67 replies to this topic

[JimmyJamJerusalem]

As we're taking over Cliffies Championship winning thread I suggest we invite Mr Scuff's over to this thread to clarify a few options soon to be available for the VX

[VXT Tim]

Also very interested, timing couldn't be better either.

[FLD]

Good shout Jimmy. Its been a good read so far.

[smiley]

Previous owner dropped the ridehight from stock to 10cm all over by fitting nitrons. Last month i replaced a cv joint, which was probably because of the more agressive angle of the shaft, due to the lowness. The car also feels to hard, and is only slightly comfortable on track. (NTR's set to 10/12 clicks from full hard, as seem to be common practice) I read most on here just drop it to 12cm on the back. So my assumption here, is that the dropping of the 4 cm has completely fooked the optimal workability of the car. So back to 12cm and a new geo, or if i insist on keeping it that low, i would need to be looking at these hubs to get it alligned again?

Edited by smiley, 27 September 2012 - 08:10 AM.

[NickB787]

interesting read

[cnrandall]

There are very few benefits of fitting different hubs on road cars. You can get down to 95mm front ride height fine on OE hubs without too many adverse effects although for a road car there is no real point in going down below 115. The only point to running very low is to maximise the aerodynamic effect of the underfloor and to do this you need to get down to 65-70mm which is completely impractical for anything but an out and out race car.

[siztenboots]

iirc from standard tyre/wheel setup if you swapped to 15" wheel all round, then you got a 40mm drop without changing wishbones or geo, albeit speedo was out by 8%

[Exmantaa]

I'm a bit surprised that these Gt hubs are now becoming such a hot topic, as I thought it was pretty common knowledge that you fcuk-up the VX's (read: Lotus chassis) wishbone geometry when you go to low on the car.
It's not that Eliseparts/Eliseshop, Nitron or whoever makes these else invented something new or magical...

If the price of these was not so high I would have bought some straight away, but I like to keep my VX on a sensible budget and I'm always looking for the cheaper options that have the same (or almost the same) result. (me like the "fiver" option )

Edit; Just want to also add the wheel size here, as 17's up front with the bigger (higher) tyre sizes have more impact on your angles than the smaller wheels up front.

What you want is restore the wishbone angles to the designed geometry, so on a lowered car you want to raise the hub relative to the wishbone pivot points. (= Balljoint centers):
For the lower TCA's we have thought about simply spacing-out the lower balljoint with a (precicely machined) conical spacer piece, as there is some excess height on the std joint nut. You cannot go to wild with this, but you could lower the joint center relative to the hub by maybe 10-15mm. Only not so sure on the safety and strength of such a modification. (In the US you can buy special longer balljoints for this purpose which have a raised conical part.)

The top wishbones all have a bolted-on piece that connects to the balljoints, so a new designed part here could do the job. If there is space enough, but I'm only looking for 10-15mm change.

(The above is not something I invented, but I spotted this solution on a heavily modified US track Elise. )

Previous owner dropped the ridehight from stock to 10cm all over by fitting nitrons.
Last month i replaced a cv joint, which was probably because of the more agressive angle of the shaft, due to the lowness.
The car also feels to hard, and is only slightly comfortable on track. (NTR's set to 10/12 clicks from full hard, as seem to be common practice)
I read most on here just drop it to 12cm on the back.

So my assumption here, is that the dropping of the 4 cm has completely fooked the optimal workability of the car.
So back to 12cm and a new geo, or if i insist on keeping it that low, i would need to be looking at these hubs to get it alligned again?

Smiley, your car is very low and uncomfortable, so I would not be surprised that you ride your NTR's bumpstops a lot... Raise it to sensible levels and with a goog geo you will probably have more fun on Oct 12.

Edited by Exmantaa, 27 September 2012 - 09:14 AM.

[techieboy]

I'm a bit surprised that these Gt hubs are now becoming such a hot topic, as I thought it was pretty common knowledge that you fcuk-up the VX's (read: Lotus chassis) wishbone geometry when you go to low on the car.
It's not that Eliseparts/Eliseshop, Nitron or whoever makes these else invented something new or magical...

Ding.

[chris_uk]

You can also use the 340R top wishbones to stop stress on the ball joints as they are welded at an angle. Atm the more you lower the car the more the wishbones point up. So the ball joints are not truely vertical with the 340r wishbones you can point the wishbones up but still have the vertical ball joint. Or more vertical anyway.

[chris_uk]

I'm a bit surprised that these Gt hubs are now becoming such a hot topic, as I thought it was pretty common knowledge that you fcuk-up the VX's (read: Lotus chassis) wishbone geometry when you go to low on the car.
It's not that Eliseparts/Eliseshop, Nitron or whoever makes these else invented something new or magical...

