It survived seven 20-minute track sessions without any mechanical failures, which is really more than I could have asked for. However, the unvented front rotors and stock brake pads were severely overheating after one lap. I was at CMP (Carolina Motorsports Park).
After reading about the Beretta upgrade on Ogre's cave, it sounds like it may introduce some unwanted brake bias. I really just want a vented version of the Fiero front rotor. I heard that a Sunbird rotor is identical other than being vented. How does the Chrysler Lebaron rotor compare?
Also I had pretty severe brake dive under hard braking, I suppose stiffer front springs and dampers are the biggest fix for this?
Any opinions on high performance brake pads?
Thanks all, 86 GT.
[This message has been edited by masospaghetti (edited 05-26-2015).]
Going with the Beretta vented brakes up front with a high performance pad, probably EBC Yellowstuff. Not sure yet about the rear. I could keep the stock rotor and use a Porterfield street pad, or go with the Beretta rotors and EBC Yellowstuff or Hawk HPS. Not sure how much difference the venting will make back there.
Next question: What would be a good shock up front to replace my comfy Monroe Sensatracs? Koni's are expensive ($90 each), there's KYB Gas-a-adjust that are much more reasonable ($30 each).
we use the GM intermediate calipers and vented rotors all around (no E-brake) Hawk HP plus pads, great initial bite, not much dust, not bad on the rotors. Shocks are Koni adjustable. I don't think just looking at price should be the issue. Tires and shocks and sway bars are the deciding factors along with driver experience for track days and autocross. You need to be able to stop before you can go fast. Also a good seat and harness system. What class were you running? Stock class should let you change the shocks, changing the brake calipers/rotors may change your classing. Always check these things out before making any mods.
PS, forgot the springs too. The bottom line is work on the suspension first. A adjustable brake bias valve would help out the brake system issues. All 3 of our track/autocross cars have that and it does make a huge difference when going to other venues and track conditions. We have two 88 cars and an 86 to play with and way too much fun. Keep us posted on your progress. here is my 88 AX car.
mcguiver, what kind of rotors are you running? I didn't see the HP Plus available for Beretta/GA rotors and calipers. The highest performance option I saw that was reasonable was the EBC Yellowstuff.
I love the Grand am swap, biggest reason is everything is so cheap! Whether it be the calipers, rotors, or pads. I actually went with it because it was cheaper than getting the original parts! Brakes are great! Also I have KYB's all around, They are great! And yeah I had a mushy Fiero until I put ST lowering springs in, course the poly helped too
So tentatively I've gone with the following configuration - tried to balance low-maintenance with track capable, hope it works out:
Beretta front rotors Beretta front calipers EBC Yellowstuff front brake pads New guide pins and hardware Koni front adjustable dampers Valvoline DOT 4 fluid Stock rear calipers and rotors Porterfield AS262 rear street pads
I'm going to wait and see what the pedal feels like before I do the S10 master cylinder conversion. Also, I may get a brake proportioning valve depending on the brake bias.
[This message has been edited by masospaghetti (edited 05-19-2015).]
the system on our 86, calipers are the GM metric units and the mounting brackets were originally sourced from Held Motorsports. The rotors are Baretta GT units from 91-92 (I believe), The pads are the Hawk HP plus. The car in the picture is an 88 Formula with the stock calipers but modified Hawk HP Plus pads. Not sure if Held sold out to someone, It was Ryan Motorsports prior to Held.
Personally I would not upgrade the front end without doing the rear at the same time. Stiffening up the front while doing nothing in the back could lead to some undesirable handling qualities. Email Chris at redshiftmotorsports.com and see what he can do for you. I think it's still the annual Koni sale time (runs April through June, IIRC) and you should be able to score a full set of Koni Specials ("Reds") for about $300 from Chris.
If you haven't yet, you could try cutting your stock springs a coil or so - that will increase your spring rate and in combination with the Konis might get you what you need.
