Board logo

escort steering rack with mx5 uprights
luke2152 - 24/6/18 at 09:44 AM

Been using mk2 escort rack with on my GBS zero with mx5 uprights as I think others do. It is the slightly quick rack from rally design (2.9 turns lock to lock). I suspect that the steering arms are shorter on the mx5 because at full lock the wheels turn more than 45 degrees. More to the point though the steering is so bloody twitchy. Pushing hard through turns at 40-60mph is better than perfect but above that it gets very easy to over correct. Been telling myself for 3 years I'll get used to it but it's not happening. Has anyone found the same with an escort rack on mx5 gear or am I just getting soft?

I'm thinking I'll try a standard escort rack. Does anyone know what that ratio is?

chris_smith - 24/6/18 at 10:51 AM

What diameter steering wheel have you got?

Camber Dave - 24/6/18 at 05:26 PM

Standard Rack - 1 turn of the steering wheel = 20 deg
Quick rack - 3/4 turn = 20 Deg

I once did an Escort Rally car that had 1/2 turn for 20 Deg

I use 20 deg of front wheel movement for checking Castor with Dunlop Gauge

MX 5 Mk 1 with power rack is 2 1/2 turns lock to lock

It reads like you have set up issues.

luke2152 - 24/6/18 at 07:17 PM

quote:
Originally posted by Camber Dave
Standard Rack - 1 turn of the steering wheel = 20 deg
Quick rack - 3/4 turn = 20 Deg

I once did an Escort Rally car that had 1/2 turn for 20 Deg

I use 20 deg of front wheel movement for checking Castor with Dunlop Gauge

MX 5 Mk 1 with power rack is 2 1/2 turns lock to lock

It reads like you have set up issues.


So on mine 50 degrees (estimated but it's more than 45 degrees) in 1.45 turns equals 34 degrees per turn. Based on that I guess mine is quicker than an escort quick but not quite as much as the extreme example you quoted. Was that 0.5turn/20degree escort manageable on the road or required a ninja to keep under control?

I agree that it could be a set up issue and I've worked on wishbone geo and alignment etc but want to make sure I get the steering ratio suitable to start with.

907 - 25/6/18 at 06:41 AM

On the Suttol I have an Escort rack, 3.5 turns lock to lock and a 350 mm o/d Momo Race wheel.


It was twitchy at first, so much so that you couldn't let go of the wheel. 100% concentration needed.


I made new wishbones with increased castor and now its fine. Only 95% needed. This is similar to my MX5 which has "fast road setup."


I would regard an average road car to need 60 to 70%.

Camber Dave - 25/6/18 at 06:56 AM

"Was that 0.5turn/20degree escort manageable on the road or required a ninja to keep under control? "

I didn't drive it but went as a passenger for about 5 miles
Ninja
One of the great cars. A full on experiance

luke2152 - 27/6/18 at 11:44 PM

So to that end where is a good source for a 3.5 lock to lock original ratio rack. I emailed a few of the obvious suppliers and it seems the quick racks are easier to find than original ratio. Or anyone selling one?

Charlie C - 28/6/18 at 08:54 AM

Have you concidered the castor angle its sounds like if theres a stability issue at speed that could be the problem.