How do I get rid of massive push
Moderators: The Dark Side of Will, Series8217
How do I get rid of massive push
Well I am starting to get irritated with how much my car pushes when I autox. Especially after riding in a Lotus Elise around the course. What are the best ways to get rid of the push that my car has so that it will actually turn in the corners? My car is an 87GT with 88 cradle, rear coilovers, and koni's. Any advice would be appreciated. Thanks, Mark
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Shaun41178(2)
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scrabblegod
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I am not sure as to the rear on yours with the 88 cradle.
On my 87 I have -2degrees camber, 7 degrees caster and 1/16 toe out.
On the rear I have -2 camber and 1/8 toe in with the rear swaybar mounted in poly.
I just had it set to these specs a month ago, and it made an amazing change in my last two events.
Gene
On my 87 I have -2degrees camber, 7 degrees caster and 1/16 toe out.
On the rear I have -2 camber and 1/8 toe in with the rear swaybar mounted in poly.
I just had it set to these specs a month ago, and it made an amazing change in my last two events.
Gene
First, understand, no matter what you do, your fiero will not handle like an Elise. If that's what you're after, just buy the Lotus. It's what I plan on doing.
What springrates are you running? Both front and rear.
What are the Konis adjusted to?
What are your alignment specs?
assuming nothing is wrong there:
For autoX, the first thing I would play with would be toe out in the front. It's like preloading ackerman.
What springrates are you running? Both front and rear.
What are the Konis adjusted to?
What are your alignment specs?
assuming nothing is wrong there:
For autoX, the first thing I would play with would be toe out in the front. It's like preloading ackerman.
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The Dark Side of Will
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Hard mods:
A) Build control into the chassis before you increase its limits. You have poly, but I would suggest 8shark's UHMW. www.8shark.com
Poly cradle bushings?
B) Fieros need wide rear tires and stiff rear suspension. It sounds like you're running 205's all around. Go MUCH wider in the back... as wide as feasbile. This may not on the surface seem to get rid of push, but it will prevent snap oversteer and reduce the car's lift throttle reaction when you do get your suspension dialed in to make the car neutral.
C) Stiffen the rear suspension. Koni coil overs with 300+# springs and a rear sway bar as large as the front bar are a good place to start.
Settings:
Alignment can make a HUGE difference in how your car handles.
Some good suggestions have already been made in that area.
Stock toe OUT front
Stock toe (or a little more) IN rear
As much camber as you can get. Eccentric lower control arm bushings help immensely in the front. Those and slotted upper ball joints should be all you need. Don't bother with eccentric upper bushings unless you're building an all out race car. With hard bushings the stock rear adjustment setup should be able to give you enough camber. I'm looking at -1.5 each side on the front and -1.75ish each side on the rear.
Castor... that's a matter of preference... I like less as it gives you better contact patch feel at the limit. Use washers to achieve a castor setting you can live with. It will be a PITA to find because you'll have to make the change, go back to the shop and measure how much it changes, calculate how much you should have to change it to get where you want, make the change, get it realigned, find out that's not what you really wanted, repeat with a different Casotr setting.
Buy a lifetime alignment from Firestone or other chain store. It's worth 10 times what you pay for it if you try frequent alignment changes.
If you have coil overs, see what you can do about getting your car cornerweighted so you can adjust the coil overs properly.
A) Build control into the chassis before you increase its limits. You have poly, but I would suggest 8shark's UHMW. www.8shark.com
Poly cradle bushings?
B) Fieros need wide rear tires and stiff rear suspension. It sounds like you're running 205's all around. Go MUCH wider in the back... as wide as feasbile. This may not on the surface seem to get rid of push, but it will prevent snap oversteer and reduce the car's lift throttle reaction when you do get your suspension dialed in to make the car neutral.
C) Stiffen the rear suspension. Koni coil overs with 300+# springs and a rear sway bar as large as the front bar are a good place to start.
Settings:
Alignment can make a HUGE difference in how your car handles.
Some good suggestions have already been made in that area.
Stock toe OUT front
Stock toe (or a little more) IN rear
As much camber as you can get. Eccentric lower control arm bushings help immensely in the front. Those and slotted upper ball joints should be all you need. Don't bother with eccentric upper bushings unless you're building an all out race car. With hard bushings the stock rear adjustment setup should be able to give you enough camber. I'm looking at -1.5 each side on the front and -1.75ish each side on the rear.
Castor... that's a matter of preference... I like less as it gives you better contact patch feel at the limit. Use washers to achieve a castor setting you can live with. It will be a PITA to find because you'll have to make the change, go back to the shop and measure how much it changes, calculate how much you should have to change it to get where you want, make the change, get it realigned, find out that's not what you really wanted, repeat with a different Casotr setting.
Buy a lifetime alignment from Firestone or other chain store. It's worth 10 times what you pay for it if you try frequent alignment changes.
If you have coil overs, see what you can do about getting your car cornerweighted so you can adjust the coil overs properly.
