Ride height question

kevins2 · #1 (**permalink**) 12-21-2013, 12:41 PM

The ERA manual states: ERA recommends that the main chassis rails be raked about 1/4" to 1/2" from front to rear.

I assume this means "positive" rake. In other words, the rear would be higher than the front. Am I interpreting this correctly?

Thanks,

Kevin

DanEC · #2 (**permalink**) 12-21-2013, 01:51 PM

Kevin - that is how I interpret it. I think that matches the ride heigth measurements in the manual that shows clearances from ground to frame - with the rear about 1/4 to 1/2 inch greater than the front.

ERA Chas · #3 (**permalink**) 12-21-2013, 02:06 PM

I set the height as measured at the flat of the lower edge of the frame, measured right in front of the brake box and at the aft edge, before the rear kick-up. I set mine at 4 7/8, F & R and I think the manual wants 5". Remember, the wider rear tires add rake by their larger diameters.
Try 5" as a baseline and readjust to taste. The lower the better.

DanEC · #4 (**permalink**) 12-21-2013, 02:28 PM

I'm considering setting mine close to flat - mostly just because in appearance a lot of the originals seemed to sit just a little low in the rear and not raked. Also a forward rake only drops that oil cooler scoop a little closer to the ground and top of speed bumps.

kevins2 · #5 (**permalink**) 12-21-2013, 02:54 PM

The manual calls for 5 1/4" at the front of the main rails and a rake to the rear of 1/4 to 1/2". It also says to drive at least 50 miles first. I have about 80 miles, so hopefully it has settled as much as it's going to. Not a big deal if it needs multiple adjustments.

Thanks for the help.

Kevin

ERA Chas · #6 (**permalink**) 12-21-2013, 03:32 PM

FWIW-my chin scoop is 3 5/8" from the ground. Avoid speed bumps (and the malls they're in) and you're fine. If you must traverse one, approach at an angle and the raised wheel is enough to clear a bump.
Also 'helicopter tape' is your friend; I only had light scuffs in it and untouched fiber glass. A patch cut to the shape of the bottom of the scoop is unseen from standing above.

kevins2 · #7 (**permalink**) 12-21-2013, 04:46 PM

Helicoptor tape comes in 8 mil and 14mil. I assume the thicker the better for this purpose. I'll check the scoop height - haven't measured that yet.

Thanks again.

Kevin

ERA 778 · #8 (**permalink**) 12-21-2013, 05:40 PM

OK, I'll bite..What is helicopter tape? Never heard of it !!!

vatdevil · #9 (**permalink**) 12-21-2013, 06:15 PM

Quote:

Originally Posted by ERA 778

OK, I'll bite..What is helicopter tape? Never heard of it !!!

Polyurethane tape....often called Racers Tape.

Bobcat · #10 (**permalink**) 12-21-2013, 07:31 PM

Kevin ... my manual says 5 1/4" in front and 5 3/4" in rear for ride hgt . measured from frame rails as ERA Charles says . Mine is a bunch lower and I sometimes run more rake than the 1/4 to 1/2 " as it seems to help the front end to not be so squirrely at high speed on the track ( 130 + ) as I don`t have a front spoiler/air dam . My suggestion is until you get some miles on the car ... several hundred , don`t worry about ride hgt . Just get it close and once everything settles in , then start lowering until you`re happy .
FWIW , I set my ride hgt with a little over 1/2 tank of fuel and my weight in the driver`s seat . I also make sure the front and rear antisway bars are disconnected while setting the ride hgts and reconnected with no preload while the weight is still in the driver`s seat .... but then I`m anal on things like this .

Bob

ERA Chas · #11 (**permalink**) 12-21-2013, 07:32 PM

Yes, polyurethane but not 'racers tape'.
3M aerospace and aircraft product catalog
Literally used for leading edge protection on fixed and rotary winged aircraft.
Mine is black but now clears are available.

patrickt · #12 (**permalink**) 12-21-2013, 07:53 PM

Quote:

Originally Posted by Bobcat

FWIW , I set my ride hgt with a little over 1/2 tank of fuel and my weight in the driver`s seat . I also make sure the front and rear antisway bars are disconnected while setting the ride hgts and reconnected with no preload while the weight is still in the driver`s seat .... but then I`m anal on things like this .

Of course he will need to set the corner weights when he does the final ride height. Nothing makes as big a difference.

