BADCAM70

I feel your pain Twin turbo,i am from Sweden we have almost the same problem i dont dare go larger than LS1 brakes in front so they fit within original 16" Iroc wheels.
Would be a major pita if the SBP found out you modified outside carmanufacturers specifications.

regards Mats

Twin_Turbo

iTrader: (25)

Do the LS1 brakes fit iroc 16s? I'm pretty sure they don't but did you test it? I didn't... I could pull a wheel off my gray camaro and find out. I could have sworn they won't fit, they are a tight it even in a 17" corvette wheel.

If the TUV found out it has modified suspension, subframe connectors in and out, modified trans, rear axle, engine, cooling system...everything LOL. They would go apeshit and fail the car immediately. It's a good thing they don't know US cars because on a AMG Merc they even scrutinized the factory cat con welds, one seam was sider than the others and they suspected tampering... they even went sofar as to fail a car on an indicator bulb that was slightly more white than the other side..complete madness over there I tell ya!!!

87350IROC

iTrader: (2)

I can test this fitment as well. I have an IROC wheel and a LS1 brake setup laying around.

Is the issue the stock wheels have to stay? And the brakes have to look stockish? If the brakes are not the issues, a Wilwood FSL caliper on the C4HD rotor works pretty well and fits inside the IROC wheel.

Twin_Turbo

iTrader: (25)

Doesn't have to look stokish, they won't know what was on there, it just has to fit behind a factory 16" wheel with stock tire sizes. I have a set of baer calipers, I have a set of rotors I can machine into hubsm have the brackets. All I need is pins, pads and abutments and I think I have the abutments covered as well (my old abutments were cut down and redrilled for a 12" setup)

87350IROC

iTrader: (2)

Sounds like you are covered then. I think I would still prefer the 13" Wilwood setup, but you can't argue with have all the parts already.

InfernalVortex

iTrader: (4)

They certainly will. mw66nova has IROC wheels on his car and runs LS1 front brakes. I have 91-92 16s and also run LS1 brakes.

It looks really nice crammed in under that wheel. Makes them look bigger than they are.



I would imagine most 12 inch rotor setups will fit.

Twin_Turbo

iTrader: (25)

That's the f body setup, I was referring to corvette rotors. They will not fit. Have spare vette rotors.

InfernalVortex

iTrader: (4)

Well I was confused by "LS1 brake setup"... Usually that means F-body, while C5 rotors mean vette. sorry I wasnt much help.

87350IROC

iTrader: (2)

...there is some good info in here. Please stay out of this thread unless you have something technical to add.

Thank You

SlickTrackGod

Since I am probably the leading expert on making a 3rd gen brake (documented) probably time I chime in with imput to this subject.

1st probelm with the video in all due respect is you are running a car on crappy brake pads and breaching the intended temp range of the pads.

Secondly, who bedded the pads

thirdly, I see there was a statement that the rotors have been on there for a few years- one could falsely believe that they are conditioned/heatcycled, but how do we know they were conditioned properly and with the right pad. More than likely they were abused from the start and have hotspots on the face.

Lastly, what propr/combo valve was used, and what is the rear setup and how well or poorly is the brake bias and brake balance as well as the car's overall suspension setup as not to unload everything onto the front brakes only?

Now to the results, I had a "stock type" configuration on my car for many years that worked exceptionally well at the speeds you say you did in the video that would never smoke like that in twice the abuse- but they were conditioned well and well matched with the proper brake compund that was also still very adequate for cold downhill use at zero temp.

I also upgrade and hand fabricated the only setup in the world that was 6POT 13.06x 1.25 rotor that fit under a factory 16x8 IROC wheel and 245/50-16 tire. I did that ONLY because the factory style Delco Maorraine pads would not handle the heat that the backing plates would yield and the bend tabs would start to release on therir own in a few weeks of use- thus the brake pads would rattle inside the calipers at low speeds AND WAS FREAKING ANNOYING- thats why I built the massive Wilwoods I did.

...and to the WIlwoods under the factory IROCS- I have a documented 60-0 in 102 feet which is exotic supercar territory.

Dean aka Vetruck

JamesC

iTrader: (5)

Please keep to topic or the thread will be locked.

JamesC

BADCAM70

Well my cure for "stock brakes suck" is in this order:

¤ Skip rubber lines go steel spun lines
¤ Get the J65 option 4wheel discs if you still have drums in the back preferably 1LE.
¤ Get the cheap spring upgrade for the proportion valve to get more grip from rear brakes.
¤ Do get hold of at least LS1 brakes F-body style up front.

