53 replies to this topic

[vocky]

And how is the feeling with them, Vocky? Do you feel any difference roll better lap times? Br,Per

 

I don't track mine, but on the road it feels so much nicer to drive

 

some pics - https://z22se.co.uk/...44#post-1241246

[Exmantaa]

Then the question is; how much improvement came pure from the raised upright centres and how much bump steer improvement is due to your new EP steering arms...   (But those uprights are nice, only can use a bit more offset for lower track work)

[FLD]

I have fixed height steering arms on mine.

[Aerodynamic]

Getting rid of the bump steer for front would be one nice thing. But for rear Im looking for grip. And with these knuckles for improving the geometry of the suspension and reduce roll and therefor more grip. Or?

[vocky]

I am running the standard rear uprights, this is because there may (or may not) be issues with cracking on non-OEM uprights where the rear tie rod connects

[siztenboots]

so which hard points actually change?

 

drive shaft angles better ?

[The Batman]

This was one of the main reasons I changed my rears was to get the driveshaft angles correct. Main reason for changing the fronts was that the upright was warped (common issue on s1) The wishbone angles are also better

[Exmantaa]

Driveshaft angles stay the same... (At least if your wheel centre position/ride height is not changed.)   These uprights only solve the wishbone angle (roll centre) issue that you get when running to low on the Lotus suspension.   From a US source: The easiest way to think about it is that the front and rear geometry are impacted differently with ride-height. As Phil said the rear requires the upper attachment point to be lower, however, it is less of a problem on a moderately lowered car than on the front. The front gets wonky at or below 120mm front ride height. The rear below 100mm or so, so most folks run into front issues long before rear. So only goodness having them on the front.

 

And that is on a Lotus S2 chassis with small 16" front wheels...

[Aerodynamic]

Isnt this one thing Eliseparts say about there upright, they have double share points and its stronger than OEM. Br,Per

I am running the standard rear uprights, this is because there may (or may not) be issues with cracking on non-OEM uprights where the rear tie rod connects

[Tonie Pettersson]

Isnt this one thing Eliseparts say about there upright, they have double share points and its stronger than OEM.

Br,Per

 

 

I had problem on mine with the design on the toe link bracket, didn´t really come up with a nice solution for it back then (never made it to the machine).

 

Compare it to EP's ultimate you can see they differ. I´m a little surprised though that the lower lip is thin and upper quite sturdy, since I had most stress on the lower. But I guess they have a lot of experience with their uprights since they have been around for a long time and they get tested hard on track by many users.

 

 

I have fixed height steering arms on mine.

 

Installed the new ones yet?

 

Edited by Tonie Pettersson, 25 October 2017 - 07:18 AM.

[Spitfire Engineering]

You could also ask why is the top one so thick?   

 

On your model if the toe link is in the centre of the tabs then the forces on the 2 tabs should be equal*, the only change to this would be if the link is not central and/or the angle of the link itself but the latter would produce a vertical force, all the forces on your drawing seem to be based in the horizontal plane?

 

* this is based on the design shown where they are both mounted on the same solid section, this may change if the section has been reduced on the back face?? and the lower supporting section weakened when compared to the upper.

 

 

 

 

Isnt this one thing Eliseparts say about there upright, they have double share points and its stronger than OEM.

Br,Per

 

 

I had problem on mine with the design on the toe link bracket, didn´t really come up with a nice solution for it back then (never made it to the machine).

 

Compare it to EP's ultimate you can see they differ. I´m a little surprised though that the lower lip is thin and upper quite sturdy, since I had most stress on the lower. But I guess they have a lot of experience with their uprights since they have been around for a long time and they get tested hard on track by many users.

 

 

I have fixed height steering arms on mine.

 

Installed the new ones yet?

 

 

 

[Tonie Pettersson]

You could also ask why is the top one so thick?   

 

On your model if the toe link is in the centre of the tabs then the forces on the 2 tabs should be equal*, the only change to this would be if the link is not central and/or the angle of the link itself but the latter would produce a vertical force, all the forces on your drawing seem to be based in the horizontal plane?

 

* this is based on the design shown where they are both mounted on the same solid section, this may change if the section has been reduced on the back face?? and the lower supporting section weakened when compared to the upper.

