Tire Rub?

[chopperroxie]

Hello all, I just installed the new fatman fab g-force drop spindle on my 71 chevelle. I also put a set of Baer 4 wheel discs and 17" tires with 255/45/R17 tires. I replaced the upper control arm with the fatman one but left the lower control arm and springs alone. The springs are about 7 years old. I also put on a set of QA1 shocks.

I now have serious tire rub on most dips and such. It seems to be rubbing on the outside of the tire and the inner fender like its mounted out too far. I had the alignment shop set it at the specs that fatman gave me. I though they were +.5 camber but not sure. I tried pounding the inner fender back a bit, but it seems to be rubbing on the edge.

Does anyone have any recommendations on correcting this. I love the ride, except for the bumpsteer, and love the stance. But the tire rub is not good, especially since I drive it daily.

Thanks

Corey

[BluEyes]

Assuming that your tire package is one that should clear I would say stiffer springs are nessacary (what's the backspace on the rims? I'm sure some guys here can help with a 'velle)

When you lower a car you also really need to stiffen the suspension to avoid just what you have here. Basically the suspension is moving just as much as it used to, but the tire is now that much closer to begin with. Stifer springs mean less suspension deflection over bumps which works with the smaller clearance you have now.
Unless you've lightened the car considerably, I wouldn't worry about heading up to the mid 400# range for the front springs with good shocks. American cars from the '70's started out very undersprung. My Camaro is at 420# and the ride is better than my LeBaron. My next step is 600# springs up front to bring the Camaro up from a sedan ride to something more suited to a sportscar.

[USAZR1]

Hello all, I just installed the new fatman fab g-force drop spindle on my 71 chevelle. I also put a set of Baer 4 wheel discs and 17" tires with 255/45/R17 tires. I replaced the upper control arm with the fatman one but left the lower control arm and springs alone. The springs are about 7 years old. I also put on a set of QA1 shocks.

I now have serious tire rub on most dips and such. It seems to be rubbing on the outside of the tire and the inner fender like its mounted out too far. I had the alignment shop set it at the specs that fatman gave me. I though they were +.5 camber but not sure. I tried pounding the inner fender back a bit, but it seems to be rubbing on the edge.

Does anyone have any recommendations on correcting this. I love the ride, except for the bumpsteer, and love the stance. But the tire rub is not good, especially since I drive it daily.

Thanks

Corey

Did the car have factory disc brakes or drums when you added the Baers? If it had drums,the new discs probably widened the track. If the car had factory discs,the track shouldn't have changed.
If that's the case,what size front wheels do you have now? What's the backspacing?
The inner fender bolts have large heads that don't help the clearances. Swapping them out for some button head fasteners will help alot.

[chopperroxie]

Thanks for the replies guys. The backspacing is 4.5", which is what newstalgia recomended for my car. The car did have 4 wheel drums so the thought about moving the wheels out might have done it too. My tires are 255's, perhaps I should have went with 245's.

So stiffer springs would help? Any brand or type you recommend? I looked around when I was doing this and all I could find wer 1" lowering springs and I certainly didn't want it lowered anymore. Does anyone sell stock height springs that are a bit stiffer. Also, will this make my ride harsher? It's already a bit harsher now.

I'll check on replacing the bolts with something with a smaller head.

Thanks Much

Corey

[chopperroxie]

I went ahead and ordered a set of the speedway springs and spacers, 575 was the lowest rate they had. It seems alot of you guys are running these.

Hope its not too harsh though, I guess with the stronger springs I can dial my QA1's back a bit, right now there at 8 I think. I like the idea of the adjustability of it. And the price is pretty good too.

What do you guys think?

Corey

[BluEyes]

Do you have a frontend weight for your car? That would let us calculate the natural frequency which is a good indicator of how soft/firm the ride should be. I'm guessing it would be in the range of 1.2-1.25 Hz, which is supposed to be pretty much what something like a Datsun 240Z or Miata comes with.
I sure hope it isn't too hard, I just ordered 600# fronts for my Camaro!

If the 575 is too hard for you though, try here: http://www.midwestmotorsportsinc.com/order_part.php?item=20500&line=AFC they have 500# springs.

[68BNUT]

I have the 700# springs with adjusters in the front of my camaro and it rides nicer than my vette did. I had the same problem your having when I put the new suspension in the front of my car. The disc brakes kicked my wheels out to far the only way to get rid of rub completly is to roll those fender lips.

[zuess4u]

I have the 700# springs with adjusters in the front of my camaro and it rides nicer than my vette did. I had the same problem your having when I put the new suspension in the front of my car. The disc brakes kicked my wheels out to far the only way to get rid of rub completly is to roll those fender lips.

Well thats good to hear, we have the same set up, "700lbs and adjusters......not sure where the car is going to sit yet though.

[MrQuick]

I had the alignment shop set it at the specs that fatman gave me. I though they were +.5 camber but not sure. I tried pounding the inner fender back a bit, but it seems to be rubbing on the edge.


i'd go -.5 to -1.0 on the camber. can you send us pictures on where it hitting? thanks

[chopperroxie]

My digital cameras not working or I would. It's hitting the fender with the corner of the outside rubber. If I did go to - camber instead of the +.5 I have, what would that do to my handling. I'd have to think Fatmanfab suggested that for a reason?

[Norm Peterson]

chopper - going from a little positive static camber to a little negative static camber will improve the front tire grip situation in turns, meaning that the car will be capable of slightly higher lateral g's and will not understeer quite as much (lateral g's and understeer are related terms/measures, but are not synonyms).

As far as any recommendation for camber is concerned, that will vary a bit depending on the rest of the car's setup, the level of enthusiasm anticipated in the car's normal operation, and a number of other considerations. It's probably easier to justify a small negative setting when you're running noticeably stiffer than OE springs, as nose dive/suspension compression under braking won't push the tires as far negative (and wear out the inside shoulders as rapidly). Fatman is likely just being conservative, as he probably does not know enough of the other details or anything about your personal driving capabilities to be comfortable recommending anything more aggressive.

As far as spring rates on domestic cars in the 3300 - 3500 lb range with SLA suspension goes, 600-ish is not a deal-breaker in terms of ride. It's not possible to get any more precise, as the suspension motion ratios also have considerable effect. FWIW, my Malibu with 640 lb/in Moogs up front and 165 lb/in in the rear is entirely acceptable on either a daily-drive or long trip basis. IMHO, anyway.

Norm

[chopperroxie]

Thanks for the info. After installing the speedway springs (575) and adjusting the ride height, it seemed to have corrected it. I think I will have the alignment shop change the camber though. Moving it from +.5 to -.5 will probably allow me to lower it even more too, as well as improve handling.

I'm loving this adjustable suspension though, adjustable ride height, adjustable QA1 shocks, this is awesome.

Thanks

Corey