Does my car suck or what? Someone talk me down! - BMW 3-Series (E90 E92) Forum

thkfast · 08-25-2009, 11:42 PM

I dyno'd my car last week and was happy with my numbers until I SEARCHED this forum and saw the numbers other people are getting! If our cars are rated at 300 HP/300 TQ stock at the engine and I'm told there is a "generally accepted" 25% loss through the drive train - specifically an automatic transmission - wouldn't a stock baseline of 240 HP/240 TQ be expected on a dyno? My 335 has automatic trans with only mod being SSTT and I'm running 91 octane. I pulled 293.89 HP / 300.23 TQ. I quickly broke out my calculator, multiplied the results by 1.25 and came up with 367 HP/375 TQ and thought - "NICE!" But, having seen stock 335's dyno on this forum at 275 HP...was my SSTT only good for about 18 HP? What is more incredible are the JB3 guys with cold air intakes and a few other goodies making 375+ HP / 420+ TQ because wouldn't that convert to 468 HP / 525 TQ at the engine? Is the 1.25 a good rule of thumb when converting dyno runs to actual HP & TQ? This was done on a Dynojet dyno at 83 degrees F. Thoughts on this?

TheAcAvenger · 08-25-2009, 11:50 PM

It's nowhere near 25%. 15% is the conservative guess.

Your best bet is to go back and dyno without the SSTT and see what you get. I dynoed 279whp, 288wtq stock and 338whp,350wtq with v3 and a dci (similar temp, sea level, 93 octane, same dyno). My results seem to be the norm, but all dynos are different. You'll only really know what the SSTT is doing with a delta.

Sidenote, IIRC, most SSTT cars were dynoing in the 305-315 range a year or so ago when they were at their peak popularity.

joyride08 · 08-26-2009, 12:02 AM

Most people dyno on dynojet dynos, they're a bit cheaper. Your numbers look like they were done on a mustang dyno, which have about an -18% drivetrain loss average. One of my good friends own's a AWD mustang dyno, and he's always stating the -18% loss on average.

So at the end of the day, the type of dyno is always a factor when comparing numbers.

rollyn2night · 08-26-2009, 02:41 AM

Yeah, I think 15% is more accurate on drivetrain loss...

enrita · 08-26-2009, 03:09 AM

my AT car dynoed Stock 250 whp on a mustang like dyno with -15% drive train loss and 310 with JB3 map 3.

Turbo>NA · 08-26-2009, 03:13 AM

Did you break in the SSTT?

Like, did you punch it a couple times so the car would get used to it?

thkfast · 08-26-2009, 10:04 AM

Definately a Dynojet dyno and SSTT was fully adapted at the time of the run. I wish I would have done numerous pulls with and without the SSTT, but as you can imagine removing it after the run would have required quite a wait for the engine to cool down enough! I'm starting to realize the dyno thing is an apples and oranges kind of thing where it may not be totally realistic to compare different cars, different conditions, different dynos! I'll have to do it again with a baseline stock pull. Here's the actual data. Thanks!

RambleJ · 08-26-2009, 10:48 AM

You need to do your own baseline to see what YOU gained. Using a standard baseline from random stock cars off of this site is not going to be very accurate.

zerodb · 08-26-2009, 10:52 AM

Dynos should be used for tuning, not for bragging rights. They are absolutely useless as a comparative tool unless used against other tests on the same car and same dyno.

I'm absolutely amazed at how much money must be wasted on these forums on dyno runs with absolutely no tuning being performed. If you want to know how much faster your car is, take it to the track. The numbers from a dyno don't mean anything. At all.

Sniz · 08-26-2009, 11:12 AM

yup don't jump

without dyno'ing your car there 100% stock you have no idea what power you have gained

GeorgiaTech335coupe · 08-26-2009, 11:20 AM

Also, check your math. Multiplying your whp by (1+percentage loss you think you have) is not equal to multiplying your engine hp by the percentage loss you think you have.

case in point:
294 *1.25 = 367.5 but does not equal
367.5 * (0.75) = 275.6

You need to divide the whp by (1-percentage loss you think you have)

294 / (0.75) = 392 hp

And the drivetrain loss is much closer to 15%. I think Dinan or Alpina (or someone) had came to that conclusion a long time ago.

roadkillrob · 08-26-2009, 11:22 AM

It could be a million things, Dyno isn't calibrated correctly, temperature is too high, poor quality gas, doing the dyno run in the wrong gear etc etc.

