wheels leave the ground frequently anyone experience this??

[Trip]

I am not sure what are the effects on the body shell but its very stiff with a OMP weld-in roll cage. I don't drive mine on public roads either but or hill's aren't smooth either. I do have softer coilovers with 280 front and 224 at the back but since i am running 225/45R16, i would most probably get tyres scrubbing somewhere in the wheelarch, and to go for a smaller and thinner wheel/tyre, i would also need to change my 310mm brake disks.

Never tried these soft coilovers so i don't know 100% it will scrub, and for my kind of racing, it will surely help going softer.

A helper spring might also help as it "extends" the travel of the coilover

 

[Fast Guy]

Mark, your rear suspension doesn't look that soft as the rear wheel seems to have hardly dropped out of the wheel arch. It looks as high in the arch as mine does on a picture of me drag launching it.
Looking at the picture I wonder if stiffer fronts would help as it looks like the front is compressing enough that the car pivots across the rr/fl diagonal lifting the rear left.

 

[Jon Olds]

Suspect the shell is nowhere near as stiff as you think it is.
Anecdotal: Years ago, after rolling a comp car I used a hydraulic ram set to try and straighten the shell and its mightily impressive how much deflection you get with relatively small loads, obviously only in certain plains.
The nissan shell is not that strong. I have followed the NME guidelines for seam welding around the pickup points. A bit off thread.
Just downgraded brakes so I can run 15's (discs got seriously hot..with big AP's and aggressive pads) so wheelarch clearance should be ok.
Hadn't thought of a helper spring. Does this work by pushing more twist into the antiroll bar? Sounds plausible. Can you get them at 62/65mm ID. Sounds good to me, and another spending opportunity. Longer the better? Is the rate important? Tell me more..

 

[Trip]

my tein coilovers have helper springs, nothing to do with the anti roll bar per se, it allows more travel without the spring coming loose. The helper spring will help somehow keep the wheel in contact with the road but there is only the force of the helper spring acting on the wheel and you would probably still get wheel spin on that side.

http://www.demon-tweeks.co.uk/Motor...ulkners_Flat_Section_Helper_Springs/1738/6351

what size are your 15" tyres ?

i did a small experiment and i drove one front wheel on a ramp 4" heigh and the rear wheel came 1/2" off the ground. My helper springs are 3" so if i understand it right, my rear springs are barely sinking 1/2" on a flat road with just the weight of the car.

 

[Jon Olds]

Rally tyres. Dunlop CR 205/585/15's About 7.5" wide. Various compounds (soft to very soft)
You recommend strong helper springs? Long enough to fill the gap left at full droop, plus a bit? That would make sense as my dampers have a slightly longer stroke than the springs. Lots to think about here. Another reason my spring rate seems so harsh is my monotube bilsteins seem to have an inbuilt spring, which is probably adding to the effective rate. ie If you compress just the damper it springs back up.
I need to use my hyd press (gauge) and a ruler and try and get some numbers so I understand it more

 

[Jon Olds]

Had a rake around 'stock'.

Options are;
330 lb front and 300lb rear OR
300 lb front and 200lb rear OR
300lb front and 300lb rear.

OR buy some springs

I have some yet to be identified Eibach springs that could go on the front. ERS 200-60-80 and ERS 250-60-100. Think 60 and 100 is the rate. Not sure the conversion.

Also, there is 3 1/2" slack in the rear shock for helper springs

 

[Jon Olds]

Bit of progress. NME rally build manual specifies 300lbin front for gravel, so that's what I'm using.

Not helpful in the rear rate tho, it just specifies a part no. 55020-RP230. Googled it : no help

Anybody have the rear NME spring rate???????????????????

 

[Trip]

no idea mate.