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| Is the Ackerman angle on the 88 really bad? It looks it. (Page 2/5) |
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olejoedad
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JUN 27, 11:08 AM
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| quote | Originally posted by Frenchrafe:
Yeah! I like upsetting pricey Porsches as wellđź‘Ť
Turbo Slug thanks you for the complements by the way.
And yes, I've tried to get the best out of what I have in terms of suspensions, without going totally nuts and custom made arms, etc...
Interesting what Todd said about feeling secure with his Fiero. I feel the same. I know it's limits and I can push it a bit.
My brother in law, who has the pricey Porsches, Corvettes, Jaguars and whatever, was pleasantly supprised when he drove Turbo Slug on a trackday. His only complaint was for the gear shift; but he should remember his old 911's...!? They shifted badly as well.
He pushed my car further than I tend to do and he found it to be quick!
Concerning '88s, I've always thought it was strange to narrow down the wheel width at the front? Is the track significantly narrower as well?
While the back suspensions of an '88 are better (on paper), it would seem that the front design didn't improve anything? |
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I'm glad your BIL liked your Fiero.
Has he had any experience in mid engined cars?
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Raydar
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JUN 27, 12:05 PM
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| quote | Originally posted by Frenchrafe:
...
Concerning '88s, I've always thought it was strange to narrow down the wheel width at the front? Is the track significantly narrower as well?
While the back suspensions of an '88 are better (on paper), it would seem that the front design didn't improve anything? |
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On the street, I would much rather drive an 88, than an earlier car.
But one of the old school Fiero autocrossers - his name escapes me - found that the most responsive (best turn-in) combination was an earlier front suspension (he had an 85) with an 88 rear cradle swapped in.
He also ran a 4.9/Isuzu combination. Some of you may remember him. Haven't seen him post for years.
He also ran the Cadero Usenet group. (Dating myself, here.)
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jelly2m8
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JUN 27, 01:23 PM
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| quote | Originally posted by Frenchrafe:
Concerning '88s, I've always thought it was strange to narrow down the wheel width at the front? Is the track significantly narrower as well?
While the back suspensions of an '88 are better (on paper), it would seem that the front design didn't improve anything? |
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88s have a wider front track than previous years.
The front suspension is a Huge improvement over the earlier, maybe a bigger improvement than the rear. Gone is the brutal harshness, no longer are you fighting the car, you are driving it. Anyone that's drivin them ' in anger' know you have to put way more effort into the steering than the reward it gives, the 88 is ' point and shoot' with way more smoothness and feel. You know what I mean, driving hard in earlier car's you do something with the steering wheel and then you see what it's doing where-as an 88, it's instantaneous, plus that steering wheel isn't fighting back.
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jelly2m8
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JUN 27, 01:25 PM
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| quote | Originally posted by Raydar:
On the street, I would much rather drive an 88, than an earlier car.
But one of the old school Fiero autocrossers - his name escapes me - found that the most responsive (best turn-in) combination was an earlier front suspension (he had an 85) with an 88 rear cradle swapped in.
He also ran a 4.9/Isuzu combination. Some of you may remember him. Haven't seen him post for years.
He also ran the Cadero Usenet group. (Dating myself, here.) |
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Ya and there was never any proof he autocrossed a proper 88 on a regular basis, just spouted thou art holy on his particular setup.
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Yellow-88
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JUN 27, 08:45 PM
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| quote | Originally posted by cartercarbaficionado:
can speak for the handling of an 88 wish I could upload a video to prove my poin. yellow as much as he prods at my patience is honestly the expert on 88 suspension improvements. I'm more familiar with how he modified his 88 now since I started doing sim software and doing some 3d modeling and mods to the fiero suspension out of boredom and wanting to make use of some newly gained chassis knowledge and found out he's doing extremely well and getting close to the limit of what the control arms and such can hapoint.
tldr. yes it ls bad compared to any modern car that someone didn't penny pinch the engineers on but can be made into a real monster with some work |
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Hello
Since Carter mentioned me, allow me to introduce my self.
I started life as a car guy and became an engineer, designer and scientist. Retireist. After spending 20 years restoring driving and racing British Sports Cars, Sweetie and I decided to try something more modern, maybe mid engine. Lets see .... Lotus, Ferrari, Lamborghini, Maserati, Toyota, Pontiac ..... Hummmm ...
We bought an 86 SE. We where bitterly disappointed. I felt "numb", the controls felt disassociated. The car rolled lite a boat. Wow.... but it made a restoration project and a great show car. We were learning a whole new thing.
I learned that the 88-was a better chassis design so I bought a 88 Base Coup. Nothing on it that didn't make it go. Yellow started as an red 5 speed iron duke. The first look on jack stands had me almost drooling. Sweetie was nodding a big smile. "This thing has potential." My experience taught me to recognize good design when I see it.
My next post on this thread will continue as ...... This is chassis 101. It may be elementary for some but not all. So please stand by. It's time for the debate.
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Raydar
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JUN 27, 11:30 PM
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| quote | Originally posted by jelly2m8:
Ya and there was never any proof he autocrossed a proper 88 on a regular basis, just spouted thou art holy on his particular setup. |
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No argument from me. I owned an 85 GT that I bought new, in 85. It became a PITA to drive. So much so that when I traded it in, in 88, I wouldn't even consider a Fiero (for several reasons, but the 85's steering was waaaay up there. At that point I didn't care how improved the 88 was.) Ended up with a Firebird Formula until '97 or so.
