ebmiller88

iTrader: (7)

I finally got it done today. Everything went pretty well except for reinstalling the stock springs...those things are a bugger to get back in the pocket, MUCH harder than the Eibachs I did last time. I haven't taken it out for a road test yet but I will tomorrow morning when I take it to get an alignment and I'll give a full report tomorrow night.

First off I must thank all the guys who did a LOT of footwork to get this thing going: Luke (89 Iroc Z), Dan (alloy/machinist), Todd (toddlsf), Colt, Scott, AJ, and others.

Luke, that bracket design was spot on...fits perfectly. Pics to follow and more will be posted on my webpage this weekend.


Ed, stoked....

ebmiller88

iTrader: (7)

Here's a shot of my only concern. I thought spacers may be needed but the caliper carrier does not touch the rim at all, it's a great fit.


Ed

ebmiller88

iTrader: (7)

Finished product:

C4 REAR rotor, 3/8" stainless bracket, stainless hardware, braided lines, "new" KYB GR-2 struts...(Thanks Tom K!!). I have no idea what type the pads are, they came with the calipers I bought.


Ed

alloy

iTrader: (16)

Great job Ed

MrDude_1

so how does she stop?

any diff in pedal feel?

what about the front to rear braking porportion? is it far off now?

does the pedal go down alot farther?

metalhead212121

ebmiller88~ Congrates on the install! How hard was it to do? Also...how much $ did that set you back?

Dan

Justins86bird

:sillylol: :sillylol: Looks like you'll need an upgrade soon

Good Job

LT1Powered85Z

So why the uproar over the C5 stuff that you directed towards me, if you had no intentions of doing such a swap?

Not only that, but where'd that thread go? I post pictures and it disappears. Hmmm...

Congrats on upgrading though...you'll like the C4 stuff a lot more than stock, no doubt.

Eric

Dewey316

congrats ed

next weekend i am doing the c4 brakes, and few other upgrades i am actualy going to install my HMS mounts too, so it looks like you will be the very last person to install 'em

alloy

iTrader: (16)

https://www.thirdgen.org/techbb2/sho...hreadid=193983

ebmiller88

iTrader: (7)

Just got back from the alignment. What a difference:

1. She stops great, much more responsive than the iron caliper system. I haven't done a panic stop yet but I know it will perform well.

2. Much firmer pedal feel. I don't know how to explain it, but it's different. I already had braided lines on it so that's not the factor...it's just firmer.

3. I don't know how to measure that without throwing it on a machine or doing a panic stop to see how the back brakes will do. Hopefully I'll learn more about the front/rear proportions and post more later.

4. No. It feels like it stops further up actually, but it's probably a combo of firmer feel and new calipers


Ed

ebmiller88

iTrader: (7)

Thanks, Dan. The hardest part (for me) was reinstalling the stock springs. Even with a compressor I had a hell of a time. I tried both recommended install procedures: using a compressor and using a jack with the ball joint bolted up...what a pain that was. I eventually got them in with the compressor, a big pry bar, and my foot.

Here's my price breakdown, give or take $10 or so:

$150 shipped: C4 front AND rear rotors, front loaded calipers, caliper pins, caliper carriers, and carrier bolts (www.corvetteforum.com)
$50: inner and outer bearings and seals, Timken and Federal Mogul
$5: New brake line crush washers and new cotter pins (Auto Zone)
$15: Bolts at Lowe's, M12x1.75 (4) and M14x2.0 (4)
$25: ARP studs, P/N ARP-100-7708 (2 sets, 10 total)
$7: New GM banjo bolts for calipers, same as 1LE, P/N 10286122 (2)
FREE... I.E. I did them myself: spindles, hubs, and adapter plates

TOTAL: $252


Ed

ebmiller88

iTrader: (7)

I hope you don't feel as if I steered you wrong or something. At first, I was VERY interested in the C5 upgrade but that almost definitely involves going to 17" wheels which I did not want to do at this time. I still think that's the way to go if you're already running 17"s or plan on going to 4th gen wheels. That's my first reason. Second, I already had the parts purchased and didn't want to go through having to sell mine and then turn around and buy more stuff, the hassle wasn't worth it.

I do recommend the C5 or LS1 brakes for a great upgrade, they look swesome especially if you go with the red Z06 C5 calipers. But, as you can see, for the same brakes as a "Baer" style upgrade for MUCH less jack, go with the C4 upgrade.


FYI:

A Baer "Sport" system, using 12" x 1.1" rotors is $965 with a $150 core charge for your spindles so they can mod them. I spent $252...I can make 3.8 "Baer" kits for that amount money.


