Heim joint questions

FWIW, it is very common to need -3* or more of static camber for race / track cars.

For reference, Spec Miatas typically run -3.5* static in front and similar in rear.  

FWIW, it is very common to need -3* or more of static camber for race / track cars.

For reference, Spec Miatas typically run -3.5* static in front and similar in rear.  

sucks to see that H2Sport is no longer around.  Their spindles used to be the go-to for maximizing geometry on the mk4 chassis.  

Yes it is, but it is front biased.  I do not know the torque handling capability of the Haldex in the TT but the similar unit in Volvos has a 1000nm torque capability.  That sounds like a lot, but that is torque at the driveshaft, not the engine.  That's after the torque multiplication of the transmission.  You can blow through that fairly easily in all but the top gears.

Either way, the front tires are powered, and you really don't want to sacrifice acceleration grip if you don't have to.

This is 100% why everyone is reiterating that you can't use other peoples' alignment settings in a vacuum.  On the old improved-touring forum there was a good thread in the VW section where people were comparing their spring rates and alignment settings, and there was a lot of difference amongst people until they figured in what differentials they used.  Torsen and clutch pack and welded diffs all needed wildly different setups because they all affect turn-in and the way power gets put down.  At the extreme ends, Torsens do not tolerate unloading the inside wheel and welded diffs almost require it, some drivers were reporting best results by deliberately hitting the curbing to bounce the inside front off the ground to help turning...

Speaking of which, driving style makes such a huge difference it isn't funny.  A car might understeer heavily with casual corner entry and oversteer mightily with a divebomb entry.  That's driver technique.  A front heavy car will always understeer as a general characteristic, nothing you can do about it but drive around it.  Just like 911s need to have their special characteristics driven around.

In reply to Pete. (l33t FS) :

Good points for sure and don't worry I'm not ignoring the advice. It's all good info I add to my knowledge base.    I'm pretty rookie compared to everyone so tbh anything I pick will be a baseline to begin fiddling with.  

I'll probably do 2.5-3.5 camber front. Then adjust to what works best.

Someone mentioned how you can't adjust the 1piece arms very far for caster.   I think he's so right.  Might be stuck on that.  

Pete. (l33t FS) 

 

 Torsen and clutch pack and welded diffs all needed wildly different setups because they all affect turn-in and the way power gets put down.  At the extreme ends, Torsens do not tolerate unloading the inside wheel and welded diffs almost require it, some drivers were reporting best results by deliberately hitting the curbing to bounce the inside front off the ground to help turning..

I'm curious about the welded diff thing. What cars do that and why? I've seen it on rwd conversion from awd.   

But is it sufficient for track handling?  Or does it lack some grip or finess that a factory rwd setup has

In reply to Tadope :

So my question is, when you say that you will make adjustments from there, what information will you be utilizing to make said adjustments? And then how will you evaluate what adjustments to make depending upon that information?

Because that matters significantly. It's why a plan, course of different and system for analyzing and measuring performance and variables is important. 

In reply to Captdownshift (Forum Supporter) :

Good point.   Tbh I'll probably be back asking questions 

But even in asking questions, you should have data parameters beyond lap times or amount of camber in the alignment setup with regards to what information you're basing adjustments on. That's why I preach pyrometers. Maximize contact patch size, then adjust toe, then dampening then spring rate. 

Paul_VR6 (Forum Supporter) said:

Tadope said:

However. Pete_vr6 has realworld experience snapping them so thats unfortunate.  But drag launches are a level that I think outclassed any of these arms

We break everything but the stock stamped steel pos work just fine. Sometimes we add a 3rd member/traction bar to them to keep the rear bushing from distorting or just use a spherical rear bushing and weld the arms on the seams. 

Do you think this is because the stock stamped/stitched arms flex enough to not load up on a single spot ? Or....? 

Tadope said:

Pete. (l33t FS) 

 

 Torsen and clutch pack and welded diffs all needed wildly different setups because they all affect turn-in and the way power gets put down.  At the extreme ends, Torsens do not tolerate unloading the inside wheel and welded diffs almost require it, some drivers were reporting best results by deliberately hitting the curbing to bounce the inside front off the ground to help turning..

I'm curious about the welded diff thing. What cars do that and why? I've seen it on rwd conversion from awd.   

But is it sufficient for track handling?  Or does it lack some grip or finess that a factory rwd setup has

I think you are thinking of the center diff.  I was speaking of the front diff on a front drive car (specifically an A2 Golf, because A1s are fragile and A3s were too heavy to be good IT cars)

1SlowVW said:

Paul_VR6 (Forum Supporter) said:

Tadope said:

However. Pete_vr6 has realworld experience snapping them so thats unfortunate.  But drag launches are a level that I think outclassed any of these arms

We break everything but the stock stamped steel pos work just fine. Sometimes we add a 3rd member/traction bar to them to keep the rear bushing from distorting or just use a spherical rear bushing and weld the arms on the seams. 

Do you think this is because the stock stamped/stitched arms flex enough to not load up on a single spot ? Or....? 

Just plain stronger.  A tubular control arm is a collection of stress risers, really.  A stamped control arm is remarkably strong for its weight.  It's amazing what can be done with sheet metal and a few creases and curves.