UltRoadWarrior9

So being an underachiever, I've wanted to put a Corvette multi-piston brake system on my 1986 IROC, front and rear. I've wanted it real bad. Let me explain the progression of this desire...

Last month I swapped out the original 2.73 drum brake rear axle for a 2002 Camaro SS 3.23 Auburn posi I purchased from eBAY for $325. Add $160 shipping from CO it was a great deal IMO. It arrived 5 days later. It's in there.

At the same time, swapping out the original 245 45 16 tires and OEM rims for 295 30 18 in the rear and 275 35 17 in the front. There in there.

Tons of threads here for the C6 Z06/C7 Z51 brakes. But they only fit 18"+ rims in front.

So this thread is meant for 17" rims in front and 18" rims out back since I can fit a wider 17" tire in the front than an 18".

Pics to come...

UltRoadWarrior9

Front (ugh, I'll paint that 2" spacer black):

UltRoadWarrior9

Rear (2002 Camaro SS 10 bolt Auburn):

UltRoadWarrior9

Now these are going on. With the help of BigBrake Upgrade. I found these Calipers on Ebay (I wish they were Red). BBU will supply front spindles/hubs/bearings/SS brake lines and caliper housing adapters.
I'll have to find the rotors and pads.

the_hamturdler

Wait, so you can fit the front calipers in a 17" wheel?? I'm extremely intrigued. How much did you pay at BBU?

kairles

iTrader: (2)

Calipers look similar to the V1/SS brembo's. Are you going with the standard 12.6" rotor or the Z51's 13.5" rotors?

UltRoadWarrior9

The 12.6" rotors for the Base 2014 Vette will fit inside 17" rims. The Z51 option has 13.6 rotors. There's also Z06 & Z07 options. Read about it here:http://bigbrakeupgrade.com/C7.htm

If you're lucky, you will find Vette owners selling their Base calipers on ebay because they upgraded their own brakes. I got mine from a guy who put 1230 miles on his 2015 Vette for $1075. They should be here this week.

I've been in contact with Scott over at BBU and he's sending me all the hardware to adapt these Brembo's to the stock front and hardware for the rear axle which is from a 2002 Camaro SS, a 10-bolt Auburn posi. All I'll need are the rotors and pads.
Scott was nice enough to send me all the part numbers too.
$385 for the front kit including spindles, hubs, bearings, seals, dust caps.
$59 for the rear adapter brackets and hardware.
I also opted to replace all original brake hoses with stainless steel lines.
$100 core charge for spindles.

UltRoadWarrior9

Got the Brembo calipers today. They're rather large, although not too heavy... I'll weigh them for sh*t's. 26lbs total for all 4.

UltRoadWarrior9

Got the parts from BBU about a week ago. Finally had some time to partially assemble the SS brake lines. You can see all the parts in this C7 partial kit, in addition to the calipers I got from Ebay.

Ordered the front Rotors and pads a couple days ago, they should be in before the weekend. $275 for pads & rotors + shipping. Then I'll be able to check caliper/rotor/pad fitment this weekend.

Ran out of money, so the rear pads & rotors have to wait awhile.

UltRoadWarrior9

Front rotors and pads arrived today. Fitment seems correct so far. I'm in no rush as I have no $$ for rear pads and rotors yet.

UltRoadWarrior9

Ordered the rear pads and rotors 2 days ago. Rear rotors were ~$100 apiece. F'in 2015 Corvette Base rear pads only available in AC Delco, were $122 + shipping for the whole thing. Should be here by monday.
I was going to wait and pay off the credit card bill, but what's another $350? So I ordered rear pads and rotors.

I did this so at least I could have it on the road and test the C7 setup with original 1986 brake master cylinder and the original proportioning valve.
More pics tonight....

UltRoadWarrior9

There seems to be a small variance in shims needed behind the hub. Scott from BigBrakeUpgrade recommended .075".

Although the rotor would spin freely with everything assembled, I thought it brought the inner pad noticeably closer than the outer pad. Scott sent me a few more shims and a new castlenut with some cotter pins, so I could experiment and get it where I wanted it. Yes, free of charge! Understand though, I am only his 2nd C7 customer. So in appreciation of the love of 3rdGen Camaro's, I'm here to share what I've learned.