Ed

fly89gta

iTrader: (1)

Congrats man!!! I will be doing the same thing over the winter after the motor and tranny are done being rebuilt..I'll have the speed after that..I'll then need to stop

alloy

iTrader: (16)

This has to do with less piston area the C4 calipers have. You will have less pedal movement and have to push harder on the pedal to get the same force on the pads with the smaller piston area. I noticed the same thing when I put the C4 brakes on my car.

TomP

That's awesome, Ed, congrats!

LT1Powered85Z

You misunderstood me. I am the person with the C5 brakes that you tore into and called "BS" on because I didn't post blue prints and I guess because I pissed you off.

Remember me?

I posted pictures and the like and backed up everything I initially stated, and the thread magically disappeared.

You didn't steer me in any direction, well maybe a negative one in regards to how I think of you...but that's a different story.

Eric

SLP_GTA

iTrader: (1)

where do you get the brakets? also do you do the same spindle mod as the 1LE?

Looks good, and just to confirm, will the C4 brakes fit under the GTA wheels, In additon the rotors look like stock 1LE are they?

alloy

iTrader: (16)

Read ed's post carefully. He is using C4 front calipers, and C4 rear rotors. Not 1LE parts.

Additionally, if you read the 1LE alternative/C4 thread, you will see that I tried a 1990 15" 5 spoke stock wheel over my C4 brakes and it cleared easily. There should be no reason the C4 brakes won't clear a GTA wheel.

ebmiller88

iTrader: (7)

Oh, hello Eric. It's OK that we might not see eye to eye. I was indeed a bit pissed that you seemed like you didn't care to help the rest of us out when we were trying to figure this out, and I can't remember if I asked you for pics or not. Whether you posted them or not, I don't know...the whole thread disappeared for reasons I don't know before I saw them. Yeah, I went off on you, but that's how I felt. I ranted because you chose not to give input where (I felt) it could have been used well by the rest of us. And I stated the reasons I went with the C4 brakes.

I'm usually a laid back, relaxed, easy going guy but you touched a nerve there. No hard feelings, and if you would, could you post another pic of your C5s?


Now, SLP_GTA:

As Alloy noted, reread what I posted and also check the "1LE alternative" thread. I listed what parts I used there also. I made the brackets "by hand", drilling the holes on a drill press and cutting the brackets on a band saw. The spindle mod is the same as the 1LE mod except you also cut off the lower part of the steering stop that sticks down from the spindle. The rotors are REAR C4 'Vette rotors, not the 1LE rotors. Here's a pic:


Ed

metalhead212121

I hate to ask but now that one brake thread has "disappeared" how does this C4 setup compare to the LS1/LE1/C5 setup? I am very interested in doing an upgraded brake system but Im still kinda bewildered by what setup I should go with...

metalhead212121

now correct me if Im wrong but Eb but isnt that a picture of the front rotor???? can you post pics of the rear??? Im very interested in the parking brake set-up.

Dan

Project:IROC-Z

UNBELIEVEABLE! C4 brakes on a Thirdgen. You guys are incredible, I applaude everyone involved in making this happen. You guys deserve a ton of credit!

ebmiller88

iTrader: (7)

You're correct, Dan. The pic is of the FRONT brakes, but I used the 'Vette REAR rotor, get it? The Vettes have two different rotors for the front and rear, and they have different offsets. I posted a pic of the two together in the "1LE alternative" thread. I could have used the front rotor but the adapter bracket would have been thinner. Using the rear rotor allows for a 3/8" thick bracket and no special machining required...it all just bolts up.


My decision to go with the C4s was wheel size...I wanted to keep my factory 16" wheels. If you have 17" wheels, go with the C5/LS1 front brakes.


Project: Contact Alloy off forum for the brackets, he may have a set. I don't have any 3/8" brackets ready at the moment.

(No advertising intended...)


Ed

Project:IROC-Z

A couple of questions if I may. One the wheel studs you are using look very long do you think they might interfere with my 89 lug nut covers (you know the black plastic things that cover the lug nuts). Two I did not want to use braided brake lines so I wondered if thirdgen or C4 rubber brake lines would be an option(just want to keep a factory apperance). Thanx

metalhead212121

Project:IROC-Z~ I dont think anyone can/could see what kinda brake lines you have when the wheels are on and the car is on the ground....

Dan

alloy

iTrader: (16)

The wheel studs can be cut down if necessary. Only takes a minute or 2 per stud. But you must use longer studs.