Like every says, so a run without the SSTT and then do a run with it and see how much gain you get, same day, same dyno, same temp!

thkfast · 08-26-2009, 06:04 PM

GeorgiaTech335coupe,

Oh my God. You're totally right! I hate math.

New plan: Remove SSTT & dyno the car stock...then reinstall, beat it a bit and re-dyno same day. Plus I'll have them do more than 1 run with each set up.

Thanks guys, I was just looking to backup my butt dyno and happened to be in OKC OK where they had a dyno ready to go. I appreciate the input.

Kroy · 08-26-2009, 07:13 PM

Quote:

Originally Posted by joyride08

Most people dyno on dynojet dynos, they're a bit cheaper. Your numbers look like they were done on a mustang dyno, which have about an -18% drivetrain loss average. One of my good friends own's a AWD mustang dyno, and he's always stating the -18% loss on average.

So at the end of the day, the type of dyno is always a factor when comparing numbers.

I was always under the assumption mustang gave higher numbers than dynojet. Someone please correct me if I'm wrong.

Sniz · 08-26-2009, 07:20 PM

Quote:

Originally Posted by Kroy

I was always under the assumption mustang gave higher numbers than dynojet. Someone please correct me if I'm wrong.

mustang's often read a lot lower than dynojets.

zerodb · 08-26-2009, 07:35 PM

Quote:

Originally Posted by thkfast

GeorgiaTech335coupe,

Oh my God. You're totally right! I hate math.

New plan: Remove SSTT & dyno the car stock...then reinstall, beat it a bit and re-dyno same day. Plus I'll have them do more than 1 run with each set up.

Thanks guys, I was just looking to backup my butt dyno and happened to be in OKC OK where they had a dyno ready to go. I appreciate the input.

Unless this is a free dyno, it sounds like you're spending a lot of money trying to make yourself feel better about spending money on that SSTT.

Shurge · 08-27-2009, 12:50 PM

Quote:

Originally Posted by thkfast

GeorgiaTech335coupe,

Oh my God. You're totally right! I hate math.

New plan: Remove SSTT & dyno the car stock...then reinstall, beat it a bit and re-dyno same day. Plus I'll have them do more than 1 run with each set up.

Thanks guys, I was just looking to backup my butt dyno and happened to be in OKC OK where they had a dyno ready to go. I appreciate the input.

That's the best way to do it... also ask the dyno if they've done other 335s and see what their numbers are (if they are willing to share)

08-25-2009, 11:42 PM	#1
thkfast Lieutenant Drives: 2010 335i Sedan Join Date: Mar 2009 Location: Eastern Iowa Posts: 415 iTrader: (1)	Does my car suck or what? Someone talk me down! I dyno'd my car last week and was happy with my numbers until I SEARCHED this forum and saw the numbers other people are getting! If our cars are rated at 300 HP/300 TQ stock at the engine and I'm told there is a "generally accepted" 25% loss through the drive train - specifically an automatic transmission - wouldn't a stock baseline of 240 HP/240 TQ be expected on a dyno? My 335 has automatic trans with only mod being SSTT and I'm running 91 octane. I pulled 293.89 HP / 300.23 TQ. I quickly broke out my calculator, multiplied the results by 1.25 and came up with 367 HP/375 TQ and thought - "NICE!" But, having seen stock 335's dyno on this forum at 275 HP...was my SSTT only good for about 18 HP? What is more incredible are the JB3 guys with cold air intakes and a few other goodies making 375+ HP / 420+ TQ because wouldn't that convert to 468 HP / 525 TQ at the engine? Is the 1.25 a good rule of thumb when converting dyno runs to actual HP & TQ? This was done on a Dynojet dyno at 83 degrees F. Thoughts on this? __________________ The likelihood of one individual being right increases in direct proportion to the intensity with which others attempt to prove him wrong. 2010 E90 335i Montego Blue / Gray Dakota Leather / ZSP ZPP STEP / SSTT / AluFelgen CS7's / M3 lip spoiler / Gloss Black Kidneys / K&N drop-in / Full-time Dual Exhaust
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08-25-2009, 11:50 PM	#2
TheAcAvenger Brigadier General Drives: 2007 E92 335i Join Date: Apr 2006 Location: 757, VA Posts: 3,073 iTrader: (1)	It's nowhere near 25%. 15% is the conservative guess. Your best bet is to go back and dyno without the SSTT and see what you get. I dynoed 279whp, 288wtq stock and 338whp,350wtq with v3 and a dci (similar temp, sea level, 93 octane, same dyno). My results seem to be the norm, but all dynos are different. You'll only really know what the SSTT is doing with a delta. Sidenote, IIRC, most SSTT cars were dynoing in the 305-315 range a year or so ago when they were at their peak popularity. __________________ 2007 E92 335i - TC Kline DA Coilovers, HPA M3 Suspension Retrofit, Quaife LSD, Stoptech 6/4 BBK, Volk TE-37s, AR Downpipes, RDSport Quads, Forge DVs, Stett OC, RB Turbos, Procede V5, PWM Meth, Helix IC, EAS DCI, Rixster VEI, M-Tech Sides, OEM Aero Lip, Rieger Spoiler, Vorsteiner V-35 Hood, Performance Steering Wheel, Anthracite Headliner, OSS Headlights