For the partial C7 kit I received, I found a spacing of .175" to be very close to ideal for both spindles. With the caliper pistons fully retracted, the rotor secured to the hub with the 1" spacer as shown in the pics and the caliper bolted down, the rotor was free to spin with an air gap of about .025" from the pads on both sides. Hint: Do NOT rely on the single small hex bolt that holds the rotor in place on the hub! Use a spacer, like in my pics or 'open' lug nuts tightened down securely.

You have to have a good eye, but you can even see the difference in the airgaps on the left & right pads on each of the front calipers. It looks like less than .020", so I'm not too worried about that variance at this point. Again, this is with the pistons fully retracted with the whole front assembly off of the vehicle, i.e. calipers/pads/rotors/hubs/spindles and with the .175" shims behind the hub.

UltRoadWarrior9

I may be able to mount these assemblies tomorrow at the shop. If not this week, possibly next week.

Here's the front C7 brake assemblies with modified spindle + C7 Base brackets from BBU and SS brake hoses. I purchased the calipers from Ebay. Pads & rotors from Rock Auto. I choose the 1" spacer because it looked like any decently made rim would clear the caliper. And I painted it black.

UltRoadWarrior9

I say decently made rim, because I like the original 1986 16" IROC rims and they fit on top of the 1" spacer without any clearance issues whatsoever.
I'll be sure to take some pics of these original rims on the new brake setup before I install the black Z06 17" rims. Years ago, I would've gone stealth and favored the original look. But being performance oriented, I need meat on the ground and wide low-profile tires can't be found in 16" variety anymore, unless they're slicks and $$$.

UltRoadWarrior9

Some pics of the 17" Z06 replica rim with 2015 C7 Base brakes on the front with the 1" spacer. Plenty of space...

I'm currently using a 2" spacer up front with the stock 1986 IROC brake setup, so this will be interesting to see after mounting the new C7 setup up front what spacer I'll need to place this wheel just slightly inside the top of front quarter panels.

UltRoadWarrior9

If you want to see the original wheels with spacers I was experimenting on another thread:https://www.thirdgen.org/forums/auto-detailing-appearance/717038-wheel-spacers-4th-gen.html
That was with the original 9-bolt rear though.

Expecting the rear 2015 C7 rear rotors and pads today. It's going to be interesting because the parts numbers differ for the rear rotors on the 2014 C7 Base and the 2015 C7 Base brake system. Both years have the same caliper & pad part numbers for the front and rear. My guess is that there might be a difference in the finish or the properties of the metal in the rotor.

UltRoadWarrior9

2015 C7 rear rotors and pads won't be in until tomorrow. Will check and compare part number discrepancy then.

One thing I am starting to worry about is a post I read here:https://www.thirdgen.org/forums/brak...ml#post5810848 by John (87350IROC) about 5th Gen Brembo's and the axle play in 3rd & 4th Gen Camaro Axles. I have a 4th Gen 10-bolt Auburn axle from a 2002 Camaro SS, and there is quite abit of movement in the axle. After jacking up the right rear side of the car, I would dare to guess it's almost .090" of movement!

UltRoadWarrior9

All parts are in for the C7 conversion. I'll have more pics during installation. Gonna make this happen within the next week.

I'm also bringing the original IROC rims and the spacers I bought for comparison pics for an original 1986 IROC look versus my dark theme. Hopefully I can make something work there with the hardware I have.

I have nothing to add on the part # discrepancy on the rear rotors. The 2014 & 2015 rotors appear to be the same and searches on the internet turned up no useful information either.

UltRoadWarrior9

The front brake install was simple and went smoothly. I swapped out the entire old system including spindle with rotors/pads/calipers/brake hoses. Took about 1 hr on a 4 post lift at work with the jacks under the LCA's.

These following pics are with a 2" spacer. When I can afford it, I'm planning on 1.75" spacers.

