pulling over 1g on the skidpad with an SC?

TintedChrome

Registered User
Ok.. I searched, and found some suspension info, but not quite what I was looking for..

Assuming I could get the car's weight distributed 50/50, or real close to, what would it take to upgrade the suspension (i.e., not completely re-design it) to pull over 1g on the skidpad? Is it even possible?

Car's more than likely going to have 305+ series rubber on the back, and 245's or 255's in the front, so there's plenty of contact patch..

Any ideas? Anyone done it and willing to spill the beans? :D

Thanks,

P
 
Cant be done with a streetable SC. You will never get 50/50 weight on a front engine car unless you pour enough concrete in the trunk to equell out the engine up front.:)
 
I though an SC is pretty close to 50/50 but Im really unsure of that....Its second hand info..Anyhow


I believe with the S/T springs, some konis...1 1/4 sway bars front and rear and a 17*9 or 8 rim with some GOOD rubber youll be there if not pretty dam close..

What you guys think?
 
I think that with S/T springs, Koni's, Sway bars, 17x9s with sticky tires in the right size, it could be done. But personally, I think that with 305+ tires in the rear and 245 or 255 in the front, he'll have way too much understeer. If you're going with 305's in the rear, I would recommend about a 275 tire in front. But I dont think you could fit that much tire under our cars.
 
Yes, it is very possible to get very close to a 50/50 weight distribution as well as a high skid pad test. There is one gentleman who several years ago managed almost 1.1g's with his bird, though he did make a lot of custom bushings for it.

John
 
Ya, I agree. Change out the crossmember and you are pretty much there. Then have some coil over mounts put on, sway bars, sub frame connectors, strut tower braces, sticky tires and you are there. Only costly part is the fab of the mounts and labor for crossmember. It can be done if you want it to happen. If I spent half as much money in suspension as I did for my engine I would be riding on rails.
 
If I'm not mistaken, the SWB tested a .98 on the skid pad. But that is from memory. But if it is serving me well, then it is easily within the grasp of the T-bird to exceed 1 g. And I believe that the T-bird is relatively close to 50/50 weight ratio. Yes, the front is heavier, but not much more than the rear. Upgraded bushings, swaybars, shocks and springs should bring you very close to that 1g threshold you seek.
 
I know that almost 1.1g's was achieved with sway bars, tokico springs and standard shocks, alot of upgraded bushings, and some other small stuff in a 96 4.6 car. No need to swap out the K-member.

John
 
Chris Wise just had his weighed it was 2320lbs front/1820lbs rear. That's alot of weight (500lbs) to move to get to 50/50.
 
K member can lose 150 off front. Battery moves 50 lbs from front to back. There's half of it. Take off hood and replace with glass one. 30 lbs. Go with headers instead of iron manifolds, aluminum radiator, less weight off front for more transfer. Just as a couple of examples. Just because there is 500 lbs diff doesn't mean you have to move or lose 500 lbs. I know Chris has a lot of this done but the front mount IC is way up front so his F/R ratio is really messed up. Just trying to point out the weight transfer factor.
 
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Now I'm no physics professor, but it seems to me that if the weight difference is 500 pounds, then wouldn't you have to move only 250 pounds to make it equal? ;)

With the K member, battery, hood, and headers I think you'd be there. Plus if you're replacing the K member you could change the geometry (if needed) to make the handling even better.
 
considering I'm gutting the car, and starting from scratch, it shouldn't be too hard to achieve as close to 50/50 as I can. I'm gonna be putting the car on scales once I'm done, and if there's a negligable difference, I'll move some stuff around. If there's a big difference, I gotta re-work it.

As for 245's causing understeer.. that's very possible. I won't know how bad it is until I drive the car. Might switch to wider rubber, but I've got to find out exactly how wide I can go in the front wheel wells. It's just that while the rear would be relatively easy to mini-tub if necessary for the 305's or 315's, I don't have the luxury of increasing the size of the wheel-wells in the front, unless I flare them. Hmm.. there's a thought.. anyone got any pics of real fender flares on a Tbird? :D

thanks for the info so far guys.. keep it up :)

P
 
Seriously a good Tire in a 245 or 255 width with a 17 inch rim should be wide enough..Chris Wise has alot of stuff upfrontthat I think would add weight such as his water to air IC setup..Also its important to weigh car with you sitting in it..a 500lb difference on a 4000lb car isnt much....I know everyone wanst massive rubber on there car but my car handled excellant with 245/45/17 comps..Now Im running a 255/50/17 to get back some of that height I lost..Still handles great...Work on your suspension first..S/T springs..There linear and highest spring rate out there..And a 1.5 drop..Konis front and rear. Sway bars 1 1/4 seems to be a good start...Then worry about rims and tires..Becaue at that point you may want to upgrade your brakes and boltpattern to that of a Cobra stang..Its what I did with a 17*8 98 cobra rim..Thsi is with the 245/50/17
car.jpg
 
I knew I had this info...Here's the curb mass (weight) of the two axles

Front: 892 (1962 lbs)-M5R2 901 (1982 lbs)-AOD
Rear: 790 (1739 lbs)-M5R2 799 (1758 lbs)-AOD

Total estimated curb weight of M5R2: 1682 (3701 lbs)
AOD: 1700 (3740 lbs)

This of course depends upon the options that the individual T-bird was equiped with. For the AOD, it is 53% front, 47% rear, and the M5R2 is the same...(less than .1% difference) That is very close to the 50/50 ratio you're looking at. These #'s are for the '89 T-bird. If you're looking for the cougar stuff, don't have it here, but I imagine that it is pretty close. I think there is just a little more wieght distrobuted to the front, but that is just speculation.

Also I got this information from the Manufacturers Motor Vehicle Specifications for the '89 Birds. I can't remember where I downloaded this info from...may have been this site...I'll check on it. It also goes into each option and the added or subtracted weight of it.
 
Way to go Professor Rob!

Rob Noth said:
Now I'm no physics professor, but it seems to me that if the weight difference is 500 pounds, then wouldn't you have to move only 250 pounds to make it equal? ;)

With the K member, battery, hood, and headers I think you'd be there. Plus if you're replacing the K member you could change the geometry (if needed) to make the handling even better.
 
That's awesome info guys, thanks..

Yeah, it's for the SC, not the Cougar.. Cougar's just the daily driver :) A-B in as little hassle as possible..

So essentially I need to redistribute ~110-120 lbs, whether by shaving weight or moving to the rear.. Hmm.. seems feasible

And along with the suspension mods you guys are recommending, it definately looks like 1g+ is "easily" attainable..

Becaue at that point you may want to upgrade your brakes and boltpattern to that of a Cobra stang

hehe... I'm already planning on the the cobra brake and bolt pattern upgrade :) It's gotta go like stink, ride on rails, and stop on a dime ;)
 
Aaron Pedroza said:
K member can lose 150 off front.

I'm not trying to be disrespectful in any way, but have you ever had a K-member out of a MN12? They really aren't that heavy. I have one from one of my parts SC's in the shop, which I weighed on an accurate heavy duty scale at 82 lbs. with the lower control arms and strut rods still attached. Here are pics of the K-member, just as it was weighed.

K-member%20top.jpg


K-member%20bottom.jpg


-Rod
 
I wondered about that too Racecougar. I been out playing with mine most of the day, and like you said its not that heavy.:confused:
 
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