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Heading to Laguna Seca, managed to get this installed before heading up. Few pics. We learned a lot during install. None of the shops I contacted have ever installed one. Took 6hrs and ended up with check engine light when done. Seems car needs to few restarts and process to clear after disconnect battery
Did the seats need to be removed? And did you get the pre cut parts for trim?
I have their roll bar in my RS and really like the fit and finish.
Oh Yes, lol, seats had to come out and luckily since the roof panel comes off, made the job a lot easier, but still 6hrs of work. This was our first time doing it, so future installs should be 5hrs.
For the trim parts, sadly CMS nor anyone else has the pre-cut trims, not sure why. The good news is, the area that does need to be cut is very small and not even noticeable. I figured I’ll get the trim peace in the future when/if I ever sell car in the future. And if bar is removed, you can’t even see the hole as the back of seat mainly covers it
What was the most difficult part? Are there only two attachment points to the car?
Well, doing it the first time, everything was kinda a difficult, but as we put everything together, it became easier process. For example under seat connectors, took us 10 min to figure out how to disconnect, but took no time reconnecting, so next install saves 9 minutes, lol. Just learning the nuances of each step, as the C8 internally is very different vs previous gens. And yes, 2 attachment points, they are below the rear seat belt harness attachment with huge/long bolt that goes into the body. It’s pretty damn solid.
Interesting that they didn't include grommets for the cut-outs? There's a chance for plastic-on-metal rattling as the plastic expands/contracts in heat/cold. Beware of that. Black electrical tape around the bar near the mating surface of it and the trim piece may tame some of that potential noise.
I'm fortunate in that I have a Chevy service department that's usually willing to do these things for me. Having a Corvette guy that knows how to pull trim pieces and electrical connections is damned handy, even if it does cost an extra penny or two.
Interesting that they didn't include grommets for the cut-outs? There's a chance for plastic-on-metal rattling as the plastic expands/contracts in heat/cold. Beware of that. Black electrical tape around the bar near the mating surface of it and the trim piece may tame some of that potential noise.
I'm fortunate in that I have a Chevy service department that's usually willing to do these things for me. Having a Corvette guy that knows how to pull trim pieces and electrical connections is damned handy, even if it does cost an extra penny or two.
they did provide template for cutout, so that was easy. Our shop is fabricator, so we had all the experience necessary to do installs. We used black electrical tape when needed to prevent rubbing, those steps were obvious along with using black magic marker and also cigarette lighten for trim pieces to ensure they don’t fray apart in the future. Again, first time, big learning curve. Just trying to remove the rear trim took us 10-15 minute to see what pieces are connected to what. Lots and lots of clips have to be disconnected in roof panels section to gain access.
I do HIGHLY recommend the advanced bar from CMS, this way you don’t need to cutout the center rear console trim!! Since these pieces aren’t being made by anyone, I’d recommend not cutting into it.
I do HIGHLY recommend the advanced bar from CMS, this way you don’t need to cutout the center rear console trim!! Since these pieces aren’t being made by anyone, I’d recommend not cutting into it.
Ordered from GM by VIN. Stored my originals and cut the replacements.
Here is the center console part number - black 1LZ. The part numbers will be different based on color and trim level. My dealer just entered my VIN to get the right combo.
Edit: Found the part numbers for the side panels. Again, 1LZ black. R.H 4036057. L.H. 40355449
I have a question that I want to ask but know upfront is going to sound negative and condescending. So I apologize for that, I genuinely want to understand the reason one would choose CMS over other options.
This harness bar does not add rollover protection, but it DOES add the downsides of a 4 point roll bar, namely that there is a bar that could hit your unhelmeted skull in a bad collision. Is the seat tall enough in the C8 that this isn’t a factor?
A 4 point roll bar is very similarly priced to this harness bar.
So my main question is why would someone choose this harness bar over a 4 point roll bar from someone like RPM?
