Worth moving steering rack? Bump steer

[Iain]

Coming to the end of my shell prep now and want to make sure I've done everything I need to.

Is it worth moving the steering rack upwards to reduce bump steer? I've seen Count Vaux Alot and CP WIPs where they have done this and it looks a good mod, but is it better than other less drastic methods, for example inverting the track rod ends?

[Iain]

CP's car with this done:

http://i205.photobucket.com/albums/bb125/cpnova/22307007.jpg

[burgo]

i cant remember who but someone has tried inverting the rod ends and said it handled like toss

[trackdaynova]

Rick Draper said this.

However I beg to differ, and I felt they added alot more positivity both in a straight line, and in corners especially.

[MK999]

Is there much needed to do that or is it just a case of taking the nuts off and pushing them in the other way? I have a feeling they're tapered. Mine is running fairly low on the front now and I know for a fact that a few mm lower the toe goes nuts as I dropped it too far at first and had to wind the coilovers back up lol

[Iain]

Yours were the rosejointed jobbies weren't they Olly?

I've seen it's possible to invert the original track rod end, which I've read handled badly (by that one person only though).

Just need to work out if it's worth moving the rack or just doing it at the rod end, either inverted or rosejointed.

[Iain]

Is there much needed to do that or is it just a case of taking the nuts off and pushing them in the other way? I have a feeling they're tapered. Mine is running fairly low on the front now and I know for a fact that a few mm lower the toe goes nuts as I dropped it too far at first and had to wind the coilovers back up lol

You can't "push them in the other way" as it's tapered in the hub. But I've heard of people drilling them out and making them tapered the other way.

It's an attempt to reduce the angle the rack arms sit at when it's been lowered, which I believe it bad for handling characteristics (bump steer).

[MK999]

yeah the more angled they are the more they induce a toe out effect under bump, and toe in under droop. I thought it was tapered tbh, maybe worth looking at if I get rosejoints :)

[The Simps]

Given by how much experience Rick had of driving his nova I wouldn't take his findings as gospel.

Straightening out the arms can only be but positive, whichever way you do it. The came from the factory fairly straight so its as vaux intended.

[burgo]

to be honest olly has had the experience on track which is where you are going to get the real results as lumps and bumps in the road can give you false readings.

[gavint5]

i dunno about whether or not the effects from such mods would be good or bad orneither but i know for sure moving the rack would be the way id go about it as i wouldnt want to mess about with drilling out the hubs and having the rod ends upside down. what rod ends would you wind up using because the wide side of the taper would become your narrow side.??? and where you gonna get a tapered bit from??? i certainly dont have the right tool for that job sitting in my box but i have a grinder and can lend a welder to do it the other way.

rose joints are another option and theres a shop locally that would do me the ones for my gear linkaege for about 6 or 7 pounds each which is awesome.

heres there details.

Cumbria Bearings & Transmissions Ltd, Bearings Stockists based in Carlisle - Contact ... Telephone: 01228 512404 Magnify telephone number. Fax: 01228 512811

tell them how you got the number from a lad called gavin thompson cause they might sort me out if im sending them custom.

[Iain]

I assume a machining shop would be able to sort the hubs out - I assume they'd drill it out and fit a tapered insert so it's the other way round.

The more I think about it, the more I actually prefer the hub modifications though, as at this stage moving the steering rack would be guesswork to get the arms straight, whereas you can tweak something like rosejoints to get the arms nice and level.

[MK999]

You mention "moving the rack" like it's easy compared to 'messing about drilling hubs and raving rod ends upside down' lol

[Stuart]

another option is to go for the spherical bearing route, but have a tapered insert made to slip into the top of the hub.And as such convert the tapered hub into a normal parallel effort and mount the RJ/spherical bearing rod end underneath with a normal 10.9 grade bolt (DON’T use 12.x) and a nice sized washer on the top.

simples

[MK999]

double post

[MK999]

That also makes much sense, probably easier to get a machine shop to make up the insert than to drill out a hub too... just out of interest, why wouldn't you use a 10.9 bolt? 12.x being hardened more likely to snap than bend I assume? but isn't the rating on bolts UTS?

[Stuart]

10.9 for suspension as its less likely to snap in sheer.

12.x is too brittle

[MK999]

Yeah I just figured it out, although 12.x might take more punishment before it snaps, a 10.9 will take less before it bends, but it will then take more than the 12.x and just bend a lot. Although for a track car you might see it the opposite way!

When I was racing RC stuff a while ago nobody liked alloy parts in the place of plastic partly because it would bend rather than snap, and trying to figure out where and why your car is handling like toss was harder than replacing broken bits lol

Am I right in thinking bolt ratings are the UTS btw? I wasn't sure.

[Stuart]

cant remember, and cant ask my bolt man as the site he uses is blocked at the moment lol.

With real cars its preferable to have a bent bolt and limp home than to snap and who knows WTF will happen lol

[Rick Draper]

Yours were the rosejointed jobbies weren't they Olly?

I've seen it's possible to invert the original track rod end, which I've read handled badly (by that one person only though).

Just need to work out if it's worth moving the rack or just doing it at the rod end, either inverted or rosejointed.

I can name 3 people at least that inverted the standard trackrods and it handled ****.

[Iain]

Any more info as to why it handled badly? Been thinking about this loads and can't see why it would differ to being mounted on top?!