Bernica · #13 (**permalink**) 12-22-2013, 11:01 AM

Quote:

Originally Posted by patrickt

Of course he will need to set the corner weights when he does the final ride height. Nothing makes as big a difference.

PatrickT, you beat me to it! I second Patrick's comments about the importance of corner-balancing the car, keeping in mind that your weight in the driver's seat is a factor used as well to get proper corner-weights for the car. Then you need to decide how much fuel to have in the tank, especially if you are running a big tank.

patrickt · #14 (**permalink**) 12-22-2013, 12:36 PM

Quote:

Originally Posted by Bernica

PatrickT, you beat me to it! I second Patrick's comments about the importance of corner-balancing the car, keeping in mind that your weight in the driver's seat is a factor used as well to get proper corner-weights for the car. Then you need to decide how much fuel to have in the tank, especially if you are running a big tank.

Well we've been down this long and winding road before. But it's not like everybody has an appreciation for corner weights. But, Lord knows I've tried to enlighten the masses... with this thread being a perfect example Best way to adjust rear coil overs for proper height on my SPF The very last post being one of my top ten all time most satisfying posts.

kevins2 · #15 (**permalink**) 12-22-2013, 12:54 PM

Lots of little details to tend to. It's been said that you're never really done with these cars, which makes them a perfect hobby. I appreciate all the helpful advice. I won't completely obsess over the ride height just yet but will tinker with it to get it close. The driver's side rear is just shy of 1/4" lower than the passenger side. I'll at least get things close and then get some miles on it.

As for corner weighting, I'll have to ask around locally to find someone to help with that.

It's supposed to rain hard tonight and tomorrow, so hopefully it will and wash all the salt off the roads so I can get it out for a drive. That would be a great Christmas.

Kevin

patrickt · #16 (**permalink**) 12-22-2013, 01:00 PM

Quote:

Originally Posted by kevins2

As for corner weighting, I'll have to ask around locally to find someone to help with that.

It's not hard. The hardest part is just finding the scales, but usually someone in your local club has them. You can even do it by cleverly cantilevering on to bathroom scales to reduce the apparent weight. But you've got to do it. The world will come to an end and you will never be happy if you don't.

kevins2 · #17 (**permalink**) 12-22-2013, 01:04 PM

Quote:

Originally Posted by patrickt

...The world will come to an end ....

Well, I certainly wouldn't want to add yet another reason for the world coming to an end. Enough of those out there already

patrickt · #18 (**permalink**) 12-22-2013, 01:15 PM

Now, if you just happen to have 16 bathroom scales sitting around.... Or, more likely, you just order 16 of them off of Amazon, set your corner weights, then return 15 of them for a refund saying you accidentally hit the wrong key on your smart phone when you placed the order.

Bernica · #19 (**permalink**) 12-22-2013, 01:34 PM

I have heard of folks renting the scales from race shops in the past. Also, if you visit a track day event, you will most likely see a few guys with them who may offer some help or a loan. Ask around at your local Cobra Clubs too.
Good luck!

ERA Chas · #20 (**permalink**) 12-22-2013, 02:27 PM

Quote:

Originally Posted by kevins2

It's supposed to rain hard tonight and tomorrow, so hopefully it will and wash all the salt off the roads so I can get it out for a drive. That would be a great Christmas.

Kevin

Some un-asked for but serious advice about the 'first drive'.
Don't bring anyone in the car with you-that's for when it's debugged and carefree.
Drive around your own block until temps and pressures come up. Until you're bored if you have to. Easier to push home if needed.
Avoid hilly terrain.
Drive in areas where you need to brake as well as accelerate-get the brakes warm.
Have a chase car with a nylon tow strap follow you; even if just around the neighborhood.
Go during full daylight hours.
Avoid desolate areas; in case you need help pushing.
Bring a simple tool box in the chase car. You may need to adjust the idle or move the distributor for example.
Especially have a vice-grips in the car with you-always. I snapped the shifter clean off at 80MPH on a 2-3 shift and used one clamped to the stub to drive home.
Watch in this order; the oil pressure, water temp and amp gauge (or volt meter).
Head back at the slightest sign of abnormal readings.
That's 3 decades of 'first drives' after building, rebuilding and modifications...

Oh and corner weighting the car is fine, especially if driven hard or on track-but don't go nuts.
You're getting hammered by cornering wiz Pattie who's greatest need for corner weighting has been the 15 MPH traffic circle near his fave restaurant...