Then I got back into Fieros. Haven't been without at least one (nearly all 88s) since then.[This message has been edited by Raydar (edited 06-28-2024).]
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Yellow-88
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JUN 28, 12:46 AM
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Hi
This may be elementary for some but not all. Please bear with me and hopefully enjoy.
Here are the basic concepts that define how a chassis behaves when outside forces are applied to it. Fortunately the laws of physics don’t break so we’ll have a dependable starting point.
Chassis 101
Ackerman is the principal that the inside steering tire will follow a shorter radius than the outside steering tire. Projected axel centerlines will meet at the same point.
Roll axis is the line between the center of mass at the front axle center line mid-point, to the center of mass at the rear axle center line mid-point.
Camber is the angle of the radial plane of a tire to the road surface. Looking from the rear to the front along the roll axis; a smaller angle on the inboard side of the tire radial plane than on the outboard side is Negative Camber. Positive is the opposite.
Zero camber is when it’s perpendicular to the road.
Toe angle is the angle of the tire radial plane relative to the roll axis looking from the top down. The roll axis would appear as a line. Toe- in is when the tire radial planes relative to the roll axis converges forward of the chassis. Toe out is the opposite. Zero toe is when the tire radial plane is parallel to the roll axis.
Bump steer refers to toe angle change caused by up (bump) and down (droop) movement of the outboard end of the control arms.
Tire contact patch is the “foot print” the tire bears on the road surface.
Scrub radius describes the circular path the center of the contact patch takes, when steering input is entered. Zero scrub radius means; the center of the contact patch is the center of rotation when steering is input. An important design parameter, rarely discussed.
There are a few others I’ll save for later.
The ideal scenario for an optimal chassis is to meet all dynamic outside forces with equal and opposite ones. And no more. Unnecessary opposite force cost contact patch friction.
The 88 chassis is a dream for an engineer car guy who’s favorite car thing is chassis. Why?
Let’s see …. First off, clearly it was the work of an engineering studio dedicated to building an actual mid-engine sports car . No, lotus wasn’t involved, but they appear to be working out of the same book. Especially at the front.
Clearly the early cars were never intended to be true sports cars. Their suspension geometry is actually worse than an MGB. Of course the MGB is a pretty nice 70 year old sports car chassis. We know that the front is from a Chevy Chevette and the rear is a backwards Citation. Brilliant on a budget …. but not a sports car.
I agree with Carter, I really like the 88 chassis as a starting point to a very serious Sports Car. I'll continue this if anybody's interested.
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82-T/A [At Work]
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JUN 28, 08:16 AM
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| quote | Originally posted by Yellow-88:
Hi
This may be elementary for some but not all. Please bear with me and hopefully enjoy.
Here are the basic concepts that define how a chassis behaves when outside forces are applied to it. Fortunately the laws of physics don’t break so we’ll have a dependable starting point.
Chassis 101
Ackerman is the principal that the inside steering tire will follow a shorter radius than the outside steering tire. Projected axel centerlines will meet at the same point.
Roll axis is the line between the center of mass at the front axle center line mid-point, to the center of mass at the rear axle center line mid-point.
Camber is the angle of the radial plane of a tire to the road surface. Looking from the rear to the front along the roll axis; a smaller angle on the inboard side of the tire radial plane than on the outboard side is Negative Camber. Positive is the opposite.
Zero camber is when it’s perpendicular to the road.
Toe angle is the angle of the tire radial plane relative to the roll axis looking from the top down. The roll axis would appear as a line. Toe- in is when the tire radial planes relative to the roll axis converges forward of the chassis. Toe out is the opposite. Zero toe is when the tire radial plane is parallel to the roll axis.
Bump steer refers to toe angle change caused by up (bump) and down (droop) movement of the outboard end of the control arms.
Tire contact patch is the “foot print” the tire bears on the road surface.
Scrub radius describes the circular path the center of the contact patch takes, when steering input is entered. Zero scrub radius means; the center of the contact patch is the center of rotation when steering is input. An important design parameter, rarely discussed.
There are a few others I’ll save for later.
The ideal scenario for an optimal chassis is to meet all dynamic outside forces with equal and opposite ones. And no more. Unnecessary opposite force cost contact patch friction.
The 88 chassis is a dream for an engineer car guy who’s favorite car thing is chassis. Why?
Let’s see …. First off, clearly it was the work of an engineering studio dedicated to building an actual mid-engine sports car . No, lotus wasn’t involved, but they appear to be working out of the same book. Especially at the front.
Clearly the early cars were never intended to be true sports cars. Their suspension geometry is actually worse than an MGB. Of course the MGB is a pretty nice 70 year old sports car chassis. We know that the front is from a Chevy Chevette and the rear is a backwards Citation. Brilliant on a budget …. but not a sports car.
I agree with Carter, I really like the 88 chassis as a starting point to a very serious Sports Car. I'll continue this if anybody's interested. |
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Hahah... you certainly have the narcissism going in the previous post, but I definitely appreciate this response, lots of good info in here. For my own personal goals... I largely don't even know where to start, but getting everything properly replaced and restored is the first goal. When I have to start putting the front suspension bolts back in, I'll make sure I read up more on this so I don't upset camber and caster.[This message has been edited by 82-T/A [At Work] (edited 06-29-2024).]
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ceverhart
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JUN 28, 10:44 AM
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please continue Yellow -88
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ricreatr
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JUN 28, 12:19 PM
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(oh sweet, havent posted that in a decade. still memeberd how)
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