Recently there was a mention in a post about the lowering of the W-body’s! It was stated that such a choice was a bad idea & I concurred, but I would leave it there at that time! I would like to address those reasons here! 

Reasons many people believe lowering a car's unsprung suspension is a good idea & will help a car handle better often comes from others who make assumptions & never do the math, really don’t understand the entire physics involved or know how to do the real work that is required to know what their actual numbers are & never truly put the car to a real test to prove it out! Yes they may take that car around a corner faster or it may corner flatter at the same speed as before & it feels good, but what if they really had to push it?

So the first fact, & you can research this yourself, is a double wishbone suspension & a macpherson strut suspension are worlds apart. The first can be infinitely fine tuned. The latter can’t! The first has many components that can be adjusted to affect roll center. The latter does not.

With a  double wishbone you can change caster, a lot, you can change camber a lot. You can effectively do a combination of movement of both caster & camber forward & out or in or rearward & out or in whichever you chose. With combinations to create many performance effects & these are just two parameters that affect suspension physics. With many double wishbone suspension you can find lowering spindles! This allows changes to the geometry of the lowered suspension with regards to CG while allowing RC to remain unchanged or altered whichever you chose. For the simplistic explanation, this amounts to the car being lowered, but roll center remains the same,with proper adjustments, as does suspension travel! 

In a Macpherson strut suspension this does not happen. There is no simple way to change caster! Camber you can, but it has limitations compared to a double wishbone. There are no lowering knuckles for Macpherson suspension for obvious reasons! The bearings are so large there is no room to alter the knuckles. As a result, suspension travel is negatively impacted. Roll center changes negatively, in a bad way automatically & you can’t do much to alter it.

Then there is this. How many truly know what their roll center is? How many know how to figure it? Better yet, how many of you can do your own wheel alignment? If all you did was put in lowering springs, & as such the car seems to corner better; then the answer to the above is you don’t know! This means if you were ever to be in a situation of needing to maneuver excessively quick, at a higher speed you might find yourself in serious trouble! 

In finality, suspensions are very complicated. There are over 100 mathematical calculations involved in setting up just a front suspension! Instant center, roll center, center of gravity, jacking force, anti jacking force, etc… to name just a few! In the end you can make an FWD handle! Not just well, but high end sports car well! But, not by lowering the car!

My approach for this was to maintain the original W calipers & just install larger dia rotors in the same manner that GM did when replacing the 10 1/2" rotors with 11 1/4" rotors.

The W calipers are more than adequate on their own merits. 

The 11 1/4" calipers are pushed further out from center by a later design in the caliper bracket adapter. Seeing as I didn't want to purchase & then alter the 95-96 adapters I reconfigured what I had on the car. To do this alteration one has to remove the adapter that is welded to the steering knuckle. One has to cut away the outer section of the *ears* that the caliper bracket is bolted to.

I sourced a length of 1/4"x2"x 12" A36 hot rolled mild steel flatbar, this bar is already stronger than the stamping of the adapters & the flatbar is thicker than the adapter by .050 thou.

Starting with the drivers side which being done 1st served as the guinea pig for any mistakes I know I would make. I cut off the adapter, gave it a blasting, laid it out on a workbench & proceeded to mock up what the new longer *ears* would look like to get what was needed. Out of the 12" of flatbar I cut 4 *ears* each the same size, from there I laid out on each one the location where I would need to drill the 9/16 hole for the thru bolt. The *ears* have to be shaped into a circular manner on their edge so as to fit into the valley on the backside of the caliper brackets & be able for me to pivot them to get the appropriate angle before tacking them to the adapter. This mod requires that the new *ears* be overlaid onto the backside surface of the adapter. The new rotors *hat* is 1/4" deeper than the original rotor so the need for 1/4" flatbar to move the caliper back inward to get the proper location for the new rotors.   

Now the adapter has to be fastened back into place on the knuckle behind the hub assembly, install the new rotor onto the hub & lock it into place with a couple of wheel nuts, bolting loosely the *ears* to the cast caliper bracket I can now place the bracket over the rotor to get an approx location where the position will be that is the same as the original caliper was placed. I now install the caliper & the new pads into the bracket & slide the entire assembly over the new rotor, getting an accurate height position for the caliper on the rotor I now need to check that all of the caliper pad is contacting the rotor face. Seeing as the 12" rotor has a larger diameter one needs to make sure that the outer edge of the rotor will clear the inside edge of the stationary bracket but get all of the caliper pad on the rotor surface. I had to remove the brackets & mount them into a bench vise an carefully remove approx .030 tho of surface inside the very upper edge of the upper & very bottom edge of the lower portion to expand the radius to get the needed rotor clearance as it spins inside the stationary bracket. 

