911sc RSR/IROC bumper fitment questions

[LeftCoastErik]

Just got my RSR bumper from Rennspeed. Quality seems solid. The top surface of the bumper seems Far too wide/deep. It hits the body and leaves the bumper shock surface 1-1.5" from the bumper bracket surface. I am assuming that I need to trim the top surface to allow the bumper to move back more. Anybody been through this? Can anybody give me a measurement of the correct width of the top surface.

Thanks

[bkreigsr]

Don't bother trimming the bumper. If you have an impact strong enough to compress the front shocks, the fiberglass bumper will be toast anyway. Leave it flush with the hood.
Bill K

[LeftCoastErik]

Not worried about the impact but the bumper needs to move rearward at least 1.5" to match the fender The top horizontal surface seems too wide. The bumper sticks out too far. If I move it in, it should actually mate with the bumper shocks anyway

[Bergo]

picture would be worth more than 1000 words in this case

[LeftCoastErik]

Here are some pics! thanks folks

[Quicksilver]

People always talk about how much fitting that fiberglass parts require but this is the first real picture showing it.

I'd call Rennspeed about it or get prepared to do a lot of trimming.

[Bergo]

wow, that's pretty bad.

[Ferrino]

I've seen that lateral mismatch before, but the fore-aft is ridiculous!

[3literpwr]

IROC bumpers seem to require lots of trimming to look right. Many installed right out of the box look horrible.

[SilverWT]

Originally Posted by LeftCoastErik

... the bumper needs to move rearward at least 1.5" to match the fender ...way

You will need to cut notches in the top surface to let it fit around the wing/tub joining area. Like in the picture below.


They will not need to be as deep, I sectioned the bumper so it fitted even further in, more here Modifying an IROC Fibreglass Bumper


Mark

[Tom '74 911]

Originally Posted by 3literpwr

IROC bumpers seem to require a lot of trimming to get to look right. Many that are install right out off the box look horrible.

This is true.

I have fiberglass IROC bumpers on my '74 911 and I definitely had to trim out a notch for the front bulkhead/trunk so it would slide backwards enough. As mentioned above and in my experience, fiberglass parts are rarely simply "bolt-on"...

Not difficult to trim/cut. Just do a little at a time and keep checking the fit as you go - easier to keep trimming than have to add material back after you trimmed too much!

Tom

[LeftCoastErik]

Thanks for the pics. That held. Peter confirms that they leave extra on top that needs to be trimmed. Yayyyy. Hope the rear and duck fit better. This is what my holiday time will be spent on. Need it done by Monday to ensure they are painted for next weekends rGruppe meet up. Hustle hustle

[dfhtrhjn]

I have that bumper but for the turbo,; yes you have to trim the top back so that it will slide back enough. It's a blessing because once you notch/cut it back, the fit will be perfect.

At least in my case the impact bumpers brackets didn't fit, way too long. I made some hillbilly crush tubes from pvc that fit those holders.

[KTL]

It needs to be notched because Rennspeed makes the bumper "shelf" too deep in the front. My front IROC from MA Shaw required no trimming to fit the '87 911 fenders. They also provided a vertical section on the bumper behind the shelf to allow fastening of the bumper to the original holes in the body. I believe these are the holes for the duckbill rubber smile.

The only trimming I had to do was trimming at the wheel arch for tire clearance due to 16x8 wheels with 225/50 tires. All of the MA Shaw parts were really nice and truly did not require a lot of massaging to look even halfway decent.

I had a Rennspeed ducktail and the quality was pretty poor. The area where the lid has a sharp corner next to the duck spoiler, to turn down and establish the bottom section of the lid, was REALLY thin and had some voids/air holes in it. I would suggest shining a light thru that area of the duck and make sure they got enough fabric and gel coat in that area.

Nice Group4 wheels. How do you like them? Sorry for the hijack, but had to ask........

[gliding_serpent]

I just ordered Getty Iroc bumpers. They seem to have a good rep for fitment. I have one of their ducktails, and fitment was good, but I will not say it did not require work... but then mine looks really nice now.

Everyone who you talk to says don't cheap on fiberglass parts as you will end up paying for it in body-shop labor, and then some, should it have fitment issues. The reality however is that they are hand made, so each will be a bit different.

[mreid]

My Shaw bumper was 1" too wide for my turbo body (1/2" on each side). I had to cut it in half, remove 1" from the middle, and bond it back together. Then trim the hood area as shown above for it to slide into place. Then it was a perfect fit and I didn't use a smile, only fender trim.

[LeftCoastErik]

I love the wheels. A little heavy but they look sweet. I'll get pics up tomorrow, but sure enough, the front fenders stretched a little and il be damned if the bumper doesn't fit just fine. Crazy! Relieved !!

[panzerfaust]

Like the campy replicas also.. Group4 colors seems to be a tad washed out?

[LeftCoastErik]

here are some pics in mock up. It lines up quite nicely!

[wayner]

You think that fit is bad. Look at how the factory did it on the SCRS!!