BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)
 





 

Post Reply
 
Thread Tools Search this Thread
      11-29-2012, 08:57 PM   #1
Bimmer13
New Member
 
Drives: 2010 BMW 135i
Join Date: Nov 2012
Location: United States

Posts: 27
iTrader: (0)

Single Turbo vs Twin Turbos

Of the many cars I've had my last car was a Mazdaspeed3 Single Turbo. In that car you could REALLY feel the turbo. In the 135i I can barely feel the turbos. Is that because its 2 smaller turbos vs 1 bigger one? Also a BOOST gauge in the 135i would've been nice. But maybe since you can't really feel the turbos in the 135i that's why it doesn't have a gauge?

Thoughts?
Bimmer13 is offline  
0
Reply With Quote
      11-29-2012, 09:11 PM   #2
Stohlen
Major
 
Drives: AW 135i
Join Date: Aug 2012
Location: Waterford, Mi

Posts: 1,228
iTrader: (2)

Garage List
2008 BMW 135i  [2.83]
You're not feeling the boost in your speed3... you're feeling the lack of it.

Turbo lag is the feeling you are getting, the time when you push the pedal down, and there is nothing until all of a sudden you're thrown back in your seat because the turbo finally comes on. The twin turbo has significantly less lag because there are two smaller turbos rather than one large one to create the desired effect. Since there is less lag, there is more power initially when you put your foot down, and thus less of that feeling as the turbo spools up to more boost.

^This is the very short answer.

Most turbo vehicles dont have a boost gauge. For the average driver it isn't necessary, so most oem's dont include it. Its added cost for little gain more than a novelty item because most oem boost gauges aren't made very accurate.
Stohlen is offline  
0
Reply With Quote
      11-29-2012, 09:59 PM   #3
splitsecond
Space Admiral
 
splitsecond's Avatar
 
Drives: 135i
Join Date: Sep 2012
Location: Chicago

Posts: 317
iTrader: (1)

Garage List
2008 BMW 135i  [0.00]
Quote:
Originally Posted by Stohlen View Post
You're not feeling the boost in your speed3... you're feeling the lack of it.

Turbo lag is the feeling you are getting, the time when you push the pedal down, and there is nothing until all of a sudden you're thrown back in your seat because the turbo finally comes on. The twin turbo has significantly less lag because there are two smaller turbos rather than one large one to create the desired effect. Since there is less lag, there is more power initially when you put your foot down, and thus less of that feeling as the turbo spools up to more boost.

^This is the very short answer.

Most turbo vehicles dont have a boost gauge. For the average driver it isn't necessary, so most oem's dont include it. Its added cost for little gain more than a novelty item because most oem boost gauges aren't made very accurate.
^Exactly.

If you look at BMW's sales and service documentation, they make a huge deal out of the fact that you can't "feel" the turbo. The idea is that you should feel the full power band at the lower RPM's, and the car should respond like a naturally aspirated engine.

When you "feel" the turbo kicking in, that just means that you didn't have enough boost at the lower end.
__________________
2008 135i Montego Blue sport pkg, premium pkg, Logic 7 sound, iDrive/Nav
Mods completed: JB4+ & FBO || LSD || BMW-P suspension + F/R sway bars || 18" Breyton GTS-R || M3 front bushings || Vogtland camber plates || BMW-P rotors + Stoptech pads |||| Acquired, not installed: BMS WW Meth kit || Logic HVI intake || Mishimoto OCC |||| Shopping for: Summer tires
splitsecond is offline   United_States
0
Reply With Quote
      11-29-2012, 10:39 PM   #4
Bimmer13
New Member
 
Drives: 2010 BMW 135i
Join Date: Nov 2012
Location: United States

Posts: 27
iTrader: (0)

Thanks for the replies. Makes sense however a boost gauge is more than a novelty. The 135i can't be in FULL BOOST the entire RPM range. It would be helpful if I could visually see when the Turbo's are in full boost.
Bimmer13 is offline  
0
Reply With Quote
      11-29-2012, 11:02 PM   #5
christopherkriens
.
 
