Ride height question

[ERA Chas]

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.

[lippy]

Originally Posted by ERA Chas

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.

Anyone have a good source for this - especially the clear? I checked the web and only found 0.75" x 36 yd, at a price of about $3k (!).

[scottj]

Originally Posted by lippy

Anyone have a good source for this - especially the clear? I checked the web and only found 0.75" x 36 yd, at a price of about $3k (!).

ISC RACERS TAPE

[ERA2076]

Interesting the concern over corner weight on an assumed street car. Unless ERA missed the manufacturing completely, I don't see how corner weighting is really going to matter much. There are lot's of other assembly tolerances that are taken for granted and are possibly not correct e.g. suspension pickup point alignment, chassis squaring, etc. all of which academically affect corner weight and all should be optimized before corner weighting. Isn't that how Shelby made his living i.e. Cobra, GT 350?

On ride height - The slight rake in chassis is just good setup. We get some component of aero working to push it down (at least at the speeds we can legally drive) and also help with squat.

If we consider track - take a look at this software and consider RC and IC and check the resultant ride height against the manual. Depending on tire height (as an example) things will change.

Circle Track Analyzer Racing Simulation Chassis Setup Software Program

I wish we could find some 1 to 1.5" dropped spindles. We could drop the CG and maintain a great RC.

Except for the entertainment value, not sure any of it pertains much to a street car. Very much applies to a track car - (especially if you build an under powered motor )

I think ERA has much balance built into their cars as designed, manufactured, and delivered. If you did not purchase a roller, then suspension blue printing makes sense. If not, other than a very good educational exercise, why bother corner weighting a street bound ERA? I doubt we could tell the difference between one that was, and one that was not, if testing were done legally on the street (that means clover leaves at legal speed).

My 3500lb mustang has not been corner weighted and for what it is and what I do with it (intermediate HPDE) it runs like stink. I would c-weight it, but I have spent a lot of time making it track-able and that is time (and $) stolen from the FIA. (much forgiving to learn in though )

We'll corner weight the FIA, but we are setting it up for track use. We have taken the time to square the sus pick up points, the steering, bump steer it, square wheel base, etc. IMHO - none of which makes much difference for a street car built to ERA standards following their manual.

Go Stanford - 3:06 to go

drop spindles?



chr

[ERA2076]

grats to State - great game - 2 great heavy weights.

chr

[ERA Chas]

Originally Posted by ERA2076

I think ERA has much balance built into their cars as designed, manufactured, and delivered. If you did not purchase a roller, then suspension blue printing makes sense. If not, other than a very good educational exercise, why bother corner weighting a street bound ERA?

Everything Cliff said in his post is exactly my experience with mine-in the '90's. Mine was a pallet car, not a factory roller. It has no add-on's but does have magnesium wheels. It's a very elemental car like S/C's were.
I did c/w it and here were the results with 1/2 tank of fuel, batt in trunk and me in it:
CORNER WEIGHT W/DRIVER: LF: 682 / RF: 648 / LR:755 / RR: 748
WEIGHT DISTRIBUTION W/DRIVER: F: 1330- 46.9% / R: 1503 – 53.1%
I made no changes and found it perfect for autox, track days and street.
Those that claim a remarkable transformation in street driving after corner adjustments are deceived by lack of force input of a racetrack. Unless the car is saddled with amenities, sound-deadner, fake aluminum and such, it will be very close right from ERA-and they will all be similar. A good alignment with a performance bias will be much more beneficial to improved 'feel'.
So the improvement after c/w is largely psychological-unless you plan what Cliff does on track.

[patrickt]

Originally Posted by ERA Chas

I did c/w it and here were the results with 1/2 tank of fuel, batt in trunk and me in it:
CORNER WEIGHT W/DRIVER: LF: 682 / RF: 648 / LR:755 / RR: 748
WEIGHT DISTRIBUTION W/DRIVER: F: 1330- 46.9% / R: 1503 – 53.1%
I made no changes and found it perfect for autox, track days and street..

That's a cross-weight of 49.5%, which is pretty darn good. Several of the Cobras on here have had much, much worse numbers than that. I was one of the first cars to be put on Peter's new digital scales, back in 2006, and Doug was able to get me to 49.9% -- with pretty much the same conditions as yours, except the battery is up front. The difference of .4% is only 11 pounds, which is two gallons of gas. I agree that your car was pretty close to perfect right out of the box, but other cars around here are not so lucky. Maybe most ERA cars are where yours was, maybe they're not. The only way you know for sure is to check.

[ERA Chas]

Originally Posted by patrickt

Maybe most ERA cars are where yours was, maybe they're not. The only way you know for sure is to check.

We should clarify by saying that's true for FE cars with Jag rears.-the FIA Windsors are somewhat different with batt location in the rr wheelwell, forward-mounted gas tanks, 50 pound-lighter rears, and of course engine weight and location.
I wonder if the Wilwoods are heavier than the standard ERA GM fronts?? I started with GMs and they weighed a ton but never actually checked-the Wilwoods came on the second rebuild.

[ERA2076]

In the case it did not weight well, based on experience with mine, I would pull all the suspension and start checking for squareness of everything associated at the chassis. I would correct that if needed and then build back checking as I go. It has to be in tolerancing stackup and should be corrected, but we are talking something really wild.

I would not discount - why do we disconnect the roll bars for weighting?

I am sure they don't all weight the same, but I would bet they all weight within some acceptable range. The components are jig manufactured.

If I purchased a new one and found such an error, I would be on the phone before the day was over and I would not be happy. After all, I purchased an ERA and waited a year(?) to get it.

chr

[Bobcat]

Good points by both ERA 2076 and Era Charles .
There is a relationship/goal that the suspension guys I know use for initial setup for track cars . The left side tires should have the same front to rear wgt distribution as the whole car and ditto for the right side . However , please note that the LS and RS actual wheel weights may not be the same because the CG`s may be offset .
So , just for the fun of it , I put ERA Charles` weights into my formulas to see how close his car was to the "ideal" setup . Pretty close .
Charles .... per my formula , you should be at : RF @ 656 lbs , RR @733lbs , LF @ 675 lbs and LR @ 762lbs . Your actual weights were RF ... 648 lbs , RR ... 748lbs , LF ... 682lbs and LR .. 755 lbs . The rule we use is , if you are within 10 lbs of the goal , don`t touch the car until you drive it . 50 lbs off , you readjust .
FYI .... my weights were all within 1 to 3 lbs of the "ideal" and the car handled great on the track . Note , I said on the track . I will bet you that a car can be off 50+ lbs and the average driver will never notice it . Also , tell someone his car was off and then say you adjusted it and I bet you he will say it handles better . We did this several times to drivers when i was doing dirt track .
I weighed/adjusted my car because : I was going to track it and I had replaced all shocks and springs and the ERA settings didn`t necessarily apply anymore for the heavier springs . They got me in the ballpark for the street , but not where I wanted to be for the track .
BTW , my suspension guy has over 20 years setting up dirt cars , SVRA , HSR cars and NASCAR truck series trucks .

[Bobcat]

The reason you disconnect the anti sway bars before setting corner weights isn`t because of the bars weight , but to eliminate any possible binding due to links being misadjusted etc . Reconnect the bars after setting the weights and make sure there is no preload on them .
It goes without saying ( I hope ) that all this is done with weight in the driver`s seat and 1/2 to 3/4 tank of fuel .
Yes , I agree that all of this is probably overkill for the street , but after all , these cars are toys for us to play with and experiment on .