laze1

iTrader: (17)

This link has some good belt installation facts;

http://www.schroth.com/installation-.../en/index.html

tomzz

the schroth belt info is very comprehensive - thanks

daveh

iTrader: (9)

I used to share your reservation about getting a competition seat. Now that I have one, I just wish I got it sooner! It's just as comfortable as the stock seat, holds you in better and communicates so much more than the stock seat. I really was amazed at the difference.

Seats comfort is a subjective thing but check out this thread for some suggestions. I've had absolutely no downsides to my cobra seat. I've retained the stock seatbelts for street use and have a safe 5pt schroth system for track use. Just be sure to have it professionally installed for safety reasons. My sub strap is welded to the floor.

https://my350z.com/forum/showthread....ighlight=cobra

first350

iTrader: (24)

The OE seat belt is still there - I fed the bottom portion through the lap belt holes on the seat. The shoulder portion of the belt doesn't go through the seat holes, it's loose.

I have a harness bar for the shoulder straps...I know many ppl discourage this b/c it's not a full cage. (I mainly autoX, so I'm less concerned with a hard crash than if I were to do more track events).

Stack

OK cool... yeah, we discourage it, but don't outright forbid it at our events (except in convertibles of course.) The corvette guys are even more opposed to the roll bar (even for track use) than most others.

first350

iTrader: (24)

+1 ... only downside (short term) was that it took some time to regain the 'seat of the pants feel' for what the car was doing. (before, my body would be sliding a lot and I could sense that I was getting closer to the edge of traction. w/ the JIC seat, my body stayed in place, and I had to hone in on different ways to 'feel' what the car was doing).

*Now when I drive(autoX) another car w/ out a race seat, I can see how much more work I'm doing just to keep myself in the seat.

tomzz

Humm - So Dave, If one was to put in the Cobra seats for some flexibility of drivers, how would you do the floor mount? Custom sliders to get the height right?. Can they fit w/o doing the door inding? What about those JDM Aghai sp?? super low sliders that some others have used for race seats in Z's? My, what a tangled web we weave. Thanks for all the good help.

mhoward1

Motorsportseats.com makes sliders for a lot of cars and seat combinations. They make a nice twin latch slider one for competition use.

daveh

iTrader: (9)

A custom install by a good race shop is the answer for taller drivers. My seat was initially so low, I had to bring it back to raise it up a bit. I'm going back for sliders next week so I'll report back when they're in, but I don't forsee any problems with my 6'1" frame considering my seat without sliders was initially 1" too low for me. My seat never rubbed on the door panel so I expect no issues with sliders.

Custom seat installs are not that much more than the off the shelf hardware in many cases and they fit better. Not an area to skimp out on in my opinion.

You might want to check with PCA if sliders are ok for their events since none of them are FIA approved. Are those JIC seats FIA approved with date stamp?

mhoward1

Actually some of the sliders have been FIA approved. According to Article 253 Appendix J on page 14, "If rails for adjusting the seat are used, they must be those supplied with the homologated car or with the seat or be certified by the seats manufacturer."

daveh

iTrader: (9)

Do you know which seat manufacturer certifies their sliders? Last I checked, which was a while ago, the big names like recaro, sparco and cobra were not certified by the manufacturer. I think it's always been one of those gray areas.

mhoward1

No idea, but I can try to do some research.

I think the big issue is FIA's testing procedure which just mounts the seat on a plate and only tests for horizonal impacts. If a manufacture deviates, they have to test it themselves and submit to FIA for review. I think FIA has opened the door since last year for more of this, hince the fairly open statement above.

daveh

iTrader: (9)

Yeah it seems to be a gray area. I haven't heard of too many people not passing inspections due to sliders.

1cockyZ

iTrader: (46)

Here is something linked from the sparco website about proper belt mounting. I was going to weld tabs on my seat base for the lap and sub belts and use a harness bar as I do time trials. I want to believe a harness with a harness bar is better in a crash than the stock 3 point belt. Welding a tab to the floor for the sub belt is not a problem. Can someone enlighten me to the benefits/comfort of a six point harness over a five.
http://www.sparcousa.com/resourceFiles/16.pdf

first350

iTrader: (24)

I don't recall seeing any date or "FIA" approval on it.

The JIC seat brackets (which mount to their slider) come with multiple height adjustments, and are slotted (left-right) so that you can position the seat just right to where it doesn't rub the door.

Billhyco

iTrader: (14)

so you used the JIC sliders along with the JIC brackets?

Stack

Great article!

Welding tabs for mounting purposes is not recommended. Strength of welds notwithstanding, you'll end up creating a mounting point where the force acting on it will be at a nearly perpendicular angle. It will bend and/or break in an impact. Plus, if something were to happen to cause the seat mounts to fail (a rear-ward impact for example) then the belts would again be rendered useless for any secondary impact.

Remember, just because you're time trialing, it doesn't mean the car isn't experiencing race-like forces and risks.

Harnesses and a harness bar, in most accidents will be safer than stock 3-point belts. BUT that also depends on how they are mounted. IMHO, its also debatable whether that set up is better than 3-point belts AND passive restraint systems (airbags). Don't forget too, using harnesses basically negates the passive systems.
If you're gonna do that, why not just use backing plates and drill holes?

Main difference is the load applied to the double anti-sub strap is reduced since its spread over two anchor points as opposed to one one. Comfort wise, depends a bit on body shape and belt adjustment.

Axelerate

iTrader: (19)

There are no good spots under the driver seat to drill holes, mainly due to it being boxed in. I am using the lap belt eye let's for my sub straps with my Cobra Suzuka seat.

1cockyZ

iTrader: (46)

The only reason I mentioned time trialing is to eliminate the possibility of car to car collision. Drilling holes in the car is not for me. I was pondering a 4 point cage(weld in) but for time trialing purposes its not required nor is a 5-6 point harness. But I want to use a race seat. So for my particular situation I need to figure out how to safely mount a harness with a harness bar. Its the lap belt mounting points. Being the seat bracket holds the stock seat belt and passes crash test and is welded on I thought that would be a good idea. I can just use a longer bolt and use the same hole that anchors the seat base to the floor and then use the stock lower mounting point behind the door. As for the sub belt every car I have seen just uses a tab welded to the floor in front of the seat. Roll cages are welded in. My first track day this year I will have my stock seat and 3 point belt and then talk to tech and look at all the other cars and ask questions. I sat up last night reading rule books about harness mounting and I need pictures. I think this is a good rule and as for the hans device 09' idea well you can't argue with either paying $800 for something that will make you faster vs. save your life. But in order to use the hans device you need a harness and compatible helmet. I am going to start another thread about harness mounting please contribute. I don't want to take this one off topic.

mhoward1

Actually, for several groups a roll bar and harness is required for Time trails. Just a good FYI so if you want to do multiple organizations.

I think we also have some good pics laying around somewhere for proposed mounting points.