If you don't have them, you might also want to look into the Moog adjustable upper ball joints for the front. With a little Dremel work you can dial in a useful amount of front camber - stock alignment variables are awful. That will help reduce understeer a little and improve turn-in.
I second tshark's opinion about the Corvette upgrade. Although the Beretta setup probably works fine on autocross, I don't think it's going to be a meaningful improvement with actual track driving. I'd do it right the first time - you can incorporate a brake bias valve for cheap if you feel you need to. There are also worlds of options for pads on the Corvette versus a very narrow selection for 25 year old midsize GM sedans.
So tentatively I've gone with the following configuration - tried to balance low-maintenance with track capable, hope it works out:
Beretta front rotors Beretta front calipers EBC Yellowstuff front brake pads New guide pins and hardware Koni front adjustable dampers Valvoline DOT 4 fluid Stock rear calipers and rotors Porterfield AS262 rear street pads
I'm going to wait and see what the pedal feels like before I do the S10 master cylinder conversion. Also, I may get a brake proportioning valve depending on the brake bias.
You will have a LOT more bias to the front than stock. Change the rear brakes to the GA/B instead of keeping the stock brakes. With the four corner GA/B, the S-10 M/C is a must. Booster is not neccesary, but some people prefer the lower pedal effort.
You must factor in the caliper piston diameter, your setup shown above will not be inherently balanced.
[This message has been edited by olejoedad (edited 05-19-2015).]
Wouldn't the larger piston diameter of the GA brakes in the front shift the bias towards the rear?
I am considering the rear GA brakes too - how much performance am I leaving on the table by sticking with unvented rear rotors? I assumed the rear brakes aren't getting that hot, but that might be a bad assumption.
Also by going with the GA brakes in the rear, I lose my parking brake - since there's inspections here in NC, that means swapping rotors and calipers for track day. Not a huge deal but still an inconvenience.
[This message has been edited by masospaghetti (edited 05-20-2015).]
Grand Am brakes front, 85 Cadillac Seville brakes on the rear (with same grand am rotor). Keeps parking brakes and almost identical bias as stock. Do not change front or rear only! It can be very dangerous.
What kind of fluid are/were you using? almost all DOT fluid, unless specifically for racing will not hold up to any sort of track use. You NEED racing fluid.
I put fresh Valvoline DOT 4 fluid in there. 480 F dry boiling point.
Also I emailed DPWood, he said he could have another run in about a week for the Seville brackets for $65.00 shipped. Now I need to decide which way to go.
[This message has been edited by masospaghetti (edited 05-20-2015).]
I have boiled DOT4 fluid in my 04 GTO at a track day, I assumed it would be good enough and after 2 hard laps I lost the pedal. It too suffers from undersized brakes.
Because of the size and low mass of the Fiero brakes, if you do track one, more heat makes it to the fluid. I wouldn't use anything but the highest boiling point fluid. Anything I could do to extend the temperature operating range of the brakes I would do, pad compound and fluid boiling point are the two most cost effective changes you could make. Pad compound is very sensitive to the temperature it his as well. Dedicated Track pads are also a must.
if you use the lebaron kit , you can choose from a big selection of Willwood AL calipers too .Check out their GM metric replacement line .Multi piston available too .
Is there any way to run the Seville rear calipers without having to modify the brake pads? The idea of having to modify a wear item like a brake pad every time its changed isn't appealing.
we use the GM intermediate calipers and vented rotors all around (no E-brake) Hawk HP plus pads, great initial bite, not much dust, not bad on the rotors. Shocks are Koni adjustable. I don't think just looking at price should be the issue. Tires and shocks and sway bars are the deciding factors along with driver experience for track days and autocross. You need to be able to stop before you can go fast. Also a good seat and harness system. What class were you running? Stock class should let you change the shocks, changing the brake calipers/rotors may change your classing. Always check these things out before making any mods.
