Finally got my Z to behave on Track!

[cbaclawski]

This is my 4th thread on the matter in the last year or so, so I both thank those who have helped, and apologize to those long tired of hearing about it!

Car handled beautifully, and boy is it fast! I had a great time driving it!

One caveat though. The stock(but recently replaced) front brakes are just not up to the task of a renowned "brake eater" track like the one I was at. (Carolinas Motorsports Park in Kershaw SC). I was running Hawk DTC 70 pads and Motul 660 fluid, but they still gave up, albeit slowly throughout the day...

I want to upgrade them, but don't want to break the bank as this is not my primary track weapon. Looking at the rotor and the size of the pads, I think I need something with a bigger swipe area.

I have a couple friends, one with stock C5 z06 calipers, and the other with stock c6 z06 calipers that they'd give me for free. I know there is an adapter needed, and I'd need new rotors and pads, but which one would be better performing? Also, will I need a new master, or is there a better master I don't "need" but would "want"?

Thanks as always!

Curt

[Dynomite]

I want to upgrade them, but don't want to break the bank as this is not my primary track weapon. Looking at the rotor and the size of the pads, I think I need something with a bigger swipe area.

I have a couple friends, one with stock C5 z06 calipers, and the other with stock c6 z06 calipers that they'd give me for free. I know there is an adapter needed, and I'd need new rotors and pads, but which one would be better performing? Also, will I need a new master, or is there a better master I don't "need" but would "want"?

Thanks as always!

Curt

Post 41 - ZR-1 (90' and 91') Wilwood Rotors and C4 to C5-Z06 Conversion (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-3.html#post1581564033)

Post 233 - Installation of Wilwood Rotors and C4 to C5-Z06 Conversion (https://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-12.html#post1590759175)

Post 122 - Wilwood C5 Z06 Brake Conversion with Sawblades (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-7.html#post1584987835)

[RussMcB]

That's great (but you didn't tell us what you changed to make it behave).

[XfireZ51]

Depending on what year ZR, u may not need to change brake booster for C6Z brakes. Mine is a 92. A bit pricey but would do both front and rear. Less expensive if u don’t care about eBrake.

[cbaclawski]

That's great (but you didn't tell us what you changed to make it behave).

I am sure the alignment helped, but I'm pretty sure what put it over the top was the real wheels and tire set I got from you!

[cbaclawski]

Depending on what year ZR, u may not need to change brake booster for C6Z brakes. Mine is a 92. A bit pricey but would do both front and rear. Less expensive if u don’t care about eBrake.

Def don't care about eBrake. Would almost prefer not to have it so I don't accidentally set it when it's hot!

[cbaclawski]

Since I first posted this, I went outside and gave it a once over, and noticed a brake fluid leak on the passenger side front caliper at the banjo bolt, and the front fluid reservoir is down about 2/3 way from "max".

I can't imagine this helped. The car was stopping straight, so I really didn't think there could have been a leak on one side, but in retrospect, that would effect pressure in the whole system. In fairness to me, I was managing 2 other cars yesterday(that others were driving). As soon as I get my Draftkings lineups in, I will investigate further.

The remaining fluid still tests fine - so I don't think I boiled it, and there was no leakage in normal driving or during the bleed. I'm assuming the leak started when the temp got high...

Regardless, I'm going to upgrade the calipers. This car will be pretty darn quick with decent braking performance!

Curt

[cbaclawski]

Depending on what year ZR, u may not need to change brake booster for C6Z brakes. Mine is a 92. A bit pricey but would do both front and rear. Less expensive if u don’t care about eBrake.

It's a 90. Based on my research so far, I'm leaning in the c5 direction. looks like all I'd need is an adapter bracket and c5 rotors. (and possibly spacers and longer studs - I have the "salad shooter" front wheels...

Thank you Dynomite for those links, I really don't like drilled or slotted rotors, but it's great information anyway!

[RussMcB]

I'm glad it's working well for you now. That must be crazy driving and supporting 3 cars at once. You're either extremely talented or crazy (or a good bit of both). :-)

That brake fluid leak is encouraging. So, maybe the stock set up is pretty good, but it sounds like you're already excited about the brakes upgrade. Go for it.

So, how are you telling us about these events and not posting pictures?! What do the youngsters say today? "Pics or it didn't happen"? :-)

[cbaclawski]

I'm glad it's working well for you now. That must be crazy driving and supporting 3 cars at once. You're either extremely talented or crazy (or a good bit of both). :-)

That brake fluid leak is encouraging. So, maybe the stock set up is pretty good, but it sounds like you're already excited about the brakes upgrade. Go for it.

