Best modern braking system upgrade? (Page 2/4)
pmbrunelle OCT 20, 08:09 PM

quote
Originally posted by Mike in Sydney:
If you are determined to do the brake "upgrade" and want to keep it balanced, you can try the Grand Am Rotor / Seville caliper upgrade for the rear. See http://www.fiero.nl/forum/A...130314-2-083566.html for information. This is supposed to allow you to keep a working parking brake.

I can't comment on the efficacy of this system as while I have the parts, I don't have it on either of my GT's yet and in all likelihood won't install them.




I installed Seville calipers on my LeBaron setup. It was a downgrade in terms of serviceability, because I mounted the calipers with the bleeders upside-down.

I wouldn't do another brake "upgrade" that downgrades serviceability... the next big brake mod must maintain serviceability.

What might work is to add a bleeder at the high point. You can buy bleeder repair kits; normally you drill + tap 1/8 NPT, then you thread in the repair insert. Not sure what keeps the insert from unscrewing when you go to crack open the bleeder some time later.

Another alternative is to use a banjo bolt with integrated bleeder. This might work if the banjo bolt is at the high point of the caliper.
Mike in Sydney OCT 20, 09:27 PM

quote
Originally posted by pmbrunelle:

What might work is to add a bleeder at the high point. You can buy bleeder repair kits; normally you drill + tap 1/8 NPT, then you thread in the repair insert. Not sure what keeps the insert from unscrewing when you go to crack open the bleeder some time later.

r.



Wonder if you could machine a flat place on the caliper and then drill it for the bleeder without the insert? I'm guessing that would prevent the insert from unscrewing when you go to crack open the bleeder.
pmbrunelle OCT 20, 11:05 PM

quote
Originally posted by Mike in Sydney:
Wonder if you could machine a flat place on the caliper and then drill it for the bleeder without the insert? I'm guessing that would prevent the insert from unscrewing when you go to crack open the bleeder.



If you can find a spot on the caliper with enough meat to cut the bleeder hole directly, that would be nice.

However, the bleeder hole looks tricky to cut (well, to me). I looked for tools to cut a brake bleeder hole, but I didn't find anything. I may have been looking in the wrong places.

It could be possible to drill a hole at the edge between the insert and the caliper, then press in a pin to prevent rotation.



I did something similar to that for the V6 throttle body.

At the air outlet to the IAC pipe, there's a pressed-in aluminium ring.

Since I wanted to cut threads in that ring (to screw a pipe plug into the hole), I needed to stop the ring from turning. I did just that technique, with three holes and pins around the ring.

[This message has been edited by pmbrunelle (edited 10-20-2020).]

wftb OCT 21, 05:54 PM
https://www.youtube.com/watch?v=t6yoGEkoQmg&t=3s

A really well done test and video of a big brake booster mod.This has been posted here before but I doubt that a lot of people have seen it.

I own a G Tech performance meter and until today I did not realize I could measure stopping distances with it. It involves doing a timed run up to the 60 mph red light comes on and then hitting the brakes till the car is completely stopped. I tried it twice, the first time I was doing 70 before I got on the brakes, the second run I got on the brakes too soon and did not get a distance.

So my distance stopping from 70 was 166 feet. And no lockup on the fronts until the car was completely stopped and that was just a small squawk from both fronts. Stops were dead straight and smooth. I know I can do better, but I doubt if I can get a really accurate distance with the Gtech. At least not my old one.

But 166' from 70mph is a huge improvement over the 200 foot distance that my 86 GT was tested at when it was new. And no premature lock up.

Willwood 2 piston GM metric style AL calipers with Lebaron front 11" discs, stock rear brakes with working parking brakes. Stock MC and brake booster. Willwood brake balance valve. Stock prop valve disabled.

I do not recommend that anyone copy what I have done. Because you really have to know what you are doing to get this right. I have experimented with 5 different calipers to get to this point. But I am happy now and it is going to stay as is.

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86 GT built 2.2 ecotec turbo
rear SLA suspension
QA1 coilovers on tube arms

theogre OCT 22, 02:30 AM

quote
Originally posted by DimeMachine:
Ogre,
I have re-read your comment about the TFS brake upgrade and didn't really understand it.

I am thinking about the GA front brakes for my application which is very specific. Stopping from 114 in the 1/4 is getting a little sketchy with the non-vented front rotor getting pretty hot. I am thinking the GA front rotor might make a decent difference for this purpose as it is vented and has more mass. I understand your concerns about liability and rear lockup issues etc on the street (which can be warm, cold, hot, icy, snowy etc) and lawyers look for any angle they can take in an injury lawsuit.

That having been said, I am interested in your opinion as to what you would do to make your Fiero stop better and safer at the RACETRACK from 114 (and hopefully closer to 120) soon.

Unless you're going to surrender the car's tag and trailer it to a track, any brake "upgrade" can have any problems in cave page and more.

TFS/GA "upgrade" will have same problems on a track. Plus Depending on Race Org Safety Rules may not pass track inspection w/ hack job to fit GA and other calipers and pads. Plus GA calipers and rotors weigh more then OE mean more unsprung weight that suspension must deal w/.

Fiero will take a lot more heat then most think but need premium pads to work better then OE w/o brake fade.
"Race Pads" may help or not depend on race type and pad formula. Oval/"road" racing is different heat load vs drag race. Some "race pads" won't work until heated and stay hot and drag or street use can see way more stopping distance, often worse w/ OE spec in the owners book, because they won't heat and stay hot.
Some brake "upgrade" may handle more heat but whether or not helps depend on race type too.