Sorry, never answered this question...I'm still in HDPE (driver training essentially), not sure where I will end up yet.
I am leaning towards the LeBaron 11.25" rotor / Seville caliper for the front w/ Beretta rotor / Seville caliper for the rear, both with HP Plus pads. Got some Motul 600 racing fluid to go with them.
I did install a rear sway bar. Front and rear bars are all poly. Tires are Dunlop Direzza 1's, these are almost at end of life, maybe one more track day left on them.
Right now I have stock seats, obviously not great for track use, but at this point not intending on changing them out.
I see that Summit has Koni front shocks for $86 each right now. I might try the front set, I don't have the budget to do front and rear yet.
[This message has been edited by masospaghetti (edited 05-26-2015).]
1) Koni Reds - Mid setting is good for the track (We race at this setting) 2) 325-350ish springs front and rear ( Race car is 400lbs - but a little stiff for any road use) 3) Coil over rears so that you can get it cross weighted (Ground Control has a nice set up - A kid there owns a Fiero and has done some good work) 4) CAMBER, CAMBER, CAMBER - balance between road and street but +2.0 is possible in rear . You will need to replace front upper ball joints with Moog adjustable and rout out the bid center hole a little at the back to get more than +1 in the front. (We race at +3.5, but that is a little rediculous on the street.) 5) Sticky Tires - look at DOT legal Toyos or similar as used on Spec Miata or Spec E30 (15") 6) Alignment - again a street vs track balance - We race at just a min amount of toe in at rear and as close to 0 as possible in the front. You probably want a little toe in the front for street use or the car will always require 2 hands to steer.
Spec E30s, heavy cars, race with small brakes like the Fiero - just vented in the front. Carbo Tech Pads are great, but if you live in cold climate might be trouble on cold mornings before they warm up (not recommended for street use)
Avoid larger wheels - they look cool but rob performance on our low HP 2.8l engines. Again, the E30s race on 205 or 215 15" just fine. Just make them sticky
[This message has been edited by plane (edited 05-27-2015).]
Awesome info - but bear in mind a Spec E30 will likely weigh less than a street Fiero. Spec E30s weigh in at under 2700lbs. Stock E30 brakes for all six cylinder models is 260mm, so about a half inch larger than the Fiero's brakes.
This does raise a good point: Like Colin Chapman said, add lightness. Dumping as much stuff as you can is like adding more brake and more power. All win.
Thanks for the information. Do you have a source for stiffer springs? All I could find were the Eibach lowering springs. I know the rears are at +0 right now, the camber bolts i got were crappy and that was the maximum, I'll have to look into that. I already have the Moog adjustable uppers in the front so I can at least get +1, not sure what they are at now.
The tires I have are pretty sticky, treadwear 140. If I buy new ones, which I will need to soon, they will probably be Toyo Proxes with 100 treadwear.
So I found a set of brackets to use Seville calipers and Beretta rotors on the rear, so I would have a matched set of Beretta vented rotors all the way around. I decided to go against the LeBaron front rotors to avoid brake bias issues. My only concern with this setup is potential for brake fade in the front. Seems the fronts will definitely fade first, won't this increase my chance of locking up the rear? Isn't it ideal to size rotors so they all fade equally?
[This message has been edited by masospaghetti (edited 05-28-2015).]
I don't autocross, but I oval-track race. The "rear bump-steer correction kit" from Arraut Motorsports really makes the rear end on my '87 stick like an 88. I also added the 88 cradle strut tower adapters to mount the top of the coil-overs inboard more - this also allowed me to run wheels with more backspacing...
Tires you say????????? With the warm weather you have down there consider the Hankook Ventus Z 214 Soft compound. They like a bit of heat to make them stick, Up here in CT the early season is a bit too cold for them but as soon as the sun comes out and the track temp comes up they are a wonderful thing to behold. Short of the new Hoosier A7 at more $$$ the Hancooks are great.