Drives: 2011 BMW 135i Coupé
Join Date: Dec 2010
Location: Minnesota

Posts: 259
iTrader: (1)

Garage List
2011 BMW 135i  [4.31]
Quote:
Makes sense however a boost gauge is more than a novelty..
It's more than a novelty to enthusiasts, for sure. But we're the exception; the average BMW Owner probably doesn't know or care what it is. Betty the soccer mom with her new 328i sedan doesn't care how much BEwst she's running.
__________________
2011 Black Sapphire Metallic / Coral Red
christopherkriens is offline   United_States
0
Reply With Quote
      11-29-2012, 11:07 PM   #6
splitsecond
Space Admiral
 
splitsecond's Avatar
 
Drives: 135i
Join Date: Sep 2012
Location: Chicago

Posts: 317
iTrader: (1)

Garage List
2008 BMW 135i  [0.00]
Well, she wouldn't be running any boost in a 328i. But yeah, I agree with your point.
__________________
2008 135i Montego Blue sport pkg, premium pkg, Logic 7 sound, iDrive/Nav
Mods completed: JB4+ & FBO || LSD || BMW-P suspension + F/R sway bars || 18" Breyton GTS-R || M3 front bushings || Vogtland camber plates || BMW-P rotors + Stoptech pads |||| Acquired, not installed: BMS WW Meth kit || Logic HVI intake || Mishimoto OCC |||| Shopping for: Summer tires
splitsecond is offline   United_States
0
Reply With Quote
      11-29-2012, 11:09 PM   #7
Greenkirby21
Vrooom :)
 
Greenkirby21's Avatar
 
Drives: C7 Stringray
Join Date: Jun 2010
Location: Dream Land

Posts: 2,607
iTrader: (1)

Send a message via AIM to Greenkirby21
Quote:
Originally Posted by splitsecond View Post
Well, she wouldn't be running any boost in a 328i. But yeah, I agree with your point.
the new 328i have a turbo 4... and I believe u can access the boost gauge through iDrive, at least I think my mom's 335i does that. If not boost, I know it tells you HP and Torque
__________________
2014 C7 Corvette Stringray - Laguna Blue - NPP Exhaust - Competition Seats
Greenkirby21 is offline   United_States
0
Reply With Quote
      11-29-2012, 11:10 PM   #8
GerryL
Private
 
Drives: 2012 135i with PPK- Space Grey
Join Date: May 2011
Location: San Diego

Posts: 63
iTrader: (0)

Quote:
Originally Posted by splitsecond View Post
Well, she wouldn't be running any boost in a 328i. But yeah, I agree with your point.
She would if it were a new 4 cylinder turbo 328.
GerryL is offline  
0
Reply With Quote
      11-30-2012, 02:13 AM   #9
froop
Colonel
 
froop's Avatar
 
Drives: 08 AW 6MT E82
Join Date: Jul 2012
Location: Sydney, Australia

Posts: 2,164
iTrader: (2)

Quote:
Originally Posted by Bimmer13 View Post
Thanks for the replies. Makes sense however a boost gauge is more than a novelty. The 135i can't be in FULL BOOST the entire RPM range. It would be helpful if I could visually see when the Turbo's are in full boost.
Go and get either a Procede or a JB4. You can change the dials on your instrument cluster to show the fuel gauge as a boost gauge. Each notch is 2.5 psi I believe so it shows up to a maximum of 20 psi.
__________________
Procede Rev 3 | PWM Meth | Mr5 Intake | AFE Scoops | ER FMIC | ER CP | TiAl BOV | AR Catless DPs | CP-E Exhaust | Forgestar F14s | M3 Strut Tower Brace | M3 Front Arms | M3 F + R Sway Bars | M3 Rear End Conversion | Moton Clubsports with Swift Springs | Vorshlag Camber Plates | ECS 2-Piece Rotors | SS Lines | Cool Carbons | BR Half Cage | BMWP SSK | BMWP Interior/Exterior Goodies | Blacklines | P3 Gauge | 1M Interior |
froop is offline   Australia
0
Reply With Quote
      11-30-2012, 02:55 AM   #10
pkimM3r
Banned
 
pkimM3r's Avatar
 
Drives: m3 saloon in granny mode.
Join Date: Dec 2009
Location: lost angeles

Posts: 7,321
iTrader: (0)