More complicated... You have bigger engine w/ auto trans and likely lower gearing... Meaning rear brakes do less then normal even when everything is 100% good.
Even at idle engine and auto trans setup has more power to the rear brakes to stop.
Likely have to check wiring and programming for the trans in PCM to making sure the trans will down shift and disable TCC locking properly when stopping the 4T__E trans.
DimeMachine OCT 22, 08:43 AM
deleted due to errors.

[This message has been edited by DimeMachine (edited 10-22-2020).]

DimeMachine OCT 22, 08:46 AM

quote
Originally posted by theogre:

[QUOTE]Originally posted by DimeMachine:
Ogre,
I have re-read your comment about the TFS brake upgrade and didn't really understand it.

I am thinking about the GA front brakes for my application which is very specific. Stopping from 114 in the 1/4 is getting a little sketchy with the non-vented front rotor getting pretty hot. I am thinking the GA front rotor might make a decent difference for this purpose as it is vented and has more mass. I understand your concerns about liability and rear lockup issues etc on the street (which can be warm, cold, hot, icy, snowy etc) and lawyers look for any angle they can take in an injury lawsuit.

That having been said, I am interested in your opinion as to what you would do to make your Fiero stop better and safer at the RACETRACK from 114 (and hopefully closer to 120) soon.

Unless you're going to surrender the car's tag and trailer it to a track, any brake "upgrade" can have any problems in cave page and more.

TFS/GA "upgrade" will have same problems on a track. Plus Depending on Race Org Safety Rules may not pass track inspection w/ hack job to fit GA and other calipers and pads. Plus GA calipers and rotors weigh more then OE mean more unsprung weight that suspension must deal w/.

Fiero will take a lot more heat then most think but need premium pads to work better then OE w/o brake fade.
"Race Pads" may help or not depend on race type and pad formula. Oval/"road" racing is different heat load vs drag race. Some "race pads" won't work until heated and stay hot and drag or street use can see way more stopping distance, often worse w/ OE spec in the owners book, because they won't heat and stay hot.
Some brake "upgrade" may handle more heat but whether or not helps depend on race type too.

More complicated... You have bigger engine w/ auto trans and likely lower gearing... Meaning rear brakes do less then normal even when everything is 100% good.
Even at idle engine and auto trans setup has more power to the rear brakes to stop.
Likely have to check wiring and programming for the trans in PCM to making sure the trans will down shift and disable TCC locking properly when stopping the 4T__E trans.[/QUOTE]

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Ogre, to further clarify, this Fiero would be trailered to the track and we are only talking about the 1/4 mile drag race. Assume starting the 1/4 mile with cold brakes and stopping from 120mph with the 3800 4t65e HD powertrain combo.

What mods if any would you do to the brakes and this was your Fiero and you were forced to take her up to 120mph in the 1/4 mile. Assume in this situation if you were not able to stop you stand a high probability of going into the sand and trees at the end of the track and facing serious injury.

Thanks in advance!

Dime


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84/87 NB, 3800SC, E-85, VS Cam, 2.8 Pulley, 4T65E-HD, HP Tuners, AEM Wideband, Regal GS Gauges, S-10 Brake Booster. 1/4 mile -11.85 at 114mph

[This message has been edited by DimeMachine (edited 10-22-2020).]

wftb OCT 22, 09:33 AM
For a car that is not driven on the street and is only track driven you do not need a parking brake. So you can put either Grand Am parts front and rear or a Lebarron setup front and rear. Or just about any big brake kit you can fit inside your wheels.

But the real problem is that stock Fiero's have a combination proportioning valve that puts way too much bias to the front brakes. The rear brakes are doing almost nothing in the stock configuration. A car that is heavier in the back like a Fiero needs a lot more braking force in the rear than a normal front wheel drive sedan that is a lot heavier in the front. The stock prop valve does not allow the kind of adjustment you need to get the front to rear balance right. And adding an aftermarket valve to the rear circuit does not work because they are designed for vehicles that have too much rear bias, ie almost every car built in the 60's and 70's. So those valves reduce braking to the rear to avoid rear wheel lockup. Exactly what the stock Fiero prop valve already does, and the opposite of what a Fiero needs.

So no matter what brakes you put on, they will all have the same problem- not enough pressure going to the rear brakes. Here are some good discussions and explanation threads about this topic.
http://www.fiero.nl/forum/Forum2/HTML/109173.html http://www.fiero.nl/forum/Forum4/HTML/064690.html

[This message has been edited by wftb (edited 10-22-2020).]

Blacktree OCT 22, 02:10 PM
If this is a track-only car, I'd delete (or disable) the stock proportioning valve. Then I'd install an aftermarket prop valve, and adjust it until the brake bias is where you want it.

[This message has been edited by Blacktree (edited 10-22-2020).]

DimeMachine OCT 30, 10:34 PM

quote
Originally posted by Blacktree:

If this is a track-only car, I'd delete (or disable) the stock proportioning valve. Then I'd install an aftermarket prop valve, and adjust it until the brake bias is where you want it.




Something to think about 4 sure!

Would take low speed controlled road testing to make sure I get the bias right for warm road/tire conditions but not too close to the edge of rear wheel lockup that a guy gets into trouble.

Thanks,
Dime