What tire pressure?

 

Yep, happens in Naga easily. Rock-hard T/A's.

Traction lok, interestingly enough, makes that easier. If only one tire was breaking loose, you'd actually have more sideslip stability. With both tires spinning, it's easier to slide it sideways.

d

 

What type of tires? I have done several 360's, breaks loose pretty easy. I am thinking about stickier tires myself.

 

When the rear tires go faster than the fronts (wheelspin) the back wants to pass the front.....solution is to turn into it slightly, yell 'Yehaaaw' and grin like a fool.

Or you could just press the throttle down a little more slowly.

I don't think I'd trade 3.08s for 3.55s. Not that big a difference.

 

Put a 2x4 under the gas pedal.

or

Switch to a 4 cylinder engine.

 

The posi and light, short car with a V-8 make it slide sideways easy and this is normal. Your ride height is a little high. If you have this problem only when turning (even slightly turning) you may be able to make it better. The FFR axle straps are too short IMHO. I drill a hole about 1" lower in the quad shock bracket and mount the strap in this hole. I don't run quad shocks. As you turn into a corner the strap will lift the inside tire if it is too short. Your ride height makes a almost too short strap too short.
The change from 3:08s to 3:55s is big and will make wheel spin and sliding sideways easier. If I was you I would put the 3:55s in it and make the axle straps longer.
Jeff Hamilton

 

Eddy
I see that you are running a 4-link rear.
are you running the donor upper and lower rear control arms, or the FFR tubular control arms.
You do not want to go stiffer with the springs or add a rear sway bar at this time. These parts will not give you the control you are looking for right now.
The three link would be the best bang for the buck you could do to the car.
Later Mark D

 

Originally posted by Jeff Hamilton:
The posi and light, short car with a V-8 make it slide sideways easy and this is normal. Your ride height is a little high. If you have this problem only when turning (even slightly turning) you may be able to make it better. The FFR axle straps are too short IMHO. I drill a hole about 1" lower in the quad shock bracket and mount the strap in this hole. I don't run quad shocks. As you turn into a corner the strap will lift the inside tire if it is too short. Your ride height makes a almost too short strap too short.
The change from 3:08s to 3:55s is big and will make wheel spin and sliding sideways easier. If I was you I would put the 3:55s in it and make the axle straps longer.
Jeff Hamilton

That's a really good suggestion. You may be preventing the suspension from doing it's job. Try lowering the ride height and I'll bet you improve your situation but I'd lengthen the straps as Jeff mentioned. I think you can get longer ones from your local auto store. They make different length keepers for truck tail gates that work great. I don't run straps with 3 link myself.

 

eddie, my car did that with four link and coilovers. I switched to 3-link and VPM front and rear bars and it sticks like glue now. Its amazing how different the car handles.
With four link the rear would kick out "too easy". I was affraid to push the car, thinking the rear would be clocked with a little gas.

 

Eddie; I am running almost the exact engine and rear end as you, including 5" ride height and the mustang arms. However I do not have the axel straps, perhaps that is your problem, because I don't get the tendence for the rear to step out that you do on acceleration. I have Goodrich 295 T/As

 

Eddie,

Many of us started with 4 link and played with it to get better results until we threw in the towel.

First drop the ride height to 4 inches, this will lower the roll center. There is nothing you can to about about the axle moving side to side but a lower stance will make a world of difference.

Be careful of on ramps because of unknow debris on the pavement from the last truck going to the dump.

Tire pressure and temperature also has a big affect.

The best investment a new Cobra driver can make is bring to to a road course for driving lessons. Learning where your car gets loose is the most important thing any Cobra driver needs to know. Don't be a fool and try to learn this on the street.

Roger

 

Originally posted by Roger:

The best investment a new Cobra driver can make is bring to to a road course for driving lessons. Learning where your car gets loose is the most important thing any Cobra driver needs to know. Don't be a fool and try to learn this on the street.

Roger

AMEN brother!!

RR

 

Some good suggestions above. But in your post you said a few things that caught my attention.

- Very mild 306.
- 20mph in 2nd gear.
- 3.08 rear gears.

At that speed your engine is only turning about 1,600 rpm's. Torque application is pretty low. These are very mild conditions, and should not induce wheel spin. That tells me there's a problem. You need to figure out what the problem is before throwing money at expensive parts like new springs or sway bars.

Changing the rear end gears to a lower number will increase torque application, and increase rpm's at a given speed. This will make your problem worse.

Here are some of the things I would look at:

1. Ride height front and rear. 5" in the rear is fine as long as you have 4" in the front. You're looking for proper balance. If you have 5" in the rear, and 3" in the front, you'll be biased towards the front, and take some weight off the rear.