After doing this I can now reinstall the assembly, position the assembled caliper & bracket, position the new *ears* over the cut off ends of the adapter, tighten down the bolts to hold the *ears* where I want them & now tack the upper & lower *ear* into position. I repeated this same procedure for the right side but it went much faster seeing that after completing the left side I now have a template use for the right side.

The welding was simple, remove everything from the car, bolt the cast caliper bracket to the adapter to prevent the adapter from warping while welding, mount them into a vise and run the beads, a flat downhand is best for this, the 71M wire puts down a nice wide bead to get maximum coverage for strength in a single pass.

This welding procedure requires a minimum of a 200 amp mig, the wire I used was a deep penetration fabrication flux core wire for argon/c02 for heavy fab work such as construction/ship building. A 70S is not recommended.

After getting everything assembled back together the last thin to cover is the new rotors hub opening, the W hubs are 70mm dia, the new rotors are 71 mm opening, this means that a 1mm shim is required to slide into the center of the rotor to properly center it over the hub. This was relatively easy, I pick up some 1mm stainless sheet steel & cut two shims 1/4" wide & to length & slipped them into the center of the rotor around the hub stub, then slide the rotor onto the hub. Worked perfect. 

It's been 2 weeks now since completion, after bedding in the new pads I have done some mild to moderate brake stops, working up to a few panic stops. The difference is instantly noticeable.

The car just hauls down to a stop in a much quicker, shorter amount of time. Now since a few years ago when I did the booster upgrade the pedal feel at that time was instantly changed. Going from a hard, less than desirable *no assist* feel to a one can literally stop the car by using ones hand on the brake pedal, the booster supplies so much assist the pedal is like a feather to press. 

The pads because of their shape do not cover the entire rotor contact face, approx 70% of the rotor surface is made use of & that's the outer portion of the rotor. I have to believe that the smaller 11 1/4" rotors see this as well, not having had any in my hands to compare the contact area with the 10 1/2" rotors I'm pretty sure that THOSE rotors may have a larger dia hat area that reduces the contact area to something similar to the 10 1/2" rotors, these Ford Crown Vic rotors have a *hat* area that is the same as the 10 1/2" rotor hat.

All in all...well worth my time & effort & what did it cost me? ...the price of a pair of new rotors & pads & a length of flatbar.

Nothing I do really does anything to get this booster to move and I am stumped on how to progress. The coter pin is out and the pedal disconnected. The master cylinder and abs contraption is off and out of the way. Theoretically, it should pop right out, yet it holds firm.

Any help would be greatly appreciated! Thank you in advance.

My initial thought was the 04 grand prix gtp comp g which had a 0.81g skidpad rating.

however after doing some more research I found that the 2002 oldsmobile intrigue GLS had a 0.84g skidpad rating

just wondering from those who have owned many w bodies which one handled the best

Any idea's?

If the oil has to be removed how much oil has to be removed? Do you ever need to drain the oil with fresh oil? What type of oil do you use? Not motor oil? Sorry for the stupid questions, that’s my only issue I have replacing these. I want to know how much to keep in there and how much to remove. Here is the factory info from my Buick shop manual.

ps no judging i recently picked a up a running/driving 92” cutlass supreme for 500 dolla so im trying to make something to scrape the floor

thanks to all i’m trying to figure out what type of wheels i want to put on and i was also wondering if a set of 18x8.5 +30 wheels would be too wide for the front or if the offset helps tuck enough

This will be for 1st gen W-body's, which include:

1988–1996 - Buick Regal

1988–1997 - Oldsmobile Cutlass Supreme

1988–1996 - Pontiac Grand Prix

1990–1994 - Chevrolet Lumina

First we will start with the Front Suspension of your car. Here you have a few choices.

1st - Held Motorsports Coilovers (Arraut Motorsports )

You can go with Held (Arraut) Motorsports Coilovers. Yes thats right Coilovers in the front of your W-Body.

http://arrautmotorsports.com/grand-prix/

2nd - Suspension Techniques

These are Front Lowering Springs. Part number is 60510

http://www.ebay.com/itm/ST-Suspensions-1-2-Lowering-Springs-for-95-01-Chevy-Lumina-Monte-Carlo-/281055438503?pt=Motors_Car_Truck_Parts_Accessories&hash=item417035a6a7

Advertised drop on these springs are 1"-1.5". Unfortunately, youll have to buy the whole kit to just use the fronts.

3rd - Eibach

http://www.rksport.com/shop/item.asp?itemid=577

These are also Front Lowering Springs. These are advertised at a 1.7" drop. Unfortunately, youll have to buy the whole kit to just use the fronts.

