New member in Michigan USA

[Dave Eastwood (Gadgetman)]

Here you can see the higher rack position and additional brace of the Mega S2K chassis.

 

[Flying Carrot Steve]

On 15/07/2025 at 18:19, evosteve said:

As he said, the holes in the steering arms are tapered for the track rod ends.

 

 

Yes, I'd totally forgotten that! 

[Andrzej]

So, is it possible to weld a bar and brackets onto an older Westfield chassis to raise the steering rack and reduce bump steer?

I wasn’t really aware how poor the front-end geometry was on the older Westfield chassis — in my case, the Aerorace, and also an older road-going version (although on the road, it’s not such an issue). I always thought the handling quirks were just part of the "kit car character" — until I had the chance to drive an MNR VortX Inboard on track, with similar power.

The MNR, designed by race driver Marc Nordon, is a completely different experience. While the Westfield feels like an evolution of an affordable road-going kit car — and you can feel that in its behavior — the VortX is much more composed and confidence-inspiring, especially over bumps and curbs. The difference was night and day.

Now I’m wondering if bump steer is the main issue here. It’s interesting that Westfield changed the design on their newer chassis to a higher-mounted rack. If that’s the case, and the steering rack position really makes that much of a difference, then welding a bar and brackets to reposition it doesn’t seem like such a complicated modification — at least not if it brings the handling closer to what the MNR delivers.

Has anyone here done this mod on an older chassis? Would love to hear thoughts or some guide how high is this bar welded ? 

[Dave Eastwood (Gadgetman)]

The chassis re-working for the. Mega S2000 was contracted out to Randle Engineering, who are behind the subtle and not so subtle tweaks and changes to the design. Which was then (initially) manufactured in-house, alongside the other chassis offered, before being made, again, like their other chassis, by an outside contractor - it was Caged, though not sure if they carried on after the factory reopened, or not.

 

(the design changes for the Sport 250 were added to the Mega S2000 chassis in house by the old WSC factory, as far as I know).

 

As a general note, be very careful with chassis mods affecting suspension or steering pick up point locations. Make sure you comply with any local legislation. And if the car is for competition, make sure changing these things is ok in the rigs for whatever series you compete in. (It often isn’t.)

 

In the UK, (not for Westfields AFAIK), but in off road circles, a lot of Land Rover/Range Rover custom hybrids lost their VIN numbers under DVSA crack downs, and I know of at least one Caterham that ended up loosing its vin number and having to be parted out and (I think) the chassis destroyed, for the same reason.

 

 

[dvd8n]

On 15/07/2025 at 14:41, Dave Eastwood (Gadgetman) said:

The Mega S2000 and Sport 250 chassis have a relocated steering rack position compared to the standard chassis; it's higher, to reduce bump steer.

 

So on these cars, the arms sit above the steering arms on the upright, with the tie rod coming in from above, and the nut going on from below.

 

I'm not sure that I understand that.  Surely, if you raise the rack then raise the ball joint location to compensate then it puts all the angles back where they were, with no effect on bump steer?  Just with a higher rack?  Or am I missing something?

 

David

[dvd8n]

I can't stop thinking about this.  Is it trying to get the track rod end position closer to the middle of the upright to minimise the effect when the camber of the upright changes?

[IanD]

Its very interesting. I wasn't away of the differences in the chassis, but then I am an old SE narrow.

But my understanding of the principle of moving the rack, and I am by no means an expert. Is to reduce the effect to steering angle and maybe toe during the normal suspension travel known as Bump Steer.

 

I understand that in a perfect world the steering arms would be straight at normal ride height and move in the same angles as the suspension arms and so ideally should be parallel to the arms and also pivot in in the same place.

 

In the picture because the steering arms/trackrods are angled down so when the suspension compresses and the arms straighten the arms in relation to the upright lengthen effecting the steering angle and ultimately the toe

 

Of course as always its a lot more complicated that this and there are always compromises with the parts available in a kit car.

All just my understanding and happy to be corrected as its a very complicated subject and am very happy to learn and understand better myself.

[Dave Eastwood (Gadgetman)]

It’s a really complicated topic, worthy of a thread on its own. It’s not a black and white thing either, many get into the idea of bump steer = bad, must eliminate.

 

The reality is, that it’s just another element, that needs to be controlled, but can also be used beneficially. Lotus for example, often use controlled amounts of bump steer beneficially.

[Dave Eastwood (Gadgetman)]

An interesting thread from the archives here: 

Rather than take this one too much further off topic.

[evosteve]

If you're looking for a bit of light reading the Race and rally car source book by Allan Staniforth has some good suspension write ups.