The only other spacer I have is a 1", and that doesn't clear due to the arm of the spindle that attaches to the outer tie-rod. I wish that could be brought in about a 1/2" for my 17" rims. Or maybe a spindle from a different vehicle would work better?

It brakes ok at low speed straight line braking with the original Master Cylinder and proportioning valve from 1986 meant for rear drum brakes. I'm not daring to test high speeds yet, until I get a 98-02 LS1 master cylinder, part #18060784. Then more tests to mod the original '86 prop valve.

Tomorrow I'm doing some tests after installing the rear C7 calipers/pads/rotors. Today I get some axle c-clips from Jeg's to tighten up the axle end play. While I have it on the lift, I'm gonna check the body to tire clearance for 1" lowering springs for the front and rear.

Also, I'm going to get rid of the red ring and probably get grey IROC-Z center caps. I had originally envisioned putting on the C4 red calipers. Also, the original lug nuts need replacing!

paul_huryk

Why don't you just move up to a set of 275-40-17 tires on all 4 corners?

A few companies make direct fit wheels that won't need large spacers: CTW Motorsports, Ronal, Hawk's...

UltRoadWarrior9

Since I have 18" rims on the rear, I've actually been thinking about putting 18" in the front as well. It looks like 18's would clear, it'll be one of the fitment tests I do tomorrow...

Tomorrow, I'm going to try alot of swapping to see what works and what doesn't with these new rims. I'm also bringing 2 front and 1 rear original 16" IROC rims with the 245 45 16's to see if I can get them to work with the 4th Gen disc rear axle and the C7 brakes.

UltRoadWarrior9

The original 1986 IROC rims didn't fit so well, especially the fronts. I'll need more time to test the fitment. I was in a rush because I had spent an hour dealing with a broken pinion shaft bolt.

Also, I found out why the axle endplay seemed a little excessive. I estimated between .060"-.090". The hole in the carrier meant for the pinion shaft is wallowed out!

It's very common for these bolts to break, and they usually break with a half thread still left on them so you can't just get a small magnet and pull the remains out. Long story short, I had to grind away some metal on the carrier and hammer the shaft out from the opposite side. This pic is with a new bolt installed after hammering out the old remains. You can also see the wallowed out pinion shaft hole.

Now the reason I was concerned about axle shaft endplay is because with these C7 calipersbolted in place, the rotor would drift in and out thereby pushing the pads and pistons back into calipers. Then the next time the brake pedal is pressed the pedal would go more to the floor because those pistons would have to be pushed out further to compensate... I drove it, turned corners, and even with the excessive endplay in these axles I didn't really notice any pedal 'fading'.

UltRoadWarrior9

Pics of old setup, yawn. And more bad news. Axles are pitted. No noise yet, but a new rear end is in the future plans. I think this diff can still handle the original 190HP from a 1986 IROC 305 ugh...

UltRoadWarrior9

13.3" rotors and caliper installed on the right side. Notice where I had to put my shims for clearance on the 2nd pic. Those caliper mounting bolts are long! Make sure they don't hit the rotor after tightening! Scott mentioned that the shims go in between his bracket and the caliper, which could be so. I might just be a bastard case with this axle.
BTW, I reused the original bolts that mount BBU's adapter plate to the axle housing. They're abit longer than needed which is ok since no interference issues, but the original bolts are higher strength metal.

UltRoadWarrior9

18" Z06 replica wheel installed, no problems. About 1/2" clearance from edge of rotor to inner part of rim and 1/2" clearance from front face of caliper to back spokes of rim.
Red ring on rim almost gone. Yes!

UltRoadWarrior9

Now onto the front 17" rim issues. I know now 17" rims are a mistake!! I wish to share why.
Here's a pic of the right side. Problem area is where the outer tie rod connects to the spindle. This is with a 2" spacer in order for clearance. 1.75" might be more acceptable but very close. The tires are 275 40 17.
Anyway, for comparison I put on the 18" wheel I had on the other side of the left rear on the right front to check clearance. What a difference! The spindle is now sitting inside the rim, no issues whatsoever there.

