3g master and booster on 1g advice

[SasaniFab]

The car is a 92 tsi, with what I'm assuming is a 1 inch mc. I recently upgraded to a 3000gt vr4 front setup. Is a 3g mc and booster worth the hassle? Is it really needed?. The rears are stock.

 

[92AWDHX40]

Yes it's a upgrade I'm doing it . It helps when running bigger brakes which I'll be doing. Lots if information on here under 3g brake booster in a 1g.

 

[gofer]

I would upgrade to the larger 3g 1.062" (17/16") bore brake master cylinder since you're replacing the calipers and have to bleed the hydraulics anyway. The brake booster change will only change pedal feel so it's really personal preference, if you like a firm pedal with not a lot of travel then keep the stock 1g BB on there. If you like a softer pedal with more travel then upgrade to the 3g BB...

 

[SasaniFab]

So I need a mc and booster from say a 2000 eclipse non abs non traction. Then modify the lines for bubble flare?

 

[92AWDHX40]

Thanks Corey I remember the thread you posted.

 

[ceedawg]

Just change to the bigger master cylinder and you'll be good even with the stock brake booster. I find the the 3g brake booster will work but the brakes and the feel to me are very touchy as far as feedback is concerned. I think the stock booster will feel better with the upgraded MC from the 3g. I have Baer brakes in the front and the Evo 9 calipers in the rear. So my setup is different even though the Baer brake calipers are much bigger than the stock mitsu fronts.

 

[Kapok6]

I have swapped both. it's not hard.

 

[ceedawg]

I have swapped both. it's not hard.

Not hard but very grabby on my car if you know what I mean.

 

[Black95TSIawd]

I thought the master cylinder affected pedal pressure. What does changing the booster do?

 

[ceedawg]

I thought the master cylinder affected pedal pressure. What does changing the booster do?

The booster handles the pressure makes it easier for you to aply the brakes only when vacuum pressure is present.It boosts the pressure needed to apply the brakes. With no vacuum booster your brakes would be hard as hell to apply.The MC basically moves the brake fluid and I would say the volume moved is affected by the size of the piston in the MC.

 

[ThunderChild]

The larger the MC bore, the more fluid it will move per amount of stroke, but more pressure will have to be applied. Smaller moves less fluid, but with less effort.

The larger 3g booster assists pedal and MC movement by applying vacuum from the manifold to the back of a large diaphragm inside the booster.

The larger or more diaphragms you have, the less effort you need to push the pedal, but this can also reduce pedal feel.hence why some ppl do a booster delete, since it allows more finite break control, but at the cost of more input effort. "Most" brake boosters have a check valve, so they store vacuum for 1-3 brake depressions for emergency situations or cases where vacuum isn't readily available (full throttle or engine dies etc)

I myself did a 3G MC and booster swap with full outlander rotors and 2 pot calipers up front.
I haven't driven the car yet, but rolling it around and using the brakes, I can tell they will grab hard. I like a firm but linear pedal, so I may swap back to a 1g booster...or more likely I'll just live with it. As a note, idk how thus would affect a factory ABS system as in deleted mine (I don't like abs systems at all).

Not a rough swap as long as you can bend a couple lines and bubble flare them.

 

[Black95TSIawd]

The booster handles the pressure makes it easier for you to aply the brakes only when vacuum pressure is present.It boosts the pressure needed to apply the brakes. With no vacuum booster your brakes would be hard as hell to apply.The MC basically moves the brake fluid and I would say the volume moved is affected by the size of the piston in the MC.

Yes, thank you. Although, I was referencing change the booster to a 3g unit, not in general.

 

[Black95TSIawd]

The larger the MC bore, the more fluid it will move per amount of stroke, but more pressure will have to be applied. Smaller moves less fluid, but with less effort.

The larger 3g booster assists pedal and MC movement by applying vacuum from the manifold to the back of a large diaphragm inside the booster.

