98+ CAMARO “LS1” Brakes: Bigger & Better Period - Page 4 - FAQ Board - Third Generation F-Body Message Boards

z28cdoyle · 10-24-2003, 11:32 PM

Ed,
Yes, my car has the 4 wheel discs and still has the stock master cylinder.

I also thought more about the caliper area difference between the single piston and LS1. The LS1 caliper piston area is only 6% more but the front brake section of the master cylinder supplies 2 calipers. So the master cylinder will have to supply 12% more fluid.

Or will it? The master cylinder has a separate brake line for each front caliper. Are there 2 pistons in line with each other in the master cylinder bore to supply the front brakes? If so, then each piston is back to a 6% increase in fluid volume. Hmm...

Slayer2000,
I have thought about the LS1 master cylinder also. I'm not sure about the threads on the brake line fittings or whether it would bolt up to our booster. I will be leaving my stock rear calipers/discs on for now. I wonder how the stock rear calipers would react to the LS1 master cylinder.

Does anyone know the diameter of the LS1 rear caliper pistons?

Chuck

MrDude_1 · 10-24-2003, 11:33 PM

Quote:

Originally posted by slayer2000
with regards to the master cylinder, couldn't you use one out of a 98 and up f body that had these brakes to begin with? I've got a 4 wheel disc setup on my car factory(90 gta). Will I need to look for a new master cylinder?

thats a good question..

doesnt the 4thgen master cyl just bolt up to the booster? im pretty sure they're the same bolt pattern atleast...

MrDude_1 · 10-24-2003, 11:35 PM

hey...

if it doesnt bolt to the 3rdgen booster, is there anyreason you couldnt run the whole 4thgen brake booster/mastercyl?

think about it... the pedals bolt up thru the boosters holes, and they're the same on 3rd and 4thgens........ should bolt in as long as it doesnt hit anything.

ebmiller88 · 10-25-2003, 08:23 AM

Thanks Chuck. IMO, I'd switch to the disc/drum (IE-1LE) master when I install these brakes with dual piston calipers. That's what the factory uses and so do I. Unless you guys are brake gurus and know much more than I do about what you're doing, in that case dismiss all I say...

And as far as I know from the illustration manual, there's only one piston in the master for each brake line, front and rear, but the front splits to each side. There's other guys that know the piston diameter of these things, I just do what the little book tells me. I know Alloy has done a LOT of research into this, maybe shoot him a line.

Ed

89 Iroc Z · 10-26-2003, 02:06 PM

I would try it the breaks with the stock proportioning valve before you switch to the 1LE valve just to get a feel of the difference. It would seem that the 1LE proportioning valve is a better match for the LS1 brakes. What valve are the C5 guys using? The C5 caliper has very close if not the same hydraulics as the LS1 caliper.

ebmiller88 · 10-26-2003, 03:21 PM

I added descriptive comments on my webpage about the LS1 brake system assembly, hopefully they will help out those of you who are doing this swap.

http://f1.pg.photos.yahoo.com/ph/tar...src=ph&.view=t

Ed

slayer2000 · 10-26-2003, 04:31 PM

My car already has 4 wheel discs but I thought the main difference would be the in the master cylinder. Wouldn't the prop valve for my car work better the a 1LE disc drum setup? I can get a 99 camaro master cylinder pretty cheap but I'd like to use my current one if I can. If it can't produce the correct amount of force on the new front discs what kind of problems am I looking at? eb, That setup you've got looks awesome! I hope mine turns out as well.

slayer2000 · 10-26-2003, 07:08 PM

Eb, I was just wondering if you could use countersunk allen head bolts for the caliper bolts. If so you would have plenty of clearance. Also could you possibly post a pic of a modified spindle by itself with no hub or bracket? I want to make sure of my cuts before I screw them up.

89 Iroc Z · 10-26-2003, 07:42 PM

Quote:

Originally posted by slayer2000
Eb, I was just wondering if you could use countersunk allen head bolts for the caliper bolts. If so you would have plenty of clearance. Also could you possibly post a pic of a modified spindle by itself with no hub or bracket? I want to make sure of my cuts before I screw them up.

Allen head bolts would give good clearance you have to buy new bolts anyways because the stock LS1 bolts are way to long. As for the spindle pics, go to the second page of the C4 thread and I posted pics of the needed modifications to the spindle: http://www.thirdgen.org/techbb2/show...5&pagenumber=2 (1LE alternative... may just work)

z28cdoyle · 10-27-2003, 09:34 PM

89 IROC Z,
My plan is to use my stock disc/disc master cylinder with the LS1 up front and the stock single piston calipers out back. I plan to test it out conservatively at low speed to find out how it works. I can always change the master cylinder if it doesn't work well.
I dumped the stock proportioning valve long ago in favor of a Wilwood adjustable unit. I would recommend this to anyone who doesn't mind bending/flaring some brake lines. The ability to tailor brake bias to what you want rather than what some GM designer decided worked well is the way to go.