That is what i am doing and do recomend all 3rd gens to do,anything more or what do you all think

Regards Mats

SlickTrackGod

My cure is simple.

buy very good quality replacement OE rotors from Brembo in the 10.5" setup. Good rotors will handle the heat better than crap china made stuff like powerslot. You can find these all day between about $50-60 each

Turn the new rotors. Never assume a rotor is good out of the box- they are decent for daily commuting, but turn them within .003 or better for performace driving.

Stillen Metal Matrix brake pads. THey are about $90 a set but a well worth the price. THere is not another brake compound that I have ever found that even compares to Stillens Metal Matrix for street /autox/light road course use. These pads are awesome and work fine at 0* also so there is no cold pad concern early in the morning going down a steep driveway or hill. They have a much higher fade range than something like the Hawks HPS, they have great bite and release properties, and they do NOT leave pad buildup on the rotors like EBC is notorious for.

Steel braided lines

J65 prop/combo vlave (no modification needed)

You are done.

THe only isses you will have with this setup is an annoying brake pad rattle inside the caliper at low speeds like cruising thrugh a grocery store parking lot. The outside pad backingplate tabs are notorious for unbending and causing the pad to slop about inside the caliper when the setup is used in high heat uses like track days, you will have to either goop them with silicone between the tab and the caliper (works decent) or just pull them out once in a while and rebend them to close the gap. These tabs need to be bent everytime on new install anyways, it is just an inherent defect in design that needs constant addressing.

Dean

This is a great working setup for Stocktype brake configurations- you will thank me later. I actually have the old setup like this sitting in my garage and is going on my Austim Mini Cooper build because they are cheap and cheerful for a small car in a roadrace situation.

Twin_Turbo

iTrader: (25)

I never had good luck with turned rotors unless they were done on a large cutting wheel, the lathe ones that turn the disc like an LP suck, the grooves are all in a spiral pattern outward and like an LP they cause the pads to skip. Just my .02

InfernalVortex

iTrader: (4)

How important are the steel lines? Ive heard of more than one bursting on the street which makes me real leery of using them.

87350IROC

iTrader: (2)

They do nothing for performance. Instead they help the FEEL of the system. Fresh rubber lines can feel very good.

Nelz

Just curious, did you document your 60-0? Your other setup was impressive, but what about this setup you mentioned with the stock brake rotor size?

kmcn47

found em on they're site for 62.14 eligible for free shipping, good info

link for anyone with 82-88 thirdgens without 1le

http://www.stillen.com/product.asp?id=MTLPADS01

paul_huryk

While this is an option, it does not address the shortcomings of the iron caliper 10.5" system - it just optimizes it at the highest level. A lower level of suck...

I will suggest at least going to a 1LE sized equivalent of better (12" 2 piston) - the increase in braking power and repeatability is too much of an upgrade to ignore.

87350IROC

iTrader: (2)

There should be no difference in a single 60-0 stop. That is basically a function of tires, car configuration, and road conditions. All brake kits a powerful enough to lock up the brakes. The problem the stockers run into is they are very small. So three things happen with heat. First of all, because the rotors are small, they have a small heat capacity. There simply is not enough metal to absorb the heat. Second, again, because the rotor is small, the cooling vanes are very short, so the convective heat transfer has a much smaller surface area to get rid of the heat. Finally, again because of the small rotor, the brake system has a smaller lever arm for the torque. This means that in order to develop an equivalent torque (which is what stops the car) the caliper needs to deliver more force than a caliper on a larger rotor. This explains why we have the big 2.5" piston. The force of the caliper on the pad, pushes the pad into the rotor and creates friction between the rotor and the pad. Friction is heat. And because the force is higher, the friction and therefore the heat generated is also higher.

So in summary, compared to a larger rotor setup, the stock setup creates more heat (more friction), has a smaller heat sink (small thermal mass), and can't reject it as fast (short cooling vanes).

This is not much of big deal on the street with decent pads. Unless you get into a situation on the highway with stop and go 0-60-0-60 which happens from time to time with heavy traffic.

It probably is also not a big deal on an average autocross course where one run is less than 2mins. There just isn't enough time or speed to build up debilitating heat.

The real problem is with very sporty canyon carving or road course style use. You average track day will have 20-25 minute sessions where you will continually be decelerating from triple digits. This creates a lot of heat.

Now, the other issue is pedal feel. Do you like a short pedal or a long pedal? Do you like a light pedal or a firm pedal? You should tailor you kit based on what you like. Brakes are a big feel item. The better they feel to YOU, the more confidence you will have. Everyone is different. To me the stock brakes have too long of a pedal. I am less sensitive to the firmness of the pedal.

See the last two columns for a comparison of pedal travel and pedal effort compared to the stock 10.5" setup for the same deceleration rate (brake torque). Keep in mind this assumes all setups use the same pad compound and all calipers have the same amount of flex. In a general sense, these are fair assumptions.

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