slow launch? what am I dong wrong?

NSFW 335i · 04-01-2012, 12:28 PM

Hello,

Well, I wanted to ask you guys why my launches from 0-60 are so slow? I have a 2008 335i with the JB3 tune, along with catless DP and a full catless exhaust. Also a single cone intake (will switch to dual soon).

well my car does "feel" fast compared to when it was stock. I recently purchased a P3 vent gauge, which gives me the option to check my 0-60 time. In map 6 with 93 oct fuel. and only 20 miles to empty remaining, I launch the car many times. My times improve from 5.5 to 5.06. But I can not do the mid to low 4's like the other people with JB3 are doing. My car is 6MT, I launch at 1500 rpm. The only thing that can be a problem is that I switched to non-rft, Continental DWS (all season sport tires). I know these do slow me down, but this much?

Or am I launching wrong? I launch with DTC, not traction off 100%.

Recently I did raced my boss on some empty streets behind our shop. He drives a newer CL600 (V12 biturbo) From a roll he would kill me, but from 0-100 I would beat him. His car 0-60 is 4.2, I am very confused.

could i be leaking boost or something? please some helpful insight would help.

Carl Morris · 04-01-2012, 02:08 PM

Quote:

Originally Posted by NewMember

My car is 6MT, I launch at 1500 rpm.

Are you spinning or chirping the tires at all? If not, you need to be more aggressive.

NSFW 335i · 04-01-2012, 02:19 PM

a little bit of tire spin, and yes chirping as well...

Letica11 · 04-01-2012, 02:21 PM

1500rpm is very low to get that sort of mass shifting. You want to be around 4000rpm and play with the clutch on launch. It's striking that perfect balance between clutch slip and wheel spin. Too much wheel spin, slow launch. Too much clutch slip, cook your clutch and slow launch. Not enough of either and you will bog your start. Watch a few pedal cams and incar cams of race starts on YouTube. Listen to what a good start sounds like.

Practice makes perfect.

JDLM · 04-01-2012, 02:23 PM

You mean besides not posting here? http://www.e90post.com/forums/forumdisplay.php?f=98

ZURICH · 04-01-2012, 02:24 PM

I think you should be launching at much higher revs, more like 3000 but I stand to be corrected.

Carl Morris · 04-01-2012, 06:32 PM

It's a fine line between bog and burn on a manual tranny RWD. Sounds to me like you've probably got a chirp...bog...wait...go. If you're willing to put more wear on the clutch you'll be faster with more RPM and a more gentle clutch engagement.

cgpublic · 04-01-2012, 07:56 PM

...all season tires.

That aside, if you really want fast launches, test drive an xi.

Carl Morris · 04-01-2012, 08:05 PM

Yeah :-). I was trying not to go there since it's not really helpful to the OP, but that's why I bought a 6MT XI. I used to drive a turbo Mustang long ago and it was a pain to launch on street tires. I went AWD with a 2-stage on the next car and it really simplified launching.

rondocap · 04-01-2012, 10:20 PM

My stock 335i on summer tires was getting a best of 5.3 average 0-60. The best I got with a 1st gear, brake boosting launch was a 5.01.

I have an automatic, though. Car launches really hard like an AWD xi I drove. In the dry, of course. Mine is just rwd - but in the dry, it hooks very strongly.

Your all season tires could be the issue, but probably your launches. RWD is hard to put more power on and not get tire spin.

michaelalex17 · 04-01-2012, 10:29 PM

you have a boost gauge and you asked if you might have a boost leak?

NSFW 335i · 04-01-2012, 11:59 PM

Quote:

Originally Posted by michaelalex17

you have a boost gauge and you asked if you might have a boost leak?

Sorry I am a noob, I have tried find similar patterns on the boost guage. So if I see something out of the normal, I know something is wrong. But I am clueless on what my car should vaccum at, what normal boost should be read on different driving styles. I just know how to press the recall button and see my peak boost =[.

Any input would be appreciated.

Idk what my guage would be doing, if I was leaking boost...