Slayer2000,
If you cannot develop the proper force on the front discs you will probably have weak braking. The LS1 pistons have greater area than the stock calipers so all other things equal, you should develop more clamping force from the front calipers. This could affect brake bias (an adjustable proportioning valve would sure help this). My theory is that the greater LS1 piston area will give you a lower brake pedal than the stock calipers because more fluid is required to move the larger pistons. I'm not sure how much lower though. Of course us 4 wheel disc guys are used to a low pedal anyway because of those poorly designed rear calipers.

z28cdoyle · 10-27-2003, 10:03 PM

Maybe you guys already know this, but I thought I'd mention it for those who don't. If you are making your own caliper mount brackets, avoid creating sharp corners. This is important on the section of the bracket that curves around the 2 outermost bolt holes. Get out the file or grinder and round off these corners instead of leaving them at a right angle.

I learned about this earlier this year when I found the torque arm bracket on my 9" rear was cracked. I took it to be welded and 3 different guys at the machine shop all commented that it was poorly designed because of the right angle corners at 2 locations. Those right angle corners are exactly where the bracket cracked. By the way, this bracket is 1/2" thick steel.

z28cdoyle · 10-27-2003, 11:11 PM

OK guys, could someone explain the spindle mods one more time?

I checked out the pics on page 2 of the C4 thread as 89 IROC Z suggested but there are a lot of pics. I do not know for sure what ones to look at.

Do we cut off the steering stop or not?

I thought I saw a page with detailed spindle mod photos somewhere. It had photos with "cut here" lines drawn in and maybe tips for what not to do. Does anyone else remember seeing this?

I hope I'm not beating a dead horse here, but I am hoping to mod my existing spindles correctly without ruining them.

Chuck

PF Flyer · 10-28-2003, 06:28 AM

Chuck ... if you can keep the stops in place, do it.

Does this mean you already have the car apart and won't coming to Summit Pt this weekend?

Mike

slayer2000 · 10-28-2003, 02:48 PM

z28 doyle, Go back to the c4 link on this page and go to the 4th post down by alloy. There's a pretty good pic of the back of the spindle. the steering stop is on that spindle so I guess you should leave them alone. I am going to try to contour mine a bit closer and smoother so my caliper has plenty of room.

89 Iroc Z · 10-28-2003, 03:23 PM

No you need to cut off the steering stop.

z28cdoyle,
Go to the c4 thread as I said above I posted pictures of the spindle modification. I didn’t post any other pics of the spindle modification in this thread so it should be straight forward.

slayer2000 · 10-28-2003, 04:47 PM

my bad, I looked at the wrong pics.

z28cdoyle · 10-28-2003, 08:47 PM

OK guys, thanks for the advice. I see the pics you are talking about 89 IROC Z. I think tomorrow after work I will fire up the reciprocating saw and grinder and start cutting.

Mike,
I won't be running at Summit this weekend. I was at beaverun the last weekend in September and incinerated my brakes. Instead of replacing rotors and spending the entry fees for another track day I decided to put the money into the LS1 swap and call it a year. I'll be back next year with some real braking power for the front straight at Summit.

PF Flyer · 10-29-2003, 06:38 AM

Chuck - sounds good. Sent you email.

Mike

ebmiller88 · 10-29-2003, 12:28 PM

I "think" the stop CAN be left alone, or have minimal adjustments made to it, with the LS1 stuff, but on the C4 system it must be removed. I just haven't got another set of spindles to try it yet.

Ed

slayer2000 · 10-30-2003, 11:24 PM

oops! I already cut mine off.

what exactly will happen if anything without those stops? Also I was wondering instead of using 1/16 spacers if you could just make the bracket 7/16? I'm planning on using flathead cap screws and countersinking them so bolt clearance shouldn't be a problem. Am I missing anything here? I also got a 98 firebird master cylinder cheap so when it gets here I'll look at how it fits(line fittings and so forth) and I'll let everyone know what I find out. I'm going to try out my stock mc first just to see what happens but if anybody gets this done before the next 2 weeks or so I'd like to hear about it.

ebmiller88 · 10-31-2003, 07:49 AM

Quote:

oops! I already cut mine off. what exactly will happen if anything without those stops?

