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911R rear lower diffuser retrofit. My take (991.2 C2S).
First off, all credit to @polobai for his pioneering on this project, please refer to his thread for more details of the process.
Since I still have the bumper off as part of my build, which has slowed down waiting for parts / back orders, I figured this would be the perfect time to do this.
My mounting is slightly different, so I decided to share in case it helps the next person.
For the front, I also used nutserts on the pre existing holes on the crossmember, but instead of adding brackets to the diffuser, I kept the front lip, and just hammered it flat and had enough room to drill two holes to mount it directly to the crossmember.
The rear mounting, it seemed hard for me to go the way @polobai did, without having interference from the headers (Soul), but I noticed two holes in the rear engine carrier, and I found there was enough clearance with the muffler mounting clamps to sneak in some brackets up there and used some hardware I had to secure it on top. All I had to do from there was to fab up 2 brackets off some 1/8” alum flat stock and drill two more holes on the diffuser.
Very happy with the end result.
Pics:
The mild trimming needed in the front part. I then hammered the front lip flat (ish) using a 4 Lb deadblow, with enough room left to drill two holes for the crossmember mount. (Also, you can see the diffuser part number on this pic).
Some detail of the fitment up front.
Trimmed the front outside fin corners to fit. Used M8 nutserts in the two pre existing holes on the crossmember. I did have to slightly drill out the holes to take the M8 nutserts. Used Allen head flange bolts to secure the diffuser. I went with stainless nutserts and bolts btw. Bent 1/8” alum. flat stock. Detail showing the mounting spot to the rear engine carrier using existing upper holes (holes are there to allow access for bolts deeper in the engine). Countersunk the holes for the nutserts on the fabricated brackets so they sit flush. Where they mount on the rear engine carrier. The money shot. 4 M8 Allen head flange bolts and the diffuser drops easily for maintenance. Feels very solid when attached on all 4 points, and all force of any impact from underneath would be directed to the frame and rear engine mounts and not the engine itself. Bolted up.
This might be awesome for protecting the belly during winter driving.
I can attest that it is awesome at scraping on every speed bump and driveway you attempt to go over or enter..... 2.5" from diffuser fin bottom to ground on my car.
Last edited by AdamSanta85; 02-16-2022 at 12:06 PM.
I can attest that it is awesome at scraping on every speed bump and driveway you attempt to go over or enter..... 2.5" from diffuser fin bottom to ground on my car.
I would sure hate that scraping sound every time I pulled in or out of a driveway or high spot!!
02-15-2022, 11:31 PM
911R rear lower diffuser retrofit. My take (991.2 C2S).
