I had my new Schroth Profi III asm harnesses installed by Mitch Piper of Piper Motorsports in Manassas, VA, yesterday. Here's a full report.

I've wanted harnesses ever since I started running HPDEs at Summit Point in my Miata more than three years ago. It's tough to maintain precise control of the car when you're being thrown around the cockpit by G forces. The standard 3-point belts don’t really hold you down well enough.

I never got around to putting harnesses in the Miata or my 944 Turbo, but I definitely wanted them in the Z before doing many track events. I've been to a Friday at the Track at Summit Point (WV) once already (see this report), and wanted harnesses before starting this season.

As background, I have run about 16 or 17 FATT or Seat Time events at Summit Point, 2 autocrosses, and a 3-day Skip Barber Racing School at Mid-Ohio. I don't race, nor do I plan to. Just HPDEs. This year I’m planning on a bunch of FATTs, Seat Times, and (I hope) a 3-day NASA HPDE at Mid-Ohio in April. Maybe a couple of autocrosses, too.

I had been thinking about putting in racing seats as well as harnesses, but the stock seats are so good that after comparing them to a couple of Sparco models, I decided that the improvement (if any) wasn't worth the expense (at least $600 each).

At the suggestion of folks at OG Racing (also in Manassas) where I've bought some of my gear, I went to Mitch, whose main business is modding cars for racing. He also drives and crews in the ST1 class.

Although belts from Sparco, Simpson, or other manufacturers could be installed exactly the same way, I chose Schroth. (It’s pronounced "shrote," BTW.) I like their cam locking system and other design features, even though they are about $100 more per seat than comparable Sparco or Simpson belts.

These three manufacturers make belts in black, red, and blue (at least). In my Lemans Sunset, red or blue just would not have worked, but I’ll bet they’d look great in almost any of the other Z colors.

Why did I get both sides done? At Summit Point (and at other schools and tracks, I’m sure) you must have the same safety equipment on both sides if you’re going to take an instructor or passenger.

The install is 6-point, with quick-release hooks so I can take everything out of the car when I’m not at the track. Installation or removal takes only a couple of minutes.

A cold clear day in Manassas:

 

Looking forward from the hatch, pre-install.

 

Mitch fabricated these two plates by cutting the threads off the eyebolts that came with the harnesses and welding the eyes to these mild steel plates he cut to fit. The plates will be welded to the deck behind the seats.

 

Here’s Mitch checking the fit and placement of the right side plate. (Both seats have been removed at this point.) He ground the paint off the deck around the plates for a clean surface for the weld.

 

Welding the left side plate in place. Mitch used a TIG welder, which I had never seen in action before. Very quiet, compared to arc welding. Mitch used it to avoid possible damage to plastic and painted surfaces, since other kinds of welding create more splatter.

 

Here is the finished driver’s side plate, after being primed and painted to prevent rust. (Note that the black paint extends beyond the edge of the plate, which has a curved corner, to cover any bare metal from the earlier grinding.) We cut slits in the cheap thin fabric that’s underneath the optional trunk mat so the eyes pop through (not shown), but didn’t cut through the mat. The mat hides the eyes neatly, and will usually be removed when I’m at the track, anyway.

 

The lap harnesses use the stock belt’s mounting point on the outboard side, simply by replacing the existing bolt with the Schroth eyebolts. Same size bolt and thread. A hole drilled through the transmission tunnel provides the inboard side lap mounting point. This is the passenger’s seat inboard point. The holes below are the seat slider bolt point (left) and a guide hole (right) that mates with a pin on the seat slider.

 

As it happened, on the passenger’s side the vertical flange at the end of the slider interfered with the eyebolt, so Mitch cut the corner off. This has no effect on the seat or its function. The red line shows the approximate original shape of the slider end. (There was no similar problem on the driver’s side.)

 

It’s a little hard to see in this shot, but this is the nut plate on the underside of the transmission tunnel. It’s a captive nut welded to a plate about 2” x 4”. They came with the harnesses, and I only needed two of the four provided.

