Sway Bars and Camber (Page 2/3)
Yellow-88 JUN 29, 11:17 PM

quote
Originally posted by hunter29:


Ok I understand, I was giving bad advice, I was told a bit more camber would keep the tire patch flat. Thanks for your input.




Your running a stock Fiero.
I have a lot of suspension stuff going in a thread on this forum called: Is the akerrman angle on the 88 really bad? it looks it. Do jump in.
jelly2m8 JUN 30, 05:04 AM
Being a certified Hunter and John Bean Tech, I had my share, your share and everyone else's share of alignment rack time. I tried this, I tried that. Unless you are looking for the most performance for one specific goal, close to or at OEM specifications is where you want to be. Much as it pains me, the Fiero dudes knew what they had and knew how to get the most out of it.
jelly2m8 JUN 30, 05:12 AM

quote
[b]Originally posted by /b]

I want to step in here with a question (86 2.8 Ferrari F 40 replica); my car is about a foot wider than stock, although suspension looks relatively stock( ( poly bushings in the front) tires are 245/ 16 front, and 295/16 in the rear. No spacers. Would this alter my suspension settings? I am going to do a self alignment this summer ( no shop here has equipment for this car) car lately is wandering on the highway.



Your transmission is not relevant, why the fuk would you think the trans is relevant?
I will suggest the over weight body and modified from stock suspension for sure. in your case, it's an expensive time consuming trial and error of what works best overall.

[This message has been edited by jelly2m8 (edited 06-30-2024).]

Yellow-88 JUN 30, 10:09 AM

quote
Originally posted by jelly2m8:

Being a certified Hunter and John Bean Tech, I had my share, your share and everyone else's share of alignment rack time. I tried this, I tried that. Unless you are looking for the most performance for one specific goal, close to or at OEM specifications is where you want to be. Much as it pains me, the Fiero dudes knew what they had and knew how to get the most out of it.



Yes .... The designers knew just how compromised the earlier cars were. The settings they chose are for a reason. For a stock pre-88 Fiero running on real roads, trust the designers. And that includes tire diameter and wheel offset.

A lot of what you hear here, is typical "hot rod" stuff. Fiero's lend themselves to modification by enthusiastic car guys. I see you as more of a "classic car" restorer. We do need some of that in the Fiero community.
olejoedad JUN 30, 10:50 AM

quote
Originally posted by stevep914:

I want to step in here with a question (86 2.8 Ferrari F 40 replica); my car is about a foot wider than stock, although suspension looks relatively stock( ( poly bushings in the front) tires are 245/ 16 front, and 295/16 in the rear. No spacers. Would this alter my suspension settings? I am going to do a self alignment this summer ( no shop here has equipment for this car) car lately is wandering on the highway.



The only TRANS that I see in this post is a body TRANSplant.......

[This message has been edited by olejoedad (edited 06-30-2024).]

Yellow-88 JUL 01, 09:27 PM

quote
Originally posted by stevep914:

I want to step in here with a question (86 2.8 Ferrari F 40 replica); my car is about a foot wider than stock, although suspension looks relatively stock( ( poly bushings in the front) tires are 245/ 16 front, and 295/16 in the rear. No spacers. Would this alter my suspension settings? I am going to do a self alignment this summer ( no shop here has equipment for this car) car lately is wandering on the highway.



Especially with an 86, witch is seriously compromised already, screwing with the scrub radius will absolutely alter your suspension "geometry". Tire diameter and wheel offset determine scrub radius. The Chevette had pretty tiny tires. The reason that stock size tires and wheels look too small on an earlier Fiero, is because the geometry of the Chevette called call for a fairly small tire. The designers didn't want to make it worse than it already was.

The correct front tire diameter to keep scrub radius within design is about 24 1/12". Giant tires on a car designed for small ones just doesn't work. What wheels are you using with those monsters? What is the offset? What is the aspect ratio of the tires?
pmbrunelle JUL 02, 07:48 AM

quote
Originally posted by Yellow-88:
The correct front tire diameter to keep scrub radius within design is about 24 1/12". Giant tires on a car designed for small ones just doesn't work. What wheels are you using with those monsters? What is the offset? What is the aspect ratio of the tires?



Bigger diameter front tires reduce scrub radius, which to me seems like a good modification for the 84-87 Fiero.
Yellow-88 JUL 05, 07:09 PM

quote
Originally posted by pmbrunelle:


Bigger diameter front tires reduce scrub radius, which to me seems like a good modification for the 84-87 Fiero.



How do you know that? Do we know what it is with stock size tires and wheels? I haven't seen an actual published number.
Bigger diameter than what? For an 88 Fiero front end, the stock tire size is 24.7" diameter with a wheel offset of 37mm.

Scrub radius is wicked hard to measure accurately in real life. Really easy with a 2D drawing of the suspension geometry.

One thought I had was to sprinkle some chalk chips a smooth surface and roll a front tire onto it. Turn the steering wheel. Zero scrub radius would create circles with a distinct dot in the center of the contact patch. A 3D Cad Model would be really nice. Does anyone out there have a scanner and CAD capabilities?
Yellow-88 JUL 05, 07:19 PM
Sorry Hunter, I forgot that you are a pre-88. I'm having trouble finding wheel offset and tire specs on the early cars. I'm sure it's somewhere.
fieroguru JUL 05, 09:45 PM

quote
Originally posted by Yellow-88:
How do you know that?



As long as the scrub radius is positive (which for all years of Fieros it is), then larger diameter wheels will raise the spindle and move the intersect point from the kingpin angle closer to the center of the wheel, which will reduce the scrub radius.

We have Bloozberry to thank for the countless hours he put into detailing the 88 Front and Rear suspension. Here is just 1 of his many 88 Fiero suspension drawings.


The 88 front was supposed to have 30% smaller scrub radius vs. the 84-87 (among other changes).

There are several of us who have done our own Fiero suspension modeling in CAD and have a pretty good understanding of the impact of common modifications (like lowering) as well as the fundamental limits of the Fiero suspension.

[This message has been edited by fieroguru (edited 07-05-2024).]