4th - Intrax

http://www.summitracing.com/parts/int-25-1-024

Once again Front Lowering Springs. These are advertised at a 1.8" drop. Unfortunately, youll have to buy the whole kit to just use the fronts.

Now moving to the Rear Suspension

1st- Birchmount Rear Monoleaf

These will replace your stock monoleaf, and nothing else. I have heard about a 2" drop, although I have not known many people to buy these, and as of late, however they are a source to lower the ass end of your W-Body! I have heard that they will make you a mono-leaf to whatever drop you need. This will match your front nicely.

Contact Information:

Birchmount Auto Spring Company

458 Birchmount Road

Scarborough, ON

M1K1M6

Telephone: (416) 698-3636

Fax: (416) 698-5732

2nd- Held (Arraut) Motorsports

Coilovers for the rear of your car. More information can be found HERE:

http://arrautmotorsports.com/grand-prix/

3rd- FAF ( Flex-A-Form ) Monoleaf

This is similar to the birchmount in the fact that it replaces your rear monoleaf, nothing else.

Now for the Gen 1.5 W-body's, which include:

1995–2001 Chevrolet Lumina

1995–1999 Chevrolet Monte Carlo

Once again, well start with the Front Suspension of your car.

1st - Held Motorsports Coilovers (Arraut Motorsports )

You can go with Held (Arraut) Motorsports Coilovers. Yes thats right Coilovers in the front of your W-Body.

http://arrautmotorsports.com/grand-prix/

2nd - Suspension Techniques

These are Front Lowering Springs. Part number is 60510

http://www.ebay.com/itm/ST-Suspensions-1-2-Lowering-Springs-for-95-01-Chevy-Lumina-Monte-Carlo-/281055438503?pt=Motors_Car_Truck_Parts_Accessories&hash=item417035a6a7

Advertised drop on these springs are 1"-1.5".

3rd - Eibach

These are also Front Lowering Springs. These are advertised at a 1.3" drop.

http://www.rksport.com/shop/item.asp?itemid=577

4th - Intrax

Once again Front Lowering Springs. These are advertised at a 1.8" drop.

http://www.summitracing.com/parts/int-25-1-024

Now moving to the Rear Suspension

1st - Held Motorsports Coilovers (Arraut Motorsports )

You can go with Held (Arraut) Motorsports Coilovers. Yes thats right Coilovers in the front of your W-Body.

http://arrautmotorsports.com/grand-prix/

2nd - Suspension Techniques

These are Front Lowering Springs. Part number is 60510

http://www.ebay.com/itm/ST-Suspensions-1-2-Lowering-Springs-for-95-01-Chevy-Lumina-Monte-Carlo-/281055438503?pt=Motors_Car_Truck_Parts_Accessories&hash=item417035a6a7

Advertised drop on these springs are 1"-1.5".

3rd - Eibach

These are also Front Lowering Springs. These are advertised at a 1.3" drop.

http://www.rksport.com/shop/item.asp?itemid=577

4th - Intrax

Once again Front Lowering Springs. These are advertised at a 1.8" drop.

http://www.summitracing.com/parts/int-25-1-024

Air Ride

This is also another option for BOTH Gen 1 and Gen1.5 cars.

http://www.x2industries.com/pontiac-1988-1996-pontiac-grand-prix-complete-air-suspension-kit-p-5726.html

*IMPORTANT NOTICE*

For all gen 1.5 W-Bodies, you can purchase all four springs in ONE set instead of buying them seperatly. Look for this as well and not just front and/or rear springs.

If you want to make your own REAR coilovers:

There are many places you can buy these same exact parts. Such as www.Summitracing.com But this is just one place where you can find these parts.

Here is a list from www.summitracing.com List includes different spring rates for the 12"x2.5" coil-over springs

You will need to choose your spring rate from these springs. I have 300#/in on my car, but its personal preference. I would stay between 250-350#/in spring rate.

http://www.summitracing.com/search/part-type/coil-over-springs/inside-diameter-in/2-500-in/length-in/12-000-in?keyword=qa1

List from www.summitracing.com for sleeves and adjuster nuts

You will need to choose the length of the sleeve. Normally a 7" sleeve will be more than enough for all the raising and lowering that one could do.

http://www.summitracing.com/parts/afc-20125a-7/overview/

Between the springs, and this kit, you have what you need to make your own custom rear coilovers.

Car has an honest 35,000 miles on it. It seems it needs a master cylinder. Car has ABS can anyone advise me how to bleed the system? I understand doing the bench bleed of the new master, my concern is bleeding the rest of the system.

Any assist you are able to offer will be greatly thanked. I will be driving 700 miles to do this so they do not attempt to drive the car to a garage while using the parking brake. 

Thanks in advance for any advice

Brock