You can use your standard brake lines with the C4 swap. But considering how much better and safer a braided line is over the 10 year old stock stuff, I'd forget about stock apprearences and go with what's the safest.

Read this thread about C4 brakes and it will answer all your questions on brake lines, hubs, rotors, etc.


https://www.thirdgen.org/techbb2/sho...hreadid=142115

Project:IROC-Z

Thanks for the info.

Parrydise7

iTrader: (1)

Ed,

Didn't you just do the 1LE swap within the fairly recent past? Now this? Wow! Looks great! Was this an easier swap than the 1LE? Any problem with the m/c or prop valve? (If you've answered this in the past, accept my apologies, I just came across this).

ebmiller88

iTrader: (7)

Project, yes the ARP studs of that length will interfere with the black caps. I have the '91 16" alloys with the center caps so it's not a problem for me...no caps. Like Dan said, you'll have to trim the stud a little. Here's another thread where Luke was discussing stud sizes and there are more options out there besides the longer ARP studs:

https://www.thirdgen.org/techbb2/sho...ighlight=studs

Ed


PS- Factory rubber lines will work fine.



PROJECT: Look at the picture in the last post in the above thread. That's what the Motormite studs look like installed and still allow the caps to fit, I'd say go with those.

ebmiller88

iTrader: (7)

Parrydise, yep, I did the full 1LE upgrade on my Iroc last year about this time. This was easier since I didn't have to replace the master or prop valve on this car, and it looks like I won't have to. I drove the car about 80 miles yesterday and the brakes feel great, real good bite slowing down. I have yet to check the parts manual to see which prop valve is used for each system (disc/disc and disc/drum), but I will check and post what I find. Hopefully, I won't "have" to change it out. I already know the master is good...they are all the same '90 and up. I will be installing a 3.42 PBR disc rear sometime in the future and I may have to swap it then.


Ed

89 Iroc Z

Good job Ed,
Great idea of using C4 rear rotors, that sure solved the problem of bracket thickness. For everyone that is wondering about the bracket. The bracket with dimensions I posted in the 1LE alternative thread will only work with C4 rear rotors. I had alloy machine me a test bracket from my CAD file and it fits perfectly. For those of you who want to use C4 front rotors you need to use alloy’s bracket design.

robertg

iTrader: (2)

which rotor setup is better, the rear? or the front?

opinions?

alloy

iTrader: (16)

Use the link I posted for the 1LE alternative thread, read the entire thread through, and make your decision as to front/rear rotors, and 3/8" or 1/4" brackets based on that. If you have questions after reading the thread, then let us know. But for now you are asking questions that you need to know the entire history of before we can answer you.

https://www.thirdgen.org/techbb2/sho...hreadid=142115

ebmiller88

iTrader: (7)

I think people are getting confused here....

Luke, I don't follow you. Your bracket design is perfect for BOTH the front and rear rotor, it works with both rotors. The ONLY difference to consider with the front and rear rotors would be bracket thickness. The rotors are the same width (12") and brake surface thickness (.80 or so) so the only difference is the hat offset. The pic is below. If you use the "shorter" rear rotor, you can use a 3/8" bracket. If you use the "taller" front rotor, you have to either mill a little off the caliper carrier bolt bosses or mill a bit off the bracket. I made 1/4" thick brackets to use with the front rotor and they are just a bit too thick as-is, so I may try to shave a bit off the carrier bolt bosses and see what fits.

Robert, I see no difference in the two except for bracket thickness. I've tried both. IMO, 1/4" thick brackets are plenty thick, but the 3/8" bracket and the rear rotor simply bolt on without machining, and therefore it's easier.


Ed

ebmiller88

iTrader: (7)

Someone last week asked how long it takes to do the mods to the rotors, spindles and such. Since I have installed my C4 kit, I took the time tonight to to the mods to the parts I just took off. I did the spindles and made the rotors into hubs in a bit over 4 hours with a lathe, drill press, bandsaw, and DeWalt drill. Here's what I learned: Dan (Alloy) showed us how to drill the disc ring off, chuck it up and turn it down into a hub here:

https://www.thirdgen.org/techbb2/sho...0&pagenumber=2

What I learned tonight saved me a LOT of time, at least all the time spent drilling holes. Here's what you do: chuck the whole thing up in a lathe, disc surface to the left/motor side and studs sticking out to the right, and make the "ring" cut pictured below your FIRST cut. The whole disc ring will come right off and you won't have to drill all those blasted holes. Then just turn the hub down to 5.8-5.9" and you're done. Sorry I didn't get a pic (no camera) but the next time I do it I'll get one.