There are other harness bars on the market from Peitz and Brey Krause that also do not require cutting the center trim, but do not add a metal bar behind your head.
I have a question that I want to ask but know upfront is going to sound negative and condescending. So I apologize for that, I genuinely want to understand the reason one would choose CMS over other options.
This harness bar does not add rollover protection, but it DOES add the downsides of a 4 point roll bar, namely that there is a bar that could hit your unhelmeted skull in a bad collision. Is the seat tall enough in the C8 that this isn’t a factor?
A 4 point roll bar is very similarly priced to this harness bar.
So my main question is why would someone choose this harness bar over a 4 point roll bar from someone like RPM?
There are other harness bars on the market from Peitz and Brey Krause that also do not require cutting the center trim, but do not add a metal bar behind your head.
Nothing negative or condescending, so you are all good. These are great questions and they should be asked and answered properly to help all owners out. So, lets dive into this.
-For the Brey Krause/etc bars, they do need cutting, see below from Brey website directly: Note: Because of mounting locations in the C8, the b-pillar plastic sail panel covers will require slot on either side to be cut. Sail panels replacements can be ordered from your GM Dealer if you do not want to cut the original panels. See Installation Instructions for Part Numbers
-From my research, every bar will somehow be attached to some part frame of the car, and that’s because there's no exposed structure to securely attach to.
-The bar is directly behind the seat, so the bar could not possible hit your head, so that part is safe.
But here is the key answer to your post, why a 4 pt harness solution? The simple answer is “HANS”. Not sure about you, but I don’t drive 10/10ths, I enjoy the track and have an awesome time, and my #1 concern for tracking is injury to the NECK, this is the most common and critical accident that can occur tracking and the only way to protect this is via the HANS device, which requires the harness bar system. The car has amazing air bags, amazing safety, but there is just no neck protection. At a local track, drive lost control of car, went sideways and hit a barrier dead center of the passenger side, the impact caused his neck to wipe so hard to the right, it snapped his neck and that’s that. If I was doing more high end racing, I would go for like the RPM or full cage, but that’s massive installation and massive cutting, so for all these reasons, its just trying to save my neck, literally. I can break an arm, leg, etc, all survivable, but neck injuries never ends well.
I agree that use of the HANS is the most important reason for a harness bar (or cage with a harness bar). Although the Simpson Hybrid S head and neck restraint is FIA and SFI approved for use with an OEM 3-point harness, I am more comfortable with a 5-point or greater system. I have not been able to find the complete installation instructions for the RPM C8 roll bar, I am very curious to see how they mount the lower part of the main hoop to the aluminum chassis as well as the upper down-bars behind the seat. There are very specific requirements for such mounting to absorb the load without the installation compromising the structural integrity of the OEM chassis (drilled holes, stress risers, etc.) Having gone through the drill of mounting a cage in an aluminum-framed C6 Z06, I can tell you it is not a trivial task. Also, I don't see a harness bar that is integral to the RPM cage at the proper height for harness strap mounting - but maybe I am missing it. There appear to be "eye bolts" in the bulkhead behind the seat, but I can't tell how they are mounted.
Edit: Here is an example of a well thought out approach to mounting the main hoop to an aluminum chassis - in this case a C7. Notice how it spreads the load over multiple surfaces and mounting points..
Nothing negative or condescending, so you are all good. These are great questions and they should be asked and answered properly to help all owners out. So, lets dive into this.
-For the Brey Krause/etc bars, they do need cutting, see below from Brey website directly: Note: Because of mounting locations in the C8, the b-pillar plastic sail panel covers will require slot on either side to be cut. Sail panels replacements can be ordered from your GM Dealer if you do not want to cut the original panels. See Installation Instructions for Part Numbers
-From my research, every bar will somehow be attached to some part frame of the car, and that’s because there's no exposed structure to securely attach to.