So, how are you telling us about these events and not posting pictures?! What do the youngsters say today? "Pics or it didn't happen"? :-)



Well, You've seen my lack of talent firsthand, so that only leaves on option. I invited 3 guys, fully expecting them all to decline, to my surprise 2 said yes and I had to improvise.


Yeah, the leak was worse than it first appeared. I walked outside in the garage late last night just to smoke a cigarette. While I was out there I had the bright idea of tightening the banjo bolt. As soon as I touched it, it just spun freely and started hemorrhaging fluid. Took me an hour to get the bolt out and the fluid to stop leaking out the now un-attached brake line. The bolt looks fine, but the caliper threads are stripped. It's a minor miracle this didn't happen on track.


Because there was too little pressure in the front due to the leak, the rears were working overtime, and I was essentially dragging the brakes all day. Fairly new DTC-70 pads are toast! For now I am going to get a replacement stock caliper and put some street pads on it(all around - which I already have). Since I can get the c5 calipers free, and the rotors are cheap, I'm going to wait to buy new race pads until I do the upgrade. (the pads will cost way more than the adapter bracket and c5 rotors)


I think without the leak, the Stock calipers would have been fine, but since the c5's are free and relatively easy to install, I figure I might as well do the upgrade...


here's a pic just to prove it happened, lol


https://i.ibb.co/n83DTrt/leak.jpg (https://ibb.co/tPZbSBF)

[Hib Halverson]

It's a 90. Based on my research so far, I'm leaning in the c5 direction. looks like all I'd need is an adapter bracket and c5 rotors. (and possibly spacers and longer studs - I have the "salad shooter" front wheels...

Thank you Dynomite for those links, I really don't like drilled or slotted rotors, but it's great information anyway!

Keep in mind that while the C5 brakes are an improvement over C4, from a tracking perspective, it won't be by much. You may find that after all that work and cost of installing the C5 brake discs and calipers, you didn't gain much brake performance, especially if your tracking involves long runs. Also, on C5 brakes, the only difference between a C5 and a C5 Z06 brake is red caliper paint and, if they have OE brake pads, more aggressive front pads.

If you're a serious trackrat with your ZR1, I'd be looking for something a bit more substantial in the front. It may cost more but the return on investment will be greater. You, also, need to add front brake ducts.

As for drilled/slotted rotors, today, drilled rotors are just for looks. The vast majority of modern brake pads do not have trouble with outgassing, which drilled rotors were invented to address. Also, all those holes decrease the brake disc's heat sinking and, unless the drilling is done right, they also can cause cracking. Slotted rotors are a better choice.

Lastly, in re: your second post, about finding a leak in the system. Before I'd sink time and money in to a C5 brake upgrade, I'd bleed the system, stick '96 GS front calipers on the car (a bolt-on), add some brake ducts in front and go track test.

Depending on how you are on brakes during tracking, you could find just having no leaks, GS calipers and better front brake cooling is adequate enough for the tracking you do.

[gtcollins@maxnet.co.nz]

Keep in mind that while the C5 brakes are an improvement over C4, from a tracking perspective, it won't be by much. You may find that after all that work and cost of installing the C5 brake discs and calipers, you didn't gain much brake performance, especially if your tracking involves long runs. Also, on C5 brakes, the only difference between a C5 and a C5 Z06 brake is red caliper paint and, if they have OE brake pads, more aggressive front pads.

If you're a serious trackrat with your ZR1, I'd be looking for something a bit more substantial in the front. It may cost more but the return on investment will be greater. You, also, need to add front brake ducts.

As for drilled/slotted rotors, today, drilled rotors are just for looks. The vast majority of modern brake pads do not have trouble with outgassing, which drilled rotors were invented to address. Also, all those holes decrease the brake disc's heat sinking and, unless the drilling is done right, they also can cause cracking. Slotted rotors are a better choice.

Lastly, in re: your second post, about finding a leak in the system. Before I'd sink time and money in to a C5 brake upgrade, I'd bleed the system, stick '96 GS front calipers on the car (a bolt-on), add some brake ducts in front and go track test.

Depending on how you are on brakes during tracking, you could find just having no leaks, GS calipers and better front brake cooling is adequate enough for the tracking you do.What would be a good setup for tracking the ZR-1

Regards Glen

Sent from my SM-G973F using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[cbaclawski]

Keep in mind that while the C5 brakes are an improvement over C4, from a tracking perspective, it won't be by much. You may find that after all that work and cost of installing the C5 brake discs and calipers, you didn't gain much brake performance, especially if your tracking involves long runs. Also, on C5 brakes, the only difference between a C5 and a C5 Z06 brake is red caliper paint and, if they have OE brake pads, more aggressive front pads.

If you're a serious trackrat with your ZR1, I'd be looking for something a bit more substantial in the front. It may cost more but the return on investment will be greater. You, also, need to add front brake ducts.

