MHD stage2+ W out DP??? NO EXHAUST

JayN54 · 10-09-2021, 01:47 AM

I was wondering if I really needed Downpipes on my 2007 335i e92 on mhdstage2+

I already have the following

Vrsf FMIC, Vrsf chargepipe+BOV, BMS dualcones, 1step colder sparks, Bosch coils, silicone inlets. However my car does not have downpipes, my exhaust is cut off where my secondary CATs would be. So it has no muffler, res, or 2ndary cats. Could I possibly run a tune like stage 2+? If it says I need downpipes it’s prolly for extra flow. bc stock cats would block it. but I have mine removed. I’m just wondering. I’m new to exhaust work and flow. Ty.

Luper52 · 10-26-2021, 02:22 PM

You definitely won't see the same performance as if you had a catless downpipe as it does inhibit the flow. I believe you could run it, but your cats will burn up or blow out their internals eventually. Better to just sell your stock cats as they will more than cover the cost of proper catless downpipes.

An alternative would be to take off your downpipes and bust out the internals, but as I said, might as well sell the OEM pipes, get legit catless downpipes.

10-09-2021, 01:47 AM	#1
JayN54 Registered 0 Rep 1 Posts Drives: 335i, 328i Join Date: Oct 2021 Location: Forest City, NC iTrader: (0)	MHD stage2+ W out DP??? NO EXHAUST I was wondering if I really needed Downpipes on my 2007 335i e92 on mhdstage2+ I already have the following Vrsf FMIC, Vrsf chargepipe+BOV, BMS dualcones, 1step colder sparks, Bosch coils, silicone inlets. However my car does not have downpipes, my exhaust is cut off where my secondary CATs would be. So it has no muffler, res, or 2ndary cats. Could I possibly run a tune like stage 2+? If it says I need downpipes it’s prolly for extra flow. bc stock cats would block it. but I have mine removed. I’m just wondering. I’m new to exhaust work and flow. Ty.
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10-26-2021, 02:22 PM	#2
Luper52 Second Lieutenant 59 Rep 217 Posts Drives: 2007 BMW 335i E90 Join Date: Sep 2019 Location: Birmingham, AL iTrader: (0) Garage List 2007 BMW 335i [10.00]	You definitely won't see the same performance as if you had a catless downpipe as it does inhibit the flow. I believe you could run it, but your cats will burn up or blow out their internals eventually. Better to just sell your stock cats as they will more than cover the cost of proper catless downpipes. An alternative would be to take off your downpipes and bust out the internals, but as I said, might as well sell the OEM pipes, get legit catless downpipes.
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