I need brake conversion help Power to Manual

[camaro__thunder]

I have the regular power brakes in my truck with disc on the front and I want to switch over to a manual setup or underfloor to gain some more room underhood and cleanup the firewall.. What setup should I go for ? I have seen this kithttp://www.performanceonline.com/sto...cat=448&page=3 and was wondering if I needed anything else for the swap ? Will I have problems stopping the 22"s with manual disc ? Or what about Hydroboost ? I am not that great with brakes. THANKS !

[72MARIO]

Or what about Hydroboost ?

Any desiel truck has it's great setup to use. Get everything. Might have to do some playing with the Power steering pump mount. A guy here in town in using it on his small block not sure what mount he is using.


As for manual disk rid of the booster and bolt the master to the fire wall and get rid of the drum porp valve buy a wildwood or similar adjustable and put it in the rear brake line. You might have to adjust the rod length from the pedal to master cyl.

[camaro__thunder]

Will the manual discs be enough to stop the 22"s ??

[XXL]

Wheel size doesn't really play into this, IMO. Your truck weighs the same, and that's what you're trying to stop. If your concern is space, there are smaller, relatively efficient boosters available. I thought about going manual on mine, but decided I'd rather have the extra power of the boost assist. I ended up with a 7" dual diaphragm booster. And it all fit under the dash with some major mods to the pedal assy and brackets.

I also contemplated the frame mount system, but didn't like the idea of my brake system being 2" off the ground, being pelted by rocks and road debris. I also didn't like the idea of a slotted hole in the floor to accommodate the bottom-up brake pedal assy.

[72MARIO]

How tall are the 22" with rubber ? The over all size cant be taller than 30" could it ?

I am running 28" and have no issues stoping my truck.

[valleycustom]

Originally Posted by XXL

Wheel size doesn't really play into this, IMO. Your truck weighs the same, and that's what you're trying to stop. If your concern is space, there are smaller, relatively efficient boosters available. I thought about going manual on mine, but decided I'd rather have the extra power of the boost assist. I ended up with a 7" dual diaphragm booster. And it all fit under the dash with some major mods to the pedal assy and brackets.

I also contemplated the frame mount system, but didn't like the idea of my brake system being 2" off the ground, being pelted by rocks and road debris. I also didn't like the idea of a slotted hole in the floor to accommodate the bottom-up brake pedal assy.

Wheel size does play a big part if it's larger than factory. Bigger the wheel means a larger rotating mass that it needs to stop. That's why you see these guys with their SUV's with 24" and 26" that are always going into the shop getting new brakes. If you go and check some of the performance brake sites you can see tests that show a stock wheel and a larger wheel setups. It takes longer to stop with a larger wheel.

[XXL]

Originally Posted by valleycustom

Wheel size does play a big part if it's larger than factory. Bigger the wheel means a larger rotating mass that it needs to stop. That's why you see these guys with their SUV's with 24" and 26" that are always going into the shop getting new brakes. If you go and check some of the performance brake sites you can see tests that show a stock wheel and a larger wheel setups. It takes longer to stop with a larger wheel.

I disagree. The overall weight of a rotating mass of a given diameter is much more for a smaller wheel, where the additional diameter is made up by tire. This is especially true when comparing "stock type" steel wheels with the typical aftermarket alloy wheel. You generally have a MUCH lighter rotating mass in an 18" wheel with a 27" tire than you do with a 15" wheel with a 27" tire (again, especially so in the car world when that 15" is going to be a boat anchor stocker). While the location of the bulk of the mass and its proximity to the rotational axis is important, the sheer difference in weight is so significant that the larger wheel will stop faster. The reason they bigger wheel guys want bigger brakes is related more to their desire for bling and their interest in upping overall brake performance rather than trying to make up for lost performance as you imply.

If your contention were true, high performance vehicles would likely come with smaller wheels, and to make up for sidewall flex on their now larger rubber, would just stiffen the sidewalls more.

[72MARIO]

It would take more stopping power to grab ahold of a bigger diameter wheel(over all diameter) like the 24"rims. I remember on a T.V show they were saying you need bigger brakes when you get the Bling rims. Never really questioned the fact they rim would be possible lighter than a stock rim.

XXL I also agree that there would be a advantage using a 18" aluminum wheel and a 27" tire being easier to stop than a 15" rally with a 28"

You aways seem to look at things a little diffirent.
Remember the post about the drop measurements ? How we need to be measureing from the center of the wheel to get accurate numbers. No one else thought of that.

Not sure how much diffirence it would really make. It would be neat to see stoping distances using a 15" steel and 20 aluminum with the same tire manufacture's tire.