 

The anti-sub belts (not shown) are mounted to the bolts that hold down the front of the seat sliders. Unlike the outside lap bolt, these bolts are not an exact match for the Schroth eyebolts, so Mitch cut off the eyes and welded them to the top of the stock bolts.

Here’s the final installation. I think they look great, and as I mentioned, I can put them in or take them out in a couple of minutes. They’re fairly bulky, so it doesn’t make much sense to leave them in for everyday use.

Note that the stock belts are still in place and fully functional. (BTW, racing harnesses are NOT legal for street use. They are obviously superior to the stock belt, but haven’t been submitted to DOT for approval. So I suppose technically a cop could cite you for “not wearing seat belts” if you were using the harnesses on the street.)

 

The proud owner in his new belts. Naturally I wore them on the drive home, but after about half an hour I took them off: too stiff and uncomfortable. It’ll be nice when they break in and soften up a bit. (BTW, what is it about cameras these days? They always make people look older, fatter, and grayer than they really are. Twenty years ago cameras didn’t have this problem!)

 

Okay, you’re probably wondering, How much? The belts were $270 a side, and Mitch did the job in 4 hours at $60/hour. So the total was just over $800. And like I said, with other belts you could pay at least $200 less.

Mitch did a clean and professional job, and he was easy to work with and didn’t seem to object my hanging around, asking stupid questions, and taking pictures. If you live in the mid-Atlantic region and would like a similar installation, I recommend Piper Motorsports.

Finally, before anyone gives me a hard time for putting in harnesses without a roll bar or cage, I thought about that and decided that the risk of a rollover in the kind of events I do is relatively small, and that the added control I get while driving is worth it. Mitch agreed it was a reasonable risk. I may go for a roll bar (Mitch estimated it at under $1,000), but it would be a tight fit around the B pillar, would probably reduce passenger’s seat movement, and would cut into storage space in the back.

If you have any questions, post them here.

Next week: airbag off switches. Report will follow.

 

I imagine that you'd use those for spirited weekend driving and autoX? Are they really uncomfortable for normal driving?

 

I wouldn't say they're uncomfortable, but don't plan on being able to look back at your blindspot.

Commasense, thanks for the write up! I plan on getting some bucket seats and harnesses soon.

 

Good stuff Commasense!

It seems that everyone in this area goes to Mitch as he always produces a top quality product. I know for a fact that I'm going to wait and install a roll bar, and at that time I'll throw in the harnesses.

Oh, and I think I'm going to be able to make Mid-Ohio, so perhaps we should plan our two-car caravan for the 7-8hr. drive.

 

great job documenting the installation!

 

Yes, uncomfortable because they're stiff, and because running them between the headrest support rods means they cut into your neck after a while. (The main advantage of a racing seat might be to space the belts out a little wider. However, don't forget that if you go for a one-piece seat, instead of an adjustable sport seat, you'll restrict access to the storage space behind the passenger's seat.)

Also, after you've snugged the harnesses down at all four points (the anti-subs don't need much adjustment) and then release them to get out, you have to free up some slack on each to latch them again. So it takes a long time (i.e. a minute or two) to hook up each time you sit down. Sure you feel cool while doing it, but it's not a quick and easy 3-second no-brainer like fastening the stock belts.

I suppose I might leave them in and use them around town for the next few weeks so they'll be broken in at least a little for my first FATT, March 7. See any of you there?

 

Won't see you at any FATTs, but I did speak with Lawrence today, and I will be at Mid-Ohio. You and I should coordinate our two-car caravan out there!

 

Check with the Tracks you're going to run. Most require a roll cage if the belt is not street legal. This is because if the car rolls with the anti sub strap your are opening yourself to a greater chance of head/neck injury. Schroth does make a 4-pt. system that is street legal and can be used at all tracks without a cage.

It is a nice install.

 

What's the difference between that and my belts? I can simply not connect the anti-sub, and presto! 4-points.

BTW, the Profi IIIs are FIA homologated.