GTA1990

iTrader: (1)

My brakes are nothing short of atrocious and I've been seriously considering an LS1 upgrade (Ed?). However, was watching a MW clip of a '91 GTA road test:
http://www.youtube.com/watch?v=mpbnEOY7ywk

They seem to quote an average stopping distance from 60 of 117 ft (see video at 5:24).

Poking on the internet this doesn't seem too bad. I have a 5.7L '90 GTA so I assume I have the 1LE rear discs. The aforementioned road test is making me re-consider the upgrade and perhaps just getting some decent disks, stickier pads, braided hoses and a complete fluid flush; in essence making sure my setup is upto factory spec, maybe with a slight edge

Just wanted to get peoples opinions - is 117ft realistic for these cars? is this a good result? For spirited street use is an LS1 upgrade really that noticeable?

Thoughts welcome guys

flaming-ford

iTrader: (7)

that distance i could consider beleivable... it's not that our cars can't stop well with factory brakes. It's mostly just what you consider well as.......

The main problem is the small rotor that leaves our brakes unable to dissipate enough heat to maintain a normal stopping distance. Also our small pad contact area really is far from optimal in terms of creating a high enough friction co efficient in the first place.

i've went the path you are talking about currently on my last camaro and was extremely unhappy with the output..... now if you on the other hand don't drive your car at higher rates of speed (50+ mph) and make agressive stops fairly often you may be quite happy with the aboe. personally i fade mine in like 3 minutes currently. my old camaro faded just as fast with fancy pads, lines the works.

RBob

iTrader: (1)

Most likely has the optional 1LE brakes. Quoted from the video: "braking is handled by large vented disks." ... "These are strong brakes and the pedal has plenty of feel."

Not talking about standard 10.5" brakes.

In this thread:

https://www.thirdgen.org/forums/brak...-night-my.html

racing geek made this statement:

"The first was 166 feet from 60mph to 0mph, and the second was 196 feet from 60mph to 0mph."

Which applies to the standard 10.5" rotor single piston CI caliper system.

I know for a fact that a '92 Camaro with the standard brakes does not stop within 117' from 60 MPH. Heck, at 60 MPH the brakes hardly feel as though they are there.

RBob.

GTA1990

iTrader: (1)

Cheers guys -

yeah I think about taking the easier/ cheaper way out but from what I've read on here, I will just end up doing it twice. Time to contact Ed for international shipping rates

RBOB - I'm in no way a 3rd gen pro but I don't think you could order the 1LE brakes solely - as in get a fully specced out GTA and then option in thE 1LE brakes aswell - it was more a racing theme package which included larger front brakes but also resulted in AC delete and a few other bits to make it competitive in showroom car racing events.

Saying that, I wouldn't be surprised if as a press car, GM sprinkled some performance dust on the tested version including some meatier brakes

racing geek

iTrader: (5)

If I remember correctly, the C6 corvette (base model?) can do it in ~110' and a 2002 Camaro can do it in ~120'.

117' for a stock 92 is highly unlikely.

Those distances I got were with the stock 10.5" rotors and single piston iron calipers on all fours.

GTA1990

iTrader: (1)

I've been mulling over this and provide the below logic for your thoughts:

Taking stopping distances out of the equation for a moment - once a brake system is locking the wheels, you would consider the clamping force to be optimal - again, in isolation of other requirements such as control, feel etc.

Many have reported the standard setup (4W disc >89) enables them to lock the wheels. I can imagine various variables such as tyre quality, car weight, even temperature on test may bias this result. I also see this doesn't occur in the MW clip (which therefore actually leads me to believe it is the standard J65 stuff!) but there can be many reasons for that. Let's just say based on forum findings and the clip the standard stuff will get you as near as dammit to locking up. This is the key assumption here and I appreciate any informed thoughts on this.

Thus in terms of a single pass braking distance, assuming the same competent driver and no other variables but for the brakes- the standard stuff should circa equal any big brake upgrades - I know we must also consider how quickly it locks up hence why I caveat with crica. Again please disregard the negative implications of locking up in terms of braking distance

Now in the real world I appreciate pedal feel, force required on the pedal, modulation characteristics (to control lockup) and also fade all are important factors which no doubt make many of us go for big brake upgrades (and why I am enquiring)

I suppose what I'm trying to say is that I'm actually inclined to believe a fairly reasonable stopping distance (perhaps not 117ft - old road tests seem to quote the 89 onwards GTA at around 130ft average) from the standard stuff in good order.

My point? - if it can get the wheels to lock surely it can't be that pathetic. Factor in today's tech. in terms of pads and some braided hoses to improve feel, DOT 4 fluid maybe sufficient for spirited street driving.

But I'm willing to listen to any thoughts, even controversial

Stephen

iTrader: (12)

My 87 GTA with the stock, small rotors in the rear, locked all 4 tires from 70mph when trying to not hit a deer crossing the road.

TRYING is the key word...I was unsuccessful & there is one less deer in the world now!

