1937-1957 Buick Oldsmobile Pontiac suspension upgrade
(→Brakes) |
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==Brakes== | ==Brakes== | ||
| − | The brakes on these cars definitely need improvement. That is not only the worst part of these cars, it is the first decision that dictates the path you follow in later steps. [The information listed here is general in nature and varies from model to model and year to year.] I’m diverting to a brake discussion here, because a decision on brakes determines the spindles you need, and you must have your spindles before you can design your suspension. | + | The brakes on these cars definitely need improvement. |
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| + | That is not only the worst part of these cars, it is the first decision that dictates the path you follow in later steps. [The information listed here is general in nature and varies from model to model and year to year.] I’m diverting to a brake discussion here, because a decision on brakes determines the spindles you need, and you must have your spindles before you can design your suspension. | ||
Earliest models had 1 ¾ by 11 inch brakes with 1 inch wheel cylinders. | Earliest models had 1 ¾ by 11 inch brakes with 1 inch wheel cylinders. | ||
Post war they were 2 ¼ by 12 with 1 1/8 wheel cylinders. The most basic upgrade would be to the later, larger, components. Control arms and spindles are unchanged for 20 years, so this is a basic bolt on. Even the shop manuals refer to this upgrade. | Post war they were 2 ¼ by 12 with 1 1/8 wheel cylinders. The most basic upgrade would be to the later, larger, components. Control arms and spindles are unchanged for 20 years, so this is a basic bolt on. Even the shop manuals refer to this upgrade. | ||
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A new split system master cylinder and power booster will be an amazing transformation of your stopping ability. Several aftermarket MC’s and 7 inch boosters, with universal pedal mounts are available. (With a V8 engine swap a 7 inch booster seems to be the max you can squeeze under the hood). I like the Geo Metro hanging pedal and 7 inch booster, but the MC is small. Didn’t chase down a match, but the center hole and bolt pattern appear to be typical GM. Be sure to get one designed for a booster application, and pay attention to the pushrod length. (Pulling the old pedals out was twice the work of putting the new one in). I located the unit just outboard of the steering column to clear the engine. Under the dash I had to bend the hanging pedal slightly to the center to get a good pedal position. I also welded on a new larger pedal pad that seems more appropriate to a large car and automatic transmission. | A new split system master cylinder and power booster will be an amazing transformation of your stopping ability. Several aftermarket MC’s and 7 inch boosters, with universal pedal mounts are available. (With a V8 engine swap a 7 inch booster seems to be the max you can squeeze under the hood). I like the Geo Metro hanging pedal and 7 inch booster, but the MC is small. Didn’t chase down a match, but the center hole and bolt pattern appear to be typical GM. Be sure to get one designed for a booster application, and pay attention to the pushrod length. (Pulling the old pedals out was twice the work of putting the new one in). I located the unit just outboard of the steering column to clear the engine. Under the dash I had to bend the hanging pedal slightly to the center to get a good pedal position. I also welded on a new larger pedal pad that seems more appropriate to a large car and automatic transmission. | ||
If you elect to do a power only upgrade and keep 4 wheel drums, be aware most MC’s are designed for a disc/drum setup and you will have to add 10# residual valves to the front lines. | If you elect to do a power only upgrade and keep 4 wheel drums, be aware most MC’s are designed for a disc/drum setup and you will have to add 10# residual valves to the front lines. | ||
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| − | So let’s consider the next option, front disc brakes. There are several ways to go here, but personally, I like the Scarebird* setup. Basically they supply the brackets for the calipers and the correct spacers for the spindles/rotors, and a tech list of parts to finish the job. | + | ===Estimated brake upgrade cost=== |
| + | *The front drums and hubs come together, at about $130 each. | ||
| + | *Wheel cylinders are $32 each. | ||
| + | *Shoes are $25 plus cores. | ||
| + | *Hardware is $15, flex hoses are $25 each. | ||
| + | *The above mentioned wheel bearings are $200. | ||
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| + | So, a complete brake job will run around $600 just for the 2 front wheels, without the master cylinder or booster. | ||
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| + | So, let’s consider the next option, front disc brakes. There are several ways to go here, but personally, I like the Scarebird* setup. Basically they supply the brackets for the calipers and the correct spacers for the spindles/rotors, and a tech list of parts to finish the job. | ||
For clarification purposes only, here is an example. On a 58 Pontiac they supply the brackets and spacers - From any source, new or used, you need a pair of 77 Bonneville 12 inch hubs/rotors, a pair of 88-91 GM truck calipers, and 2 choices of flex hoses depending on whether you want them 12 or 15 inches long. | For clarification purposes only, here is an example. On a 58 Pontiac they supply the brackets and spacers - From any source, new or used, you need a pair of 77 Bonneville 12 inch hubs/rotors, a pair of 88-91 GM truck calipers, and 2 choices of flex hoses depending on whether you want them 12 or 15 inches long. | ||
Note: From CPP (Classic Performance Parts) you can get a tapered bearing conversion kit. | Note: From CPP (Classic Performance Parts) you can get a tapered bearing conversion kit. | ||
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Update. I ended up with a corvette 1 inch master cylinder and a 7 in single stage booster. | Update. I ended up with a corvette 1 inch master cylinder and a 7 in single stage booster. | ||
| − | My opinion is: close enough. The brakes are a vast improvement over manual drums, but not perfect. Stopping power is great to about the last 20% of pedal travel. I made several panic stops to test the system. At the very bottom, you just can’t push hard enough to lock them up. Simply put, the system needs a 9 or 10 inch booster to be perfect. The tech man I spoke with at CPP felt the 7 inch dual diaphragm would have been better, but not much. There simply isn’t enough power in a 7in booster to lock up a set of 215x75 15s on a 3500 pound car, on dry pavement. The reason I say close enough; this would only be an issue in a total panic situation, to a full stop, on dry pavement. In that situation, do you want them to lock up? | + | My opinion is: close enough. The brakes are a vast improvement over manual drums, but not perfect. Stopping power is great to about the last 20% of pedal travel. I made several panic stops to test the system. At the very bottom, you just can’t push hard enough to lock them up. Simply put, the system needs a 9 or 10 inch booster to be perfect. The tech man I spoke with at CPP felt the 7 inch dual diaphragm would have been better, but not much. There simply isn’t enough power in a 7in booster to lock up a set of 215x75 15s on a 3500 pound car, on dry pavement. The reason I say close enough; this would only be an issue in a total panic situation, to a full stop, on dry pavement. In that situation, do you want them to lock up? |
==Front Suspension== | ==Front Suspension== | ||
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