Front view geometry input please

[CoryM]

Hey guys,
Fiddling around with some front suspension geometry (front view) and am looking for input.
Here are some specs:
Building a "Locost" aka Seven (caterham wannabe)
Less than 1500lbs wet
200bhp V6 powered
Probably end up being a bit front heavy
4link, Live axle rear. no roll centre height set yet.
205/50r15 street tires
54" track
90" wheelbase
9.25" tall spindles

Static camber -1.5 degrees
Outside wheel camber -0.5deg @ 3 degrees roll and 1" of lift.
Inside wheel camber -2deg @ 3 degrees roll and 1" of lift.
Static Roll centre height 2.75"
Lateral roll centre movement 1.44" towards outside tire @ 3 degrees roll and 1" of lift.
Static Swing arm length 101"

What I am wondering, is how much inside wheel negative camber can I allow? I can't find any specs for it, but it seems like it could be better. As well you you think I would do better to reduce the swing arm length a bit more to try and reduce the lateral roll centre movement? I have fiddled around for a while, and this is getting to be close to the best compromise I can come up with.
My aim is first, have a predictable car, and second not have an understeering pig. For the later maybe a lower front roll centre would be wise?
Thanks for any input.
CoryM

[MrQuick]

You can always increase the weight to the rear.

How about the height of the upright? Factory unit?
Any cad illustration?

[deuce_454]

Probably end up being a bit front heavy
4link, Live axle rear. no roll centre height set yet.


now is the time to engineer it correctly!

wr2 the roll center i would do a wattslink with frame mounted propeller, that way upui can adjust the rollcenter height bu moving the prop up and down.. and the rollcenter stays fixed in correlation to the center of gravity as the suspensuin moves thru its travel...

wr2 the engine... keep it as light and far rear set as possible, rather spens alittle extra on the right engine than have a front heavy car... i would check into somthing like a hayabusa I4 or turbo rotary... both ate very light engines.. the mazda 2 rotor will hit 300 Hp easy with a blowthru carb and isnt expensive at all...

If you are biased against the above engines.. atleast considder that an iron block v6 weighs more than an LS1.. and once you get into tuning them the gen3 is cheaper... (and i know what id choose)

[CoryM]

You can always increase the weight to the rear.

How about the height of the upright? Factory unit?
Any cad illustration?

Certainly trying to get the weight as far back as possible. It probably won't be too bad but I think traction is always going to be an issue.
Height of the upright is 9.28". From a 90 miata but reamed out to accept different balljoints. Very unusual knuckles, lots of SAI. I'm kind of wishing I had used something else, but not sure what at this point.

No cad drawing at this time. Other than a few points on the grid to reference from that is. The geometry program I am using is an old dos based program and damned if I can get it to "print screen" or go to a window.

Duece, To me the watts link is too much fooling around and extra weight (says the guy running pushrod suspension :rotfl: ). A long panhard bar with adjustable points works for me. I've looked to bike engines, but this is a low-cost locost and I need some reliability. Same applies to the rx7. The LS1 is too much for this chassis. I am already pushing what it can take with the V6.

Thanks.
Cory

[deuce_454]

i hear ya.. it was just mt point that a 5.3 with a carb puts out well over 300 Hp and weighs less than a v6.. and it can be yours for less than 2 grand including the carb setup...