On the topic of suspension - best approach to bottoming?

[twobone]

While cornering fast, if I hit any kind of bump I think I hit my bumpstops or the tire rubs in the fender. The impact makes a bloody aweful scraping/crunch sound near my hip (assume it is the rear spring).

 

Does that imply too soft a spring?

 

Should I crank up the damper adjustment at the rear?

 

Thanks

[jlumba81]

Its not the exhaust scraping the ground?

[twobone]

I don't think so. The exhaust is on the opposite side, but I will check it out

 

thanks

[slomove]

May be totally off here but does your car have a live axle rear end?

 

If so, you can check if the propshaft will hit something like propshaft hoops or chassis parts in the tunnel when the springs are compressed.

 

I had that when I first installed the hoops too low and it gave a horrible screeching sound next to my butt, especially when driving with passenger.

Probably not good for the joints when that happens.

 

Gert

[jbanker]

might have to raise your rear ride height or change to heavier springs. I would check the ride height first.

[Ian7]

... I think I hit my bumpstops or the tire rubs in the fender...

 

1. are the damper shafts visible? if so, put a tywrap snug around the shaft right against the damper body, go drive, then see if the tywrap is now hard up against the top stop.

1b. if no access to damper shaft, look for a way to lightly attach something to the fixed chassis that will get knocked off by some moving part of the suspension near full travel; will need to be creative, but can be done.

2. squirt a good amount of baby powder or equivalent on the underside of the fenders, then drive, see if the tire rubs it off.

[MHKflyer52]

Dose it occur in both right and left turns.

Check bushings on suspension as they could be worn out which would let the components move and possibility come into contact with other parts.

If you have adjustable spring seats you could adjust them to compress the spring a little and see if it still happens as that will preload the springs if I am not mistaken and make it slightly stiffer.

[khamai]

Typically you'll need to uprate the springs. Assuming you have coil overs, options:

1) new springs with higher spring rates

2) new springs with variable rates (stiffen with more compression)

3) replace rubber stops in the dampers/shocks with tapered lotocones (act as a rubber spring).

 

Stiffening dampers/shocks will not have any affect upon the suspension travel.

 

Cheers,

Kiyoshi