GTA1990

iTrader: (1)

Just wanted to pre-empt an update on this that I've picked up a collection of stock fitting bits (as below) and shall be fitting this weekend. Hopefully I'll provide some constructive info for future 3rdgen-ers weighing up stock over upgrades.

I have acquired:
Solid EBC Front Discs
EBC Red stuff pads (front)
New RUBBBER reybestos brake hoses front, rear and centre t-piece
Unchanged rear ILE Stuff (pads/ discs unknown but apparently in good useable condition)
Dot 4 brake fluid for a complete flush

Will report back

lowflyr

Also check to make sure you do not have a vacuum leak to your power brake booster and supply line. I had a rotted line on one of my previous cars that made it feel terrible. I could still lock the brakes, barely.

blacksunshine'91

iTrader: (10)

I'm not so sure you do. You might, but I don't think so. IIRC, the '91-'92's had the PBR (a.k.a. ILE) rear calipers, but I don't think they started doing that until the '91 model year. Anybody, please correct me if I am wrong.

-Eldon

JamesC

iTrader: (5)

All rear disc cars, 89-92, were equipped with PBR's (single-piston alum calipers) and 11.7" rotors.

JamesC

Stephen

iTrader: (12)

On disc brake 3rd gens.....
82-88=iron calipers (magnet sticks)......89-92=aluminum calipers (magnet doesn't stick)

Real easy to reach under a car & see which you have, by just using a magnet.

GTA1990

iTrader: (1)

Pretty sure its the pbr stuff. Magnet idea sounds so funny but it logically is a definitive test .

Should hopefully have the stuff fitted this coming or the following weekend - car is generally getting there

Drew

iTrader: (58)

I can tell you that the 88-down 4 wheel disc setups are so bad they're usually worse then the drum/disc brakes. Aside from a so-so design, that hardly works under ideal conditions, most of the time the rear discs don't do anything at all. It really says something that GM outsourced the brakes to PBR to correct the problems.

The 89-up PBR rear discs are a huge improvement. Even when they're in rough shape they still do a decent job of stopping the car. When I bought my Formula the brakes were notably better then the brakes on earlier cars I'd driven including my 87 Iroc. After several years the brakes were showing their age and the car was getting hard to stop. New rotors in front and new pads all around improved the braking. Then after another year or so the brake warning light on the dash came on and braking was really bad, almost as bad as my 61k mile 87 Iroc. I determined that the brake fluid was heavily contaminated from a cast iron replacement master cylinder, which was plugging up the combination valve and various hardlines.

After obtaining a NOS combination valve, changing the master cylinder to a stock aluminum unit, inspecting the flexible hoses, and fully flushing the old fluid and bleeding with new clean fluid, the brakes are greatly improved. They're the best they've ever been. A few years ago I would have been very tempted to upgrade to at least 1LE brakes, but now the stock J65 system is more then adequate.

My opinion is that most people never really give the stock brakes much of a chance. When the system is in good condition, it's very good on the street. Granted it doesn't work nearly as well as the brakes get hot, but that shouldn't be a problem on the street.

JamesC

iTrader: (5)

Use a mag if you wish, but an easier test is to simply compare the front brake calipers with the rears, which are finned alum and look nothing like the iron Delco-Moraines. Or check the pics in the following link:

https://www.thirdgen.org/forums/faq-...iscs-89-a.html

JamesC

Reid Fleming

iTrader: (2)

Many people don't and will not believe what I have to say.

My parents bought my GTA brand new in 1989. They also bought an 89 Corvette brand new. From day one, both of them said that the GTA would stop better than the Corvette. It shouldn't. The Corvette is lighter and has 12" all the way around. Yet it just does.

As far as locking up the tires, I've tried doing a quick brake stop to see how well everything is working and at what point lock up occurs. It'll darn near choke me in my seat. Even then, locking up the brakes is almost impossible to do. You can do it. But it's like you have to push down as hard as you can and then push a little bit more on top of that. So it seems that the stock system (at least on my car) was set up to get peak performance before achieving lock up. As such I've never worried about accidentally locking up the brakes under an emergency braking situation.

GTA1990

iTrader: (1)

Hope everyone is good

Just an update had the abovementioned fitted to my car. The brakes are noticeable better. In terms of peddle distance the brakes bite earlier adn the overall force is stronger. Peddle remains progressive and probably is the most communicative thing in the car!

Initially there seemed some wobble at breaking but that seems to have subsided. There is however a remaining whine from the front when braking - this may be the red-stuff pads / a bedding in byproduct.

Net result is I am content. A refresh of the system to stock spec except for upgraded pads has provided an adequate braking system for a street driven 350 with mild performance upgrades (Well, just headers and a 3" exhaust ). Test was approx an hours driving on country roads mixed hard/ progressive braking -no realised fade.

Purely my opinion but hope this helps (most prob. will add to the confusion) anyone considering a big brake upgrade and uses their car entirely for street use

FireInMe17

Mine locked up on me when I was trying to miss a deer at 55, when they did the deer stopped in the middle of the road and looked right at the car and I couldn't stop in time and I hit it Fortunately it only cracked the grill, and I was able to slow down to about 35-40 in a short distance.