08-26-2009, 12:02 AM	#3
joyride08 Joyride Drives: 2007 335i \| Black/Black/Alum Join Date: Apr 2009 Location: Detroit, MI / Louisville, KY Posts: 71 iTrader: (2)	Most people dyno on dynojet dynos, they're a bit cheaper. Your numbers look like they were done on a mustang dyno, which have about an -18% drivetrain loss average. One of my good friends own's a AWD mustang dyno, and he's always stating the -18% loss on average. So at the end of the day, the type of dyno is always a factor when comparing numbers. __________________ 2007 335i Coupe \| MT \| Black/Black/Alum \| Sprt + Cold + Prem pkgs

08-26-2009, 03:09 AM	#5
enrita Major General Drives: 335i - Big turbos Join Date: Sep 2008 Location: Italian in Sweden Posts: 6,988 iTrader: (0)	my AT car dynoed Stock 250 whp on a mustang like dyno with -15% drive train loss and 310 with JB3 map 3. __________________ 07 335i AT - TD St.2 Turbos - COBB (Custom Cobb mapping by http://www.protuningfreaks.com/) - JB4G5 ISO - Okada Coils - NGK 5992 Plugs - E85 Walbro - Injen Intake - Helix IC - Snow Stg. 3 - Stett CP - AR DPs - midpipes 100 HJS Cats - Bastuck Quad - PSS10 - QUAIFE LSD - BMS OCC - Forge DVs - AR OC - ALCON BBK - M3 Chassi - Dinan CP - Velocity M rear Toe arms - Advan RZ-DF - Level 10 AT upgrade - Alpina AT Flash

08-26-2009, 03:13 AM	#6
Turbo>NA xbox gamertag: HuGeBluEmOnKeY Drives: M-Sport LCI Join Date: Aug 2008 Location: SoCal (626) Posts: 3,762 iTrader: (2)	Did you break in the SSTT? Like, did you punch it a couple times so the car would get used to it? __________________ E92 335i alpine white \| black dokota \| auto \| zpp \| zsp \| heated \| iPod - ltbmw : vorsteiner : linea corsa : h&r : k&n : e92-lighting : expectalot-vinyl - --GONE--

08-26-2009, 02:41 AM	#4
rollyn2night Lieutenant Drives: 07 E92 335i Join Date: Sep 2008 Location: NJ/NY Posts: 431 iTrader: (0) Garage List 07 e92 335i [0.00]	Yeah, I think 15% is more accurate on drivetrain loss...