-The bar is directly behind the seat, so the bar could not possible hit your head, so that part is safe.
But here is the key answer to your post, why a 4 pt harness solution? The simple answer is “HANS”. Not sure about you, but I don’t drive 10/10ths, I enjoy the track and have an awesome time, and my #1 concern for tracking is injury to the NECK, this is the most common and critical accident that can occur tracking and the only way to protect this is via the HANS device, which requires the harness bar system. The car has amazing air bags, amazing safety, but there is just no neck protection. At a local track, drive lost control of car, went sideways and hit a barrier dead center of the passenger side, the impact caused his neck to wipe so hard to the right, it snapped his neck and that’s that. If I was doing more high end racing, I would go for like the RPM or full cage, but that’s massive installation and massive cutting, so for all these reasons, its just trying to save my neck, literally. I can break an arm, leg, etc, all survivable, but neck injuries never ends well.
Thanks for the well thought out reply!
I opted to go with a Simpson Hybrid S for my HANS with 3 pt OEM harness, but the pricing is very similar to just installing a harness bar 🙂
I am all about the HANS and don’t want to drive without one when I have a helmet on.
I opted to go with a Simpson Hybrid S for my HANS with 3 pt OEM harness, but the pricing is very similar to just installing a harness bar 🙂
I am all about the HANS and don’t want to drive without one when I have a helmet on.
yes, those are amazing, used them first time at Ron Fellows Race School, pretty cool product. With the GT2 seats, I slide around too much, so the 4pt harness keep me secure!! Trying to find and swap to Competition Seats was way to complicated, way too expensive and errors codes you can’t remove. But if sliding around in your seat will be issue, go CMS or other system
yes, those are amazing, used them first time at Ron Fellows Race School, pretty cool product. With the GT2 seats, I slide around too much, so the 4pt harness keep me secure!! Trying to find and swap to Competition Seats was way to complicated, way too expensive and errors codes you can’t remove. But if sliding around in your seat will be issue, go CMS or other system
I have the same CMS bar sitting around waiting for a good weekend to install it. Glad to know I'll have to reserve a few hours.
I am assuming you are keeping the GT2 seats? I have Competition Seats but those don't have a center cutout for a 5 point. (I am not sure how I feel about a 4 point for safety). For that reason, I am just going to do a Sparco seat and AMT seat base.
I have the same CMS bar sitting around waiting for a good weekend to install it. Glad to know I'll have to reserve a few hours.
I am assuming you are keeping the GT2 seats? I have Competition Seats but those don't have a center cutout for a 5 point. (I am not sure how I feel about a 4 point for safety). For that reason, I am just going to do a Sparco seat and AMT seat base.
The CMS site also let’s you purchase the Scroth Profi ASM II harness, it’s designed for anti-submarine, so it acts like 5/6 pt harness, it’s specifically certified for this use and I believe it’s the only one available in the market. But yes, comp seat and GT2 seat doesn’t appear to really have any advantages. I thought the comp seat would allow for 5/6pt, but it doesn’t. Seems lame not to make that available as it’s so common for trackers like us.
Just remember, by removing seat, you will lose airbag and car throws a code!!
The CMS site also let’s you purchase the Scroth Profi ASM II harness, it’s designed for anti-submarine, so it acts like 5/6 pt harness, it’s specifically certified for this use and I believe it’s the only one available in the market. But yes, comp seat and GT2 seat doesn’t appear to really have any advantages. I thought the comp seat would allow for 5/6pt, but it doesn’t. Seems lame not to make that available as it’s so common for trackers like us.
Just remember, by removing seat, you will lose airbag and car throws a code!!
Yea good points. I am tempted to pick up the Schroth ASM II and stick with the comp seats. I wish they had a bit more lateral thigh support but harness may be enough. I have a sabelt 5 point that I can get rid of if I decide on Schroth.
05-28-2024, 12:04 AM
CMS Harness Bar Finally In!!
