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PostPosted: Tue Apr 05, 2016 8:24 pm 
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I am looking to improve the "feel" of my brake system. Like you said, city driving could be better. It still stops fine, but I have to really give it a push and it seems the pedal barely moves at all.

Slowing down at the top end of the track going 150mph is fine. No issues there.

Currently I have:

95 DSM master cyl. I can't remember if it's FWD or AWD, but I believe the latter
93 Mirage 1.5L booster
89 Mirage turbo prop valve
Rallyguy Big brake kit front with EBC red pads
Stock 1G/GVR4 rear calipers with EBC red
Stainless lines throughout


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PostPosted: Tue Apr 05, 2016 9:06 pm 
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So, likely the stainless lines provide that direct feel, where you don't get the extended movement of the pedal as you push harder (like with rubber lines expanding).

Unless you aren't receiving full booster effect ... that could cause a stiff pedal feel upon engagement, if all other things considered are operating properly. Usually you will notice very extended stopping distance or the car "driving off" when at a stop (moreso with automatic transmissions).

I had a Mini (turbo model) at the shop, that is on it's 3rd or 4th vacuum pump in 6 months. All you do is bolt them on, check the hoses attached and confirm booster operation ... that car would attempt to drive away in drive/brake on/idle ... fine under all other conditions. Vacuum gauge direct on pump would yield almost 30 inhg new, and 5-15 inhg once affected and operating poorly. Hot or cold. I can understand "hard pedal" from this under-boosted scenario. Leaving a booster hose off can do this too, but your engine would run like a bag and the corresponding hissing sound is a major giveaway.

It could simply be the feel of the booster setup as engineered for the 4G cars. Crackerman posted years back about using the 1" Diamante Master with dual piston calipers and saying it was spot on. I assume he was using a turbo booster sitting in it's native environment.


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PostPosted: Sun May 15, 2016 10:34 pm 
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Quote:
I am looking to improve the "feel" of my brake system. Like you said, city driving could be better. It still stops fine, but I have to really give it a push and it seems the pedal barely moves at all.

Slowing down at the top end of the track going 150mph is fine. No issues there.

Currently I have:

95 DSM master cyl. I can't remember if it's FWD or AWD, but I believe the latter
93 Mirage 1.5L booster
89 Mirage turbo prop valve
Rallyguy Big brake kit front with EBC red pads
Stock 1G/GVR4 rear calipers with EBC red
Stainless lines throughout
What is the torque range "cold" for those EBC red pads? I'm wondering if we are comparing cold/mid/hot temps appropriately, because as you step up the pad line-up, you step up temp ranges when using the slot load pads in most cases, but not all.
When did the reds get installed ... and was anything changed at the same time?

Some pads won't bite and have proper feel until they are up to temperature. Horror stories of old vintage race cars that skinny people couldn't bring to a stop when cold, heck even some new super cars are like that.


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PostPosted: Mon May 16, 2016 12:27 am 
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Location: tampa
I run EBC reds. I love them for the rotor friendly, wheel friendly (no dust) and powerful quiet braking. but theres a caveat. they dont like all rotors. on plain cheap rotors they sucked when cold. I mean really suck. no brakes from 100mph stop. once warm they were fine. I suspect pad buildup on the rotor. cause when they used the pads on custom rotors with drill and slot pattern it transformed the pads to nothing short of awesome cold to hot. not sure if its the drilled/slot pattern or quality of rotor material that makes the difference. these custom brakes shaved 26lbs from stock dual piston outlander rotor setup. both setups 11.5in rotor.
Image
Image


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PostPosted: Tue May 17, 2016 10:46 pm 
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The Silent Administrator
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Well, that tells me all I need to know about the Red formulation, and rotors that "cut" the pads for more bite. Starting torque must be lower than "F" range (most consumer pads are FF {cold/hot}) using cheaper rotors, and better than "F" when hot. Wilwood's pad torque ranges are listed with their pads, and they have me leaning towards max torque at cold, and a steady climb up to the 800+F mark where they won't be king, but aren't anywhere near as bad as stock. To survive a track day would be nice, without smoking the compound to oblivion.

Thanks for that post lancerman, it helps to get a "feel" on what certain brake platforms are doing. Outlander rotors are large and heavy, you said it!


