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New design help- bounce some ideas off you guys?
garage19 - 23/5/08 at 01:03 PM

Now the Indy is nearly finished, my TIG welding skills could be classed as competent and i'm getting to grips with solidworks it seems it might be time to start designing a middy!

Basic idea so far is to build a small, light and locost single seater. It will be powered by a bike engine.

First two decisions i am stuck on are as below. Some input from felow builders would be appreciated and hopefully will help me make my mind up.

#1 Which uprights should i use?? I don't particularly want to make my own to keep things simple. I like the idea of having a Ford stud pattern but that limits it to Sierra or cortina. The cortina ones are ok but getting rare and the sierra ones, although plentiful, look heavy and clumsy.

Other options i have thought about are MX5 ones but if i use a ford diff this would mean custom driveshafts.

#2 Engine/person layout. The two layouts i'm considering are central driver with engine behind or engine on left and driver on right. I like the idea of a central driving position but can see that the side by side format would allow a shorter wheelbase. The only problem is it would have to be a left hooker due to the chain drive being on the left of the engine.

Any input most appreciated.

Doug.

garage19 - 23/5/08 at 01:21 PM

PS. has anyone used this program for their suspension design?

I saw another one that was on a website called the racers edge or something but can't find it now. Does anyone have a link?

kb58 - 23/5/08 at 02:54 PM

quote:
Originally posted by garage19
PS. has anyone used this program for their suspension design?

what program?

kb58 - 23/5/08 at 02:57 PM

quote:
Originally posted by garage19
... Other options i have thought about are MX5 ones but if i use a ford diff this would mean custom driveshafts.

Even if you force your design to have the same track width as the upright, or diff, you're always going to need custom axles to match the different parts you're mating.

cloudy - 23/5/08 at 03:06 PM

cortina/sierra parts would still be my choice, lots of aftermarket parts available to match....

andyd - 23/5/08 at 03:52 PM

quote:
Originally posted by garage19
Basic idea so far is to build a small, light and locost single seater. It will be powered by a bike engine.

Hi Doug. When you told me the other day of your plans I recalled seeing about the Sprint R single seater which is R1 powered. I've looked on their site but I couldn't find a close up/clear picture of their rear end setup. My guess though (and based on the rear shots they do have on the page I've linked to above) would be that they've mounted the engine directly behind the driver and used offset drive shafts. Does anyone know if that's the case?

I also recall someone mentioning custom drive shafts being made for about £70? Or did I dream about that one?

Personally I'm going the route of fabricating (or at least designing and getting someone else to fabricate) my own uprights/hubs so that I get the best suspension geometry for my purposes. I'll still use Ford PCD for now although I may still change that as yet. I know that doesn't help you so I'll add that due to Cortina upright shortages (even though I've just sold some ) I'd be inclined to go with Sierra ones and get the best setup by compensating with the rest of the suspension.

I'm going to go the offset drive shaft route with a chain drive diff too so that the engine will be more central. If I don't, the engine will be over toward the offside too much for a decent balance especially when driving alone... not that I'm a lard ar$e or anything.

sucksqueezebangblow - 23/5/08 at 03:54 PM

#1 use Raceleda uprights and hubs, they are light alloy Ford replacements.

#2 Turn the engine sideways on the left side of the car, fit drive flange and prop shaft, then you have a right hooker!

Ians - 23/5/08 at 05:34 PM

Ians.. Rescued attachment 146.jpg
Rescued attachment 146.jpg

garage19 - 23/5/08 at 06:40 PM

Ian,
looks like you have now built cars using both layouts. Which one do you prefer?

I think i'm going to stick with cortina uprights and sierra rear bearing carriers.

I can always make my own light weight versions as mini projects at the end.

Are the raceleda ones not an exact swap for cortina ones anyway?

Andy,
I've looked at the sprint R as part of my research. You can tell its no 100% racecar but for a budget trackday car it looks good.

What sort of bodywork do people prefer? If i was going inline config i think it would have to be formula style body work where as the parallel config would be full body shell like Ian's. I wonder which would be easier to make?

garage19 - 23/5/08 at 07:22 PM

quote:
Originally posted by kb58
quote:
Originally posted by garage19
... Other options i have thought about are MX5 ones but if i use a ford diff this would mean custom driveshafts.

Even if you force your design to have the same track width as the upright, or diff, you're always going to need custom axles to match the different parts you're mating.


Nice to have your input Kurt. I really enjoyed reading your book.

[Edited on 23/5/08 by garage19]

kb58 - 23/5/08 at 07:38 PM

Thanks

The axles serve admirably to translate from one brand of differential to another brand of upright, which is really convenient. The only other option is to use the entire rear end from something like the Miata.

garage19 - 23/5/08 at 07:59 PM

quote:
Originally posted by kb58
quote:
Originally posted by garage19
PS. has anyone used this program for their suspension design?

what program?


Sorry Kurt, this program:

http://www.bevenyoung.com.au/suswin.htm

Susprog3d

garage19 - 23/5/08 at 09:17 PM

This was the other suspension prog i was looking at.

http://www.racingaspirations.com/suspensiongeometry.php

Much much simpler but its a shame it doesn't show the co-ordinates of the chassis pick up points.

Playing with it has generated a few more questions

For a track day car with occasional road use what sort of suspension travel do i need and what sort of camber gain per mm should i be looking for?

Alan B - 23/5/08 at 11:12 PM

quote:
Originally posted by kb58
Thanks

The axles serve admirably to translate from one brand of differential to another brand of upright, which is really convenient. The only other option is to use the entire rear end from something like the Miata.


Exactly my thinking. Unless you are lucky to find something like the Miata set up that suits you exactly its easier to treat driveshafts as the custom part that brings otherwise mismatched goodies together.

chrisf - 26/5/08 at 12:16 PM

I used miata halfshafys mated to a Ford diff on my se7en. On the diff side, an aluminum adaptor bolts to the diff and the CV bolts to that.

My halfshafts were too long, so I cut an sleeved them, then had them TIG welded together. Knock on wood, but they have survived 2 summers of abuse and 2 hours of track time as well.

My car is very light though, and my bike engine isn't exactly a torque monster.

--Chris

rpmagazine - 26/5/08 at 01:09 PM

Susprog works well and is cheap enough for what you get.