Need suggestions for my front suspension

michel schryer · #1 (**permalink**) 01-23-2011, 04:09 PM

My cobra kit car has brand new QAi coil overs and a fox manual rack and pinion and I found the front kinda loose when I hit bumpy road and the steering become shaky.
Would a bump steer kit solve the problem,what do you suggest I do to correct that. Would a realignment necessary after putting a bump steer kit (if it's the right way to go),thanks guys.
Can't drive here in Canada yet,it's freezing cold so that is my spring project.

Tommy · #2 (**permalink**) 01-23-2011, 04:28 PM

If you know exactly what is wrong, then fix it. If you don't know exactly what is wrong, you can either throw parts at it and hope for the best, or take it to someone who understands race car suspensions and can tell you what you need done. I suggest the latter. Good luck.

bobcowan · #3 (**permalink**) 01-23-2011, 08:47 PM

You have all new parts, and sounds like quality parts. Unless you screwed up on the assembly, we can assume the suspension is OK.

The next thing to do is check all the alignment specs. And be sure and check your tire pressure. You'de be amazed at what a couple of pounds of pressure can do.

Before buying a bump steer kit, actually measure your bump steer and see what it is. You don't need to spend a lot of money, you can make your own measuring tools.

michel schryer · #4 (**permalink**) 01-25-2011, 08:10 AM

How much tire pressure pressure do you use for street driving,my pressure might be too high that why it's a little bumpy on rough pavement.
As far as the suspension installation,it was done by the manufacturer and I noticed that the front coil over where not installed the same way than the back ones,they are the same shocks but they are reverse in the front or the other way around,not sure if the spring has to go on top or bottom but he told me it was for weight purpose for the front,not sure I understand the logic behind that,anybody reading this can enlight me abou this,thanks !

Michel

bobcowan · #5 (**permalink**) 01-25-2011, 08:26 AM

It's not uncommon to install them upside down. There is a very slight weight advantage to moving unsprung weight to sprung weight. But it's so small it's not worth talking about. The real reason is just to get it to fit right.

Tire pressure is generally 1 psi per 100 pounds of total car weight. That's a good starting point. On street tires, I generally run about 24psi, set with a tire pyrometer. But differant tires need differant pressure, so you my find 22 or 26 works better.

michel schryer · #6 (**permalink**) 01-26-2011, 09:42 AM

My tires are kelly charger,295 on 15" rims rear and 235 front mounted on team 3 rims and I had 30 psi in them at least so I will lower the pressure and see what happens.
The car is well put together,everything is new on that car and so I will follow your advice on the tire pressure,thanks a lot

Michel

mdross1 · #7 (**permalink**) 01-27-2011, 05:55 PM

It sounds to me like your toe in is wrong or could be the wrong caster.If you had an alignment done and did not give them specifics who knows where they come up with specs.I called Cobra Restorer's for mine and was at the rack to be sure it was what I wanted.Good Luck

michel schryer · #8 (**permalink**) 01-31-2011, 11:44 AM

My suspension was set up at the corner garage with the specs from the manufacturer by two experienced technicians (the owner and an older guys), it took them 4 hours to set it up,hard work. I had never driven a Cobra before so I don't know what to expect in term of road handling. I was hoping the handling to be like my Mini or close . I will try with less pressure in the tires,they are very hard right now,will see if it makes a difference,thanks !