As for drilled/slotted rotors, today, drilled rotors are just for looks. The vast majority of modern brake pads do not have trouble with outgassing, which drilled rotors were invented to address. Also, all those holes decrease the brake disc's heat sinking and, unless the drilling is done right, they also can cause cracking. Slotted rotors are a better choice.

Lastly, in re: your second post, about finding a leak in the system. Before I'd sink time and money in to a C5 brake upgrade, I'd bleed the system, stick '96 GS front calipers on the car (a bolt-on), add some brake ducts in front and go track test.

Depending on how you are on brakes during tracking, you could find just having no leaks, GS calipers and better front brake cooling is adequate enough for the tracking you do.


The Z is not my primary track car, but at this point the track is where I drive it most, primarily due to the installed 1 piece seats and 6 pt harnesses.(does that even make sense?)

I agree that the c5 calipers would be a modest upgrade at best, but since they would be free and I needed new pads anyway, the only extra cost/work would be a $150 adaptor plate and new rotors. I totally agree with you regarding drilled/slotted rotors. At this point they are pretty much just for looks and eating brake pads while wearing out faster...

Since I first posted, I ordered a new set (front and rear) of Hawk DTC-70 pads, and a replacement j55 caliper from Autozone. The caliper arrived in 48 hrs, but the Pads took about a week to arrive(yesterday). I had decided to wait for the pads to arrive to install the new caliper and pads at the same time. After waiting patiently for the pads to arrive, I went out after work yesterday and despite the caliper box from Autozone having the correct part # on it, inside was a jl9 caliper, which obviously didn't fit around the installed rotor.

So now I am back to square one. Upon close inspection of the banjo bolt, I can see the threads are worn, I can slide it a good 1/4 inch into the caliper without turning it, and it won't hold any torque at any depth. A replacement bolt seems to "bite", but I am concerned about the internal threads on the caliper so I don't want to just change bolts and hope for the best. About an hour ago I ordered the correct m10-1.0 thread tap. When it arrives I'll try to revive the threads on the caliper, and if it feels good, I'm going to run with it(and maybe some Loctite). If I mess it up worse, I'll just order another caliper and hope they send the right one this time.

Since the c5 calipers are free, and the effort/cost to install them seems minimal, I'll probably do the swap next time I need front pads.

I'll definitely thoroughly bleed the system once I'm satisfied with the components.(I always do before every track day in any car...)

I've really struggled getting this car to be driveable on track. I'm really close, and think it will be pretty darn quick once I get it 100% sorted...

Thanks for your advice, (and giving me a reason to tell my caliper story!)


Curt

[VikingTrad3r]

I've really struggled getting this car to be driveable on track. I'm really close, and think it will be pretty darn quick once I get it 100% sorted...


Curt

Curt, i took my zr1 to the track and my 86 4+3 that was stock with better rubber and c4 grandsport brakes handled far better.

I'd like to make my primary zr1 the track car but it was all over the place and im not sure if it was the extra weight or the old tires or the alignment.

what have you done to get to your z so close to be a monster on the track?

do you have a thread that shares what you have done?

Merry Christmas!

[cbaclawski]

Curt, i took my zr1 to the track and my 86 4+3 that was stock with better rubber and c4 grandsport brakes handled far better.

I'd like to make my primary zr1 the track car but it was all over the place and im not sure if it was the extra weight or the old tires or the alignment.

what have you done to get to your z so close to be a monster on the track?

do you have a thread that shares what you have done?

Merry Christmas!


The car already had the Lingenfelter 368 package so power was never an issue. I started with seats and harnesses, a 3.73 rear, and had it sent up to Marc Haibeck for a thorough mechanical sorting and a new tune.

Then the Master Cylinder failed on it's maiden run(spoiler: I put it in a tire wall), so I replaced the master, installed the DRM bias spring, and replaced all 4 calipers. Hawk DTC-70 pads all around, and motul 660 fluid. (In addition to substantial front end body work).

Next time out it was still virtually undriveable, so I had it aligned. Turns out it was way off.

3rd try, it was much better but still really loose, so I bought better rear tires from a member here (RussMcb).

4th try, Finally the car handled great, but the leaky front caliper described in this thread caused poor braking performance that deteriorated throughout the day. - New caliper should be here tomorrow...

I'm a regular Track Rat, but have a few cars I track much more frequently, so it's taken me a while to get to this point...

Here are a couple threads I made with more detail, and some great advice from others: (in chronological order)

http://www.zr1.net/forum/showthread.php?t=29988

http://www.zr1.net/forum/showthread.php?t=30024

http://www.zr1.net/forum/showthread.php?t=30535

http://www.zr1.net/forum/showthread.php?t=30741

Merry Xmas!!!

Curt