It def feels like a turbo to me.
pkimM3r is offline  
0
Reply With Quote
      11-30-2012, 04:08 AM   #11
Bmwbreed
Major
 
Drives: 2013 BMW 135i
Join Date: Jul 2012
Location: Rota Spain (US Forces)

Posts: 1,166
iTrader: (3)

Send a message via Skype™ to Bmwbreed
Quote:
Originally Posted by Bimmer13
Thanks for the replies. Makes sense however a boost gauge is more than a novelty. The 135i can't be in FULL BOOST the entire RPM range. It would be helpful if I could visually see when the Turbo's are in full boost.
Well without a gauge you won't have the actual output number but according to BMW these engines make maximum torque from 1500rmp (1200 if n55) to the 5k range before power drops off. So theoretically it should be in full boost between those rpm numbers. This Is also why you can't quote feel the turbo. With full torque/boost output starting at such a low rpm there's really no time to anticipate it. It's just past idle basically
__________________

2013 BMW 135i Alpine white/coral red JB4 stage 2/ AFE stage 2 sealed intake box/ VRSF 3.5 inch catless dp/ Dinan exhaust/ Alpine V3 6000k HID angel eyes/ JB speed AW rear lip spoiler/ OEM mud flaps. ER charge pipe/ VRSF 7 inch FMIC forge star CF5s 19x8.5 and 19x9
Bmwbreed is offline   United_States
0
Reply With Quote
      11-30-2012, 09:29 AM   #12
Stohlen
Major
 
Drives: AW 135i
Join Date: Aug 2012
Location: Waterford, Mi

Posts: 1,228
iTrader: (2)

Garage List
2008 BMW 135i  [2.83]
Quote:
Originally Posted by christopherkriens View Post
It's more than a novelty to enthusiasts, for sure. But we're the exception; the average BMW Owner probably doesn't know or care what it is. Betty the soccer mom with her new 328i sedan doesn't care how much BEwst she's running.
Thats exactly what i just said
Stohlen is offline  
0
Reply With Quote
      11-30-2012, 03:09 PM   #13
IZAGLO
Mbira
 
Drives: Sedonna Red 09 135i SOLD
Join Date: Jan 2010
Location: Garage cleaning Brake Dust

Posts: 1,009
iTrader: (3)

I have to agree that a Turbo car should have a boost gauge for monitoring.... I had a Defi Boost gauge in my last car and loved it and now have the P3 Vent Boost gauge in my 135i which IMO is OEM looking and quality....amazing piece and should be standard on the 135i...it's that nice.
As far as "feeling" the boost like in a Speed3 or STI....yea, its the shitty lag of those cars your are feeling and then you get bombarded with boost from the turbo...it's fun for a bit but after a very short period the lag get's real old....The refinement of having 2 Turbo's and very little lag is really nice on the BMW ...
__________________
IZAGLO is offline   United_States
0
Reply With Quote
      12-02-2012, 11:47 PM   #14
Bimmer13
New Member
 
Drives: 2010 BMW 135i
Join Date: Nov 2012
Location: United States

Posts: 27
iTrader: (0)

Quote:
Originally Posted by IZAGLO View Post
I have to agree that a Turbo car should have a boost gauge for monitoring.... I had a Defi Boost gauge in my last car and loved it and now have the P3 Vent Boost gauge in my 135i which IMO is OEM looking and quality....amazing piece and should be standard on the 135i...it's that nice.
As far as "feeling" the boost like in a Speed3 or STI....yea, its the shitty lag of those cars your are feeling and then you get bombarded with boost from the turbo...it's fun for a bit but after a very short period the lag get's real old....The refinement of having 2 Turbo's and very little lag is really nice on the BMW ...
Exactly. Why wouldn't a turbo car have a gauge? If nothing else it give the driver more info about the car. Even if BMW claims that the car is in full boost from "idle" up to 5K RPM it still would be nice to see exactly where the motor and the turbos are at peak.
Bimmer13 is offline  
0
Reply With Quote
      12-03-2012, 02:23 AM   #15
Stohlen
Major
 
