BryanKlingele

I have a 21 black HTC and I'm looking to add the 5VM grounds effects to the car. I have looked at the GM kit, but I must admit I'm not fond of drilling into the side of my car where all the others only required drilling into the bottom of the car.

I was looking for your opinion on which kit you have installed and why you choose them. I know I don't want exposed carbon fiber and want the carbon flash color to match the rest of the car. I also saw Extreme Online Store, saw their promo video. makes a front splitter, but the side skirts are not out yet.

Thank you for your time and input, it's apprecatied.

Bryan

Petraptor

I went with C7Carbon and it does not require one to drill into the body! The product was first class!

Petraptor

I went with C7Carbon and it does not require drilling the body! They have an excellent product!

BryanKlingele

I just went to the C7 website and I was not able to see how they attach. I'm guessing you have to drill into the bottom of the car only which seems to be far more common.

Bryan

C8gman

I went with C7 Carbon for the side skirts and front splitter in Carbon Flash. The side skirts attach with several drill and rivet points on the underside of the car. They also use one 7mm screw that is there from the factory. Search for member JerryU as he has a very thorough write up on the C7 Carbon skirt/splitter install. It came in very helpful when I put mine on.

JerryU

^^^
Yep, here it is with full details of the GM install as well. GM not only use a bolt, they require a very strong 3M adhesive and use 3M tape: http://netwelding.com/Side_Skirts.pdf

You'll see I used a small amount of 3M tape but it's probably belts and suspenders. The bottom rivets and GM existing bottom bolt will do a fine job the thicker fiberglass parts C7 Carbon uses.

MAD Matt

FWIW, When I finished fabricating my dive planes for my car I was looking at a 3M product that was black in color and thicker than their 5952 so I reached out to Thomas Janos at 3M. Here is his email reply. Straight from the horses mouth.

Thank you for contacting 3M innovation company.
3M does not suggest the use of any of our industrial adhesives or tapes for use outside a moving vehicle unless the bond joint is designed and tested by a qualified engineer and reviewed for the required safety guidlines.
3M does not perform any wind tunnel testing on it's industrial products. We also suggest using mechanical fasteners as well.
That said, the thicker version of 5952 is 5962. This is the only black options we offer.
If you need further/addittional assistance or prefer to speak directly with a specialist, please call 800-362-3550 and the first available representative will assist you.

Thanks,
Tom

While I went ahead and used their product to install my dive planes, I would highly consider mechanical fasteners on anything larger. That's why rivets and bolts are use by GM to install these pieces. The last thing you want is for your ground effects to blow off at triple digit speeds....if you go there. Better safe than sorry.

rsl2715

Yep was going to use the tape but now will go with tape/rivets.Thanks

JerryU

^^^
Would never use just tape for side skirts, splitter or spoiler. GM uses the same drilled holes and rivets as C7 Carbon on the bottom. After my research finding why the C7 Carbon supplied 3/16 inch aluminum rivets with a steel mandrel caused the composite rocker panel to "pull out" I found the holding force of rivets! As noted in the pic below, a steel mandrel has a holding force per rivet of 520 lbs. However that is about the force being applied as the mandrel fattens the rivet head. It was excessive for the composite rocker panel so the expanded head made a hole that size and the rivet fell out! Fortunately, only happened once and I switched rivets! I substituted with the same 3/16 aluminum rivets BUT with an aluminum mandrel. It's holding force is still 320 lbs, although 200 lbs less. But the aluminum mandrel broke where it was supposed to at the "Break Notch" before the force was so high that it pulled through! Much more holding power than an adhesive! Once I switched all rivets held find. With 7 rivets and the OEM bolt the total holding force is >2000 lbs!

The reason, IMO GM uses all three attachments methods AND a bolt through the fender is the thin carbon fiber part is more flexible than the thicker fiberglass C7 Carbon. Where GM uses a bolt in the fender on the winglet area, it is a thin section and using a thread was probably easier to build. C7 Carbon uses a several square inches in a wide flat area that contacts the fender. I elected to used two strips of 3M double sided automotive (as it's called) tape in that flat area to prevent any vibration rubbing on the fender. It's a very sold attachment and has worked fine for ~4 months.

The thin GM 5VM also uses a very strong 3M adhesive (# 06695) that is used to attach windshields. I used a similar window adhesive when I built my street rod. Found it hard to extrude out of the cartridge with a hand gun. Found out later from a "pro" installer he placed the cartridge on a hot engine to get it to flow! Window shops also use air powered caulking guns! Have no idea how easy it is use the 3M product.

I talked with a manufacture of carbon fiber 5VM copies and asked what he thought about GM's use of a fender bolt, adhesive and 3M tape. He felt the bolt through the fender was probably the side skirt manufacturers design based on how they produce their product. He felt the 3M adhesive was because of the amount GM uses in the C8 and may have been specified by them! He thought their use of the 3M automotive tape that comes with the GM product was to hold the side skirt in place while the cartridge adhesive cured. I recall using a 2X4 and wedges to press against the two rear side windows I used adhesive to mount on my street rod! Left for a day while the adhesive cured. That was 21 years ago and technology has moved on!

Difference of GM and C7 Carbon is easier to visualize with a pic!