How much horsepower can a 335xi handle?

XZ2V · 05-28-2021, 08:45 PM

So my 335 xi have about 80k miles with new turbos how much can push it before I risk breaking parts and other things in the car? I really want to be able to get to around 500-550 hp with similar torque numbers. Is this possible?

MikeP335i · 05-29-2021, 10:16 AM

I'm headed toward this goal as well. Right now I'm on a stage 2 motiv ethanol tune on stock turbos. All good just normal maintenance so far. I have pure HF in the plan once the stocker go. My shop has a lot of experience with N54 platform and thinks I'm good to about 550 - 600 excepting hard launches. They say the dif and axles are a weak point. This is also where you need to worry about your transmission from what I understand as they likely have some considerable mileage. There aren't any big transmission upgrades available as far as I know. I'm curious to see what others say, there was a guy in Chicago that had a thread going about his high horsepower x drive build. Good read.

Bimmer_Bro · 05-30-2021, 10:27 PM

Quote:

Originally Posted by XZ2V

So my 335 xi have about 80k miles with new turbos how much can push it before I risk breaking parts and other things in the car? I really want to be able to get to around 500-550 hp with similar torque numbers. Is this possible?

Should be possible. Make sure you do the full transmission service.
Also use xhp stage 3 if you aren't already. Worth every penny.

I believe 600 ish the the max the auto trans can handle. Above that and the internal clutches start to slip.

whyzee125 · 05-31-2021, 02:57 PM

Maintenance is key for longevity. If you don't drive like a goon/launch all the time, never push the car when cold, and keep an eye on your logs, you can push that power level with confidence.

550whp is a bit of a tricky number though as you mentioned you have new turbos so I'm guessing you want to keep them. The max power you can reliably make on stock turbos is about 480whp on full e85, so if you'd be satisfied with that, it's pretty cost effective.

Beyond that you'd need to either go upgraded twins or single turbo which increases costs significantly, although single turbo at that power level is very reliable.

MikeP335i · 06-01-2021, 10:30 PM

I've flashed the xhp transmission tune in the past 2 weeks. Stage 2 for now, but I'm planning to try stage 3 soon. I had the transmission service with fluid, pan and solenoids. Not cheap, but hoping to make the trans last. I'm at 96K. Anyone have any experience on interpreting the clutch wear from the XHP diagnostics? Haven't reset any adaptions and hear mixed opinions on that.

05-28-2021, 08:45 PM	#1
XZ2V New Member 1 Rep 5 Posts Drives: BMW 335xi Join Date: May 2021 Location: CT iTrader: (0)	How much horsepower can a 335xi handle? So my 335 xi have about 80k miles with new turbos how much can push it before I risk breaking parts and other things in the car? I really want to be able to get to around 500-550 hp with similar torque numbers. Is this possible?
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05-29-2021, 10:16 AM	#2
MikeP335i Private 15 Rep 67 Posts Drives: 2009 335xi Join Date: Sep 2018 Location: Annandale, VA iTrader: (0)	I'm headed toward this goal as well. Right now I'm on a stage 2 motiv ethanol tune on stock turbos. All good just normal maintenance so far. I have pure HF in the plan once the stocker go. My shop has a lot of experience with N54 platform and thinks I'm good to about 550 - 600 excepting hard launches. They say the dif and axles are a weak point. This is also where you need to worry about your transmission from what I understand as they likely have some considerable mileage. There aren't any big transmission upgrades available as far as I know. I'm curious to see what others say, there was a guy in Chicago that had a thread going about his high horsepower x drive build. Good read.
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05-31-2021, 02:57 PM	#4
whyzee125 Brigadier General 2003 Rep 4,030 Posts Drives: Dinan stage 2 335i Join Date: Jul 2014 Location: Chattanooga Tn iTrader: (0)	Maintenance is key for longevity. If you don't drive like a goon/launch all the time, never push the car when cold, and keep an eye on your logs, you can push that power level with confidence. 550whp is a bit of a tricky number though as you mentioned you have new turbos so I'm guessing you want to keep them. The max power you can reliably make on stock turbos is about 480whp on full e85, so if you'd be satisfied with that, it's pretty cost effective. Beyond that you'd need to either go upgraded twins or single turbo which increases costs significantly, although single turbo at that power level is very reliable.
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06-01-2021, 10:30 PM	#5
MikeP335i Private 15 Rep 67 Posts Drives: 2009 335xi Join Date: Sep 2018 Location: Annandale, VA iTrader: (0)	I've flashed the xhp transmission tune in the past 2 weeks. Stage 2 for now, but I'm planning to try stage 3 soon. I had the transmission service with fluid, pan and solenoids. Not cheap, but hoping to make the trans last. I'm at 96K. Anyone have any experience on interpreting the clutch wear from the XHP diagnostics? Haven't reset any adaptions and hear mixed opinions on that.
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