registered Member
I concurr with ldorado on that issue.....one less turbo to cook.....
and a lysholm or roots type blower is the best choice for "slap it on and go" performance
__________________
Reply With Quote
  #6 (permalink)  
Old 12-19-2007, 07:54 PM
gnastydent's Avatar
Master License
 
Join Date: May 2006
Location: sc
Rides:bmw 325es 1986
Region: USA - South East
Posts: 199
gnastydent is a New Registered Member
well when you think about it the twin turbo has 3 cylinders powering it comparied to the 6 powering the single. single large ball bearing turbo like the t51 kai
Reply With Quote
  #7 (permalink)  
Old 12-19-2007, 11:22 PM
Street License
 
Join Date: Nov 2007
Location: ohio
Rides:BMW M3 95
Region: USA - North East
Posts: 20
twinm3 is a New Registered Member
ONCE YOU GO BOOST YOU NEVER GO BACK!!!
Reply With Quote
  #8 (permalink)  
Old 12-23-2007, 09:07 AM
Street License
 
Join Date: Dec 2007
Location: Sweden
Rides:BMW 325i -87
Region: Europe
Posts: 15
Nisse977 is a New Registered Member
It it better for the turbo-spolup when it is only 3-cylinders that i banging in to the impeller. 6-cyl it to smooth if you understand what i mean. Why do you think the old Alpina B10 Biturbo had two turbos, and why does the new 335i have two. Toyota Supra, Nissan Skyline and so on.
I have a friend that is working on Saab. He is mapping the turbo engines for them, and he says it is a little bit better to have twinturbo on a strait six engine than just to have one. But like i said, one works good also, but maybe you will have little more lag.

Another thing is if you have one turbo with two intakes... then it is also best to have 3-cyl in one hole and the other 3 in the other. So just don´t put al cylinders to one pipe.

But ofcourse like you said, it is easier and cheaper to only have one turbo.

Read the book Performance Tuning Forced Induction by A. Graham Bell then you understand more
Product: Forced Induction Performance Tuning

Last edited by Nisse977; 12-23-2007 at 09:12 AM.
Reply With Quote
  #9 (permalink)  
Old 12-23-2007, 01:08 PM
Highboosted's Avatar
Road Race or Die
 
Join Date: Jan 2005
Location: St. Louis
Rides:SPEED DENSITY!!!
Region: USA - Great Plains
Posts: 619
Highboosted is a Permit Holder
Depends. That's my final answer.

Want to have the fastest Skyline? Twin turbo setup in parallel.

Want the fastest Supra? Single turbo.

Want a torque monster? Positive displacement supercharger.

Want the bolt-on-and-go compromise? Centrifugal supercharger.

Want the "dyno queen" monster? Huge single. (Larger the compressor and turbine, the more efficient)

Have a V style engine? Best bet is twins, because going single gets tricky and expensive.


PS The 335i has twins for packaging and emissions purposes according to BMW. Smaller compressors allows them to close-couple the turbos, ports, and catalysts (lights off the cats faster), which is the only way they could make it meet the new regs on emissions, and it allows them fit it all in the engine bay. A single would make the runners longer, and the downpipe to the cat longer (because the single would not fit directly next to the engine), which would make it not pass emissions. If lag was the major concern, they would have used a Garrett VGT turbo like Ford and Porsche did.
Reply With Quote
  #10 (permalink)  
Old 12-23-2007, 09:47 PM
Master License
 
Join Date: May 2007
Location: RI
Rides:Turboed 98 ///M3/ 93 turbo 240sx/ 2007 X5
Region: USA - New England
Posts: 52
DC47A is a New Registered Member
I really want to thank High Boosted and Nisse for brining two really good posts together! You both brought some great information together!!!
Reply With Quote
  #11 (permalink)  
Old 12-25-2007, 11:45 AM
gnastydent's Avatar
Master License
 
Join Date: May 2006
Location: sc
Rides:bmw 325es 1986
Region: USA - South East
Posts: 199
gnastydent is a New Registered Member
i think its just a sales thing also, if you own a supra or a skyline then you got money and if someone say 1 turbo your like, o ok a labarin has a turbo but when you say twin it like omg 2 turbo that must be like twice the boost. i still go with single large because you can push more boost faster cause 2 med size turbos will take longer than 1 single large turbo. and you also got to think about the air flowed to the intake because it maybe 30 at the turbo but 25 at the throttle body i just think personally i choose 1 single large air flowing monster it also way less confusing in setting up the maps.
Reply With Quote
  #12 (permalink)  
Old 12-28-2007, 04:17 AM
E30stain's Avatar
Sherminator
 
Join Date: Aug 2006
Location: everywhere
Rides:'95 Triton turbo diesel
Region: Australia
Posts: 522
E30stain is a New Registered Member
as far as in know...
*single large turbo = longer spool up but bigger top end power
*twin turbo in series = smaller one spools up gives engine more low down power to spool larger one up quicker (only know a couple of drag cars with this setup... knowledge of this comes from very very very big diesel engines on ferries ect. that dads driven.\
*twin turbo in parrallel = 3cyl on each turbo... many different applications of this setup can be set up for low down power or huge immense amounts of power although the turbos of today are big and efficient enough to not need this sort of setup.

im not an expert so if someone wants to correct what ive just said :P oh and the series setup is really weird but the engines its used on are that big and boosted that the oil actually has to be heated and then pumped through the engine for a good 15-30mins before startup... so yeah not the best setup to consider on a car let alone one to be used on street.
Reply With Quote
  #13 (permalink)  
Old 01-01-2008, 04:45 AM
Street License
 
Join Date: Dec 2007
Location: Sweden
Rides:BMW 325i -87
Region: Europe
Posts: 15
Nisse977 is a New Registered Member
Yes most dragcars has one single turbo. But Vidar Strand has twinturbo setup on his M3 E36 dragcar with S38 engine (E34 M5 engine).

Look here!
V.S Motor - Vidar Strand

BMW M3 E36 3,9 - 1422bhp / 1610Nm (1186ft.lbs torque) - engine buildt by V.S Motor




And here you have some movies when he was driving it on some car meetings in Sweden 2006. the best time was 7,64s @ 293km/h on 1/4mile That´s a fast Beemer!
V.S Motor - Vidar Strand

Last edited by Nisse977; 01-01-2008 at 05:15 AM.
Reply With Quote
  #14 (permalink)  
Old 01-18-2008, 10:18 AM
TRANCe36's Avatar
Master License
 
Join Date: Mar 2007
Location: Chicago
Rides:e36 coupe
Region: USA - Great Lakes
Posts: 83
TRANCe36 is a New Registered Member
WHY IS ONE OF THE OPTIONS TURBO + SUPERCHARGER, WOW
Reply With Quote
  #15 (permalink)  
Old 01-18-2008, 11:01 AM
itsabimmerthing's Avatar
Anti-bandwagon
 
Join Date: May 2005
Location: Tellico Plains, TN
Rides:2004 M3 vert, manual
Region: USA - South East
Posts: 1,120
itsabimmerthing is a Permit Holder
I wouldnt ever twincharge, but it has been done. A shop twin charged a mini cooper with excellent results. Many people take the 4agze supercharged mr2, and slap a turbo with it. VW actualy has a new car comming out with twin charging technology. Its not impossible, and not that far from being a fad.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 01:06 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0 ©2011, Crawlability, Inc.
RV12
DTM Power © 2013
Message Board Statistics