2. Tire brand. I'v not used those tires. And I have heard of a lot of people using them . But their low cost and lack of traction rating would indicate to me that they are on the lower end of the performance scale. But still should be more than enough for your car. I wouldn't think changing them would be overly helpfull.

3. Tire pressure. This - I think - is where the money is. If the pressure is too high the tire will bulge out in the middle. The tire will be very hard, and your effective contact patch will be very small. Set your cold tire pressure at 24psi. That seems just about right on my car with BFG KDW's.


4. Rear end alignment. Makes sure the axle is square in the chassis.

 

Eddie, I have the 4 link using stock control arms with the VPM coilovers. You should Try remove the axle straps as they're not needed with the vpm coilovers. My rear end steps out only when I want( nail the trottle mid corner ) I'm using sticky BFG KDs 275x17. ride ht is 4.5in., 3.27 gears- very controllable at autocross. even got a FTD with my Kumho710s. Ditto tire pressure and track training coments.
Aloha, Karl

 

Originally posted by NiceGuyEddie:
Topic: my rear end keeps sliding out

I thought this thread had something to do with Plumbing!

 

Are you using the donor gas pedal? I started with that and found it was more of a "trigger" than a pedal. Maybe Russ Thompson's pedal will allow for more gradual acceleration.

 

Try a belt?

 

Eddie,Its cold here in New England so a lot of us run tire pressure at 20 to 22 lbs. Have BFG 295/50/16 4-link 4 inch ride front and 5.25 rear.Have 331 stroker,3.27 rear and T5 and rear has not come loose yet with alot of fast corners!! Also lower tire pressure makes for softer ride for your backside.

 

Ok, more seriously. You're describing power oversteer. Cobra's, and other rear wheel drive high power to weight ratio cars, have this problem. To an extent it can be fixed by improving the grip of the rear end - tire pressure, 3 link, gripier tires, ride height, etc. However, driver education on how to handle the situation with such a car is a good idea. Cobra's will have this problem (most would call this a benefit!) no matter what you do.

Good luck - there's a lot of good advice here, but keep in mind there's no escaping this situation. Be careful.

Nate

 

A Torsen dif will make night/day difference
Marc A

 

After a number of driving schools and 10 years of road racing experience, I would suggest autocross over track driving to learn the limits of the car. My reasons for this are because in autocross things happen at a much lower speed and have a much lower chance for doing damage to both you and your car. My 3rd drivers school, after a year of racing was 3 days, in pouring rain. I probably learned more there than at any other time because of the slow motion factor. Just my thoughts, YMMV.

 

1. i will check tire pressure and advise
2. no other markings on the tires except SUMIMOTO and the tire size
3. axle straps are not installed
4. my rear has posi
5. stock mustang control arms

can you really upgrade to 3-link? i thought the frame was slightly different.

 

What you described in VERY normal. I have a similar set-up and can lose the rear going into second if I'm not paying attention when taking corners. These cars are VERY light and even a stock 302 with stock gears WILL get you into trouble.

 

Eddie,
I ran the 4 link and upgraded to the bolt on 3-Link on my MK-II. There is some cutting of tabs and some drilling of big holes, but it is an option.

Today - I can walk to rear in second from 20 mph with my 200K stock 302 T5, 3.08s. You have the torque to do it. I have to kick it pretty hard to do it, and it will tell me when the steering is not perfectly straight.

I think that 4 link was better for straight line than the 3 link. BUT the 3-link provide a much broader "sweet spot" in the curves. You know as you start to get to the edge of traction. With my 4 link - it was a yes/no switch.

I also agree that AutoX is better for learning limits - you are doing 30-60. You get to spin by yourself. The cones don't break the fiberglass.
Locally the SCCA stuff is hard core competition, not a great starting place for "playing" at the limits, learning is OK. But the schools are really good.

I have been AutoXing for 2 years now. I am slow, and I know it is me. I feel better on the street as I know more about what the car can & will do. But like said in many posts before - these cars are unforgiving mistresses.

Learning takes time, enjoy the path

 

Having just finish a upgrade to a 3-link in a Mark I...it is a pretty large job in a car that is complete. I have one the new gen 3-link kits and a lot of the fun comes from the piece that bolt to the frame, uses 5/8 bolts, 4 of them and it takes some time to cut out part of the 4link bracket and getting the 3link bracket in. btw I had to pull my passenger seat and cut thru the alum. panel so I could get the bolts in. I would wait until your are ready to change gears because you will need to pull the rear end out anyways to put in the 3link. I don't have a many miles on my 3link right now (around 60) but I can feel the difference so far. In the meantine try lowering your ride height and drive the car. take your time to get to know what the car will do.