Rough Ride

[tonywy]

Hello everyone, new to the forum and the Cobra world. Recently purchased what I think is a mkll build. This car came from the Hampton area in N.Y. Absolutely love this car and wouldn't trade it for anything. Problem is that the car ride is a bit rough. I live in ne Pa where the roads are horrible at best. I was reading here that tire pressure and spring rates play a big part. This car has Pro Shocks coil over front and the red Koni rears. Big block car 500lb springs front and 350 rear. Looking for suggestions on springs and I am considering a front sway. I like the design of the Breeze set up for the sway. Played with Corvettes in the past and found that light springs and heavier sways seem to work well. Looking for set up suggestions.

[edwardb]

You don't mention what you're running for tires and tire pressure. You're right, it makes a big difference. Also would help to describe more about the suspension, specifically the rear. Solid axle or IRS? Donor or new parts? In the end you may need to adjust your expectations as well. These things do have a stiff ride even at best.

[Jeff Kleiner]

500# front with 350# rear is the factory spring combination for a straight axle roadster. Adding only a front bar without a corresponding increase of stiffness in the rear will exacerbate the 500/350 combination's natural tendency to understeer. My experience is that softening front springs does not make a noticable change in the ride however softening the rear does...but at the expense of handling and roll. Kind of a take your choice sort of thing. What are you running for tire pressures? Shouldn't be over 24-25 no matter whether they're 15s or 17s.

Good luck,
Jeff

[CraigS]

I agree w/ Jeff, the rear has the most effect on ride. I'd go to 250 rear springs in a heartbeat. It will also be good to verify, while they are apart, that the rear Konis are set to their softest setting. 500 fronts are actually on the soft side so I wouldn't change them yet. Although I agree softer springs and more bar is usually a good idea, I'd hold off an a front bar for now. Since ProShocks haven't been used by FFR for quite a while, I'd also think about FFR konis or Breeze QA1s for down the road, but let's do one step at a time.

[Itchief]

I built my complete kit and it came with 350lb rear springs and the ride was very harsh

Talked to Mark from breeze automotive and put a set of 250 lb springs and the ride is much better still stiff but much better on my back

Rick

[Mark Reynolds]

Tony,

I recommend you check your suspension for binding.
On the front remove the tire and coil-over and the spindle should be free to be lifted up and drop down under its own weight.
If not, disassemble and check the upper arm pivots as they tend to seize up w/o at least annual maintenance.
The lower arms tend to get pinched when the bolts are tightened. If the arm is stuck then lubricate at a minimum.
If the arms fall when the the bolts are loosened then our bushing tubes will free them up: http://www.breezeautomotive.com/details.php?prod_id=601

Any issues with the rear suspension are most noticeable because you are sitting so close to the shock. Absolutely try some 250lb springs. Also, and perhaps more important is, the lower arms with polyurethane bushings in a 3 or 4-link arrangement are a bind fest. You can eliminate most of the bind and enjoy a much more compliant ride with Breeze rear lower arms: http://www.breezeautomotive.com/details.php?prod_id=1114

Hope that helps!

[walt mckenna]

These cars are a little rough riding compared to your daily driver, so you will need to get comfortable with that fact. Like you, I live in PA where the roads are either very good or very bad, so you need to compensate in a way that works for you. My solution is to run 15 psi on the street and 25 psi at the track for the best combination of comfort and performance.

[WIS89]

Walt-

Do you really run 15 PSI? Do you run it on all four? How does the car handle? How has your tire wear been?

Not trying to play 20 questions, I am just trying to understand your post a bit better.

Thanks for any amplifying info!

Regards,

Steve

[tonywy]

Guys ,thx for all the great advice. Going to make changes one at a time starting with tire pressure and checking for front control arm bind. Buy the way, this is a solid axle car with 15" BFG tires.

[walt mckenna]

Walt-

Do you really run 15 PSI? Do you run it on all four? How does the car handle? How has your tire wear been?

Not trying to play 20 questions, I am just trying to understand your post a bit better.

Thanks for any amplifying info!

Regards,


Steve

I have been at 15psi (for street driving) for about a year and a half now with no detectable difference (from 22 psi) in handling, temperature, or wear. The only logical explanation I can offer is that my tires have around 4,000 lbs of excess load carrying capacity (total load carrying capability of my tires is 6,348 pounds minus 2,348 lbs for my car). At the track, my tires would scuff like a dry eraser on asphalt (at 15psi) but not with normal street driving. I have been going to use an infrared temp sensor to detect a temperature difference between the two pressures but I just haven't done it yet.

[tonywy]

Mark, you area dead on. The lower front arms are binding so I ordered the bushing kit. I also changed the heim ends on the shocks, they had play in them. Pro Shocks with FFR 500 lb springs. Will let you know about the rear control arms.Thanks for the info.

[Mark Reynolds]

Tony - shipped yesterday via Priority Mail. For some reason lately just MA to PA comes up 3 day service (used to be 2). Anyway scheduled to arrive Thursday. Looking forward to your results!