[BimmerHausPerformance]

I just got some nice new plugs and regapped them to .020 after getting some rich to lean errors. Old plugs were white and powdery (which means hot and lean) and they had a .032 gap. I have an 02 simulator (due to catless dp) which allows me to control how lean or rich I am so I set the voltage down to .75 which per the simulator is the richest acceptable value before throwing CEL for OBDII.

It ran a 12.32 which I was really happy with. Not sure if anyone else has any 1/4 mile times... seems like a lot more people in the 3 series are modding the n55's. Here is what I have:

AFE chip
Catless DP
Armytrix exhaust
CDV delete (6sp MT)
BMS Intake
Wagner knock off FMIC
O2 simulator
93 oct

[JDMSteven]

Incredible! 0-60 in 4.5 and its a RWD car? Wow!

[BimmerHausPerformance]

Could the OBD Fusion program itself be off? Or are these #'s reasonable? I have no idea... it is reading right from my ECU and uses GPS I believe...

[byebyev8]

I think they messed up on that slip? Maybe its a 13.32. There's no way that car ran a 12.3 at only 105mph

[BimmerHausPerformance]

It's an electronic slip so it's not messed up. I did some research and it's completely possible to have that ET with those trap speeds.

I was more curious if anyone else with similar mods has any 1/4 times they could share.

[ziekxq]

Stock 2011 535i does 1/4 in 14 seconds. There is no way that car can do 12.3 with just those mods and AFE chip. If it were true I should be doing 10 seconds with my pure stage 2 lol which I highly doubt that I am even near that.

[BimmerHausPerformance]

I figured as much, that's why I posted this. I don't think that OBDII reader is accurate though, in theory, it should be. Have you not dyno'd your car or ran a 1/4 mile? What mods do you have?

[ziekxq]

12.32 would mean you are almost as fast as stock GTR that comes with 595hp and does 1/4 mile in 12.1 seconds with curve weight of 3800~.

Pure Stage 2
VRSF FMIC
Catless DP
MP Exhaust
Chargepipe
Custom turbo inlet
K&N Aircharger Intake
xHP Trans tune
MHD with custom tune
LPFP Stage 2
93 octane

Next on list is probably:

Custom intake
Precision racewerk coils
Helix HPFP Overdrive Unit
TMap N20 sensor

[AmuroRay]

Ehh, a guy at the track ran 12.2 @113mph with his M235i. Bolt ins and JB4 Map 5 and a few gallons of race fuel?

[ziekxq]

Originally Posted by AmuroRay

Ehh, a guy at the track ran 12.2 @113mph with his M235i. Bolt ins and JB4 Map 5 and a few gallons of race fuel?

M235i is much lighter car plus with race fuel and map 5 he was probably close to or at 400whp. Completely different car.

His F10 with AFE is probably making 310whp + 4200 pound vs m235i close to or at 400whp with 3500 pound.

[Bmw doubles]

Also depending on which year N55 you have, the outlet on the DP is either 3.5" or newer ones 4". Plus N55's ECUs are not the same across the board. Meaning what is programmable and what is not (missing tables).

[Rayzor]

No Disrespect, I would take those times with a pinch of salt. For the mods you have I would estimate low 13s to high 12s
I suggest you try simulating that time using a Dragy or Vbox.

[kimoboy]

Is there difference between 3.5" and 4" in power gain.

Originally Posted by Bmw doubles

Also depending on which year N55 you have, the outlet on the DP is either 3.5" or newer ones 4". Plus N55's ECUs are not the same across the board. Meaning what is programmable and what is not (missing tables).

[kimoboy]

I see you have XHP trans, it it any good. My friend has it in his 340i and made the car slower, because less boost !! less traction.

Originally Posted by ziekxq

12.32 would mean you are almost as fast as stock GTR that comes with 595hp and does 1/4 mile in 12.1 seconds with curve weight of 3800~.

Pure Stage 2
VRSF FMIC
Catless DP
MP Exhaust
Chargepipe
Custom turbo inlet
K&N Aircharger Intake
xHP Trans tune
MHD with custom tune
LPFP Stage 2
93 octane

Next on list is probably:

Custom intake
Precision racewerk coils
Helix HPFP Overdrive Unit
TMap N20 sensor

[ziekxq]

Originally Posted by kimoboy

I see you have XHP trans, it it any good. My friend has it in his 340i and made the car slower, because less boost !! less traction.

I am not sure why he is seeing less boost? I have no such problem, is he running JB4 or flash tune? I have MHD and I am not using linear throttle option either.

To me xHP is awesome... Fast shifts, consistent boost in all gears, and I have AWD so no traction issues. Only time I had traction issue is when I changed launch control power by 35 percent over stock. Dropped it down to 25 percent over stock on launch control and no traction issues.

He can setup torque values by gear to get better traction.

[BimmerHausPerformance]

What is the deal on the n20 TMAP sensor, what is the benefit there?

[AZ-MCRacer]

Originally Posted by BrowBMW

What is the deal on the n20 TMAP sensor, what is the benefit there?

If you are exceeding 21PSI, the stock 2.5 bar sensor can't read it, so you go to the 3.5 bar that is standard on the N20 platform. It isn't needed on stock turbo, but for aftermarket that goes higher boost you need it.

[Bmw doubles]

Originally Posted by kimoboy

Is there difference between 3.5" and 4" in power gain.

I think indirectly there is, meaning faster exiting of gases meaning you can advance timing and allow for more heat to escape faster. It also means faster spool.

[SC300T]

So I'm interested in the 02 simulator. Did you do this to the primary, pre-cat wideband 02 sensor, or the one after the cat? IIRC the N55 F10 has just two 02 sensors, the primary wideband and the one after the cat.

I didn't think the one after the cat did much other than to check the catalyst efficiency.

Did the 02 simulator change the driving response when you changed the voltage offset to make it richer?

My N55 seems to naturally run lean and it hesitates and is not responsive. I don't think BMW ever gave it enough tip-in fuel (acceleration fuel). I'm wondering if this 02 simulator can get it a little richer, and therefore more responsive.

AFE chip
Catless DP
Armytrix exhaust
CDV delete (6sp MT)
BMS Intake
Wagner knock off FMIC
O2 simulator
93 oc

[BimmerHausPerformance]

The simulator was post-cat since I have a decatted downpipe. I wrote up a tutorial on it if you want to read it. But after doing my research I would not recommend the 02 simulator I did, there are simply better options out there. It cost me about 200 bucks total and I'm going to ditch what I did and do an MDH flash. That's a lot better way to go and should only cost about 500 total. The problem with the o2 simulator as well is the fact that it's static. It doesn't ever change the signal to the ECU. You set the voltage, and that's what it is, period. So it doesn't adjust fuel flow and I have been getting lean errors periodically when I'm at higher RPMs. An MHD tune should adjust the fuel based on the tune I load and also remove the CEL for the O2 since I don't' have a cat. I hope this helps. Thanks.

[ziekxq]

You want to do o2 simulator after the cat. I would recommend you take it off asap before you damage the engine or something. The order it should be in is: Turbo > (Catless dp > first o2 snesor > no cat since it is Catless > similulator) > exhaust piping.

I put brackets because that is all on downpipe. The first o2 sensor help ECU decide the AFR and second one after the cat just monitors if there is a cat and it is doing its job. So placing the simulator there tricks the second sensor. I have o2 bung installed there.

[BimmerHausPerformance]

The O2 simulator is after the cat in my case. That's the one that causes a CEL since there is no cat.