The larger or more diaphragms you have, the less effort you need to push the pedal, but this can also reduce pedal feel.hence why some ppl do a booster delete, since it allows more finite break control, but at the cost of more input effort. "Most" brake boosters have a check valve, so they store vacuum for 1-3 brake depressions for emergency situations or cases where vacuum isn't readily available (full throttle or engine dies etc)

I myself did a 3G MC and booster swap with full outlander rotors and 2 pot calipers up front.
I haven't driven the car yet, but rolling it around and using the brakes, I can tell they will grab hard. I like a firm but linear pedal, so I may swap back to a 1g booster...or more likely I'll just live with it. As a note, idk how thus would affect a factory ABS system as in deleted mine (I don't like abs systems at all).

Not a rough swap as long as you can bend a couple lines and bubble flare them.

So the booster assists the MC. Pretty standard stuff.

The larger MC moves more fluid per given "push" of the pedal. The larger booster makes it "easier" to push?

 

[ceedawg]

If you just put on the larger MC the stock brake booster will suffice trust me!!! It's not like the stock brake booster is small like the one on a Toyota yaris or hyundai accent. It's a descent size so a bigger MC with a bigger piston works as others here have shown.

 

[ThunderChild]

So the booster assists the MC. Pretty standard stuff.

The larger MC moves more fluid per given "push" of the pedal. The larger booster makes it "easier" to push?

Essentially yes

If you just put on the larger MC the stock brake booster will suffice trust me!!! It's not like the stock brake booster is small like the one on a Toyota yaris or hyundai accent. It's a descent size so a bigger MC with a bigger piston works as others here have shown.

This may be indeed the case. Depending on the particular use of the car, a 1g booster/3g MC may be the ticket to a balanced system.
Other cars may benefit from the bigger booster, especially if you're on a short drag course and need to bleed off speed quickly, and don't want shin splints from pressing the brake pedal. Haha

 

[Kapok6]

I myself did a 3G MC and booster swap with full outlander rotors and 2 pot calipers up front.
I haven't driven the car yet, but rolling it around and using the brakes, I can tell they will grab hard. I like a firm but linear pedal, so I may swap back to a 1g booster...or more likely I'll just live with it. As a note, idk how thus would affect a factory ABS system as in deleted mine (I don't like abs systems at all).

Not a rough swap as long as you can bend a couple lines and bubble flare them.

That pretty much sums up my brake system, but I didnt have to bubble flare anything. Just bend some lines and screw them in.

 

[ThunderChild]

did you just leave the double flare on the lines? they may seal initially but ive heard from a few others they have started leaking eventually with the standard vs bubble flaring them. i bubble flared mine since i did the abs delete at the same time and it was simple to do.

long as its working i cant knock it, i just didnt want to chance it personally. leaky brakes suck and have bad timing IME

 

[92AWDHX40]

Who's running a 3g brake master with a 1g booster gonna redo set up looking for opinions.

 

[1990TSIAWDTALON]

Does high boost effect the 3g booster? Will it hold 40lbs psi?

 

[Eddie Tsi]

I'm running this with cts-v 4 pistons and evo x rotor, works great.

Who's running a 3g brake master with a 1g booster gonna redo set up looking for opinions.

 

[gofer]

Does high boost effect the 3g booster? Will it hold 40lbs psi?

The BB should never see boost, the OE line that goes from the IM to BB has a check valve in it.

 

[92AWDHX40]

Corey I'm running the dual piston brakes. Just wondering about the feel of it. I got the 3g . For free from marry just curious if it's worth it.

 

[1990TSIAWDTALON]

Good to point out. When I FIRST got my car it had NO check valve in it so I added one but it was too late, the BB had seen boost and was leaking under vacuum
. I didn't think to check for that when we first drove it home, but it was a cobbled up mess from the Army Mechanics that had thrown it together so I am not surprised.
Thanks Corey.

 

[1990TSIAWDTALON]

. Morning Vic!!!!

 

[Geeb]

After I finally get my build together I'm looking at 3g master/booster and cts v 4 pots with 2000/2001 cobra 13" rotors...

I have to check, I hope they'll fit under my evo 8 enkeis... I'm pretty sure I saw a few that did them (one for sure on a 2g)