Darrin's MMR BOSS based GT40

[Dave P]

The way I have understood it and had it explained to me by a friend in the racing seat belt business. Is that certain items in the vehicles manufacturing require DOT approval. Seat belts, brake lines, tail light lenses, windsheilds are just some of the parts I have seen the DOT approval stamp on. If they have a DOT your good. Most aftermarket companies do not want to spend the money to pass the DOT requirements. For example if you order custom made Speigler brake lines from where I work they are DOT approved. The enforcement is left up to the police and inspectors.
Here in NC you have to have a motorcycle helmet with DOT on it or you will get pulled over.

 

[Dave P]

I found this video about the Schroth belts
[ame="http://www.youtube.com/watch?v=uGfrL3PcwtA"]Schroth Safety Harness Video - YouTube[/ame]

 

[Mark R]

Notice how the seat bases on the Schroth test are angled up on the front of the seats. That is also a proven method of reducing the 'submarine' effect. In their control test, the seats seem to be mounted in more of a stock , or flat config. That seems a bit misleading when they claim their belt design alone prevents it.

 

[Bill Musarra]

Two other things to notice.
1st. In the beginning when the girl puts the shoulder harness on, there is a slack in the belts or maybe an inertia spring in place?
2nd. The videos show you why you need a Hans device in your cars:stunned:

Bill

 

[Brett James-McCall]

Guys, remember this is Darrin's build log. Let me know if you want me to move the harness discussion elsewhere...

 

[Darrin]

Guys, remember this is Darrin's build log. Let me know if you want me to move the harness discussion elsewhere...

Well it did kind of get hijacked, but I don't mind at all and it is seat related. It has made me rethink the Sparco's a bit too. Will probably still go with them as I doubt I can find a seat that tilts and gives you 6-point harness support at a reasonable cost but I am at least going to look more now. The car is more set up for racing safety wise (roll cage, foam filled fuel tanks, etc) so I guess it would make sense to follow through with the harness if at all possible.

 

[Brett James-McCall]

How about making your own? You can fold the ally and get someone to Tig where you need it. I thought about doing this, but ended up buying some fibreglass shells to go original style.

 

[Darrin]

How about making your own? You can fold the ally and get someone to Tig where you need it. I thought about doing this, but ended up buying some fibreglass shells to go original style.

I figured trying to get a tilt mechanism in would be a pain and end up costing a lot more when it was all said and done. The Sparco R100 for example is only about $600/set!

I'm going to do some more searching this weekend and will update everyone if I find something that will work as a 6 point, tilt, small enough to fit, and not be too expensive.

 

[Darrin]

Part of the front done. Got a hard panel to do next...lots of bend in it.

 

[Bill Musarra]

Drrin,
Don't be in too big of a hurry to secure that top and front panel. You will be going in that direction for the pedals, steering, water pipes and wiring. At least to rough them in.
You are making good progress. Steady as she goes

Bill

 

[Darrin]

Thanks Bill. Right now I just have the top in with Cleco pins and it will stay that way for now. I plan to rivet in the side pieces now though. The very front I am planning to do later as you say.

 

[Darrin]

Another day another panel cut. LOL

Really stuck now though. The next panel needs to take a very, very odd shape in my opinion. Looks like it should go across the top (all 14" of it) then back at and angle, then bend of the left side and pull forward to mate up on the left at the vertical bar where the other panel already is.

 

[Darrin]

Some progress on my project. Front driver's side paneling riveted, rubberized undercoat applied, and A-arms loose fitted. Also completed driver's side fuel tank and top sill work. Next I will rotate the chassis 180 and finish the passenger side (space limitations) as I wait on some more laser cut panels.

Also think I've decided on the Sparco R100 seats. About the only things low and narrow enough to fit the car with a good reputation.

What do you all think about the rubberized undercoat? Leave it as is, or spray something else over top of it? It's kind of ugly stuff but it sure helps keep the noise down from rocks that hit the panels (I tested it before and after).

 

[Darrin]

Here is the seat I am going with.Google Image Result for http://www.sparcousa.com/sites/default/files/products/00961%20Black-black.jpg

 

Nice seat Darrin but make sure fully it will fit, the 40 is more a lay down driving position and I have trial fitted different ones in the past.
Also belts, I have 3" wide Willans and there a bugger for normal road use, look good yes, but I'm going to put a normal inertial reel set for everyday comfort as well as the 3" for serious usage.

 

[René]

I would not have any problems with that rubberised undercoat, if its a plus to keep road-noise and tire noise and gravel stuff down even the better (me thinks)

 

[Bill Musarra]

Darrin,
On the panels try using heavy paper like butchers block to get the lines needed for the paneling. I did that and it made the layout a lot easier. The lines are tough to lay perfectly for algnment so some overlap may be necessary. Here is mine during construction.

On your seats, I agree that what is needed is a seat that is laid back a bit. Try and see the seat in person, you want and actually sit in it to confirm that is what you really want. It needs to conform to the firewall to get you under the door. I am only 5-9 and I tried some that were made for the corvette and they wouldn't clear the door, or align with the roll bar. I went with Racetech which has a laid back seat, but isn't for everyone in that is truely a race seat and the model I chose was for the Saker car in Australia. I wanted a seat that actually held you in. The old original seats left me wanting to hang on to something every time they took a turn even with the seat belts on.
As for harnessess, I feel the 2" belts are more comfortable than the 3" ones, especially if you are considering a Hans device. They have a tendancy to cut into the neck a bit and are hard to adjust. take a look at the Schroth web site for good information on seatbelts and installation etc. even if that isn't who you choose.They lay their research out there for all to read. If you are cosidering a cage for safety then make sure your head clears all metal pieces. There are some good cage coverings that are SFI & FIA approved that will save your noggin. The pipe insulation won't save you.

Bill

 

[Darrin]

Thanks Bill. Most of the panels I have left are laser cut from templates but I do need to fabricate a few more.

The Sparco R100 tilts to pretty much any position you want. The height is 36.7 which, with rails, just fits with some to spare (not much...but should be enough).

Here are the specs on it. http://site.racinglab.com/images/sparco_seatsize5.gif

It's about the smallest I can find that allows for tilt and has a very low seating area.

 

[Darrin]

Anyone use this stuff? 100^ Rattle Trap Sound Deadener Noise Killer

I ordered 25 sq ft of it. Should be in tomorrow. Plan to use it behind the driver's seat, the front foot well area, and maybe in the doors if I have enough left.

 

[Bill Musarra]

Darrin,
Just malke sure the sides of the base of the seat comes up high enough to hold you in place. the original type seats don't come up enough for my taste. Felt like I was sliding around in the seat even with the seat belts on. Had to reach up to the dash to keep me stable.
On your insulation. The stuff you are using looks awfully thin. I am using DynaPad.
DynaPad

This stuff has 4 layers and is .4" thick. It is heavy at 1 lb./ft.. I can tell you that I don't have AC in my car(yet) and probably won't. This summer will tell. The one long trip I took in it(80 miles over 10 hours time) I didn't even get warm. Some stop and go, but mostly highway. Started out in 40F and it got up to high 60s during the day. All I did was remove the drivers side window for the mid day run. Amaziing how little turbulance there is at highway speed. The trick to it as I see it is to insulate the front firewall(footwell area) really well and isolate the heat from the radiator from getting to the footwells. To accomplish that you have to extend the nostril(s) to the base of the radiator and seal all the sides or do like I did and build a dam to block it off.

The same goes for the firewall infront of the engine. For that I used a combination of Dynamat and then a layer of Dynapad. You can never insulate too well. don't worry about weight. With the power these cars have it won't detract at all.