7" or 5" FMIC for MHD Stage 1+?

bobbby · 04-29-2019, 04:25 PM

Stock engine, VRSF chargepipe, no plans to get catted downpipe (need to pass smog), currently running MHD stage 1

No track days, only spirited street driving, car is daily driver

Is 5" VRSF FMIC good enough to handle the extra power of MHD 1+ or should I get the 7"?

MartinWake · 04-29-2019, 05:18 PM

5" is fine bro, I still have my stock one and its good for now...

Pinscher · 04-29-2019, 05:27 PM

The 7 is for upgraded turbos. Just going 7" will take your turbo's longer to fill and built up pressure(turbo lag)?

Why not 5" stepped?

scrllock · 04-29-2019, 06:49 PM

Quote:

Originally Posted by bobbby

Stock engine, VRSF chargepipe, no plans to get catted downpipe (need to pass smog), currently running MHD stage 1

No track days, only spirited street driving, car is daily driver

Is 5" VRSF FMIC good enough to handle the extra power of MHD 1+ or should I get the 7"?

5" HD is perfectly fine even for MHD stage 2+. Wouldn't bother with anything bigger unless you think you might want to upgrade your turbo eventually.

Turbod · 04-29-2019, 07:39 PM

I tend to disagree with all of this logic. This is something you only want to upgrade once. A 7 inch intercooler isn't an absurd size. You will not notice lag with a 7 inch intercooler. Is it needed for a minor tune, no, any aftermarket intercooler will work fine.

This is a single gear pull, 3rd gear at 15 psi with a 7 inch intercooler. My IATs start at 68F and end at 77F. Ambient temps were about 66F.

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TheGoodTheBadTheUgly · 04-30-2019, 12:16 AM

I absolutely agree with Turbod!

I have an ETS 7" FMIC and when I was thinking about whether buying the 7 or 5" I went for the big one since it is something that I was planning on doing once. I am currently on Stage 1+.

Sure you get a bit more "lag" but this gets overshadowed by many factors like the cooler IAT that the 7" provides you. Sure the 5" will do the job, but think well about what you want to do after that, because in every case, the advantageous colder IATs on a thermodynamic level will give you more power.

Turbod · 05-01-2019, 06:21 PM

Another datapoint. I did a 1/4 mile pull today. Ambient temps were 59F. At the start of the run my IATs were 78F and at the end I was at 109F which is a gain of 31 degrees. Boost was at 16 psi and timing was about 10 degrees. I am running the old 7 inch core from VRSF.

Pladi · 05-01-2019, 10:06 PM

bigger is better ... even blondes know that , go for 12 inch....

mike@x-ph.com · 05-02-2019, 12:52 AM

5" HD

DiFFv1 · 05-02-2019, 07:03 AM

Quote:

Originally Posted by Pladi

bigger is better ... even blondes know that , go for 12 inch....

I love you and these posts...

Pladi · 05-02-2019, 01:43 PM

Quote:

Originally Posted by DiFFv1

I love you and these posts...

You remind me of a lost puppy lol Desperate for attention and a new owner

DiFFv1 · 05-02-2019, 02:26 PM

Quote:

Originally Posted by Pladi

Quote:

Originally Posted by DiFFv1

I love you and these posts...

You remind me of a lost puppy lol Desperate for attention and a new owner

That was impressive

, i must say sadly this is my 3rd time around as an owner

starbuck · 05-08-2019, 01:44 PM

Quote:

Originally Posted by mike@x-ph.com

5" HD

Agreed. I got the VRSF 5" Stepped with the new finpack revision. Without the finpack revision I would have go with 7", however the new 5" sees temp drops during a pull.

I don't log, but use a P3 gauge for IAT measuring and see my temps stay relatively flat and sometimes even drop 1 or 2 degress during and just post a pull.

mike@x-ph.com · 05-08-2019, 06:52 PM

Quote:

Originally Posted by starbuck

Agreed. I got the VRSF 5" Stepped with the new finpack revision. Without the finpack revision I would have go with 7", however the new 5" sees temp drops during a pull.

I don't log, but use a P3 gauge for IAT measuring and see my temps stay relatively flat and sometimes even drop 1 or 2 degress during and just post a pull.

Tiago@VRSF · 05-10-2019, 12:00 AM

The new VRSF 5" Stepped HD performs as well as the old 7" HD due to it's redesign.

We've had nothing but great results from our new mid-tier FMIC which was engineered for those interested in 450-850whp. The new 7.5" Competition HD stepped FMIC is the latest evolution of our 7" HD and fills the bumper much better than the standard 7" while saving a few pounds.

If you're looking to break records, go with the 7.5" Race, otherwise the 7.5" Competition is your best bet

Here's a few pics of our prototype units for a size comparison.