It's been debated, but unless you turn hard left or right, and THEN hit a curb, nothing will happen. The lowest bolt head will take the place of the stop. Only a SEVERE hit will damage the bracket, but all you'd have to do would be to replace it and you'd be back on the road. I SERIOUSLY doubt much will hurt the 3/8" thick bracket...it's a bonzer!!

Quote:

Also I was wondering instead of using 1/16 spacers if you could just make the bracket 7/16?

Again, 7/16" is really overkill for bracket thickness and would be a bitch to cut and drill, unless you have it lazer cut then I guess it would work. My brackets will stay 3/8". Good idea on the countersinking idea. I thought of that but decided not to. I do want to refine the design to do away with the need to make clearance there though.

Ed

z28cdoyle · 10-31-2003, 10:44 PM

I have one side of my car almost finished. I am still using my mock up bracket made of plexiglass but it is working well enough to decide where holes need to be and where to grind for clearance. For anyone making their brackets, the plexiglass is nice to use to get a pattern to make your real bracket. Easy to cut/drill, and transparent to see where the holes have to go.

I used the bracket drawing posted by 89 IROC Z. I moved the holes for the caliper carrier a little. I spent a lot of time tweaking the position of the carrier so the brake pads were contacting the rotor face properly along with leaving as much clearance as I could get from everything else around the caliper.

Steering stop
I cut mine off. I tried to find a way to leave it on but I just do not think it will clear the lower caliper carrier bolt. Maybe if you use an Allen head bolt you could leave it and just grind for clearance.

You may not need it anyway. On my car the steering stop on the A arm still contacts the bottom arm of the spindle about 1/2' forward of the bracket bolt. The steering stop on the A arm seems to be mounted at an angle such that it was never really contacting the extension on the spindle that we cut off for this mod.

I think you could fab another stop easily enough to replace the one that was cut off.

ebmiller88 · 11-04-2003, 06:44 AM

Quote:

Also I was wondering instead of using 1/16 spacers if you could just make the bracket 7/16?

Note how Baer also uses "spacer washers" on their 9 bolt brake system backing plates in the thread below. They weld the washers to the plates and then "cad" plate them for protection. These plates go for $150 if you buy them outright!!!

http://www.thirdgen.org/techbb2/show...hreadid=207413 (PBR Brakes for a '89 Aussie 9bolt Rear in '91RS)

Chuck, how's the swap going?

Ed

z28cdoyle · 11-04-2003, 10:02 PM

OK guys, I don't understand what went wrong. I finished my final bracket tonight out of 3/8" steel. It looks real nice but it won't work because it is too thick. When I bolt this up, the caliper carrier is touching the rotor even without the spacer washer Ed mentioned. WTF? The only option I can think of now is to start all over again with a 5/16 thick bracket and no spacer washers. This may center the carrier over the rotor. I may even have to go all the way down to a 1/4" bracket with spacers...boo!

Any ideas what happened?

Oh by the way, with my other development bracket I tried the setup in my 16" GTA wheels...bad news...the caliper rubbed the wheel. It was rubbing on the honeycomb part of the wheel not the weld bead. I think with new brake pads this may be a big problem since grinding the stiffening ribs on the caliper won't help here. Lots of clearance witht the 5 spoke IROC wheels though. Looks like the GTA wheels will have to go on Ebay.

slayer2000 · 11-04-2003, 11:54 PM

At least you guys got that far. I can't find a piece of scrap steel to save my life! I did find the 12mm 1.75 flathead capscrews at a fastenal dealer. I have everything else ready to go except for that and some paint. This may take me a few weeks

. z28cdoyle, I may have the same problem. My mockup bracket is 1/4 thick cardboard and 2 1/16 washers and it looked a little close. I hope I just made a mistake but if I can I'll see if I can find out something this week.

385LT1 · 11-05-2003, 06:21 AM

Um..... guys..... we are not suppost to post ANYTHING that has to do with 4gen f bodies, its against the rules....

ya..... i got yelled at for sharing 4th gen info.... sorry about the bad news... this is a third gen only site...

MrDude_1 · 11-05-2003, 08:06 AM

Quote:

Originally posted by 385LT1
Um..... guys..... we are not suppost to post ANYTHING that has to do with 4gen f bodies, its against the rules....

ya..... i got yelled at for sharing 4th gen info.... sorry about the bad news... this is a third gen only site...

haha... we get the point. dont post this crap in every thread mentioning 4thgens jsut because one mod was a stupid **** to you.

slayer2000 · 11-05-2003, 10:16 AM

Since we're talking about modifing 4th gen parts to fit 3rd gen cars I doubt it'll be a problem.