Drives: AW 135i
Join Date: Aug 2012
Location: Waterford, Mi

Posts: 1,228
iTrader: (2)

Garage List
2008 BMW 135i  [2.83]
Quote:
Originally Posted by Bimmer13 View Post
Even if BMW claims that the car is in full boost from "idle" up to 5K RPM it still would be nice to see exactly where the motor and the turbos are at peak.
Where have they claimed that?
Stohlen is offline  
0
Reply With Quote
      12-03-2012, 05:01 AM   #16
flinchy
Colonel
 
Drives: 130i
Join Date: Nov 2011
Location: QLD, Australia

Posts: 2,846
iTrader: (0)

Quote:
Originally Posted by Stohlen View Post
Where have they claimed that?
yeah.. cos it's not.. it's like 2k ish boost STARTS.. then 3k is full boost or so?
flinchy is offline  
0
Reply With Quote
      12-03-2012, 06:47 AM   #17
Bmwbreed
Major
 
Drives: 2013 BMW 135i
Join Date: Jul 2012
Location: Rota Spain (US Forces)

Posts: 1,166
iTrader: (3)

Send a message via Skype™ to Bmwbreed
Quote:
Originally Posted by Stohlen
Quote:
Originally Posted by Bimmer13 View Post
Even if BMW claims that the car is in full boost from "idle" up to 5K RPM it still would be nice to see exactly where the motor and the turbos are at peak.
Where have they claimed that?
He's probobly referring to my post where I said that BMW rates the engines being capable of 300lbs of tq from 1500 rpm up to the 5k range. At least that's what the graph shows in the brochure on the page with engine info. Then I said that's why there's practically no lag because not long past idle it's making the max tq that its rated at. So inbetween those numbers (1500-5000rpm) would be a good guess as to when it should be in full boost.
__________________

2013 BMW 135i Alpine white/coral red JB4 stage 2/ AFE stage 2 sealed intake box/ VRSF 3.5 inch catless dp/ Dinan exhaust/ Alpine V3 6000k HID angel eyes/ JB speed AW rear lip spoiler/ OEM mud flaps. ER charge pipe/ VRSF 7 inch FMIC forge star CF5s 19x8.5 and 19x9
Bmwbreed is offline   United_States
0
Reply With Quote
      12-03-2012, 09:16 AM   #18
Bimmer13
New Member
 
Drives: 2010 BMW 135i
Join Date: Nov 2012
Location: United States

Posts: 27
iTrader: (0)

I think it's very interesting how nobody really KNOWS exactly when the car is at full boost yet BMW doesn't put a boost gauge on a blown car.

BTW yes I was referring to Bmwbreed post. I STILL don't know when the car is at full or partial boost.
Bimmer13 is offline  
0
Reply With Quote
      12-03-2012, 09:36 AM   #19
Stohlen
Major
 
Drives: AW 135i
Join Date: Aug 2012
Location: Waterford, Mi

Posts: 1,228
iTrader: (2)

Garage List
2008 BMW 135i  [2.83]
Quote:
Originally Posted by Bmwbreed View Post
He's probobly referring to my post where I said that BMW rates the engines being capable of 300lbs of tq from 1500 rpm up to the 5k range. At least that's what the graph shows in the brochure on the page with engine info. Then I said that's why there's practically no lag because not long past idle it's making the max tq that its rated at. So inbetween those numbers (1500-5000rpm) would be a good guess as to when it should be in full boost.
Just because a car is at max torque doesn't mean its at max boost. If your engine hit max boost at 1500 rpm, the engine would do nothing past 4000rpm.
Stohlen is offline  
0
Reply With Quote
      12-03-2012, 09:53 AM   #20
Bmwbreed
Major
 
