andrewj91rs

i have a 1991 camaro rs, has 1le brakes up front and disk in the rear. i looking to get rid of my booster so i can get some clearance. i found a 4th gen kit at summit https://www.summitracing.com/parts/bmr-mbk001 comes plate the firewall plate. will ths fit my 91? or if anyone know of an almost complete kit?!?? ive seen some things home made but i dont really want to get crafty with the brakes cause im going to drive this car hard when im done

andrewj91rs

has anyone used this http://www.paracing.com/racingstore/...roducts_id=209 ????

manualbrakes.com

Don't forget www.manualbrakes.com.

http://www.manualbrakes.com/f-body.html

Call me if you have any questions about the conversion.

91 camaro racer

iTrader: (2)

so if i have the low drag calipers i will have to buy new ones to use your kit?

manualbrakes.com

You can buy new, but any remanufactured caliper will work as they will most likely be rebuilt to NON low drag (normal) specs. Why? Because they will work with both the 1982-1997 step bore master cylinders and 1978-1981, 1998-2004 strait bore master cylinders. LOW drag calipers can only work with a step bore master cylinder. A NON low drag (normal) caliper can work with BOTH step bore and strait bore master cylinders.

For any of the vehicles listed below, the front caliper part numbers should be the same. These front calipers are considered D154 "metric" calipers.

These calipers were used on:
1978-1988 G-Bodies (Monte Carlo, Regal, Cutlass, etc.)
1982-2004 2WD S10 Trucks and SUVs with single piston front calipers.
1982-1992 F-Bodies with single piston front calipers.

From the factory:

1978-1981 "G-bodies" used NON low drag (normal) calipers and a strait bore master cylinder (7/8" bore for manual brakes and a 24mm bore for vacuum boosted brakes).

1982-1988 G-bodies used LOW drag calipers and used a step bore master. There was no manual brake option for these years. The vacuum boosted master cylinder had a pressure bore of 24mm and a volume bore of of at least 31.5mm and up to 36mm depending on year.

1982-1997 2WD S10s Trucks and SUVs, single piston front calipers, came LOW drag calipers and utilized the same master cylinder as the g-body cars. The only difference was the reservior. The manual brake versions of these trucks came with a step bore master cylinder. It had a 24mm pressure bore and a 1-1/8" volume bore to work with the low drag calipers.

1998-2004? 2WD S10s Trucks and SUVs, single piston front calipers, came with NON low drag (normal) calipers and used a 1.0" strait bore master cylinder.

1982-1992 F-bodies, single piston front calipers, came with LOW drag calipers and used a step bore master cylinder with a 24mm pressure bore and volume bore from 31.5mm to 36mm depending on year.

The above vehicles from 1982-1997 used LOW drag calipes and came with a step bore master cylinder for the LOW drag calipers to function correctly.

The only differences between a LOW drag metric caliper and a NON low drag normal "metric" caliper is the piston seal. The NON low drag caliper has a beveled seal which allows the piston to retract a little further into the caliper's bore.

Because the piston retracts further into the caliper's bore, it will need extra fluid volume to get the pads back up against the rotor. A step bore master cylinder has two bore sizes. It has a larger bore size to supply the fluid volume to get the pads back up against the rotor and a smaller bore size to create high line pressures for greater clamping forces at the caliper.

LOW drag calipers are only used on the front brakes.

The manualbrakes.com KIT uses a 7/8" bore master cylinder. Smaller bores create higher line pressures and less effort by the driver to stop the car. The trade off of a smaller bore master cylinder is the pedal travel will slightly longer.

The manualbrakes.com KIT with a 7/8" bore master cylinder is designed around a front piston area of 4.9 square inches of volume. 4.9 square inches of volume is a 2.5" single piston caliper (stock metric caliper size), 1.75" dual piston, or 1.75" four piston. Going to an oversized piston front caliper will require a larger 24mm or 15/16" bore master cylinder.

Almost any rear drum setup will work well with manual brakes as the wheel cylinders do not require the same volume of fluid a caliper does.

For manual brakes, a 7/8" bore master cylinder can be used with a stock volume (4.9 square inches) front caliper and a rear caliper with 2.0" diameter single piston, 1.38" diameter twin piston, or 1.38" diameter four piston calipers or smaller. This is a volume of 3.14 square inches or less. If you go with a rear caliper of more than 3.14 square inches, then you most likely need to upsize your master cylinder to the next larger size. The next larger size is a 24mm or 15/16" bore master cylinder.

I hope my ramblings made some sense. Please let me know if you have additional questions.

andrewj91rs

it was a lot but i think i understand. because i have rear disc ill need the larger 24mm or 15/16? then cause i have the 1le brakes im good to go and domt need to replace the calipers?

NoEmissions84TA

iTrader: (1)

Have you considered a hydroboost?
Leave everything as is and just replace the vacuum booster with the hydroboost unit.

manualbrakes.com

Though the 1LE calipers have more pistons, they require roughly the same amount of brake fluid to fill them as the stock single piston caliper, so the master cylinder size will stay the same. I would go with a7/8” bore master cylinder with the 1LE front calipers and the stock rear calipers.

andrewj91rs

I NEED ROOM!!!!!!!! ID LIKE TO USE 2 M90 SUPERCHAGERS ON MY 4.8 LS

andrewj91rs

do i need to change them out though? for the non low drag. i believe i read on the manual brakes website saying the 82-92 non 1le needed replacing. not really clarifying for the 1le. id like to get your kit and call it a day. then also would i use my original portioning valve.

RBob

iTrader: (1)

May want to consider a front brake upgrade at the same time. There are several choices using PBR calipers and larger rotors. Sounds like the car may need it anyway.

RBob.

manualbrakes.com

No, you should not have to change out the 1LE caliper. The metric, single piston, D154 calipers from 1982-1997 were the only ones LOW drag on the third gen f-body, g-body, and S10 trucks and SUVs.

Any replacement metric, single piston, D154 caliper, is manufactured to NON low drag (normal) specs. The caliper part numbers are the same for 1978-2003 rwd g-body, third gen f-body, and S10s. They remanufacture them to NON low drag specs so they will work with both step bore master cylinders (1982-1997) and strait bore master cylinders (1978-1981,1998-2003).

TallTim

iTrader: (2)

Did this 3 yrs ago. I'm just off the road course and the brakes worked really well.

I upgraded the fronts, put in a Wilwood prop valve and went to a manual master cyl.

Brakes are hard to push but you will get used to it.

https://www.thirdgen.org/forums/orga...la-how-go.html