Race Seat, Harnesses & Harness Bar

[Highwayman]

Can anyone please give me some advice on fitting a race seat and harnesses to my 944 track car. I've just put a deposit down on a set of race seats, and so now need to sort out fitting them and sourcing a set of harnesses, but would appreciate a bit of a steer on the best way to do this.

How easy is it to fit a side mounted seat, or does it very much depend on the width of the seat and how it may or may not line up with the existing mounting holes? Also, for the harnesses, it appears that the lower rear seat belt mountings would be good for a set of 4-point harnesses, but I'm a little concerned at the angle that they would be fitted in relation to the seat tops. I understand that the maximum angle should be 45 degrees, and I'd guess that these mounting holes would exceed that (I don't actually have my seats fitted to be able to confirm it just yet [].

Presumably this is why you need a harness bar, to improve the angle by guiding the belts at or near horizontal from the seat holes? Any thoughts on the best harness bar to buy and where from? There seem to be lots of options in the States, but nowhere near as many in the UK. Alternatively, how difficult is it to get one made for the job?

Any help appreciated, as I'm trying to get the car up together for the new track day season [].

Phil

 

[944 man]

Whose seats and which model? More importantly, how wide are they between their sidemount fixing holes? If you measure them accurately then I will do the same with mine (which fit onto the OEM floor mountings and are in my spare room) and we can take it from there.

If you use Sparco sidemounts and you havent bought 'Super GT' width seats, then its relatively straightforward. Essentially, the trick is to make the seat fit the mounts, rather than trying to make the seat with mounts attached fit the car.


Simon

 

[944 man]

The belts will still be at a legal angle if you use the rear belt mounts, especially if you tilt the seat in its sidemounts, which also gives extra head/helmet room.

You might be better welding mounts to the leading edge of the rear load deck though. I know that the American market loves 'harness bars', but I wouldnt bother with one without a rollcage, if I were you.

Id also suggest that you buy a CG-Lock and dont fit a harness unless youre also fitting at least a rear cage (and if you are Id suggest one from Rollcentre Racing as theyre reasonable and very sensibly priced).

Properly mounted racing seats, a rollcage and properly installed harnesses three things that belong together and if you pick any two then youll end up with a car thats more dangerous than when you started.


Simon

 

[Highwayman]

Thanks Simon, I haven't picked up my seats yet (due Friday), so not sure of the width exactly. Sounds like it's a case of trying them out with the existing holes to start with then, and hopefully should find some alignment.

Not sure I quite understand why a cage is essential with a race seat and harnesses, as it seems relatively straightforward to get them fitted safely without a cage. Is there a particularly reason why you say that?

Thanks for the tip of Rollcentre Racing. I've had a look at their website, and will drop them a line and see if they can help.

Phil

 

[Peter Empson]

Slightly off topic, but I read somewhere that due to the MOT changes coming in over the next 1-2 years it is necessary for our cars to have drivers seats on runners. I haven't looked into this as my car already has one, but it's just a heads up in case it does become an issue...

 

[majorporsche]

This regulation re adjustable seat has come into Ireland too. It seems to derive from an EU Directive to say that seats in cars must retain their orignal adjustment features, ie fore aft and I suppose even up/down. I bet there is an EU beaurucrat somewhere who hates modded cars and has just got a promotion to being the man who looks after regulations for car interiors.

 

[Peter Empson]

ORIGINAL: majorporsche

and I suppose even up/down.

Bother, does a cushion count []

 

[edh]

Also been stated as a requirement for the 'ring - fore/aft not up/down (although I'm not sure they have ever checked) - which is why I will mount my seats on runners.

 

[edh]

ORIGINAL: Highwayman

Not sure I quite understand why a cage is essential with a race seat and harnesses, as it seems relatively straightforward to get them fitted safely without a cage. Is there a particularly reason why you say that?

Phil

In a car without a cage, your head is the first thing that will be in the firing line in a roll - the harness holds you in the seat, stopping you getting out of the way.

harness + cage (rear) or 3 point belt + no cage IMO

 

[Highwayman]

Thanks, that's useful advise, just in case...

Phil

 

[944 man]

As Ed says... the main advantage with a harness, when you arent crashing, is that they hold you, but a deep racing seat will do that more than adequately, so a safer three point belt will be ideal. Conversely if you fit the rear cage and certainly if you fit the full cage, then you want to be held rigidly in place to keep your head away from the tubing if it all gets exciting.

 

[944 man]

With regards to the new MOT test: fixed seats certainly arent a reason for failure, only seats which should adjust but wont will fall foul.

VOSA has already stated that removed airbags and fixed seats on substantially altered vehicles wont be a reason for rejection and the usual MOT rules will still apply, so a non-airbag wheel will only cause the vehicle to fail if the light is on. If the wheel has been removed and theres no dash warning then it will pass.

This is my current understanding, but VOSA may yet change their position.


Simon

 

[944 man]

ORIGINAL: Highwayman

Thanks Simon, I haven't picked up my seats yet (due Friday), so not sure of the width exactly. Sounds like it's a case of trying them out with the existing holes to start with then, and hopefully should find some alignment.

Exactly. Fix the Sparco sidemounts to the vehicle floor using the existing captive nut fittings. The original Sparco mounting holes should line up, but if theyre different then adapt them as necessary, having worked out where the seat needs to be for you (Im tall, so fixed suits me, but you can use the OEM runners on the drivers seat to get it forward, if you wish).

Youll probably find that when the side mounts are fitted that theyre wider than the Sparco seat thats that you have bought. Measure very carefully and then cut 25mm aluminium bar to the correct size to fill the gap on either side. Drill this through the centre and youll have 4x aluminium bobbins which will safely fit the seat to the side mount and then secure using longer bolts.


Simon

 

[CarreraRSR]

To fit my Cobra Suzukas and seat mounts to my 924 took a fair bit of trial and error and drilling/re drilling of new holes in to the mounts to get it right. The seat mounts are bolted to the existing floor holes to give enough head/helmet room. The seats had to be reclined/tilted back as well. Seats were fitted, adjusted, refitted at least 6 to 10 times to get right. A right PITA!! but satisfying once done.

Cue another gratuitous use of another photo of my car!!