Drives: 2013 BMW 135i
Join Date: Jul 2012
Location: Rota Spain (US Forces)

Posts: 1,166
iTrader: (3)

Send a message via Skype™ to Bmwbreed
Quote:
Originally Posted by Stohlen
Quote:
Originally Posted by Bmwbreed View Post
He's probobly referring to my post where I said that BMW rates the engines being capable of 300lbs of tq from 1500 rpm up to the 5k range. At least that's what the graph shows in the brochure on the page with engine info. Then I said that's why there's practically no lag because not long past idle it's making the max tq that its rated at. So inbetween those numbers (1500-5000rpm) would be a good guess as to when it should be in full boost.
Just because a car is at max torque doesn't mean its at max boost. If your engine hit max boost at 1500 rpm, the engine would do nothing past 4000rpm.
I never said it was at max boost that entire time. Just somewhere inbetween that rpm range. You always seem to read very literal into what someone says in a thread. Lighten up bro.
__________________

2013 BMW 135i Alpine white/coral red JB4 stage 2/ AFE stage 2 sealed intake box/ VRSF 3.5 inch catless dp/ Dinan exhaust/ Alpine V3 6000k HID angel eyes/ JB speed AW rear lip spoiler/ OEM mud flaps. ER charge pipe/ VRSF 7 inch FMIC forge star CF5s 19x8.5 and 19x9
Bmwbreed is offline   United_States
0
Reply With Quote
      12-03-2012, 10:45 AM   #21
bradleyland
TIM YOYO
 
Drives: 2013 M3
Join Date: Jun 2010
Location: Vero Beach, FL

Posts: 1,685
iTrader: (0)

Garage List
Quote:
Originally Posted by Bimmer13 View Post
Thanks for the replies. Makes sense however a boost gauge is more than a novelty. The 135i can't be in FULL BOOST the entire RPM range. It would be helpful if I could visually see when the Turbo's are in full boost.
In what way would it help? What is the benefit of knowing your boost level in a stock car? Once you're modded, I totally understand, but stock, I just don't see the benefit.

Peak boost is not necessarily peak power (horsepower). Peak boost will often correspond with peak force (ft-lbs/newton-meters), but if you're driving for performance, you're more interested in power band and power peak.

If you're interested in knowing where your engine performs best, go do a dyno run. They're usually pretty cheap. If you're running stock, you can just Google image search for 135i N55 dyno and browse the results to get a feeling for where your car is making power.

If you're drag racing, you're most interested in determining shift points. Those are based on acceleration profiles for each gear. Peak acceleration should occur with peak power, so once you have a dyno, you know your shift point (or roughly). With a turbo car, you can sometimes benefit from short shifting a bit. If you really want to know, you get an accelerometer app for your smartphone, and you datalog an acceleration run in each gear. You combine the plots, and you look for the cross-overs. That's your shift point.
__________________
His: 2013 ///M3 - Interlagos Blue Black M-DCT
Hers: 2013 X3 28i - N20 Mineral Silver / Sand Beige / Premium, Tech
Past: 2010 135i - TiAg Coral Red 6MT ///M-Sport
bradleyland is offline   United_States
0
Reply With Quote
      12-04-2012, 06:31 AM   #22
flinchy
Colonel
 
Drives: 130i
Join Date: Nov 2011
Location: QLD, Australia

Posts: 2,846
iTrader: (0)

a boost gague is more useful for diagnosing issues, if you're not hodling boost smoothly, or not hitting targets, you can clearly see it on a gauge...

also, due to how gearing works, acceleration at redline relative to in a higher gear should pretty much always be better.. unless your car REALLY tapers off badly.

all you have to look out for is don't hit the limiter, as the car retards and loses LOTS of power and acceleration.
flinchy is offline  
0
Reply With Quote
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Forum Jump


All times are GMT -5. The time now is 12:52 PM.




1addicts
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST