Reynard 84F Restoration

[Max.Brass]

As the feedback has been so helpful, I thought I'd try my next question.

What have others done to modify/adapt their cars to install the wider mounting harness shoulder straps for the HANS device? The ultimate mod, I suppose, would be to weld in two more bushings, but are there other solutions?

Thanks all,

Max

[Lotus7]

A photo of the current arrangement might help generate appropriate ideas

[Max.Brass]

Good idea!

There are two horizontal bushing through the chassis to mount the shoulder straps, the upper two in the photo. I believe they are 5/16" ID.

I'm not sure of the recommended mounting width for the HANS shoulder straps, but I know it's wider.

Any suggestions will be welcome. Please excuse the cruddy appearance of the car, the photo was taken the day I received the car and hadn't even cleaned it at this point. It was gross!!

Thank you,

Max

[Lotus7]

I'd remove that horizontal 'U' shaped sheet metal (6 screws), you may find a square tube running laterally across the car that you could easily weld two more sleeves into (with vertical axes), that would take bolt-in harness ends.

[Max.Brass]

I was able to take some petter photos when I got home.

The existing bushings are .375" I/D x .50" O/D x 1.12" long on 4.0" centers in a 3/4" square tube. I think the easiest solution is to make some more bushings and have them welded in. I just need to figure out the spacing required for the HANS.

[SteveG]

Maybe this will help


Steve

[tlracer]

Based on the info in Steve's very useful post for Hans belt installation, it sounds like the existing 4" centres are quite good as-is. Because of this I'd be inclined to refit the seat (if you have one!) and try a dummy set-up of belts to see how they route now.

If they're allowed under US regs, the bushes you have would allow the use of eye bolts for fixing the shoulder straps.

[Purple Frog]

I think the stock bushings are way too low for proper belt mounting. The belts are not supposed go downward behind the shoulders (see HANS instructions above). Usually in older Reynards we have to weld in a new structure to properly position the belt mounts.

I might be able to find pictures later today. Keith Averill has also done the mod to Steve Myers car in the past with photos posted here about 14 years ago.

[Max.Brass]

Based on the info in Steve's very useful post for Hans belt installation, it sounds like the existing 4" centres are quite good as-is. Because of this I'd be inclined to refit the seat (if you have one!) and try a dummy set-up of belts to see how they route now.

If they're allowed under US regs, the bushes you have would allow the use of eye bolts for fixing the shoulder straps.

Unfortunately, I do not have a seat but I think I can mock-up some plywood for a seat back and test fit the belts and HANS. I'm quite wide in the shoulders, but I guess its really the width of the HANS that really matters.

Max

[Max.Brass]

I think the stock bushings are way too low for proper belt mounting. The belts are not supposed go downward behind the shoulders (see HANS instructions above). Usually in older Reynards we have to weld in a new structure to properly position the belt mounts.

I might be able to find pictures later today. Keith Averill has also done the mod to Steve Myers car in the past with photos posted here about 14 years ago.

I had a feeling that the mounts are on the low side. I'd really appreciate any photos you might be able to find. I'm fairly short, 5'10", so will sit quite low, but I think it will be tough to achieve the 10-20 degrees that HANS recommend.

Thank you

Max

[tstrang]

Here's a photo of how I built an attachment point for properly locating the shoulder harness for HANS on my 84 Reynard. I've noticed there seems to be many variations in the "84" frames but this worked for me.

[Rick Kirchner]

echoing what Purple frog said as well as Strang. When I started using a HANS the mounts were very low and EXTREMELY painful when using the HANS. I had two vertical bars welded in and two sets of bushings installed in a similar way to what was existing. That way you have some options once you actually fit yourself in.

The other thing is that those low mounts allow the belts to crush you into the seat, which actually provides decent lateral support. Once you have HANS mounts that lateral support goes away and you have to get it through the seat.

[kea]

As stated earlier, we made a modification to shoulder mounts on the 88 Reynard of Steve Myers because of the low shoulder belt mounts hurting his back (come to think of it, that was an issue I had in my Ralt RT-1).
This was pre-HANS device.
We included two different height points for the shoulder belts, not knowing what size driver may eventually drive it. When we went to using a HANS device, he had no complaints. Others did.
It then became apparent that the HANS made the issue more evident.

We changed a number of cars after that.

6 inches between mounting points is the maximum that should be used, for any vehicle.

[Max.Brass]

Keith,

My Seat Belts are better suited to a vertical bolt mounting for the shoulder straps. The horizontal bushing/bolt puts the end fitting in bending and is not ideal.

Do you recall the height you found best for you bushings? I'm thinking I could do a horizontal cross tube 3/4 x 3/4 with the bushing protruding 1/8" top and bottom. This would give two positions about 1 1/8" difference in height.

If anyone has a Reynard seat they might sell, it would help with checking the driving position and belt alignment.

Thanks all!

Max

[kea]

The belt mounting tabs that Willans uses, are so tough, that it broke a Whitney punch one time when someone in my shop was trying to enlarge the hole in one. It's very strong.

If the belts are mounted slightly below your shoulder/HANS (as they should be), then the belts will be traveling upwards anyway..

I had a customer crash test the mount and belt fastening method one year, on the opening lap of the SCCA Run-offs (at Road America that year).The gearbox, broke in half. The engine had the intake manifold broken off, etc, etc. When the car was done, we basically threw it away, but the shoulder mounting system and belts held (it even bent the twin-tube Reynard roll hoop slightly to one side). . This was a BIG hit.

So, I wouldn't worry about the upward angle of the belt mounting tabs.

[Max.Brass]

Probably a lot to do with the squishy thing that's being restrained!

My difficulty is that I have no seat to mock-up the belt alignment, and I want to get the chassis to powder coat ASAP I'm going to sketch-up some ideas this evening.

Thank you,

Max

[azjc]

What I did on my '88 Reynard - similar to your chassis

[Purple Frog]

You really don't want to use the seat that came with the car in 1984. Not a safe option. You want to pour a foam seat . Just saying.

[Purple Frog]

You don't want shoulder belts "holding you down"... it can cause vertebrae compression breaks during an incident.

How we made HANS work in one Reynard:

[Max.Brass]

You really don't want to use the seat that came with the car in 1984. Not a safe option. You want to pour a foam seat . Just saying.

I completely agree, but having a seat now would enable me to to a trial seated in the bare frame so I can estimate the height to make the shoulder strap attachment point to the chassis.

I have a plan in mind for the chassis mods, just have to go pick up some 3/4" square tubing and get cutting!

Thank you,

Max

[tlracer]

I completely agree, but having a seat now would enable me to to a trial seated in the bare frame so I can estimate the height to make the shoulder strap attachment point to the chassis.

I have a plan in mind for the chassis mods, just have to go pick up some 3/4" square tubing and get cutting!

Thank you,

Max

Having a seat - even a fairly accurate mock-up - would help immensely in getting the belt anchorages decided.

For the tubing, I'd suggest either T45 or 15CDV6. Both have the necessary mechanical properties, excellent weldability with no post-welding heat treatment required and are fine to use with other grades of carbon steel.

[Max.Brass]

Having a seat - even a fairly accurate mock-up - would help immensely in getting the belt anchorages decided.

For the tubing, I'd suggest either T45 or 15CDV6. Both have the necessary mechanical properties, excellent weldability with no post-welding heat treatment required and are fine to use with other grades of carbon steel.

Hi,

T45 equivalent in the US is 4130, I'm not aware of an equivalent to 15CDV6 though. Square 4130 seems expensive at $34/ft for 3/4" x 3/4" x 0.49" here in LA!

I know only the Roll Hoop was built from T45 and the rest of the chassis was ERW I think.

No leads on a seat probably means my woodworking skills are going to be tested to make a semi-viable mock-up!

Max

[Gary_T]

https://www.apexspeed.com/forums/sho...t-epoxy-amount

I'd say build a bead seat - even though you know you'll need to change it later, once you figure out positioning in the car.

[DanW]

Hi,

T45 equivalent in the US is 4130, I'm not aware of an equivalent to 15CDV6 though. Square 4130 seems expensive at $34/ft for 3/4" x 3/4" x 0.49" here in LA!

I know only the Roll Hoop was built from T45 and the rest of the chassis was ERW I think.

No leads on a seat probably means my woodworking skills are going to be tested to make a semi-viable mock-up!

Max

How are your foam board fab skills? Buy some 1" foam insulation board, cut it with a hot knife and set it in place to suit your purposes. Much easier than plywood. https://www.lowes.com/pl/insulation-...106-4294511582

[Max.Brass]

https://www.apexspeed.com/forums/sho...t-epoxy-amount

I'd say build a bead seat - even though you know you'll need to change it later, once you figure out positioning in the car.

The problem is there are no pedals, steering wheel or gearshift parts on the bare chassis so I'd hate to waste the cost of a bead seat when the likelihood of getting it right is pretty low.

Max

[Purple Frog]

Instead of an expensive bead seat kit, you could use something like West Marine two part foam and a large trash bag. Been there, done that. The above mentioned foam board would be easier to shape than wood. YMMV

[Max.Brass]

Instead of an expensive bead seat kit, you could use something like West Marine two part foam and a large trash bag. Been there, done that. The above mentioned foam board would be easier to shape than wood. YMMV

Oh boy do I have stories about making seats with 2-part foam! Lets just say it ended with the driver getting a hair-cut!!

I think the foam board idea is a pretty good one too!

Max

[tlracer]

Hi,

T45 equivalent in the US is 4130, I'm not aware of an equivalent to 15CDV6 though. Square 4130 seems expensive at $34/ft for 3/4" x 3/4" x 0.49" here in LA!

I know only the Roll Hoop was built from T45 and the rest of the chassis was ERW I think.
Max

T45 and 4130 aren't equivalent materials, which is why I suggested the former or 15CDV6.

Unlike 4130, T45 doesn't need any heat treatment after welding to avoid brittleness and cracking. It can also be welded to other steels without problems, again unlike 4130, so would be a better option.

15CDV6 is available in the US:

https://www.aircraftmaterials.com/da...st/15cdv6.html

This would also be a better option than 4130 as, again, it doesn't need any post-weld heat treatment.

Added: There's a useful comparison here:

https://proformancemetals.co.uk/what...r-a-roll-cage/

[kea]

Oh boy do I have stories about making seats with 2-part foam! Lets just say it ended with the driver getting a hair-cut!!

I think the foam board idea is a pretty good one too!

Max

For some of my customers, it's taken more then one 2-part foam seat to figure out how they want to sit while driving.. Shift arm clearance, back support/position, angles that are not uncomfortable for long periods while racing, can't always be seen when sitting in the shop and in a car that you haven't driven before. Two-part is quick and easy. Then, once you know, go the expense (and safety) of a bead seat.

[DaveW]

Instead of an expensive bead seat kit, you could use something like West Marine two part foam and a large trash bag. Been there, done that. The above mentioned foam board would be easier to shape than wood. YMMV

Believe it or not, I'm still using the 2-part foam seat we made at Citation in 1994 when were building my car. Works very well, and is still in good shape with a few layers of duct tape on its surface. Supports my body well and has survived (and helped me survive) a few nasty wrecks w/o issue.

[Rick Kirchner]

If you look around on this site somewhere you'll find my instructions for a homemade bead seat, and in the homemade method you end up with enough stuff to make three seats for less than the price of a pro kit.

[billtebbutt]

Believe it or not, I'm still using the 2-part foam seat we made at Citation in 1994 when were building my car. Works very well, and is still in good shape with a few layers of duct tape on its surface. Supports my body well and has survived (and helped me survive) a few nasty wrecks w/o issue.

Most of us cannot fit into our circa 1994 seats, Dave......
bt

[DaveW]

Most of us cannot fit into our circa 1994 seats, Dave......
bt

Actually, I've had to add padding. In '94 I probably weighed ~175-180 lb. Now I'm ~152 and a couple inches shorter.

[billtebbutt]

Actually, I've had to add padding. In '94 I probably weighed ~175-180 lb. Now I'm ~152 and a couple inches shorter.

Now you're just bragging!!!!
bt

[DaveW]

Now you're just bragging!!!!
bt

Nah - just getting older.

[Max.Brass]

So, I decided to quickly model the chassis so I could explore the options for adding the new shoulder strap mounts. I think in SolidWorks!!

I think this is the way I'll go. I like having the vertical tubes going to 'nodes' on the chassis, but can't avoid having the horizontal tubes mounting mid span. I did look at triangulating back to the front engine mount, but I think it a bit overkill. I'm not sure of the actual heights, but it's a parametric model so once I've decided I can adjust the model.



I welcome any comments,

Max

[Max.Brass]

T45 and 4130 aren't equivalent materials, which is why I suggested the former or 15CDV6.

Unlike 4130, T45 doesn't need any heat treatment after welding to avoid brittleness and cracking. It can also be welded to other steels without problems, again unlike 4130, so would be a better option.

15CDV6 is available in the US:

https://www.aircraftmaterials.com/da...st/15cdv6.html

This would also be a better option than 4130 as, again, it doesn't need any post-weld heat treatment.

Added: There's a useful comparison here:

https://proformancemetals.co.uk/what...r-a-roll-cage/

I have had no luck finding T45 or 15CDV6 in the US. It might be possible to import large quantities, but I'm looking for a few feet!

I've used 15CDV6 in Europe and it is a very good material, but here in the US 4130 rules. Everyone knows how to process and weld it etc. I've done as simple as a torch normalization on some parts, so I think this is going to work out OK.

Appreciate the helpful advice!

Max

[jrh3]

I have had no luck finding T45 or 15CDV6 in the US. It might be possible to import large quantities, but I'm looking for a few feet!

I've used 15CDV6 in Europe and it is a very good material, but here in the US 4130 rules. Everyone knows how to process and weld it etc. I've done as simple as a torch normalization on some parts, so I think this is going to work out OK.

Appreciate the helpful advice!

Max

I wouldn’t hesitate to use round 4130 or DOM

[kea]

Your "drawing", in my viewpoint, a little excessive.
We used mild steel for the construction of our shoulder mounting design. And as I mentioned, it's been "crash" tested.

[tlracer]

I have had no luck finding T45 or 15CDV6 in the US. It might be possible to import large quantities, but I'm looking for a few feet!

I've used 15CDV6 in Europe and it is a very good material, but here in the US 4130 rules. Everyone knows how to process and weld it etc. I've done as simple as a torch normalization on some parts, so I think this is going to work out OK.

Appreciate the helpful advice!

Max

If you're confident you can work with 4130 then you should be okay; given that the rollover tubing is T45 it would seem logical not to introduce another material, though.

Having seen various components, eg. wishbones, made from 4130 that have split due to poor or non-existent heat treatment after manufacturing, I admit I am not a huge fan so tend to avoid it unless absolutely necessary.