04-01-2012, 12:28 PM	#1
NSFW 335i Lieutenant 107 Rep 559 Posts Drives: 08 e92 335i Join Date: Oct 2009 Location: ny iTrader: (7)	slow launch? what am I dong wrong? Hello, Well, I wanted to ask you guys why my launches from 0-60 are so slow? I have a 2008 335i with the JB3 tune, along with catless DP and a full catless exhaust. Also a single cone intake (will switch to dual soon). well my car does "feel" fast compared to when it was stock. I recently purchased a P3 vent gauge, which gives me the option to check my 0-60 time. In map 6 with 93 oct fuel. and only 20 miles to empty remaining, I launch the car many times. My times improve from 5.5 to 5.06. But I can not do the mid to low 4's like the other people with JB3 are doing. My car is 6MT, I launch at 1500 rpm. The only thing that can be a problem is that I switched to non-rft, Continental DWS (all season sport tires). I know these do slow me down, but this much? Or am I launching wrong? I launch with DTC, not traction off 100%. Recently I did raced my boss on some empty streets behind our shop. He drives a newer CL600 (V12 biturbo) From a roll he would kill me, but from 0-100 I would beat him. His car 0-60 is 4.2, I am very confused. could i be leaking boost or something? please some helpful insight would help. __________________ 08 E92 335i AW Coral Red 6MT Fully Loaded\|AA DP\|BMS DCI\|JB4 G5\|Milltek full exhaust\|SSK\|Stett CP\|Tial bov\|Tinted window\|HID Fogs\|M3 Front\|Mtech Rear\|VMR V710\|ACS pedals\|V1 hardwired\|BMW Performance Parts-Shift knob-Boot-E-Brake-SteeringWheel\|CF Parts CSL trunk-V35 Hood-ACS roofspoiler\|Red Pre-LCIs\|Tow hook Plate\|Clutch Stop\|
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04-01-2012, 02:19 PM	#3
NSFW 335i Lieutenant 107 Rep 559 Posts Drives: 08 e92 335i Join Date: Oct 2009 Location: ny iTrader: (7)	a little bit of tire spin, and yes chirping as well... __________________ 08 E92 335i AW Coral Red 6MT Fully Loaded\|AA DP\|BMS DCI\|JB4 G5\|Milltek full exhaust\|SSK\|Stett CP\|Tial bov\|Tinted window\|HID Fogs\|M3 Front\|Mtech Rear\|VMR V710\|ACS pedals\|V1 hardwired\|BMW Performance Parts-Shift knob-Boot-E-Brake-SteeringWheel\|CF Parts CSL trunk-V35 Hood-ACS roofspoiler\|Red Pre-LCIs\|Tow hook Plate\|Clutch Stop\|
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04-01-2012, 02:21 PM	#4
Letica11 New Member 1 Rep 14 Posts Drives: E91 335i M-Sport Touring Join Date: Mar 2012 Location: New Zealand iTrader: (0)	1500rpm is very low to get that sort of mass shifting. You want to be around 4000rpm and play with the clutch on launch. It's striking that perfect balance between clutch slip and wheel spin. Too much wheel spin, slow launch. Too much clutch slip, cook your clutch and slow launch. Not enough of either and you will bog your start. Watch a few pedal cams and incar cams of race starts on YouTube. Listen to what a good start sounds like. Practice makes perfect.
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04-01-2012, 02:23 PM	#5
JDLM Banned 73 Rep 3,277 Posts Drives: 2009 335i Sedan Join Date: Aug 2008 Location: Kansas iTrader: (4)	You mean besides not posting here? http://www.e90post.com/forums/forumdisplay.php?f=98
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04-01-2012, 02:24 PM	#6
ZURICH Major 41 Rep 1,153 Posts Drives: E91 320d Touring M Sport Join Date: Jul 2011 Location: Wettingen iTrader: (0)	I think you should be launching at much higher revs, more like 3000 but I stand to be corrected. __________________ M Sport Package, (PDC), front / rear, Cruise control Mystic Blue Metallic, Beige Dakota leather, Alarm, Automatic transmission, Panoramic glass roof, Heated Seats, Lumbar etc etc "I don't Fuck around but when I do, I dont fuck around"
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04-01-2012, 06:32 PM	#7
Carl Morris Captain 19 Rep 650 Posts Drives: 2008 335xi 6MT Join Date: Feb 2012 Location: San Jose, CA iTrader: (0)	It's a fine line between bog and burn on a manual tranny RWD. Sounds to me like you've probably got a chirp...bog...wait...go. If you're willing to put more wear on the clutch you'll be faster with more RPM and a more gentle clutch engagement.
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04-01-2012, 07:56 PM	#8
cgpublic Lieutenant 22 Rep 508 Posts Drives: 2015 A3 2.0T Quattro Join Date: Dec 2007 Location: Brooklyn to Bronxville iTrader: (0)	Gosh Dong... ...all season tires. That aside, if you really want fast launches, test drive an xi. __________________ Present: 2015 Audi A3 2.0T Quattro \| Scuba Blue \| Sport Past: 2011 E90 335 xDrive (March Build) \| Deep Sea Blue \| Saddle Brown \| Brushed Aluminum Packages & Options: Premium \| Sport \| Cold Weather \| BMW Apps, iDrive & iPod Past: 2008 E90 328xi \| Montego Blue \| Dakota Black \| Brushed Aluminum Packages & Options: Premium \| Sport \| Xenon \| CA \| Heated Seats \| iPod
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04-01-2012, 08:05 PM	#9
Carl Morris Captain 19 Rep 650 Posts Drives: 2008 335xi 6MT Join Date: Feb 2012 Location: San Jose, CA iTrader: (0)	Yeah :-). I was trying not to go there since it's not really helpful to the OP, but that's why I bought a 6MT XI. I used to drive a turbo Mustang long ago and it was a pain to launch on street tires. I went AWD with a 2-stage on the next car and it really simplified launching.
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04-01-2012, 10:20 PM	#10
rondocap Captain 154 Rep 622 Posts Drives: 335i Sedan Join Date: Feb 2012 Location: NY/NJ iTrader: (1)	My stock 335i on summer tires was getting a best of 5.3 average 0-60. The best I got with a 1st gear, brake boosting launch was a 5.01. I have an automatic, though. Car launches really hard like an AWD xi I drove. In the dry, of course. Mine is just rwd - but in the dry, it hooks very strongly. Your all season tires could be the issue, but probably your launches. RWD is hard to put more power on and not get tire spin.
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04-01-2012, 10:29 PM	#11
michaelalex17 Brigadier General 596 Rep 3,386 Posts Drives: Manual Wagon Join Date: Aug 2010 Location: CT iTrader: (4)	you have a boost gauge and you asked if you might have a boost leak?
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