UltRoadWarrior9

Now pics of the clearance of the right front with a 295 35 18 on there. Too tight!
It wasn't rubbing on the lift, but most likely will rub on the road. I will have to investigate this setup further. The rubber was millimeters away from the strut and during turning very close to the LCA and front sway bar. Pics are left & right max.

PAFORM350

Damn nice setup

UltRoadWarrior9

Here's a pic of the IROC with 2 sets of 295 35 18's on the right side, identical offsets, front and rear rims and 1" spacer up front. Remember, 4th gen axle in the rear with no spacer and C7 brakes. It looks real good IMO!

And a final side view... Hope this inspires some of you! I've seen 2015 and 2016 Vettes and they are inspirational! We must take their parts! (The final side view was with the 17" wheels in front and 18" wheel in rear)

greezemonkey

iTrader: (14)

That last picture (side view) says it all...great work! hows it perform vs the factory stuff?

UltRoadWarrior9

Thx. Still a work in progress. I have a replica C6 Z06 front wheel setup (from eBAY)on order, should be here this week. Instead of the 275 40 17's, which have outer tie rod interference issues, I ordered 275 35 18's for the front to match the 295 35 18's in the rear. 10.5" wide rear rims, 9.5" wide in the front rims. Identical offset of 56mm for front and rear rims.

UltRoadWarrior9

Sorry greezemonkey, I didn't really answer your question!

Currently, with the stock '86 prop valve w/no mods and original master cylinder meant for rear drum brakes on a 10-bolt 4th gen disc rear diff and the C7 Calipers/Pads/Rotors it stops noticeably better, but more work needs to be done. I sorta feel a nose dive when braking moderate to heavy. But I did my wheel swap the same time I did the C7 brake swap, so it's hard to tell if the nose dive is due to the car sitting higher. What I would like to do is measure the temp of the front and rear rotors with an IR laser temp gun.

When this thread continues, I'll post 1 pic of the final tire/rim setup. I got the rims and tires in today. Also, temps of the rotors after several 60-0 stops, which is highly subjective, but it will give an idea of what the original setup is doing with the C7 gear on there.
Then to keep the thread on topic, I'll continue posting after I get a 1LE Master Cylinder, get rid of the proportioning valve, T the front brake lines to the MC, and add an aftermarket adjustable proportioning valve for the rear calipers.

UltRoadWarrior9

Nothing is ever easy is it?!

Thought I'd try to do a quickie install tonight...

Had an issue fitting the 275 35 18s on the 1" spacer because the studs protrude too far from the BBU hub (no complaints). I'll have to cut the studs down tomorrow.
With the 2" spacer for the 17x10.5" rims and 275 40 17s was no problem., although the rubber was just a tad past the fender.

Will have pic tomorrow of the inside of the 18x10.5" rear rims. They fit perfect on the hub with the1" spacer during initial fitment.

UltRoadWarrior9

Final look as to why I didn't like the 17x9.5" 275 40 17 setup up front w/2" spacer. To correct this issue I decided not to spend money on a 1.5" spacers and have the rim less 1/4" away from the outer tie rod. I spent the money on an 18x9.5 275 35 18 setup for the front w/1" spacer. Pics to come...
Passenger side is cambered in more than the driver's side. That's why the driver's side tire is sticking out more. I'll fix that after new adjustable struts and 1" lowering springs.

Height comparison pics too 17" front 18" rear.

UltRoadWarrior9

18" wheels all around now. Height still the same due to the 17's were 40 profile and 18's are 35.

UltRoadWarrior9

Also, on my way back from working on this I did a temp test with an IR laser temp gun after 4 moderate braking stops from 60-0 to test the C7 brakes and got readings of 272 degreesF for the front and 201 degreesF for the rear. Not too bad for original MC and prop valve but still needs adjust.

Couple last pics of the car inside the bay. Lighting is too dark though. Dang, I lost the pic from the other angle!

