James' GT-Forté scratch build GT40 MkI

Southern GT uses 2mm to keep the weight down.
Although the chassis's vary from manufacturer to manufacturer the general shapes are the same, they have to be.
There's much more 40mm tube than 25 and 20 in the chassis
Food for thought ?

 

[James Harvey]

Cheers Keith - definitely a good topic to discuss. I don't want to get something like this wrong....

3mm sounds like a massive thickness though. The early GTDs must be like tanks!

I'll drop Darren a note to see if he can provide any further info / thoughts.

Does anyone know what the other manufactures use?

Cheers
James

 

[Mick Ridley]

Hi James,

Im sure that Dax used 40mm x 1.6mm ERW box on ther GT40.s

Ive got your calipers on the bench ready for despatch. Ive lost your address, so can you please send it to me again, and ill send the calipers to you this week. my addy is [email protected]

mick

 

[James Harvey]

Fantastic - thanks Mick. I'll PM you my address...

I asked Darren about the GTS chassis. The GTS chassis was developed with more triangulation than the GTD chassis and if you arange the tubes correctly you can pass the loads throughout the chassis and share the load across a lot more material. ie it's not how much material you have that counts, but how you use it. Plus the GTD was probably a bit heavier than it needed to be.

As David mentions, most of the guys over on locostbuilders use 1.6mm. Or sometimes even lighter (1.2mm) for track based cars.

 

Hi James, Good news then, I'm sure Darrens done his homework.
Thought I'd ask though.
It would be interesting as your chassis progresses to actually see where any extra triangulation is added.
Most chassis differ but not too much.
Keep posting.

 

[James Harvey]

Hi Keith

Hopefully mine will look like the picture below.

I found a photo of a GTD chassis here. I'm no chassis engineer, but to me it looks a bit 'squarer' with less tubes. Like most things in life I guess there's more than one way to design a chassis.

Thanks for asking. I'm sure there'll be many other areas to come where I could do with input...!

Cheers
James

 

[Renato]

Hi James,

Congratulations on the purchase and good luck with the build.
Keep on the good work, every day...
The picture is of my chassis so if you need any closeups let me know.
I'm starting my build soon...

Renato

 

Hi James,
I can see the many extra 25mm tubes, in fact the chassis is different from so many out there.
Darren has kept the basic shape, which of course you have too but changed considerably its structure.
That should keep Tornado off his back... OPPS Sorry
I would be interested to know the chassis weight as in the picture and if the extra tubing adds weight and rigidity.
That GTD picture is sure well out of date now.

Looks good. Should be very rewarding seeing it progress.

Thanks for showing

 

[René]

that looks like an interesting chassis James, although I must say the GTD chassis as linked looks a bit poor, here is a better version, also more pictures.
you can see it looks like the tubes are ticker or look ticker...

T.R. Lane Fabrications |

 

Hi Rene ,
Although incomplete that Chassis looks thin, The engine looks so big and high up.
Accelerate hard and the engine look like it would jump out and overtake the driver !

 

[Brett James-McCall]

Rene, That's not a GTD chassis.

This is a GTD chassis, in fact I believe the photos are of the one I bought: http://www.gt40s.com/forum/garage-sale/13690-gtd-chassis-available-again.html

 

[René]

I thought perhaps different made, some modern version? and other engine.
I was mislead then by the title :rolleyes2: were they say GTD40 Chassis.

some other GTD were I could see a part of the chassis are indeed more the link you added, thanks.

 

[James Harvey]

Cheers Renato. Good luck with your build too. Keep us posted with how you're getting on... You'll no doubt be on the road by the time I've got my chassis looking like yours

Brett - yep, that's the same GTD chassis design as I put a link to, but with all the view points. Thanks.

 

[René]

just seen the website again of the GT-forte parts, impressive chassis and parts I must say, those chassis look pretty rigid, also more complex to make
looks more rigid then the GTD and Tornado and sort likes (space frame cars)

 

[Darrin]

Hi James,
I can see the many extra 25mm tubes, in fact the chassis is different from so many out there.
Darren has kept the basic shape, which of course you have too but changed considerably its structure.
That should keep Tornado off his back... OPPS Sorry
I would be interested to know the chassis weight as in the picture and if the extra tubing adds weight and rigidity.
That GTD picture is sure well out of date now.

Looks good. Should be very rewarding seeing it progress.

Thanks for showing

I don't think the extra tubing was to keep anyone at bay as it was to correct some deficiencies found though simulations (side note, he posted an analysis of a lower A arm that showed where it was weak and why their design differed). I also know the thing meets specs for racing some circuits in the UK so that is probably part of it as well.

I'll have one of the chassis in hand by mid December (scheduled to be picked up by the shipper this week I think). Once it's in I'll weigh it and post what I find.

To me, 50-75 pounds is not too much to add for a stronger chassis and I doubt it it adds that much.

 

[Darrin]

Here are a couple shots of mine with a lowered seating area from above and below. Doesn't show the full chassis but it does show the detail a bit better.

 

[René]

looks pretty strong to me, so that is the chassis for the Coyote engine
saw it today on facebook.

 

[Darrin]

looks pretty strong to me, so that is the chassis for the Coyote engine
saw it today on facebook.

Yes, it's one set up for a Coyote, left hand drive, and lowered seating area. Other than that it's the same as all of the ones they sell.

 

[James Harvey]

I've got the lathe all sorted now - stripped, cleaned and painted. I've done a few test pieces and think it's working well.

 

[Bill B]

Nice job on the lathe rebuild / cleanup. Nothing beats being able to turn your own little round bits when needed. Looks like you have a good stock of vino to enjoy while turing those bits out. I would be afraid of breaking the bottles with them that close to the machinery... Regards, Bill