[valleycustom]

Originally Posted by XXL

I disagree. The overall weight of a rotating mass of a given diameter is much more for a smaller wheel, where the additional diameter is made up by tire. This is especially true when comparing "stock type" steel wheels with the typical aftermarket alloy wheel. You generally have a MUCH lighter rotating mass in an 18" wheel with a 27" tire than you do with a 15" wheel with a 27" tire (again, especially so in the car world when that 15" is going to be a boat anchor stocker). While the location of the bulk of the mass and its proximity to the rotational axis is important, the sheer difference in weight is so significant that the larger wheel will stop faster. The reason they bigger wheel guys want bigger brakes is related more to their desire for bling and their interest in upping overall brake performance rather than trying to make up for lost performance as you imply.

If your contention were true, high performance vehicles would likely come with smaller wheels, and to make up for sidewall flex on their now larger rubber, would just stiffen the sidewalls more.

Well the 22" intro vista 6 II with 285/35-22 I have are pretty heavy, more than a stock wheel and tire combo. Check out these links.

http://www.baer.com/media/contentdet...?contentid=166

http://www.moderntiredealer.com/t_in...TOKEN=15666262

[valleycustom]

If your contention were true, high performance vehicles would likely come with smaller wheels, and to make up for sidewall flex on their now larger rubber, would just stiffen the sidewalls more.

Sorry I had to laugh at that one.

[camaro__thunder]

Whoa! debates are fun

Specification 265/35-22
Sidewall 3.7"
Radius 14.7"
Diameter 29.3"

With as low as my truck is I dont think I could go any bigger, it would be taller than my hood and bedsides
I am going to put together some parts rather than buy a "kit" that will stop good. Gotta tub the firewall still

[valleycustom]

Originally Posted by camaro__thunder

Whoa! debates are fun

Specification 265/35-22
Sidewall 3.7"
Radius 14.7"
Diameter 29.3"

With as low as my truck is I dont think I could go any bigger, it would be taller than my hood and bedsides
I am going to put together some parts rather than buy a "kit" that will stop good. Gotta tub the firewall still

There is a universal brake booster kits that mounts sideways under the dash. I'm planning installing something like this on another truck I'm going to be starting soon, but doing this requires tons of fab work. Yeah if your BD to the door you have no more room. I'm working on a 69 that is bd to the rockers and I have about an inch before the rear tires stick out above the bed.

[XXL]

Originally Posted by valleycustom

There is a universal brake booster kits that mounts sideways under the dash.

This is what I'm using... (clickie the pic'ie)

[XXL]

Originally Posted by camaro__thunder

Whoa! debates are fun

I am a master debater.

BTW, the Baer/LRM article doesn't indicate anything to contradict my contention on wheel performance (except the claim that a +n wheel is heavier than a stocker, which is debatable at least, and most certianly not a constant). The rest of the article tells me why I should buy their product-- because it works better than stock. Well, I agree completely with that. But that doesn't have any direct connection to a bigger diameter wheel being easier/harder to stop.

Let the master debating continue... :happy:

[67Fleet]

It's actually a proven fact many times over that if you have two wheel/tire setups with the same overall diameter, that the one with the larger wheel & less rubber will be heavier. Metal (even billet aluminum) is more dense and heavier than rubber. The rotational mass is greater and thus harder to stop. Big wheels wreak havoc on stock braking setups. Ask ANY tire store. It's simple physics.

[valleycustom]

Originally Posted by 67Fleet

It's actually a proven fact many times over that if you have two wheel/tire setups with the same overall diameter, that the one with the larger wheel & less rubber will be heavier. Metal (even billet aluminum) is more dense and heavier than rubber. The rotational mass is greater and thus harder to stop. Big wheels wreak havoc on stock braking setups. Ask ANY tire store. It's simple physics.

[bs25j]

kinda off the subject but what size and backspacing are you runnign on your 22's. Im gona try and fit 22's all around on my 68 and want to get an idea of what i should be looking for.

[valleycustom]

Originally Posted by bs25j

kinda off the subject but what size and backspacing are you runnign on your 22's. Im gona try and fit 22's all around on my 68 and want to get an idea of what i should be looking for.

I have 22x10's and they have a 6.5" bs. I also narrowed the front 1.5".

[XXL]

I like seemingly authoritative statements that start like this...

Originally Posted by 67Fleet

It's actually a proven fact

From an article at TireRack (also not a definitively authoritative source, but one that debunks the "proven fact" statement above)...

Original Equipment (OE) BMW 3-Series Alloy Wheels and Tires

16" x 7" sized OE BMW wheels and 205/55R16 91H-sized Michelin Energy MXV4 Plus tires

The aluminum alloy wheels which came as Original Equipment on our 3-Series test car features cross-spoke styling and weigh an estimated 20.5 pounds each.

