grand am brake wheel fitment (Page 1/2)
swing69 SEP 19, 08:53 PM
I have a stock 85 2m6 SE. I'm going to first do the 11" booster swap....then possibly the grand am front brake swap.
Does that swap fit over the stock 14" SE rims?
thanks
IMSA GT SEP 19, 11:21 PM
One of the members on here did the conversion and said it fit fine with 14 or 15 inch wheels. Unfortunately he is no longer on here to ask. I'll let someone else chime in to verify.
batboy SEP 20, 01:18 AM
I did Grand Am brakes in about 2001 or so. I switched to 15" Grand Am wheels about 6 months later. So, if I'm remembering correctly, the Fiero 14" wheels will fit. The standard Grand Am wheel was 14" plus optional larger sizes.
theogre SEP 20, 12:42 PM
GA "upgrade" will Not work right or at all w/ stock rear brakes. Worse when Big MC is used too.
See my Cave, Brake Upgrade

Many "Brake Upgrade" fan boys are no longer here or elsewhere because they wrecked, junk or worse sold the car to nubes w/o a clue. And not just for Fiero...
Sadly Some have bought such a car and find to fix them cost a lot of $ and time eater and junk or sold the car again.

Good luck if you wreck and Insurance Co's finds out you have brake and other "upgrades..."

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

OH10fiero SEP 20, 02:02 PM
I bought a Fiero from someone who did the Grand Am break conversion and the first thing I did was pull them off and go back to stock, pedal whet almost to the floor before the break started to grab and pads at all 4 wheels were brand new. The upgrade probably could work better with a master cylinder change but losing the emergency brakes was not worth the conversion to me so I never bothered to try and get it to work.
olejoedad SEP 20, 03:11 PM
Yes, the GA swap will fit 13"-15" wheels.

You need to do all four corners and change the master cylinder to keep the system balanced.

Do this before the booster change.

Do not follow your above posted plan, as your system will be VERY biased to the front and will not be controllable in a panic stop condition.
Dennis LaGrua SEP 20, 07:41 PM
Unless you are going for a completely stock look, I would recommend 17" wheels with the 5 x 100 mm wheel pattern and 35mm offset. . They really modernize the appearance. You could choose an OD of the new tires to match the OD of the old to keep the speedometer reading and wheel speed accurate. Fiero tire sizes, especially the 14" sizes are getting very difficult to find.

------------------
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olejoedad SEP 21, 12:43 PM

quote
Originally posted by Dennis LaGrua:

Unless you are going for a completely stock look, I would recommend 17" wheels with the 5 x 100 mm wheel pattern and 35mm offset. . They really modernize the appearance. You could choose an OD of the new tires to match the OD of the old to keep the speedometer reading and wheel speed accurate. Fiero tire sizes, especially the 14" sizes are getting very difficult to find.




If you do this, the GA swap will not be as effective due to the rotating mass of the wheel/tire combo being farther from the center of the point of rotation.

The 17" wheel would allow for increased rotor diameter, which would provide better braking.
theogre SEP 21, 06:21 PM

quote
Originally posted by olejoedad:
If you do this, the GA swap will not be as effective due to the rotating mass of the wheel/tire combo being farther from the center of the point of rotation.

no quite
OE Brakes or crap GA "upgrade" will have same function when...

quote
Originally posted by Dennis LaGrua:
You could choose an OD of the new tires to match the OD of the old to keep the speedometer reading and wheel speed accurate.

That also saves Total Gear Ratio for the powertrain not just keeps Speedo accurate so have same gearing and engine load getting on the highway and passing.
See my Cave, Gear Ratio

13" or 14" to 15" rims can been done and nearly match the OD of stock tire too for "base model" and other Fiero too. I did that 10+ years ago. (Some Fiero have 15" rims but ignore them right now because most are stagger size w/ wider on the back.)
Even 16" rims can be done like this.

You have more choices for 15" tires.

Quick way to find "correct" Alt Sizes is use TireRack.com etc that list them.
Some rims cat's still list Fiero and other old cars too so you don't guess buying them.

17" rims and tire to match OE OD means thin sidewall tires. That has some problems and easier to break a tire and/or the rim when have RR tracks, bad roads, etc. beating them.
Is why many new vehicles using 16 or 17 or larger rims as OE still have 55, 60 etc profile tires on them..

[This message has been edited by theogre (edited 09-21-2021).]

pmbrunelle SEP 21, 06:32 PM
Check the accuracy of your speedo using a known-good speed reference; stock is not necessarily accurate.

I used a GPS to verify my speedo. I have the red VSS gear, like I'm supposed to have with 215/60R14 tires, and the speedo reads low.

I'm getting bigger OD tires (255/40R17), and those tires will bring the speedo reading close to reality.