HTH...Ed

MrDude_1

OMG thanks... thats fuggin brillant...


i should have thought of that



**puts drill away**

well, i know what i will be doing during lunch tomarrow.....

alloy

iTrader: (16)

I realized that I didn't need to do the chain drilling after my first rotor I did that way. But, and this is a big "but", unless you have a carbide insert parting tool to go in and drop the rotor section off, the drilling is the best way for a "back yard wanna be" machinist to get rid of the rotor section.

If you do have a carbide parting tool holder, then you have to be real carefull when that rotor section comes loose. It can get real ugly real fast. That spinning rotor has a lot of energy stored in it and when it comes loose can do some damage if you aren't carefull.

So just be carefull when doing this, OK?

MrDude_1

mmk, so when the rotor part dropps off on the lathe, what do i have to do so it catches and doesnt fall and fly around everywhere???


or should i just do as planned and drop the rotor part, then take the ring off?

alloy

iTrader: (16)

The rotor is somewhat contained by the live center i nthe lathe chuck, and the tailstock. It shouldn't come out of the lathe completely, but can and will rattle around when it drops off. I broke a parting tool blade on one rotor when the ring came off and hit the tool holder support blade. $26 down the drain on that one. But luckily I have a modular parting tool holder, so I only lost the $26 support blade, and not the $145 holder. So basically You just drop the ring off and hope it doesn't get you or hurt the lathe.

For a novice, I still beleive it's best (and safer) to drop the rotor off with chain drilling. If you have a drill press, you are only talking 1/2 hour for both rotors to do this.

Either way, be carefull.

MrDude_1

i dont want to chance breaking the lathe, so i think i'll just take the time to play it safe and drill and remove the majority of the rotor first...

LT1Powered85Z

First off, I'll touch on what I replied with before, before the thread was deleted.

I rarely check this board (have been more frequently as of this last week and due to being attacked) and I had never seen the thread in question before posting saying I had already been there done that. So when people started assuming that I had been watching it unfold and was "withholding" information proved that people are lame. First of all I'm not required to share ANY information that I have, anything people share is by their choice, so to tell me I was in the "wrong" is BS.

Anyway...

Here's what my set-up looks like. These was taken 1 week ago today, at my club's "Performance Driving Experience" hence the different wheels and the slicks.

Pic 1. For reference...
Pic 2. Disregard the chips in the paint...that's the result of running slicks that are too wide. I had the 18s in the rear and the 17s up front originally and the 17s are over an inch taller and they caught the fender and messed it up. Oh well...gotta get it fixed.

So yeah...there are my C5 brakes. Can't call BS now.

Eric

ebmiller88

iTrader: (7)

Thanks Eric, nice ride you have there.

Public apology: I apologize for going off on you on the boards.

Ed

LT1Powered85Z

Thanks Ed...I appreciate it.

Eric

metalhead212121

so when does this thread and the other thread (LS1 brakes) become stickeys (again)????

Dan

ebmiller88

iTrader: (7)

Hopefully a mod will hook us up again...

Here's the pic I forgot to attach to my post yesterday. The "taller" front rotor is on the left, the "shorter" rear rotor on the right. The difference is a hair more than 1/8" which is why the 1/4" bracket is still just a tick too thick with the caliper carriers not shaved down a bit..


Ed

bigals87z28

Ed, very nice my friend, very nice!!! Never thought about putting vette brakes on... I plan on doing the Baer kit in a few years and maybe fabbing up a 4 piston/2 piston set up... we will see. Right now, trying to pour magic into the 305... ill worry about stopping later hehehe.

Mongoose

iTrader: (2)

Looks good Ed. Appears to be a good alternative to the 1LE setup. A couple of quick questions: First,how does far does the rotor's additional thickness push out the front wheels? Also,is that why you put the stock springs back in instead of the Eibachs you had installed previously-for tire clearance?

ebmiller88

iTrader: (7)

The wheels are only pushed out the thickness of the rotor hat, about 3/16" or so...I havent' taken the rotor hat thickness measurement but I will tomorrow. You can't tell at all by looking at the car and there are no rubbing issues with the wheelwells or GFX.

I kept the stock springs since the RS is my "driver" car and I really don't have that many mods to it...it's only a 305 and I want to keep it close to stock as possible so it's easier to sell when the time comes. Also, the car sits just about as low as my Iroc does with lowering springs so I didn't want any more drop. With the new KYBs I got from Tom K. and all new bushings up front, it rides beautifully.


Ed

Mongoose

iTrader: (2)

I guess I wasn't paying attention. For some reason I thought you did this to your IROC.