The Energy MXV4 Plus tires used as Original Equipment on our BMW 3-Series are Grand Touring tires which blend some of a performance tire's looks and handling with a standard passenger tire's longer life and more comfortable ride. The Energy MXV4 Plus incorporates an advanced version of Michelin's Radial XSE Technology (which consists of a Smart Tread Compound, Optimized Casing Shape and Optimized Mass Distribution). The OE Michelin Energy MXV4 Plus tires weigh 22.5 pounds each.

When combined, the weight of the Original Equipment Energy MXV4 Plus tires mounted on the BMW alloy wheels results in a 42.5 pound Tire & Wheel Package.

On the road, the OE BMW alloy wheels and Energy MXV4 Plus tires were praised for their good ride, low noise, real world handling and steering feel. The car felt balanced and generated a relatively light steering feel that felt appropriate for the car. This combination made it easy to understand the combination of real world ride, noise and handling qualities that BMW engineers wanted for their 3-Series sedan. On the track, this combination was rated as responsive and predictable while providing good braking, cornering traction and handling. However, as expected, this car turned in the slowest lap times of the three combinations tested.

Plus Size Wheels & Tires Using Lightweight Wheels

SSR Semi-Solid Forged 17" x 8" alloy wheels fitted with 245/45ZR17-sized Pirelli P Zero Asimmetrico tires

The SSR aluminum alloy wheels used in this test feature five-spoke styling and a unique manufacturing process called Semi-Solid Forging (SSF). Using a process originally developed for aircraft and automotive parts which require high strength, low porosity and lightweight, SSF produced wheels use a special aluminum alloy which is heated until it has about the consistency of warm butter, and then it is forced into the mold under high pressure. This results in a strong, lightweight wheel that offers many of the traits of wheels forged in the traditional ways, but costs less to manufacture and therefore is available at a more affordable price. The lightweight 17" x 8" SSR aluminum alloy wheels on our 3-Series test car weighs a scant 17 pounds each.

The Pirelli P Zero Asimmetrico Max Performance tires used in this test feature a lightweight construction and an asymmetric tread design developed to maximize the tire's ability to put the power down whether accelerating, braking or cornering. Additionally, the P Zero Asimmetrico tread compound combines traditional carbon black with a special blend of silica and synthetic polymers to enhance wet traction and reduce rolling resistance. The P Zero Asimmetrico is used as Original Equipment on many performance vehicles, and for that matter, the tires in this test have been used as Original Equipment on the BMW E36 M3. The 245/45ZR17-sized Pirelli P Zero Asimmetrico tires weigh a respectable 21.5 pounds each.

When combined, the weight of the Plus One-sized P Zero Asimmetrico tires mounted on the SSR Integral alloy wheel results in a 38.5 pound Tire & Wheel Package which is actually 3 pounds lighter than.

...

In addition to that one semi-reference, I offer...

(From Kuhmo Tire web site, the first one I found with tire weight info)


245/35R19 93Y BSW 8.0 - 9.5 25.8 9.8 on 8.5 9 220/AA/A 19.9
245/40R18 93Y BSW 8.0 - 9.5 25.7 9.8 on 8.5 9 220/AA/A 25
245/45R17 95Y BSW 7.5 - 9.0 25.7 9.6 on 8.0 9 220/AA/A 25.5
225/50R16 92W BSW 6.0 - 8.0 24.9 9.2 on 7.0 8.5 220/AA/A 25.7

You'll notice that the tires are getting heavier as the wheel diameter decreases and the overall diameter stays (roughly) the same. Makes sense. There's more rubber.

I couldn't find any reliable sources for wheel weights for a particular model that would span the above sizes-- 16" - 19" (or anything close)... so I don't have any credible data to present to show the wheel weights getting higher as size goes up. Which, of course, they do. But even if the difference between a like-width, same model wheel from 16" to 19" was... I'll be generous... 10#, 5.8# of that would be offset by the tires above. So you're talking about net of 4.2#... x 4 corners = 17#. Is it your contention that I need to beef up my brakes because I've added 17# to my vehicle? That's about how much one of my trips to the pizza buffet weigh... so I would need to upgrade my brakes before leaving Cici's

[brad2]

Recess it into your firewall.

[valleycustom]

Originally Posted by XXL

I like seemingly authoritative statements that start like this...




From an article at TireRack (also not a definitively authoritative source, but one that debunks the "proven fact" statement above)...




In addition to that one semi-reference, I offer...

(From Kuhmo Tire web site, the first one I found with tire weight info)


245/35R19 93Y BSW 8.0 - 9.5 25.8 9.8 on 8.5 9 220/AA/A 19.9
245/40R18 93Y BSW 8.0 - 9.5 25.7 9.8 on 8.5 9 220/AA/A 25
245/45R17 95Y BSW 7.5 - 9.0 25.7 9.6 on 8.0 9 220/AA/A 25.5
225/50R16 92W BSW 6.0 - 8.0 24.9 9.2 on 7.0 8.5 220/AA/A 25.7

You'll notice that the tires are getting heavier as the wheel diameter decreases and the overall diameter stays (roughly) the same. Makes sense. There's more rubber.

