4 point or 5 point harnesses?

Technical Area Motorsport & Trackday Preparation
2

Hi all,

 

Looking to get some decent harnesses for my Mk1 '5 with GC rollbar installed.

 

I can’t decide between 4 or 5 points - Will mainly be used on the road but I am planning to do a good few trackdays soon :) 

 

 

I only want 3" straps (thinking either TRS 5 points with the non-seatbelt style buckle (MOT SAFE?) at approx £130 or OMP 4 point seat belt buckle style for £110 each.)

 

 

Any words of wisdom greatly appreciated.

 

Thanks!

3

As per the previous advice in numerous other threads given to you previously in this forum, and elsewhere:

  1. Don’t use race harnesses on the road. Properly fitted, they’ll restrict your movement to an extent that you are a potential hazard to others. If you can still move around with them fitted, well you might as well put yourself forward for the Darwin Award. Retain standard seatbelts for daily use.

  2. Replace seatbelt bolts with UNF threaded Eyebolts like this:

Note, you don’t need the anti-sub belt like this tool has.

  1. Order clip in FIA-approved belts. Doesn’t matter which brand. Generally they’ll have aircraft latches because they are more reliable. Remove clip in harnesses at MOT time if you are scared the inspector won’t like the look of your race-look MX5. You can’t buy FIA belts that are not 3".

  2. If you intend using the car for road use and track day use, 4-point is enough. You won’t need a 5 or 6 point as you will be tracking on road tyres and not actually racing. You won’t actually be driving as hard as you imagine. Your tyres won’t be up to it.

If you feel that you need an anti-sub belt, I recommend that you invest in a Nomex race suit and Hans device for those trackdays (Proban suits are cheaper, and can pass muster if you stitch on some badges). Don’t forget the plumbed in fire suppression system.

I assume you have already scrapped the original seats, and don’t require advice/pointers on seating.

4

Hi T,

If you are going to use 4 point harnesses I would always recommend the use of a 5th crotch strap. This will hold the ‘hip’ strap in the correct position when you pull on the shoulder straps to tighten the belts. If the buckle is pulled up towards the stomach/chest the belts will do more harm than good if you have an accident. For track use I would also recommend arm restraints in any open car.

Having driven Caterham 7s for many years I have never felt that the full harness system has made me a potential hazard to others, my lack of skill or over enthusiasm may be, but not the belts.

 

5

4. If you intend using the car for road use and track day use, 4-point is enough. You won’t need a 5 or 6 point as you will be tracking on road tyres and not actually racing. You won’t actually be driving as hard as you imagine. Your tyres won’t be up to it.

 

I’m avast at the moronicness of that statement.

6

I’m appalled at the incongruity of the last line and suggest the following amendments:- 

For AVAST (Stop/cease) read AGHAST (Dismayed).  For MORONICNESS (?) read IDIOCY.

 

7

I’m sure you’ve already purchased the harness but for others reading this, I’ve just bought a Takata Drift III wrap around harness. It’s a 3", 4 point harness wrapped around a GCFabrications rollbar and used on a Sabelt GT-090 seat. Fits beautifully, holds me SERIOUSLY well and whilst it does restrict movement (Struggle to get to electric window switches and I have to release belt to get to glove box or the exhaust tunnel box), I think a bit of extra care when looking over the shoulder is all that’s needed.

 

Highly recommend. 

8

Hopefully not a fake Takata belt.


9

i had 4 point harnesses in my mk1 and hated them as no matter how i adjusted them the buckle always seemed to high for my liking, swapped them out for 5 points and they were so much better.