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PostPosted: Wed Jun 08, 2016 6:52 pm 
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Thinking about bigger/stronger booster ratios and what might work. Maybe I am barking up the wrong tree because a car in this weight category might not need this much booster/feel once my 1-1/16" master and quad piston fronts are in (single piston rear calipers which are essentially 1G and GVR4 rears for surface area/identical).
Not looking for feather weight pedal option with nearly instantaneous lockup, far from it. I don't have enough experience mixing and matching values to assume I know the magical formula to this point. But if someone else comes upon this, the research of stock parts and their technical data is there. Only thing that isn't listed is the depth of most of those boosters. Some are too wide for stock platforms, some are too deep to accomodate lines without having new ones made and formed to accomodate this issue.
Was thinking a Galant booster in 5:1+ range with similar depth of the unit would mate up nicely, but sometimes the part in the cabin could cause issues. Seems most look similar, likely all sharing the same bolt pattern/spread, but the rod in the center could have different depth of engagement, etc. Not sure of the total or needed adjustment. So, for now, I hypothesize what would interest me to see work at some point.
For now, a rebuilt booster is here and awaiting installation. I say this knowing I want to paint the bare casting that is coated in oil, to preserve longevity as Cardone puts it .... I'll leave it there because nothing in my engine bay is naked.

Quote:
C53a:
FWD 4.0:1 Non ABS 7/8" Master
*sedan got the same booster ratio (4.0:1), but smaller 13/16" Brake Master cylinder like all 1.5L models - my info may have come from 1989-1990 so don't quote me on all sedan disc/drum combinations

USDM Galant cars:

Up to 1990.5 Models
FWD 4.0:1 Non ABS 7/8" Master Disc Drum
FWD 5.0:1 w/ABS 15/16" Master Disc Disc
AWD 5.0:1 Non ABS 15/16" Master Disc Disc
AWD 5.5:1 w/ABS 1" Master Disc Disc
^^^ All single piston front calipers

Up to 1992 Models
FWD SOHC 4.0:1 7/8" Master Non ABS Disc Drum
FWD DOHC 5.0:1 15/16" Master Non ABS Disc Disc
FWD 5.5:1 1" Master w/ABS Disc Disc
^^^ All single piston front calipers
AWD 5.5:1 1" Master Non ABS Disc Disc
AWD DOHC NA 6.0:1 1" Master w/ABS Disc Disc
^^^ Alll single piston front calipers
AWD DOHC Turbo (VR4) 6.0:1 1" Master w/ABS Disc Disc
^^^ Dual piston front calipers, only model Galant to get this option

1993 Models
SOHC 4.0:1 7/8" Master Disc Drum
DOHC 5.0:1 15/16" Master Non ABS Disc Disc
DOHC 5.5:1 1" Master w/ABS Disc Disc
Quote:
Colt/Mirage 1994 North America FSM

Booster Ratios
4.5:1 NON ABS
6.0:1 w/ABS

Effective diameter of power cylinder
205mm (8") NON ABS Single
180 + 205 (7" + 8") w/ABS Tandem

Master Cylinder Diameter:
13/16" NON ABS
15/16" w/ABS

Colt/Mirage 92-95 in the British FSM

Booster ratios:

2WD 1300, 1600, 2000D 4.5:1 or 6.0:1 with ABS
Effective diameter of power cylinder 205mm (8") - Vacuum type single NON ABS
13/16" Master Cylinder Diameter NON ABS
Effective diameter of power cylinder 180+205mm (7"+8") - Vacuum type tandem w/ABS
15/16" Master Cylinder Diameter w/ABS

2WD 1800 5:0.1 or 6.0:1 w/ABS
Effective diameter of power cylinder 230mm (9") - Vacuum type single NON ABS
13/16" Master Cylinder Diameter NON ABS
Effective diameter of power cylinder 180+205mm (7"+8") - Vacuum type tandem w/ABS
15/16"" Master Cylinder Diameter w/ABS

4WD 1600 5:0.1 or 6.0:1 w/ABS
Effective diameter of power cylinder 230mm (9") - Vacuum type single NON ABS
13/16" Master Cylinder Diameter NON ABS
Effective diameter of power cylinder 180+205mm (7"+8") - Vacuum type tandem w/ABS
15/16"" Master Cylinder Diameter w/ABS


Evo 4-5
Non-Evolution Lancer 6.0:1
Evolution (all models) Lancer 4.5:1

Power cylinder effective diameter 180+220
Master Cylinder inside diameter:
EVO 4
Non-Evo 23.8mm
Evo 2 piston caliper setup 25.4mm
EVO 5
Evo GSR RS maker option Monoblock 4 piston Brembo 26.9mm


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PostPosted: Wed Jan 11, 2017 10:56 pm 
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Location: Duluth, MN
for boosters I run a 92ish elantra brake booster and master, and it feels great with the wilwoods! I forget what the ratios were, but I do know they were bigger.


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PostPosted: Wed Jan 11, 2017 11:06 pm 
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Location: Ottawa, ON, Canada
Elantra booster from 92-94.5ish and the Colt/Mirage\Summit higher trim option boosters are all identical and higher than the 3.5:1 of the base CSMs.