I couldn't find any reliable sources for wheel weights for a particular model that would span the above sizes-- 16" - 19" (or anything close)... so I don't have any credible data to present to show the wheel weights getting higher as size goes up. Which, of course, they do. But even if the difference between a like-width, same model wheel from 16" to 19" was... I'll be generous... 10#, 5.8# of that would be offset by the tires above. So you're talking about net of 4.2#... x 4 corners = 17#. Is it your contention that I need to beef up my brakes because I've added 17# to my vehicle? That's about how much one of my trips to the pizza buffet weigh... so I would need to upgrade my brakes before leaving Cici's

Quit playing with little tonka wheels. Find a source that talks about wheels over 19". Have you ever held a 22" wheel with a tire on it? HEAVY!!!

[67Fleet]

Originally Posted by valleycustom

Quit playing with little tonka wheels. Find a source that talks about wheels over 19". Have you ever held a 22" wheel with a tire on it? HEAVY!!!

We're not talking about magnesium wheels on euro or tuner cars. You're splitting hairs here. valleycustom and I were making blanket statements about big rollers (20" & up). Obviously there are exceptions to the rule, but the fact remains that if you are going with big wheels, you need to upgrade the brakes, and simply going to a non-power assist braking system with no upgrades to calipers & rotors is just simply dangerous and asking for trouble. It's definitely a safety issue.

"Is it your contention that I need to beef up my brakes because I've added 17# to my vehicle? That's about how much one of my trips to the pizza buffet weigh... so I would need to upgrade my brakes before leaving Cici's"

You need to consider the fact that 17# of added rotational weight translates to a lot more than 17#'s of cargo weight. It will be an exponential increase. Again, simple physics.

[67Fleet]

Originally Posted by brad2

Recess it into your firewall.

Brad, that's pretty trick looking. Is that your truck? If so, can you expand on what it took to make that setup work?

[valleycustom]

[QUOTE=67Fleet"Is it your contention that I need to beef up my brakes because I've added 17# to my vehicle? That's about how much one of my trips to the pizza buffet weigh... so I would need to upgrade my brakes before leaving Cici's"[/QUOTE]

What's Cici's?

[XXL]

Originally Posted by 67Fleet

You need to consider the fact that 17# of added rotational weight translates to a lot more than 17#'s of cargo weight. It will be an exponential increase. Again, simple physics.

Yes, I am well versed in the "simple" physics as this relates to angular momentum and the location of the mass in relation to the rotational axis (though, admittedly, it's been a while). My example above was meant to debunk your previous "it's a proven fact" fallacy statement... and it does... and that's a proven fact

Originally Posted by valleycustom

Quit playing with little tonka wheels. Find a source that talks about wheels over 19". Have you ever held a 22" wheel with a tire on it? HEAVY!!!

So you're suggesting that these "simple" laws of physics change behavior for wheels > 19"? Interesting.

Can we accept the following axioms?

1. For a given wheel design/type, the larger the diameter, the more mass they have
2. For a given tire design, with a constant diameter, the larger the wheel mount, the less rubber required, and therefore the less mass they have

If yes, then as wheel diameter goes up which increases wheel mass, there is a corresponding (though not necessarily equivalent) reduction in tire mass, creating a net "wheel - tire" change in overall unsprung/rolling mass. ASSuming that the wheel mass is 2x the reduction in tire mass (bold assumption in some cases, as presented in my previous data from Falken, etc.), then the net mass with increased wheel diameter isn't astronomically higher... but, clearly higher nonetheless.

Having said all that, this doesn't immediately translate into "dude, you're gonna need to upgrade your brakes"... which has been the essence of many replies. The anecdotal "fact" is, I've replaced the stock 15x7 wheels on my Tahoe with 18x8's, kept the tire diameter at 27", and my brakes work fine... arguably as well as before. Another anecdotal "fact" is that I've done similar with my raggedy old '69, going fro 15x6 stockers to 17x8's. Ditto... the brakes are as crappy as they were before (though I'm working on that-- not because the wheel size suddenly uncovered a mysterious design flaw, but because they're crappy 37 year old brakes, and they were crappy new brakes 37 years ago). camaro_thunder didn't fall off a turnip truck (neither did I, btw ), and he'll make a good choice, and he'll be safe (except for his intense desire to remove his front bumper the slow way ). All of you upgrading to dubdubdub 28's, by all means, please upgrade your brakes if you're concerned about not stopping. I don't want you to rearend me at a stop light.