UltRoadWarrior9

Final spec's:
1986 IROC Z-28, OEM suspension
Front & Rear Calipers, Pads & Rotors from 2015 Corvette Base brake system.
C7 Upgrade Kit from BigBrakeUpgrade including preassembled spindles, hubs, bearings and adapter brackets and SS brake lines all around.
Rear axle from 2002 4th Gen Camaro SS.
Rear Rims are 18x10.5" Black Corvette C6 Z06 replica rims, 56mm offset.
Rear Tires are Continental DWS 295 35ZR 18.
Adjustable rear panhard bar from Spohn.
Front Rims are 18x9.5" Black Corvette C6 Z06 replica rims, 56mm offset.
Front Tires are Continental DWS 275 35ZR 18.
1" billet aluminum wheel spacers for front.

Some final pics of the setup in good light:

dannyboyemt

Looks really good! Fitment looks amazing.

BBU.COM

Nice Work Sam ! You did a really great job of documenting your conversion, I was glad to be able to help!

UltRoadWarrior9

Thanks!

I'm actually sorta cautious to push this setup on cornering until I get my UMI sub-frame connectors welded in. It was the first bit of money I spent on this car after I bought it for $500. And the sub-frame connectors are just sitting in my garage.
But right after I did the brake rotor temp test on a lonely country road, I did a launch from stop and that Auburn posi and those rear 296 35ZR 18 tires grip! I swear I was up to 60 mph in about 5-6 sec's. Quite a change from a peg leg rearend with 245 45 16's!

A few final pics. I had forgotten to post some clearance pics like I did when I had 1 of the 295 35ZR 18 on the right front, which was too tight for comfort IMO.

First, the studs on the hub were cut down so the 18" rim fit flush against the 1" spacer. Then the spacer lug nuts torqued to 100ft/lbs. Probably should've used a thread lock like lock-tite, but I've never had a problem since I'm real cautious in torquing wheels. I did use lock-tite on the caliper bolts.

UltRoadWarrior9

Car was running, turned the wheel all the way to the left, then just let up abit to ease up pressure from the power steering pump. Then locked the steering wheel. Raised it up and took some pics. LEFT MAX Clearances are left and right tires. Was difficult to take a decent pic of where the tire came close to the strut, but there was about 1/2" clearance there as well

UltRoadWarrior9

RIGHT MAX. Right tire only. Forgot to take pics of the left side. Got interrupted and lost my train of thought.

scooter

iTrader: (11)

100 lbs is a lot, I think it's only suposed to be 85 for the M12 bolt (or something like that)

UltRoadWarrior9

I got my info using Mitchell on Demand and it said 90 ft/lbs for the aluminum wheels and 80ft/lbs for the standard wheels is the spec. I figured 10 more ft/lbs couldn't hurt especially since I'll rarely take off the spacers now AND they are spacers and not the rims which the spec is meant for. Also, I used 100ft/lbs for 19mm spacer lug nuts and 19mm wheel lug nuts.

Just FYI, the caliper bolts I torqued to 120 ft/lbs because they were 22mm bolts. I couldn't find info on the proper spec's since 2015 Corvettes are so new. Plus this is a mod, so one has to consider that...

BTW, thanks for double checking me scooter because this is a safety issue. I looked up some specs for common size steel bolts I got from www.engineershandbook.com for common reference so at least someone can be within an acceptable range when doing this kind of work.

scooter

iTrader: (11)

I guess if you're not taking them off frequently it could be OK, but it CAN hurt by fatiguing the bolt/stud. There really is no need to go outside/above the range. If I dont know the torque either, I will look up the fastener for the size and use the middle to the bottom of the range

IROCgiraffe

iTrader: (3)

Those brakes look Great!

PAFORM350

Nice job! Looks awesome.

TPI TERR

iTrader: (9)

They look great . Any pics of the rear conversion ? Any way to have the e brake working ?

UltRoadWarrior9

I do. Check out post #23 & 24.
As for the parking brake, you will have to ask Scott at BigBrakeUpgrade.com and see if he has plans to make the hardware. I chose not to pursue the parking brake. 7 more years here in NC and my '86 IROC will be considered a 'classic car' and will not need a state inspection.

BBU.COM

Absolutely, I have a parking brake for these Email me for details