[40 Cylinders]

I finished reading 37 pages on the M3/4 forum on exhaust systems, upgrades, etc.... I was interested in knowing the cell count on the stock system vs a 200-cell mod... I saw a reference to the stock being 700/800 cell... Does anyone have info on the stock catalytic converters ? Does BMW use HSJ converters or some other brand ?

[aerobod]

Originally Posted by 40 Cylinders

I finished reading 37 pages on the M3/4 forum on exhaust systems, upgrades, etc.... I was interested in knowing the cell count on the stock system vs a 200-cell mod... I saw a reference to the stock being 700/800 cell... Does anyone have info on the stock catalytic converters ? Does BMW use HSJ converters or some other brand ?

I wouldn't have thought HJS as a specialist manufacturer could provide the volumes or meet the price that BMW needs across their product lines, more likely BASF would be the main supplier of the converter cores, with Bosch or similar as the assembly vendor.