Stopping Power???

[BlwnGazkit]

Hey all, I just installed new 17" wheels and have noticed a decrease in stopping power. I realize that I'm going from 25.8" OA to 27.2" OA so some decrease was expected, but NOT this much!!

I currently have Non-power Granada front and drums in the back. Anyone have any ideas on the best way to fix this?? I have a power booster I was thinking of adding, but not sure that will help as much as I think it will.

 

[rbohm]

weigh the old tire and wheel and compare it to the new tire and wheel, i think you will find a substantial weight gain. this translates into rotating mass that makes stopping more difficult. first thing is to upgrade you pads to a performance pad. and yes i would also upgrade to power brakes as well.

 

[truck90278]

The decrease in braking is not unusual when going to larger wheels, it really is basic physics. by going to the larger moment arm (distance from center to the outside of the wheel/tire) more braking is required. The "mechanical advanataage" (in this case disadvantage) has been increased with larger wheels/tires. When 13" rotors are installed on a vehicle the braking advantage is increased. This is similar to using a larger pry bar to loosed tough nuts. You may have to go to the booster,

 

[Big_B]

Be sure to laugh at the next 8,000 pd SUV you see with 22" wheels and stock brakes. Unless you are in front of them, in which case you should get out of the way.

 

[zookeeper]

That weight gain shows both in decel and in accelleration as well. There's a local know-it-all who has a (he thinks) badass '68 Chevelle with 20's in the back and 18's up front. Not only does it look dumb, but he took it to the drags last year and ran in the 17's. I'd bet money the car would pick up at least a second in et by switching to 15's. He has no traction at all with the thin sidewalls and he's packing who-knows-how-much extra rolling weight.

 

[BlwnGazkit]

Lol, yeah like I said, I expected braking to be more difficult. It's just I didn't expect it to be this much harder!

So do you all think that the Granada setup will be ok once the booster is added? Or should I start looking into a larger brake setup like the Cobra setup MustangSteve has?

 

[65fastbackresto]

My nephew

has a 2005 silverado, had stock wheels and tires which he repalced with 20 inch wheels. Not only can he not even think of smoking a tire now, his truck follows grooves in the road, drives terrible, and stops even worse then that. He has eaten up 3 sets of rotors in 30,000 miles too.

 

[rbohm]

Lol, yeah like I said, I expected braking to be more difficult. It's just I didn't expect it to be this much harder!

So do you all think that the Granada setup will be ok once the booster is added? Or should I start looking into a larger brake setup like the Cobra setup MustangSteve has?

i think once you upgrade to a better brake pad, and add a power booster, the granada brakes in front will be fine. one more thing i recommend is using a large drum brake in the rear. cobra automotive, along with a number of others have an 11 x 2 1/4" drum brake kit from an F150 that will really help in stopping your car, and taking the load off hte front brakes. you do however want to install an adjustable proportioning valve in the system as well.

 

[BlwnGazkit]

has a 2005 silverado, had stock wheels and tires which he repalced with 20 inch wheels. Not only can he not even think of smoking a tire now, his truck follows grooves in the road, drives terrible, and stops even worse then that. He has eaten up 3 sets of rotors in 30,000 miles too.

As soon as these tires wear out I'll be dropping down to 235/45's that'll gimme the same OA diameter as my old tires on 14" rims.
That should help with the braking, but I suppose that until then I'll be counting on this booster setup I'm about to add.

 

[65fastbackresto]

I just put a Granada setup on yesterday

Its either really easy to install or I did something wrong. I kinda figured it might be hard, but I didnt even need a flaring tool, it all just plugged up, with a little bending here and there.