GrimmSpeed HiFlow Exhaust Manifold Crosspipe

Part #: GRM 001001
MSRP: $230.99
( 4 reviews )



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Brand: Grimmspeed
Flange Thickness: 12mm
Installation Hardware Included: Yes
Piping Coating: No
Piping Flex Joint: Yes
Piping ID: 2.00in
Piping Material: 304 Stainless Steel
Piping Taper: No
Mfgr. Warranty: 2 Year
Return Policy:

RallySport Guarantee - 30 Days

Items that are covered under the RallySport Guarantee offer a 30 day no questions asked return policy.

RallySport Guarantee items may be returned within 30 days of the original invoice date and must include all the original parts and contents for a refund.

The RallySport Guarantee does not apply to products that have been modified, damaged, misused or abused. All returns require an RMA (Return Merchandise Authorization) Number, and freight charges are strictly non-refundable. For more information regarding our freight refund policy, please refer to our return policy page found HERE.
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Subaru Impreza
WRX STI 2004, 2005, 2006, 2007WRX STI Limited 2007WRX STI Hatchback 2008, 2009, 2010, 2011, 2012, 2013, 2014WRX STI Special Edition Hatchback 2010WRX STI Limited Sedan 2011, 2012, 2013, 2014WRX STI Limited Hatchback 2011, 2012, 2013, 2014WRX STI Sedan 2011, 2012, 2013, 2014WRX 2002, 2003, 2004, 2005WRX Sedan 2008, 2009, 2010, 2011, 2012, 2013, 2014WRX Hatchback 2008, 2009, 2010, 2011, 2012, 2013, 2014WRX Premium Sedan 2010, 2011, 2012, 2013, 2014WRX Premium Hatchback 2010, 2011, 2012, 2013, 2014WRX Limited Sedan 2010, 2011, 2012, 2013, 2014WRX Limited Hatchback 2010, 2011, 2012, 2013, 20142.5 GT Sedan 2009, 20102.5 GT Hatchback 2009, 2010
Subaru Legacy
Sport 1991, 1992, 1993, 1994GT Limited 2005, 2007, 2008, 2009GT 2005, 2006GT spec.B 2006, 2007, 2008, 2009
Subaru Baja
Turbo 2004, 2005, 2006

What's one of the most overlooked anti-flowing Subaru pieces you ask?? ...The stock exhaust manifold crossover. 50% of your exhaust gasses are passing through this tiny tiny pipe and that is not good. Well here comes the solution for this problem.

Welcome the GrimmSpeed Version 2 Subaru Exhaust Manifold HiFlow Crossover. Well they've decided to step it up a notch with the first revision of the crossover. Meet HiFlow Crossover v2. Immaculate welds, smooth as butter 2" stainless steel, thick 12mm stainless flanges. You can't beat this piece.

Customers have seen up to 15 HP INCREASE when combined with a PnP Subaru Exhaust Manifold. This unit is built from 2" 304 Stainless Steel throughout, maximizing exhaust flow from cylinders 1 and 4 to the manifold collector for faster turbo response. This unit has a flex in the center to allow for easier installation and for thermal expansion during hard driving.

This includes all the gaskets necessary for installation.
This product has no user uploaded media. You can upload your photo or video of your install by posting a review.




Worth The Money
Shane Hollis 8 months ago
Fits perfect, and looks badass on my 05 sti. Plus you get good gaskets with it. Makes it even better. Didn't take very long to install either.
Verified Purchase
Great buy :-) ...
cylomatik17333 1 year ago
Install was easy.Fitment was great the install video helped out a lot. I installed this with the Invidia High Flow DP and I am VERY happy with it. It is very high quality and everything I expected. Thanks GS and RSD ...
Verified Purchase
battlefield220041439 3 years ago
Paired with a DIY PnP Header, this thing made me spool about 300rpm sooner than normal and makes me hold boost much better. overall a great product. Also, as the review before me stated, fitment was spot on!
Verified Purchase
Quality you would expect from grimmspeed
dkohnert72989 4 years ago
Thick beefy flanges, perfect welds and fitment was spot on!


  • AnswerQ: 13 xt  Rocker 1 year ago

    if i combine this with an uppipe should i get my forester tuned to get the most out of it? or will these just be good to go?

    • A: Hello, To take full advantage of the parts a tune would be recommended, however, it's not needed to run the car. Mike

      sales559bb8b6bb86418e5b8c258d 1 year ago

  • AnswerQ: Crosspipe  castrocigar2341611 2 years ago

    Is this like a downpipe where its *offroad vehicles only* or am I smog okay?

    • A: We do not have the ability to confirm that parts will pass emissions. These parts are meant for offroad use only.

      Nick S. 2 years ago

  • AnswerQ: What map?  HogDweeb 2 years ago

    When i get my replacement engine, I'm gonna put this on.. but i dont have the software to read the AP maps. will any of their OTS maps have a tune for this, or do I need a protune? Gonna be doing a stage 2.

    • A: This crosspipe does not require any tuning and you can use the OTS maps, depending on your other mods.

      Zach G. 2 years ago

    • A: Couple posts down, Mike said that a tune is required....

      HogDweeb 2 years ago

    • A: You will gain more power with a custom tune, but in our experience we have found that tuning is not required for a crosspipe alone.

      Zach G. 2 years ago

  • AnswerQ: Curious  JohnM. 2 years ago

    Is this compatible with the invidia ELH?

    • A: A full header set would replace the need for this pipe.

      Nick S. 2 years ago

  • AnswerQ: Tune? without will it cause damage?  Aaron Roth 2 years ago

    I understand you have answered this question a few times already but I was curious as to if I do purchase this and install it will not tuning it cause any serve or minor damage? I wish to just upgrade from my OEM one to this but I have no plans on tuning for atleast another 5-7 months down the road. So can this cause any damage from not being tuned? Thank you RSD!

    • A: If you don't plan to tune for it your best option is to leave it off until you're ready. Mike

      sales559bb8b6bb86418e5b8c258d 2 years ago