84-87 12" Corvette Brake Swap... (Page 27/28)
Jncomutt FEB 20, 01:17 PM
Updated year range for MC. I had 67, it's supposed to be 77.
E.Furgal FEB 21, 01:14 PM

quote
Originally posted by Will:


Incorrect.
From the factory, the wheels DO center on the hub pilot.
Using brake upgrades with separate rotors does indeed reduce the length of the protrusion such that the wheels no longer contact it.
After doing the upgrade, the wheel is then centered by the lug nuts. This is NOT the same and is NOT as good as a positive location via pilot & bore.
However, this seems to be "good enough" that people don't have any problems with it.

I think it's sloppy and one of the major problems with Fiero brake upgrades. Would you trust that the lug studs locate the wheel well enough that it won't shake you into a crash at 150+ mph?


preamble I know this is an old thread

from What I gather conical lug nut seat wheels, the conical seats center the wheel the center hub fitment is more about weight so the lug studs are not carrying the vehicles weight, the hub center is..
having said that, I'd use ARP(for exp) studs over a parts store "dorman/help" . The Fiero isn't that heavy so the center hub isn't as big as an issue as it would be on a truck,

Cajun FEB 21, 08:34 PM
Is replacing the MC with a Corvette MC as straight forward as noted? I did note the fitting sizes are different from the Fiero MC.

thanks
Will FEB 22, 04:17 PM

quote
Originally posted by E.Furgal:

preamble I know this is an old thread

from What I gather conical lug nut seat wheels, the conical seats center the wheel the center hub fitment is more about weight so the lug studs are not carrying the vehicles weight, the hub center is..
having said that, I'd use ARP(for exp) studs over a parts store "dorman/help" . The Fiero isn't that heavy so the center hub isn't as big as an issue as it would be on a truck,



Still incorrect.

The hub pilot locates the wheel. Period. (Yes, there are lug-centric wheel/hub combinations, but the Fiero is NOT one of them, nor is any GM product to my knowledge).

The weight of the vehicle is carried by the FRICTION of the wheel to hub flange interface. This friction is enabled by the clamping force of the lug studs/nuts clamping the wheel against the flange.
sardonyx247 FEB 22, 11:48 PM
I had someone come down to the shop with all the swap brackets, MC, calipers etc.
Looking it all over I found a huge flaw, then saw this post so I read through it to see if it had been covered, so far no one has even noticed it.

on the MC, where it bolts to the booster, it has a huge deep hole for the pushrod to sit in, the Fiero MC only has a dimple.
What I am getting at, to be correct you need a longer pushrod between the booster and the MC, otherwise instead of a metal rod pushing on the MC you have only plastic the surounds the rod doing all the pushing.

Has anyone else noticed this or addresed it in any way?


------------------
"DRIVE IT LIKE A FIERO"
'84 Fiero, engine to be determined '87 Duke (Sold)
'87 Quad 4 H.O.
'87Blue GT 3.4L Swap Completed!!!!!!!! Boosted!!!!!!!
^^^^ Now in the Construction Zone^^^^
Las Vegas Fiero Club Parts/Sales/Service/Club
Fiero Road Club Of Northern Nevada

KaijuSenso FEB 23, 01:02 PM

quote
Originally posted by Will:


Still incorrect.

The hub pilot locates the wheel. Period. (Yes, there are lug-centric wheel/hub combinations, but the Fiero is NOT one of them, nor is any GM product to my knowledge).

The weight of the vehicle is carried by the FRICTION of the wheel to hub flange interface. This friction is enabled by the clamping force of the lug studs/nuts clamping the wheel against the flange.



This is correct. To add, conical lug nuts/bolts (while helping center the bolt pattern in the tangential direction) are designed to give more friction surface between the fasteners and wheels to resist loosening when properly torqued.
sardonyx247 FEB 24, 05:28 AM

quote
Originally posted by sardonyx247:

I had someone come down to the shop with all the swap brackets, MC, calipers etc.
Looking it all over I found a huge flaw, then saw this post so I read through it to see if it had been covered, so far no one has even noticed it.

on the MC, where it bolts to the booster, it has a huge deep hole for the pushrod to sit in, the Fiero MC only has a dimple.
What I am getting at, to be correct you need a longer pushrod between the booster and the MC, otherwise instead of a metal rod pushing on the MC you have only plastic the surounds the rod doing all the pushing.

Has anyone else noticed this or addresed it in any way?




Anyone?.?
E.Furgal FEB 24, 09:56 AM

quote
Originally posted by sardonyx247:


Anyone?.?



I haven't seen both side by side, but if the fiero booster stub has more girth than the vette pushrod hole in the masters piston.. it might not matter..
I know on my 71 c-10 the master for a emanual brakes and the power have different depth holes and girth in the piston in the master..
not knowing if the vette master use was for power or manual brakes,
it be good to know, with this threads age we might not get the answer without going to a parts store and looking at masters, IIRC that vette master listed if it is for power brakes originally, is the same as the 78-81 ws6 t/a's that had 4 wheel discs..
finding a local parts store with the masters on the shelf may prove to be out of the question.

[This message has been edited by E.Furgal (edited 02-24-2015).]

sardonyx247 FEB 26, 03:18 AM
OK, Here are some pics of a Vette (not sure year, but this is the one with the same size line fittings as the Fiero) and the Fiero MC.





From what we could measure the pushrod between the booster and MC needs to be 1 5/16 ths of an inch LONGER than the stock Fiero rod.

This is to put the info in here.

With this type of MC if you don't get the right rod you will only have plastic pushing on the MC instead of a metal rod.
I haven't done this swap, I was only looking over a club members (good member) supplies he had gathered for this swap when I came across this.

[This message has been edited by sardonyx247 (edited 02-26-2015).]

Jncomutt MAR 08, 04:41 PM
I still have a spare vette MC at my shop that I was considering installing on another car. I will check next time I'm there if it is the same as yours.