Quick Rack Steering

[Paul Mac]

I know this topic has come up before, so apologies. However.... what are peoples' experiences of Qucik Rack Steering (either percentage) as I've read a few horror stories. How much of a, positive or negative, difference does it make ?

 

Thanks....

[Barry]

I haven't got a qucik rack but I have got a 22% quick rack. I originally had a standard rack, but after a prang at Goodwood, as I was going to have to change the bent one, a quick one seemed sensible.

 

To start with, there was a certain amount of 'stickiness', I would find that after a while on the motorway, changing lane required a real tug on the wheel. The car would then shoot across to the lane I wanted and it required another effort to pull it straight.

 

After a while, and Jim Whiting filling up the rack boots with some kind of oil, it all settled down.

 

The only downside I've found is that the turning circle isn't so good (the car has flared wings). It's almost as if the % increase has been achieved at the expense of manoevrability at very low speed. However, I wouldn't change it now, the steering is very positive, very direct.

 

ymmv

 

Barry

[Alex Wong1697456877]

I have the standard 8% rack which took a bit of getting used to. My old car had the 0% rack which gave a great turning circle and was easier to drive on the road.

 

Nigel Marston has gone to a 22% rack and he feels it's a bit much. So much so that he's put a bigger steering wheel on the car to counter it.

 

The steering is definitely heavier with the quick racks and I still preferred my old crossflows 0% rack for the road but on the track, somehow the extra steering weight and twitchiness becomes unnoticable and for me, the 8% rack is about as fast as I'd want it to be.

 

Alex

 

Alex Wong

alexwong@compuserve.com

http://www.alexwong.net

Home : 44-(0)121-440 6972

Fax : 44-(0)121-440 4601

Mobile : 44-(0)468-038618

[SLR No.77]

I have the 22% quick rack and would generally enforce all the previous comments. No sign of stickiness though. You have to think of the rack as purelly a gearing system like any other. The higher the gearing (0% rack)the easy to turn but little feedback from the road. Lower gearing (22%) makes stiffer stearing but masses of feedback - on occasions on the road enough to induce bump-steer as your arms are litterally shaken around. I fitted a bigger wheel, up from 260mm to 280mm to reduce this. It can also depend upon tyres. Grippy tyres such as 21Rs increase the feadback problem on the road. For primarily road use, stick to 8%.

Stu.

[Graham Perry]

A quick rach is a must if you are planning any motorsport. It enables you to catch the tail of the car with a quick flick of the wrist in oversteer situations. I have had one about eight years and it has needed adjusting a couple of times to please the RAC scrutineers. This is easy to do with a spanner and allen key. It is very sentitive to how it is set up though and slight binding in its use is not unknown, although this is only noticeable with the wheels of the ground and can easily be adjusted out.

[Mike Bees]

I switched from the 8% quick rack to the 22% and am very pleased with the change for both road and track use. Next time I'd go for the 22% from the start.

 

The rack ratio has nothing to do with bump steer. Bump steer happens without any movement of the steering wheel. It's caused by the effective length of the steering arm changing when the wheel moves up or down with respect to the body.

 

Getting your front tracking/camber/castor set up to suit the wheels/tyres & your usage pattern and checking the bumpsteer is the right way to fix nasty front-end habits. Masking them (which you can do to some extent) with a low-geared rack isn't, IMHO.

 

The se7ens mailing list had a good discussion on bumpsteer recently. Go to http://www.se7ens.net/cgi-bin/wilma/sevens, type "bump;steer" (without the quotes) in the search box, check "Restrict matched files", select "January 2000" from the list of months, and click the search button.

 

Mike

[SLR No.77]

Hi Mike. Term "bump steer" used out of context, ie. not related to steering geometry but to general seven hell on seriously bumpy roads (or is that "modern roads"?). Every car is susceptible to the odd jolt through the wheel from time to time, being more noticeable with a quicker rack. Checked out the info on the mailing list. VERY interesting.

Regards,

Stu.

[Slipper man]

It all just goes to show that everyone's different. My view is that, having tried a +8% rack, I hated it. One of the things I love about driving the Seven is how light it feels to drive. With a fast rack the steering weights up, and the car feels like a truck in comparison. I can see the benefit for track use, but on the road I much prefer the 0% rack

[V7 SLR]

Alex is right, I have a 22% rack and I was considering a slightly larger steering wheel to counter the extra leverage needed to turn the wheel. I didn't buy the bigger wheel in the end, preferring to persevere with my 260mm MOMO. Now that I'm used to the car I'd advise anyone to go with the quicker racks. They're grrrreat (Tony the Tiger says so) for winding-on opposite lock (ask Alex - he's seen it in operation from behind). With ACB10's the car tramlines and feels twitchy, but this can be reduced by careful suspension setting up. Go for it.

[Alex Wong1697456877]

Having driven Nig's car with it's 22% rack, I'm now convinced that it wouldn't be hard to get used to it. Going back to my 8% rack after driving his car made me realise that the 22% gives an almost kart like steering response and I'm sure that it's perfect for the track. I'm still not convinced if the car's to be predominantly a road one though.

 

Nig did demonstrate the ability to catch the back end in a rather splendid, if not intended bit of power oversteer. Great viewing from behind but I'm not sure how clean Nig's behind was!

 

 

 

Alex Wong

alex.wong@lotus7club.co.uk

http://www.alexwong.net

Home : 44-(0)121-440 6972

Fax : 44-(0)121-440 4601

[V7 SLR]

The power slides are forced, but the speed with which the car sometimes lets go can be a moment for concern.... Leads to a clench rather than a change of trousers though. The 22% rack has turned me into the fastest opposite locksmith in the West.