EGbeater

iTrader: (35)

For Evo owners who take their cars to road courses for open track days, time trials or time attack racing, or wheel-to-wheel road racing, it is recommended or required that you have a dedicated tow point on both the front and the rear of your car. The reason for this is that in the case that you have an incident that requires that your car be towed back to grid, if you don't have a good tow point, your vehicle might be damaged in the process of recovery.

The Evo comes from the factory with tow hook locations under the car, but in my case, the front tow location is covered by my splitter, so I needed to add something to the front. In the rear, adding a highly visible tow point means the track employees don't have to waste time figuring out where to attach a tow strap.

I chose these OMP tow rings because they are fairly inexpensive ($30 each), functional/proven (they're FIA certified), and they have long enough of a attachment bolt to work for the way I chose to install them (through the OEM bumper crash beams). I didn't want to go with any sort of flat ring that sticks out from the front of the vehicle, which could damage the rear of someone else's car if I were to hit them, or even get you hung up on their vehicle, which is why such a tow ring is illegal in some road racing events.

And while the soft nylon straps would also fit the bill, I'll admit I decided not to go that route because I don't like the way they look installed... reminds me of an unretracted seat belt hanging out of the bottom of the door.

You can buy the OMP EB/571 tow ring from Pegasus Auto Racing Supplies (https://www.pegasusautoracing.com/pr...asp?RecID=5178) or Hare Racing (http://www.hrpworld.com/index.cfm?tp...action=product).

*** IMPORTANT DISCLAIMER ***

I cannot guarantee that this installation method will hold up to towing if the tow vehicle yanks the car really abruptly, as opposed to gently and gradually applying pulling force; ESPECIALLY if your Evo's crash beams or crash beam attachment points are weakened from rust. The OEM crash beams on the Evo are intended to provide support and strength upon impact, not to be pulled on.

Also, if you do happen to crash into something with the nose of the car with the OMP tow ring installed as described below, whether that's another car on track or a track barrier, the crash beam could certainly deflect backwards enough for the end of the bolt and nut to damage the intercooler behind it. In my case, my intercooler is an inexpensive XS Power/SSAC unit, so no great loss if it were to be damaged in such a way.

Okay, now on to the DIY installation instructions and pictures.

First, the front tow ring.

Obviously, you must have the OEM crash beam in order to install it like this. As I stated before, if you have an Evo that's been exposed to salt in the winter, this may not be a good plan, as the steel of the bumper beam where it attaches to the unibody might be rusted and weakened... this could be a problem, as the bumper beam is only attached to the car with four smallish (I believe they're 6mm-diameter) bolts, and obviously the bumper beam wasn't designed to be pulled on; it was designed to be pushed inwards. You could get around this problem by welding the bumper beam to the car's frame though, if you're okay with never removing the crash beam afterwards. I added a washer under two of the OEM bolts that attach the beam to the car, since the holes in the bumper beam for those two bolts are bigger than they need to be for some reason.

Here they are in the packaging:



They weigh about a half pound each (I only used one of the nuts):



Here's the pilot hole I drilled in the passenger-side of the bumper beam... this area of the beam is exposed with my CWest style front bumper cover:



In order to make the the OMP ring work for this installation, you have to do two things: ensure that you have enough room behind the BACK of the bumper beam and your intercooler for the end of the mounting bolt and the nut (about 5/8"); and cut down the bolt to exactly the right length to interface with the nut but also maximize clearance to the IC. I had to adjust the position of my XS Power/SSAC eBay intercooler slightly by tilting the top of it back to gain enough room. If you have an OEM intercooler, I don't think you'll have any clearance issues for the end of the tow ring mounting bolt.