04-29-2019, 04:25 PM	#1
bobbby Bobbby 34 Rep 59 Posts Drives: 2011 bmw 335i sedan Join Date: Mar 2018 Location: Los Angeles iTrader: (0)	7" or 5" FMIC for MHD Stage 1+? Stock engine, VRSF chargepipe, no plans to get catted downpipe (need to pass smog), currently running MHD stage 1 No track days, only spirited street driving, car is daily driver Is 5" VRSF FMIC good enough to handle the extra power of MHD 1+ or should I get the 7"?
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04-29-2019, 05:18 PM	#2
MartinWake Lieutenant 84 Rep 414 Posts Drives: CL55 AMG Join Date: Nov 2018 Location: Miami iTrader: (1) Garage List 2011 BMW 335i [0.00] 2016 BMW 320i [0.00]	5" is fine bro, I still have my stock one and its good for now...
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04-29-2019, 05:27 PM	#3
Pinscher Lieutenant 117 Rep 513 Posts Drives: 2008 335i Join Date: Jan 2018 Location: Vancouver iTrader: (0) Garage List 2008 335i - Stock [0.00] 2007 BMW 328 - 330 ... [0.00]	The 7 is for upgraded turbos. Just going 7" will take your turbo's longer to fill and built up pressure(turbo lag)? Why not 5" stepped?
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04-29-2019, 07:39 PM	#5
Turbod Major 400 Rep 1,210 Posts Drives: 2014 E84 X1 35i M Sport Join Date: Mar 2015 Location: Oregon iTrader: (0)	I tend to disagree with all of this logic. This is something you only want to upgrade once. A 7 inch intercooler isn't an absurd size. You will not notice lag with a 7 inch intercooler. Is it needed for a minor tune, no, any aftermarket intercooler will work fine. This is a single gear pull, 3rd gear at 15 psi with a 7 inch intercooler. My IATs start at 68F and end at 77F. Ambient temps were about 66F. __________________ 2011 E92 335i \| 11.7@125 SOLD 2017 Camaro SS \| 12.7@114 SOLD 2019 Audi TT RS \| 10.5@130 SOLD 2020 F97 X3M \| 11.0@123 2023 G80 M3 xDrive
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04-30-2019, 12:16 AM	#6
TheGoodTheBadTheUgly Captain 287 Rep 692 Posts Drives: 2011 E90 335i xDrive Join Date: Feb 2018 Location: Gatineau iTrader: (0)	I absolutely agree with Turbod! I have an ETS 7" FMIC and when I was thinking about whether buying the 7 or 5" I went for the big one since it is something that I was planning on doing once. I am currently on Stage 1+. Sure you get a bit more "lag" but this gets overshadowed by many factors like the cooler IAT that the 7" provides you. Sure the 5" will do the job, but think well about what you want to do after that, because in every case, the advantageous colder IATs on a thermodynamic level will give you more power. __________________ TOTALED \| 2011 E90 335i xDrive - BMS Cold Air Intake - ETS Charge Pipe - ETS 7" FMIC - MHD Stage 2+ - GFB DV+ - PE Mod - VRSF Catless Downpipe - xDelete - xHP Stage 3 2015 E84 X1 35i M-Sport Last edited by TheGoodTheBadTheUgly; 04-30-2019 at 12:31 AM..
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05-01-2019, 06:21 PM	#7
Turbod Major 400 Rep 1,210 Posts Drives: 2014 E84 X1 35i M Sport Join Date: Mar 2015 Location: Oregon iTrader: (0)	Another datapoint. I did a 1/4 mile pull today. Ambient temps were 59F. At the start of the run my IATs were 78F and at the end I was at 109F which is a gain of 31 degrees. Boost was at 16 psi and timing was about 10 degrees. I am running the old 7 inch core from VRSF. __________________ 2011 E92 335i \| 11.7@125 SOLD 2017 Camaro SS \| 12.7@114 SOLD 2019 Audi TT RS \| 10.5@130 SOLD 2020 F97 X3M \| 11.0@123 2023 G80 M3 xDrive
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05-01-2019, 10:06 PM	#8
Pladi Lieutenant Colonel 722 Rep 1,753 Posts Drives: 2011 335i xdrive Join Date: Nov 2017 Location: Waterloo, ON Canada iTrader: (0)	bigger is better ... even blondes know that , go for 12 inch....
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05-02-2019, 12:52 AM	#9
mike@x-ph.com BimmerPost Supporting Vendor 27187 Rep 196,351 Posts Drives: 07-335/12-328/18-M4/21-M4CP Join Date: Sep 2013 Location: Las Vegas iTrader: (23)	5" HD __________________ Check out our current sale by clicking on this link! https://x-ph.com/sale/ Phone number 702-494-9435
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05-10-2019, 12:00 AM	#15
Tiago@VRSF 2108 Rep 43,350 Posts Drives: F90 M5 Join Date: Dec 2007 Location: Doral, FL iTrader: (99) Garage List 2014 F30 328xi [0.00] 2015 F82 BMW M4 [0.00] 2013 Ducati 1199 Pa ... [0.00] 2008 BMW 335i [0.00]	The new VRSF 5" Stepped HD performs as well as the old 7" HD due to it's redesign. We've had nothing but great results from our new mid-tier FMIC which was engineered for those interested in 450-850whp. The new 7.5" Competition HD stepped FMIC is the latest evolution of our 7" HD and fills the bumper much better than the standard 7" while saving a few pounds. If you're looking to break records, go with the 7.5" Race, otherwise the 7.5" Competition is your best bet Here's a few pics of our prototype units for a size comparison.
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