 

 

 

That I could ask yes .

 

This was awhile ago but I remember I was playing around with different options for the toe link. In the picture the force is put on the two holes angled ~10° to simulate the angle on toe link (but only 10° in the horizontal plane, no vertical), and the lower one moves since it has no material underneath it to hold it back (my novice explanation ).

 

The analysis is from this version I think, with a fixed height on the rod (so no chance of adjusting bump steer).

 

 

This really is a poor man analysis though . To get it more accurate I should of course have had the rod in place (like in the picture above) together with the bolt and nut and also investigate at what angles the toe link operates in.

This was just something I was toying with when I was bored at work .

[Doctor Ed]

is the plot showing stress or deflection (cant read it, but i suspect mm deflection) if its deflection, then its easy to understand why the lower moves more even though both have the same applied force

[Tonie Pettersson]

Yes correct, it´s deflection (my bad using stress in my comment).

[FLD]

Isnt this one thing Eliseparts say about there upright, they have double share points and its stronger than OEM.

Br,Per
 

 
I had problem on mine with the design on the toe link bracket, didn´t really come up with a nice solution for it back then (never made it to the machine).

 
Compare it to EP's ultimate you can see they differ. I´m a little surprised though that the lower lip is thin and upper quite sturdy, since I had most stress on the lower. But I guess they have a lot of experience with their uprights since they have been around for a long time and they get tested hard on track by many users.

 
 

I have fixed height steering arms on mine.

 
Installed the new ones yet?
 

Yep, absolutely perfect

[Nev]

Getting rid of the bump steer for front would be one nice thing. But for rear Im looking for grip. And with these knuckles for improving the geometry of the suspension and reduce roll and therefor more grip. Or?

 

If you need more rear grip (and assuming your rear tyres are wearing evenly) then I can't see changing uprights making much difference. Better to spend the money on wider arches and wider wheels and tyres, as that really does make a difference IMO. My rear end grip is way better now (both with straight line acceleration and cornering) with 285mm tyres. Soft(ish) rear springs and soft coilovers will help with grip too for 2 reasons I can think of.

 

Edited by Nev, 26 October 2017 - 08:54 PM.

[Aerodynamic]

Hi Nev. I hsve alreasy widened my fenders once to get my 255s to fit. And have thought about 275/40 17 but these will be even bigger my suspension angles will be even worse and it will be tough finding wider wheels for this. I will do others things to find more rear ens grip. But these uprights with the higher center must do something? And I assume one of this is changing roll center so you get less roll with same hardness of springs?! Or why do people buy these uprights?

Getting rid of the bump steer for front would be one nice thing. But for rear Im looking for grip. And with these knuckles for improving the geometry of the suspension and reduce roll and therefor more grip. Or?

  If you need more rear grip (and assuming your rear tyres are wearing evenly) then I can't see changing uprights making much difference. Better to spend the money on wider arches and wider wheels and tyres, as that really does make a difference IMO. My rear end grip is way better now (both with straight line acceleration and cornering) with 285mm tyres. Soft(ish) rear springs and soft coilovers will help with grip too for 2 reasons I can think of.  

[Nev]

I think the main reason for buying these hubs is that you can lower the car by 4cm without affecting the wishbone angles. This means the roll centres stay the same as designed and the suspension sits in the centre of the bump curve as designed. Both these functions are important (best to read about elsewhere if you don't understand them). Also it means you can make these changes without having to buy new (shorter) dampers + springs.

 

There a couple of disadvantages too though:

 

1. The hub carrier bolt threads are only aluminum, so the HCB mechanical grip (which I like to overtighten with 12.9 bolts) are a weak point. Their advert implies these have steel threaded inserts, but they don't.

 

2. The front hub carriers will need approx 1 CM of spacers to get 0 degrees (ie OEM) camber. This is designed with intent, but you need to be aware of it.

 

 

Edited by Nev, 27 October 2017 - 08:35 AM.

[siztenboots]

technically , the roll centre will change ( due to the ground plane moving ) 

[Aerodynamic]

Does anyone know what the Roll center height is on std VX 220 for front and rear

And how this is effected with a 30mm lowering, with same outer tire diameter?!

 

Br, Per