Ding.

Im not suprised in the slightest, as soon as someone who seems to know what they are talking about (no offence to those who actually do, scuffers/chris) says something everybody just jumps on the band wagon and must get it because they believe that its going to help them by just outlaying a bit of cash.

These hubs would only benifit a number of people here, an amount i can probably count on my hand. The rest either dont track it enough or are not good enough in the first place to really make use of the hubs.

[Scuffers]

For the lower TCA's we have thought about simply spacing-out the lower balljoint with a (precicely machined) conical spacer piece, as there is some excess height on the std joint nut. You cannot go to wild with this, but you could lower the joint center relative to the hub by maybe 10-15mm. Only not so sure on the safety and strength of such a modification. (In the US you can buy special longer balljoints for this purpose which have a raised conical part.)

issue with these is that the increased leverage you now have over the base of the upright and the ball joint itself.

it's quite possible to 'bend' std ball joints, adding 15mm to them pretty much guarantees this in a motorsport environment, you then have to consider the flexibility of the upright itself, as you have just increased the leverage over that too.

Yes, it's a cheap solution, no, it's not something I would use (you also have to consider that you have just changed the ratio of the top to bottom wishbone too by making the effective upright 15mm taller)...

As said, you have to consider what your ride hight targets are in light of the intended use, and you need to include the dimensions of the tyres in this.

All that said, when you consider the original design and setup of the std car, if you want to lower it, then using GT uprights is a good solution, all be it not a cheap one!

[Aerodynamic]

When we are talking about drop in ride height we are speaking about drop with std outer diameter +/- maybe 7mm or so? Anyone knows where to buy these hubs for lowest price? I have been thinking of CAD my own hubs this winter as ask a someone to machine them for me. BR, Per

[Scuffers]

These hubs would only benifit a number of people here, an amount i can probably count on my hand. The rest either dont track it enough or are not good enough in the first place to really make use of the hubs.

don't disagree, although the reasons for using them is not just for geometric reasons....

yes, for 99% of everyday VX owners, they would be borderline pointless, and as I said on the other thread, on their own they are not going to be much benefit to you (the other thread is about a very specific application, ie TA and the like)

[chris_uk]

Of cause, thats kind of the point i was making in a ham fisted way. As i see it its a calaboration of parts together which work in unison to get the desired result.

[smiley]

Smiley, your car is very low and uncomfortable, so I would not be surprised that you ride your NTR's bumpstops a lot... Raise it to sensible levels and with a goog geo you will probably have more fun on Oct 12.

It's on the to do list.
Me asuming the previous owner who liked to track the car also knew what he was doing when fitting the nitrons, seems to be the biggest screw up.
Back to the drawing board.

[Exmantaa]

issue with these is that the increased leverage you now have over the base of the upright and the ball joint itself.

it's quite possible to 'bend' std ball joints, adding 15mm to them pretty much guarantees this in a motorsport environment, you then have to consider the flexibility of the upright itself, as you have just increased the leverage over that too.

Yes, it's a cheap solution, no, it's not something I would use (you also have to consider that you have just changed the ratio of the top to bottom wishbone too by making the effective upright 15mm taller)...

As said, you have to consider what your ride hight targets are in light of the intended use, and you need to include the dimensions of the tyres in this.

All that said, when you consider the original design and setup of the std car, if you want to lower it, then using GT uprights is a good solution, all be it not a cheap one!

An offset lower balljoint should be matched with a similar offset upper balljoint, so the upright would keep the same effective length.
But exactly like you said; the increased leverage on the lower joint and possible bending of the balljoint shaft would be my primary concern. That US modified Elise did experience something like that and was solved by a collar around the longer balljoint shaft...
(I have pics somewhere of this modification)

But I can see that the GT uprights solve more problem points in the std road versions than wishbone angles alone, as those were simply not designed for race specifications. (Stiffness, bearing cooling, race caliper mounting etc. etc.)

[siztenboots]

could you fit the steering trackrod upside down , ie. bolt point upwards

is the main benefit of the GT hub better control of toe, or is it tyre contact patch

image courtesy of vocky

[Scuffers]

An offset lower balljoint should be matched with a similar offset upper balljoint, so the upright would keep the same effective length.

EH?

how you going to be able to lower the top ball-joint by 15mm? (ie, make is shorter)?

[Scuffers]

could you fit the steering trackrod upside down , ie. bolt point upwards

is the main benefit of the GT hub better control of toe, or is it tyre contact patch

err... no.

it's about roll centres....