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PostPosted: Tue Sep 04, 2018 10:44 am 
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Location: SoCal and Wisconsin
Bringing this back,

I verified the booster is working.

However, I disconnected the vac line from the booster and took a drive. There was almost no difference in brake performance. The pedal was a little bit harder and did a little bit less, but that was it. It took the same great amount of leg force to stop the car. It's also impossible to lock up the tires because the pedal is so hard.

What should I try at this point? Could this be a pivot/dowel adjustment at the brake booster? Or is the 1" master causing this? You mentioned going even bigger on the master which to me, would seem like it would make this problem worse.

Thoughts?

_________________
90 Mirage LIL EVO 940awhp
14 Audi R8 V10
07 LS460L, 01 LS430
13 Tundra TRD S/C, 96 T100
96 Land Cruiser GT35R


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PostPosted: Tue Sep 04, 2018 10:52 am 
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Posts: 1527
Location: Denton, Tx
You may have already done this, but when I had issues with brakes, they started out great and seemed to suck just a few months later.
I changed the brake fluid.
Made a world of difference. It was a whole new car.

_________________
If speed kills, then i shoulda been dead awhile ago. There is no such thing as "Too Much Power". There is no excuse for a lost race. Do you view the rev limiter as a fun limiter?or as a shift point? And we all know, more boost=more fun.


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PostPosted: Tue Sep 04, 2018 11:08 am 
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Location: SoCal and Wisconsin
Not the fluid, it's new ATE blue. I've had this problem ever since I went to the smaller 93-96 1.5L Mirage booster and 2G master with the big brake kit. I changed too many things to know what is causing this issue.

_________________
90 Mirage LIL EVO 940awhp
14 Audi R8 V10
07 LS460L, 01 LS430
13 Tundra TRD S/C, 96 T100
96 Land Cruiser GT35R


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PostPosted: Tue Sep 04, 2018 11:59 am 
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Location: Tucson Az
my 94 mirage had a hard peddle also..
converted to rear disc with new rotors and calipers..
it was a 1.6 with auto 173 hp lol
elantra larger booster with 3k gt 1 1/16 master

when i put the e-brake on and tried to stall up it would pull thru the brakes as if the rears werent working at all...
no matter what I did it didnt help.. it took almost a month for the black to wear off the rotors.. but it stopped so I left it alone.....

now that I have seen your post Jason (and I know u want to run smaller booster).. I think back to mine.. and the rear brake line is the farthest out from the booster.. and if it wasnt getting pressure then that is why my rears didnt work...

I would check on a old master the distance of travel the plunger has.. then measure urs.. it might just need adjustment.. also I assume it has the check valve in the hose from the intake? it might be blocked or plugged....

just throwing out a few ideas.........

Steve

_________________
Steve 89 colt 2.3 stroker stock top end. evo3@20 psi 13.489@99.30mph 3/10 2012
On drag radials.auto trans.launching @ 5 psi and no traction thru 2nd.


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PostPosted: Tue Sep 04, 2018 1:04 pm 
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Location: SoCal and Wisconsin
Booster, hose, vacuum is all working correctly.

Booster vac hose connected or disconnected there is VERY little change to the pedal feel. It's very hard either way and only moves an inch or so.

What I'm trying to decide is if I should buy a new, smaller master cylinder (smaller than 1"), try and install the huge 3G mirage booster, or go through the hassle of trying to adjust the plunger. Which one of those three is causing this issue?

_________________
90 Mirage LIL EVO 940awhp
14 Audi R8 V10
07 LS460L, 01 LS430
13 Tundra TRD S/C, 96 T100
96 Land Cruiser GT35R


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PostPosted: Tue Sep 04, 2018 1:25 pm 
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Posts: 1527
Location: Denton, Tx
I am wondering if you may have a vacuum leak of sorts in the booster.
Try a replacement booster for what you have, and don't forget the inline vacuum check valve either.

If you don't have a check valve now, it may be significantly weaker than with, as 4g's with big cams and aftermarket manifolds produce pretty crappy vacuum compared to stock.

_________________
If speed kills, then i shoulda been dead awhile ago. There is no such thing as "Too Much Power". There is no excuse for a lost race. Do you view the rev limiter as a fun limiter?or as a shift point? And we all know, more boost=more fun.


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PostPosted: Tue Sep 04, 2018 4:05 pm 
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Location: SoCal and Wisconsin
Booster hisses out air when I remove the booster line and the check valve works.

I shortened the booster rod coming out of the booster and going into the master cylinder bore by several threads and braking is improving already. I think I need to keep shortening that rod, that may be part of my issue.

_________________
90 Mirage LIL EVO 940awhp
14 Audi R8 V10
07 LS460L, 01 LS430
13 Tundra TRD S/C, 96 T100
96 Land Cruiser GT35R


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