My Nova 16v Project

We had to do a bolt check once a month on my old turbo as they would always find a way of vibrating loose! Even the locknutted ones.

Not sure what happened but guess something fell off/cae loose. Hope you can get it sorted and get back on track.

Yup - not saying a bolt check isn't required after a trackday, or a couple of hundred miles, or less.

But this was literally one 46mile journey, then it sat for a week.

Speaking to JamSport again today to sort something out

what came loose then?

actually, you probably won't answer that I'm guessing.


Just read your report.

I'm in 2 schoold of hought here. Either the rear toe is causing it to be unpredictable or it is too stiff and you can't feel the car getting to the point it wants to slide until its gone?

I've added some rear toe out to my Nova on the rear stub axles bolts. I've barely driven it but the rear does fell very 'unplanted'. Is that anything like what you are experiencing Olly?

That vid on youtube, on the curborough spring looked pretty god damn scary mate, hope your car is ok.

CG - exactly that, it almost feels as if it's RWD but in a very very odd sense, it doesn't feel as 'suckered/ planted' to the road as it used to - but maybe this is because of the front 'guessed' settings we've done.

nath - certainly got my adreniline going thats for sure!

Sorry to hear about your problems - I'm sure you'll sort them eventually

One thing that does concern me is your rear geometry - toe out ?


Basic rule of thumb,for a good all round clubman set up

Front:
1.5- 2.0 deg. negative camber
Try for the maximum castor you can get with whatever tca/tie bar set up you have on the car,increased castor will assist turn in.
(Note if on nylon or rubber tca bushes at chassis mount side beware of pulling the tca too far forward when going for maximum castor or you will distort the bushes and restrict bump & rebound travel)

Tracking:
1mm per side TOE OUT

Rear:
1/4 to 1/2 deg negative camber
Tracking +- 1mm-2mm toe in (NEVER TOE OUT) unless you are going in for the national drift championships!

Of course this is only a good basic starting point,a cars overall handling will also depend on bump steer,spring ratings,damper bump & rebound spec,bodyshell stiffness ect.

The above set up which is considered the ideal set up data is taken from the original GM GpA cars.

So bottom line is- set up the car so you the driver feel comfortable and confident with it.

If you need to fight the car on every bump/corner,then it's wrong,change the settings,test and test again until you feel at one with the car,then you will see your times tumble.. :thumb:




Dave

thanks for replying Dave :thumb:

I have identical front geometry setup to what the Nova grpA build manual says, apart from build manual says have 4degress positive castor.

However I could only get 3deg pos castor, as my tiebars are too long - so I'm having some shorter ones made, and replacing my inner TCA bushes for rosejoints too, then I will go for 4degress positive. Providing clearance isn't an issure on the tyres - if it is a problem, then I will take a grinder to the front of my wings.

Front camber is (was) -2degrees.
Front toe is 1mm toe out

When I return to JamSport, I am keen to return my rear geometry back to factory 1mm toe IN, they did advise me it would introduce oversteer, but I like to provoke it, rather than it happening on a whim.

I understand I need to test it, thing is I had it done on Monday, found some issues on Saturday, then Sprint on Sunday - so it was impossible. Especially as I wouldn't drive at the speeds it could be tested on the roads, I'd wait until my next trackday

Hmm interesting this one.

Maybe I should apologise for saying "not the stiffest chasis" looks like you're pretty much there.

Thing is I've seen this behaviour before on a BMW and the only thing I can conclude is it's transfering the weight just too quickly for the ride height and other aspects of the setup.

When you reach this lvl you will find absolute limits for the settings. Understand that without lowering the car more to counter the tip, you won't get round the bend any faster as you'll just get under/over steer instead.

You should feel proud that you've pushed things this far.

Have you seen the video of a trials mini that can brake so hard the front tips into a massive endow? The setup is so good it's now up to the driver to make it go anywhere up to that stage of weight transfer.

Only by turning in slower and/or taking a wider line at that speed could you hope to keep the car more level given how it is now. Adding weight and/or areodynamic aids / lowering center of gravity will be the only path to that corner again at that speed or faster.

Sorry to say it but understand how a car feels / behaves in terms of under / over / neutral steer does not always correlate with time taken. ~That setup might be the fastest you can make it without altering any of the 3 above mentioned.

And I guess that's what it comes down to; having a car that's only 99% as fast but feels 99% safer and gives you the confidence to consistanly perform. Deciding what's best for a sprint only car might be quite different to say a circuit racer where things like tyre preservation are a key factor.