[trackdaynova]

I can name 3 people at least that inverted the standard trackrods and it handled ****.Rick, define the word 'handled' for me please, as I can't remember seeing your Nova Turbo on any circuits, or 100mph+ bends, or a series chicanes, or a hairpin :)

Also, Clio 172s, 182s, Cups, Trophies, Megane Sports all run inverted track rod ends also, as standard :thumb:

[Rick Draper]

Rick, define the word 'handled' for me please, as I can't remember seeing your Nova Turbo on any circuits, or 100mph+ bends, or a series chicanes, or a hairpin :)

Also, Clio 172s, 182s, Cups, Trophies, Megane Sports all run inverted track rod ends also, as standard :thumb:

Slight difference there when you go using them as a example as they have the geometry designed to be ran like that. Thats like saying a renault with a 1.2 engine handles the same as a nova with a 1.2 engine you cannot compare.

I ran them on my XE and tried them again on my LET both with the same results. Dont know about rose jointed track rod ends but the inverted standard ones i ran did not work at all.

[MK999]

The geometry would be the same steering wise on a lowered nova with them inverted as a standard car with them in the normal setting, so they were designed with the geometry like that.

Inverting them will bring the bump steer back towards the levels more like a normal nova, only reason that would make it handle badly would be if you actually liked the effects the bump steer induced.

[Iain]

the inverted standard ones i ran did not work at all.

Explain how they didn't work please?

Not trying to have a dig, am genuinely interested to hear your opinion, and what the problem with doing this is.

[dmaxtaxie]

I need to reread this about ten times to start to get it visual type but my question is: what is the location of the steering rack where it is mounted to the frame in relation to the tie rod ends. Behind - straight line , or forward of the tie rod ends for best handling assuming the pivot points are in line for the control arms and rack.

[The Simps]

I need to reread this about ten times to start to get it visual type but my question is: what is the location of the steering rack where it is mounted to the frame in relation to the tie rod ends. Behind - straight line , or forward of the tie rod ends for best handling assuming the pivot points are in line for the control arms and rack.


The rack all sits in line with the attachment to the carrier unless you obviously start dialling in castor and moving te carrier.


http://img.photobucket.com/albums/v310/TheSimps/Nova/Nova%20Coupe%20Project/07-06-094.jpg


Hopefully these pics will help a little. In standard position and my nova dropped to the floor you can see the angles...

http://img.photobucket.com/albums/v310/TheSimps/Nova/Nova%20Coupe%20Project/16-10-0810.jpg
http://img.photobucket.com/albums/v310/TheSimps/Nova/Nova%20Coupe%20Project/16-10-088.jpg

[burgo]

looking at your pics simps and knowing how low yours is it doesnt look as if there is enough angle to justify the inverted track rods. i say move the rack

[Count Vaux Alot]

Hi people just to put this 'rack moving' into perspective here is mine post move - i raised the rack 25mm.

This is the height the car is at currently

http://i248.photobucket.com/albums/gg167/Count85/Track%20day%20nova/steeringrackangle001.jpg

And the rack angle with the track rod ends in the standard position on the top as it were

http://i248.photobucket.com/albums/gg167/Count85/Track%20day%20nova/steeringrackangle002.jpg

http://i248.photobucket.com/albums/gg167/Count85/Track%20day%20nova/steeringrackangle003.jpg

http://i248.photobucket.com/albums/gg167/Count85/Track%20day%20nova/steeringrackangle008.jpg

And the TRE's they are RJ's but still in the standard position

http://i248.photobucket.com/albums/gg167/Count85/Track%20day%20nova/steeringrackangle009.jpg

http://i248.photobucket.com/albums/gg167/Count85/Track%20day%20nova/steeringrackangle010.jpg

The arms now sit very nearly level and IMO it was a worth while mod in the 'while your there you might as well' sense but if you were going to strip out the car to do it then just do the hub carriers

Here is the section of my wip that covers rack raising

click (http://www.pngclub.com/forum/showthread.php?t=109412&page=25)

I hope thats of some help :thumb:

[corsakid]

Rick Draper said this.

However I beg to differ, and I felt they added alot more positivity both in a straight line, and in corners especially.

i agree with olly! the rose jointed tre's i have fitted on the advise of olly have had a really positive effect on the car gives a lot more feel i :thumb: .

i have moved the track rod ends from the top to the bottom of the hub carrier to keep the steering arms level when on its feet

[peester]

so all this moving rack and upside down t.r.e's; it a must on low low cars then??

[burgo]

its not a must dave but its a mod worth doing whilst your doing everything else

[Iain]

Cheers for the pics Simps and Count, still in two minds whether to do this or not! Count, how much is yours lowered roughly? It's hard to tell with wide wings.

[Count Vaux Alot]

I will measure the front panel to ground clearance tomorrow

[Iain]

Count! Your memory is rubbish lol

Did my own measurements today, slightly misleading pictures as the arm is bent but it gives a rough idea. Placed the susp on and roughly where the wheel would sit:

http://iainel.co.uk/images/forums/SteeringRack/IMG_8964.JPG

http://iainel.co.uk/images/forums/SteeringRack/IMG_8965.JPG

Where the arm sits with the rod in the standard place:

http://iainel.co.uk/images/forums/SteeringRack/IMG_8969.JPG

Where the arm sits with the rod mounted underneath:

http://iainel.co.uk/images/forums/SteeringRack/IMG_8970.JPG

Like so:

http://iainel.co.uk/images/forums/SteeringRack/IMG_8973.JPG

http://iainel.co.uk/images/forums/SteeringRack/IMG_8976.JPG

This position looks optimal to me, almost horizontal, pointing a tiny bit down if any? Think I'm going to invert the TRE rather than move the rack!

[MK999]

just out of interest why didn't you do it on the other side? or is that one bent worse lol Looks pretty good to me tbh :thumb: pretty sure that's about where mine sits, so I might have to look into this further sometime soon!

[Iain]

I had bolted the lower arm, tiebar, strut and hub in to place by the time I went to fit the rack and couldn't be bothered to move it all across lol It gives a good enough indication.