I used a long screwdriver to check that the two holes I drilled were inline and fairly straight:



Here you can see that the washer and the locknut together are 9/16" thick, which is why you need 5/8" between the back of the bumper beam and the IC. I actually filed down the end of the locknut to gain another 1/16" without affecting the nylon locking insert within:



The OMP EB/571 is about 4 1/2" long, or 114.3mm:



Marking how much needs to be cut off with a Sharpie:



After you cut it, it should be about 73mm of shaft:



And it ends up being seven ounces rather than eight and a half:



Here's a closeup of the two OEM mounting holes for the bumper beam to the Evo's unibody... I used a washer under the head of the bolt that goes through that larger hole on the left:




Done and crashbeam ready to be reinstalled... hard to tell, but the locknut has been shaved down a touch:





Doesn't look like much, but there's 1/8" of clearance to the IC:



Done (yes, I spraypainted the one washer on the outer side of the crash beam black so it blends in better):





Okay, now the rear ring.

I again opted to mount the tow ring through the OEM bumper beam. Doing this requires putting a hole through the rear bumper cover (as well as the styrofoam insert behind it) but it's right behind where the license plate goes, so it's not visible with the plate installed. It only take a minute (and a 19mm open-ended wrench) to remove or install it, but you could put a hole through your license plate as well so you can leave it installed permanently, although Officer Unfriendly might be compelled to give you **** about how that's illegal.

For the rear, the length of the OMP ring's mounting bolt is just fine; it doesn't need to be cut down.

I used a cheap drill jig to help keep my holes through both layers of the bumper beam straight/lined up:



Checking with the screwdriver again to ensure the two holes in the bumper beam are straight and lined up with the hole in the bumper cover:



Done:



How it looks from underneath, which is where you need to tighten the nut down... don't overtighten it, since all you'd be doing is flexing the bumper cover inwards. As long as the all of the nut's threads are engaged, that's enough. Remember, if/when the ring gets used, it'll be pulled on, not pushed against.



Final note: these steel OMP rings will vibrate when your car is running and moving, so to keep them from making rattling noises (and to keep the yellow paint from wearing off) I stuck a black ziptie through the hole in the pin, behind the loop, and cut it off short, about 3/4" long. This takes up the slack and shuts them up.

Remember, installing tow rings is just like bringing rain tires to an event: extra assurance you won't need them!

GTisRule

iTrader: (5)

Just curious about pull out strength. It's a pretty small washer thru the hollow crash beam. I'd like to think that the tow hook should be able to support the entire weight of the vehicle as suspended by a crane or something. I'd be worried the nut/washer combo might pull thru the bumper if it were pulled on very hard. (Worst case, car is in a ditch or something and needs to be picked up or pulled up an enbankment of some sort.)

Just my .02

EGbeater

iTrader: (35)

You have a valid point. Alternately, you could put a hole in the back side of the bumper beam large enough to a put a 19mm socket through it, then fasten the nut and washer down on the inside of the front side of the beam on top of a long stack of washers (the shaft of the OMP tow ring isn't threaded down enough to do it without the washers).

That would eliminate the clearance issue of the bolt to the IC, but I'm not sure that'd really be any stronger in terms of resisting pull-through. It still comes down to the structural integrity of a single layer of bumper beam. Someone with welding capabilities could cut a big access hole in the back of the beam and then weld in a thick reinforcement plate inside the bumper beam, though. I think 1/8" steel would pretty much eliminate the possibility of pull-through.

I'm not stating I know what I'd done to be a structurally sound mounting method, or that I've used these tow rings multiple times under different conditions as "proof" they're solid.

But assuming the wheels are still on the car and pointing in the right directions, it doesn't actually take that much force to move a 3,000 to 3,300 pound car. At our local road course near Denver, CO (High Plains Raceway), the track staff will sometimes use a four-wheeler (ATV) to retrieve a car. And think about how easily two people can get a car rolling up to 5 mph or so (on flat ground and on pavement at least).

I'd be more concerned about the bumper beams ripping off the car, than the tow ring itself ripping through the bumper beam. But that's just my gut feeling, unsupported by an empirical evidence or testing.

GTisRule

iTrader: (5)

Was just wondering while looking at the photos. I do a few hillclimbs a year, and some cars are retrieved by crane when they go off. I fear my lack of towhooks

EGbeater

iTrader: (35)

You mean, the crane's got the entire car off the ground by the tow hook?

Uh, yeah... I would NOT trust the way I've installed these tow rings to work for that kind of "towing."

GTisRule

iTrader: (5)

Haha absolutely. It's a cliff on one side of the road typically!