08-26-2009, 10:04 AM	#7
thkfast Lieutenant Drives: 2010 335i Sedan Join Date: Mar 2009 Location: Eastern Iowa Posts: 415 iTrader: (1)	Definately a Dynojet dyno and SSTT was fully adapted at the time of the run. I wish I would have done numerous pulls with and without the SSTT, but as you can imagine removing it after the run would have required quite a wait for the engine to cool down enough! I'm starting to realize the dyno thing is an apples and oranges kind of thing where it may not be totally realistic to compare different cars, different conditions, different dynos! I'll have to do it again with a baseline stock pull. Here's the actual data. Thanks! __________________ The likelihood of one individual being right increases in direct proportion to the intensity with which others attempt to prove him wrong. 2010 E90 335i Montego Blue / Gray Dakota Leather / ZSP ZPP STEP / SSTT / AluFelgen CS7's / M3 lip spoiler / Gloss Black Kidneys / K&N drop-in / Full-time Dual Exhaust

08-26-2009, 10:48 AM	#8
RambleJ Lieutenant Colonel Drives: F10 535i M-sport Join Date: Oct 2008 Location: Back in teh so cal Posts: 1,928 iTrader: (2)	You need to do your own baseline to see what YOU gained. Using a standard baseline from random stock cars off of this site is not going to be very accurate.

08-26-2009, 10:52 AM	#9
zerodb Private Drives: 2008 E92 335i Join Date: Aug 2009 Location: Santa Barbara, CA Posts: 53 iTrader: (0)	Dynos should be used for tuning, not for bragging rights. They are absolutely useless as a comparative tool unless used against other tests on the same car and same dyno. I'm absolutely amazed at how much money must be wasted on these forums on dyno runs with absolutely no tuning being performed. If you want to know how much faster your car is, take it to the track. The numbers from a dyno don't mean anything. At all.

08-26-2009, 11:12 AM	#10
Sniz Lieutenant General Drives: e92 335 - gone // e36 M3 turbo Join Date: Mar 2007 Location: Ellicott City, MD Posts: 10,464 iTrader: (1)	yup don't jump without dyno'ing your car there 100% stock you have no idea what power you have gained __________________

08-26-2009, 11:20 AM	#11
GeorgiaTech335coupe Lieutenant Colonel Drives: Black BMW 335i coupe Join Date: Mar 2007 Location: USA Posts: 1,850 iTrader: (0)	Also, check your math. Multiplying your whp by (1+percentage loss you think you have) is not equal to multiplying your engine hp by the percentage loss you think you have. case in point: 294 1.25 = 367.5 but does not equal 367.5 (0.75) = 275.6 You need to divide the whp by (1-percentage loss you think you have) 294 / (0.75) = 392 hp And the drivetrain loss is much closer to 15%. I think Dinan or Alpina (or someone) had came to that conclusion a long time ago. __________________ Legal Disclaimer: Anything I or anyone else says about my vehicle on this website(e90post.com or any affiliated or nonaffiliated sites), pertaining to modifications, is only to gain acceptance from my/our peers, and does not actually represent anything actually existing on my car, and thus, cannot be held against me in any issues, i.e. warranty claims, that may arise.

08-26-2009, 11:22 AM	#12
roadkillrob Brigadier General Drives: 2008 335Cic, 2011 X5 35i Join Date: Jul 2007 Location: Boston Posts: 3,277 iTrader: (13)	It could be a million things, Dyno isn't calibrated correctly, temperature is too high, poor quality gas, doing the dyno run in the wrong gear etc etc. Like every says, so a run without the SSTT and then do a run with it and see how much gain you get, same day, same dyno, same temp! __________________ 2008 E93 335i 2014 X3 35i

08-26-2009, 06:04 PM	#13
thkfast Lieutenant Drives: 2010 335i Sedan Join Date: Mar 2009 Location: Eastern Iowa Posts: 415 iTrader: (1)	GeorgiaTech335coupe, Oh my God. You're totally right! I hate math. New plan: Remove SSTT & dyno the car stock...then reinstall, beat it a bit and re-dyno same day. Plus I'll have them do more than 1 run with each set up. Thanks guys, I was just looking to backup my butt dyno and happened to be in OKC OK where they had a dyno ready to go. I appreciate the input. __________________ The likelihood of one individual being right increases in direct proportion to the intensity with which others attempt to prove him wrong. 2010 E90 335i Montego Blue / Gray Dakota Leather / ZSP ZPP STEP / SSTT / AluFelgen CS7's / M3 lip spoiler / Gloss Black Kidneys / K&N drop-in / Full-time Dual Exhaust

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