Hi there, I have an 86 GT, and I'm wondering what the easiest brake upgrade would be. I've heard of using brakes out of just about every GM vehicle, but I'd like to know what costs the least and would be the easiest to install. I've heard about Beretta rotors, lebaron rotors, Blazer 4wd calipers, all sorts of things, but I want to know what I could use as a direct fit replacement for the stock brakes since I can't modify a lot. Would it be any easier to buy slotted/cross-drilled brake rotors with high-performance pads? Anyways, let me know guys, because I need to know... Now that I've gotten my idling/surging and other mechanical issues taken care of, I wanted to do the brakes because the existing brakes, well... Just aren't that great.
My other question is, will getting the 88 rear swaybar make the car less prone to understeer and more likely to oversteer? (I like oversteer ) How much of an improvement on handling is adding the swaybar?
Thanks in advance! -Mulholland GT
------------------ 1986 GT Getrag 5-speed
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02:16 AM
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Mulholland_GT_Racer Member
Posts: 387 From: Iowa City, IA USA Registered: Aug 2005
You need a sway bar mounting kit with the end links and the brackets. You can find the hardware at most autopart stores or www.fierostore.com they also sell the correct rear sway bar.
[This message has been edited by avengador1 (edited 09-22-2005).]
I took an '84 front swaybar with its OE middle mounts off the donor, and added end links to the A arms and voila. Essentially you take a pair of links, eliminate the top rubber bushing and reduce the distanced in the middle to about 1" by trimming the little spacer sleeve and buying a 5" #8 grade bolt.
Works great.
As for brakes, the cheapest by far is the Grand Am conversion. If you use the Grand Am rotors on the rear you have no ebrake, but in terms of cost, it is cheaper than stock and improves braking. Run a search on Grand Am and you will get some good descripts.
I used 89 GrandAm Front Calipers, Pads, and Rotors on the back of my 86GT. The only thing you need to do is bend back the dust sheild for the rotors so they don't rub. its a direct bolt on and costs about 100 dollars for the whole setup. The braking is about 100000000000 times better.
Nick
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08:19 AM
Francis T Member
Posts: 6620 From: spotsylvania va. usa Registered: Oct 2003
As for a simple while not very costly and everyone has their own idea as to what cheep is, I did and recommend this, slotted front rotors with Portfield RS4 pads and steel lines all around plus hi-temp brake fluid. My car stops much better with now fade at all. And slotted rotors do help a lot with venting the gasses that cause brake fade.
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Mulholland_GT_Racer Member
Posts: 387 From: Iowa City, IA USA Registered: Aug 2005
I didn't think up that combination myself, I basically ask the same question you did about a year earlier and had two mx racers suggest it. If it was good enough for them, I figured it would do fine on the street and it has. Now if you're thinking about taking your car to a road course, I'd go with the bigger rotors etc setup. My son-in-law drove my 86GT and wants to do the same brake upgrade to his 87GT.
From what I understand and this is only how it was explained to me...correct me if I am wrong...a mid engined vehicles weight transfer during braking is different then that of a front engine vehicle. In a front engine vehicle the front brakes do about 80% of the breaking because of all the weight being up front. In a mid engine vehicle rear brakes do the 80% because the weight is back there. If this is true then the GA rear upgrade would be the best bang for the buck and I would install a set of slotted rotors and some performance pads up front. This is my plan of attack atleast.
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09:34 PM
Mulholland_GT_Racer Member
Posts: 387 From: Iowa City, IA USA Registered: Aug 2005
From what I understand and this is only how it was explained to me...correct me if I am wrong...a mid engined vehicles weight transfer during braking is different then that of a front engine vehicle. In a front engine vehicle the front brakes do about 80% of the breaking because of all the weight being up front. In a mid engine vehicle rear brakes do the 80% because the weight is back there. If this is true then the GA rear upgrade would be the best bang for the buck and I would install a set of slotted rotors and some performance pads up front. This is my plan of attack atleast.
*feels stupid*
I think I'll do the same thing.
-Mulholland GT
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10:52 PM
Sep 24th, 2005
FastIndyFiero Member
Posts: 2546 From: Wichita, KS Registered: Aug 2002
From what I understand and this is only how it was explained to me...correct me if I am wrong...a mid engined vehicles weight transfer during braking is different then that of a front engine vehicle. In a front engine vehicle the front brakes do about 80% of the breaking because of all the weight being up front. In a mid engine vehicle rear brakes do the 80% because the weight is back there. If this is true then the GA rear upgrade would be the best bang for the buck and I would install a set of slotted rotors and some performance pads up front. This is my plan of attack atleast.
Nope. The only time the rear will have a greater weight on it than the front will be in the first fraction of a second that it takes for it to load the front. Hell, you could take the back rotors off and the front would be doing 100% of the braking.
The momentum shift properties are still the same, maybe a little more of the braking percentage shifts to the rear by it being midengine but the majority still relies up front, the nose of the car dips and the rear lifts on braking loading the front end. A 10 speed bicycle where center of gravity is about even is a good example, lock up the rear brakes and you slide, lock up the front brakes and you flip.
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05:48 AM
FierOmar Member
Posts: 1646 From: Glendale, California, USA Registered: Dec 2001
Could be going out on a limb here, but... as I understand the Fiero starts with approximately 56% of the weight on the rear, leaving about 44% on the front. My prior research revealed that there is approximately 15-17% weight transfer upon heavy (but not locked up) braking. The actual weight transfer depends on multiple factors, including ride height, spring rate, total vehicle weight, etc.
Now assuming a weight transfer of 16%, the Fiero would have 60% of its weight on the frond under heavy braking, leaving 40% on the rear. This concept also explains why FWD cars will end up with the front brakes doing about 80% of the braking (not uncommon for them to have 60% or more weight up fornt under static conditions).
Comparing the Fiero to other front engine with rear drive cars, adds food for thoutht. Assuming for the sake of discussion that our theoretical car was approximately 54% front & 46% rear under static conditions (by comparison, early Mazda RX7 comes close to 50-50). Under heavy braking conditions, the weight transfer would load the vehicle to 70% front, leaving 30% on the rear.
Acceleration reverses the weight transfer. Although I am not certain on this point, I seem to recall that the same weight transfer towards the rear will occur given the same G-force (e.g. acceleration vs. braking). Assuming that this is correct, the Fiero would have 72% load on the rear under hard acceleration while our theoretical car (see above) would have 62% load on the rear.
Kind of makes me wonder if a mid-engined car might not be well suited for road racing. More effective four wheel breaking during approach to turn, and greater loading on the drive wheels during hard acceleration. Hmmm. Just might work.
------------------ FierOmar
[This message has been edited by FierOmar (edited 09-24-2005).]
) How much of an improvement on handling is adding the swaybar?
