F36 B48 420i vs 430i

Sophar · 10-30-2023, 07:00 AM

Hi,

to preface, I am driving a LCI version f36 420i, and my engine number is b48b20m (medium output). I am looking to tune this engine to stage 1, and i have been running RON98 (https://www.esso.com.sg/en-sg/our-products/supreme-plus) even before tuning, and will likely not change as i understand fuel quality is important after tuning.

Problem: Research have led me to think that most cars on this forum are 428i/430i b48s, which are different. Some quick searches on realoem shows that the piston for 430i (11259468869) and 420i (11259468870) have a different "Length gudgeon pin", where the former is 55mm vs 51mm. but all other parts of the piston is similar.

Question: would you say that this leads to more issues with a stage 1 tuned engine, assuming i do regular maintenance (have been doing at 4-5k km, 5-6mths intervals) with premium petrol (above)? my current mileage is 34k km, and entirely stock (other than aesthetics such as rims, tires and brakes).

Sophar · 11-05-2023, 04:07 AM

Anyone with indepth knowledge kind enough to help out? or has anyone here ran BM3 stage 1 on a 420/320 for an extended period with 0 issues.

Note: further reading had me understand that 430/428 pistons have lower compression 10.1:1 to tolerate higher boost pressures, hence are way more tolerant of a simple ECU tune.

10-30-2023, 07:00 AM	#1
Sophar New Member 5 Rep 8 Posts Drives: BMW F36 Join Date: Jun 2023 Location: Singapore iTrader: (0)	F36 B48 420i vs 430i Hi, to preface, I am driving a LCI version f36 420i, and my engine number is b48b20m (medium output). I am looking to tune this engine to stage 1, and i have been running RON98 (https://www.esso.com.sg/en-sg/our-products/supreme-plus) even before tuning, and will likely not change as i understand fuel quality is important after tuning. Problem: Research have led me to think that most cars on this forum are 428i/430i b48s, which are different. Some quick searches on realoem shows that the piston for 430i (11259468869) and 420i (11259468870) have a different "Length gudgeon pin", where the former is 55mm vs 51mm. but all other parts of the piston is similar. Question: would you say that this leads to more issues with a stage 1 tuned engine, assuming i do regular maintenance (have been doing at 4-5k km, 5-6mths intervals) with premium petrol (above)? my current mileage is 34k km, and entirely stock (other than aesthetics such as rims, tires and brakes).
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11-05-2023, 04:07 AM	#2
Sophar New Member 5 Rep 8 Posts Drives: BMW F36 Join Date: Jun 2023 Location: Singapore iTrader: (0)	Anyone with indepth knowledge kind enough to help out? or has anyone here ran BM3 stage 1 on a 420/320 for an extended period with 0 issues. Note: further reading had me understand that 430/428 pistons have lower compression 10.1:1 to tolerate higher boost pressures, hence are way more tolerant of a simple ECU tune.
	Appreciate 0 Quote