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Series8217
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Well my when I had the car aligned last summer the guy couldn't get it to what I wanted. I think it ended up with only -1 deg front, 0 toe, I moved as many washers as I could to increase caster. I have slotted ball joints and moved them as far as I could, but still could only get -1 degree. I kinda forget what the camber was in the rear, but it couldn’t have been more than -1 deg. The rear also had 0 toe and it has 325# 10" springs. The front shocks are about 2/3 full hard. The car has the stock front 87GT swaybar and stock 88 rear bar. Also stock front springs. I am running 33psi front cold, and 35psi rear cold.
As for the rear, the shocks have about 2.5 turns from full soft to full stiff. I have been running them at 1 turn from full stiff since the middle of last summer. When at full stiff, it was harder to tell where the traction limit was, making it harder to recover when it did break loose. I may try going to a half turn since I have been getting good at drifting the car under control when I need to.
I know that I need better alignment settings. I have slotted ball joints moved as far as possible and I did move washers on the UCA to increase the caster. When I was building the car I was debating getting the 8Shark bushings. Now I wish that I had, since I would have gotten more camber and eliminated the squeaky poly. I didn’t even install grease fitting in the poly. :cussing: I might replace the bushing next year. I will get wider tires for the rear next year. I have heard the wider tire in rear thing before, but I just like being able to rotate them since the car eats up the rear tires a lot faster. I guess I could buy two rear sets.
Any help would be appreciated. I’m going to an autocross on Sat, so I’ll try stiffening up the rear and see how that goes. –Mark
BTW I have a spinout video from two weeks ago I could post if anyone wants.
As for the rear, the shocks have about 2.5 turns from full soft to full stiff. I have been running them at 1 turn from full stiff since the middle of last summer. When at full stiff, it was harder to tell where the traction limit was, making it harder to recover when it did break loose. I may try going to a half turn since I have been getting good at drifting the car under control when I need to.
I know that I need better alignment settings. I have slotted ball joints moved as far as possible and I did move washers on the UCA to increase the caster. When I was building the car I was debating getting the 8Shark bushings. Now I wish that I had, since I would have gotten more camber and eliminated the squeaky poly. I didn’t even install grease fitting in the poly. :cussing: I might replace the bushing next year. I will get wider tires for the rear next year. I have heard the wider tire in rear thing before, but I just like being able to rotate them since the car eats up the rear tires a lot faster. I guess I could buy two rear sets.
Any help would be appreciated. I’m going to an autocross on Sat, so I’ll try stiffening up the rear and see how that goes. –Mark
BTW I have a spinout video from two weeks ago I could post if anyone wants.
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Doug Chase
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I think your alignment settings are pretty good. 1 degree negative is not bad for what you have to work with in the front.
Zero toe in the rear will definitely help. Sometimes too much so be careful while you're learning the new setup.
Adjusting the rear shocks will control how the car handles on turn-in. Stiffen up the shocks to get a little rotation and make the car turn in better. Soften them up if it wants to snap on turn-in. You're better off not trail braking for the time being.
When I was autocrossing I found that when you start fine tuning you can do about 1/4 turn increments. Use larger increments at first them work smaller as you get closer.
If the car turns in well but pushes in the middle of the corner, then you will need to change either springs or sway bars. Stiffen up the rear roll rate, either with springs or a bar, and / or soften up the front roll rate, either with springs or a bar.
Larger rear tires will make understeer worse, so save your money for now.
Tuning handling in this way is simple, it just takes time and money. And tires make the biggest difference of all, so consider that when you're deciding where to spend.
Zero toe in the rear will definitely help. Sometimes too much so be careful while you're learning the new setup.
Adjusting the rear shocks will control how the car handles on turn-in. Stiffen up the shocks to get a little rotation and make the car turn in better. Soften them up if it wants to snap on turn-in. You're better off not trail braking for the time being.
When I was autocrossing I found that when you start fine tuning you can do about 1/4 turn increments. Use larger increments at first them work smaller as you get closer.
If the car turns in well but pushes in the middle of the corner, then you will need to change either springs or sway bars. Stiffen up the rear roll rate, either with springs or a bar, and / or soften up the front roll rate, either with springs or a bar.
Larger rear tires will make understeer worse, so save your money for now.
Tuning handling in this way is simple, it just takes time and money. And tires make the biggest difference of all, so consider that when you're deciding where to spend.
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The Dark Side of Will
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I disagree about the battery. The last thing you want to do for push is put more weight up front.Pyrthian wrote:stiffen up your rear sway bar (or soften your front sway bar) & move your battery up front.
Also, the very concept behind the Fiero--mid engine car--is that the engine is where it is in order to minimize the car's moment of inertia. Moving the battery to the front actively counteracts this goal by spreading mass out across the car instead of concentrating it and thereby increasing moment of inertia instead of reducing it.
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The Dark Side of Will
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Hehe... Spinouts are cool. Is it anything like that one in which a V8 Fiero on stock suspension and tires gets about 540 degrees?Dough19 wrote:Well my when I had the car aligned last summer the guy couldn't get it to what I wanted. I think it ended up with only -1 deg front, 0 toe, I moved as many washers as I could to increase caster. I have slotted ball joints and moved them as far as I could, but still could only get -1 degree. I kinda forget what the camber was in the rear, but it couldn’t have been more than -1 deg. The rear also had 0 toe and it has 325# 10" springs. The front shocks are about 2/3 full hard. The car has the stock front 87GT swaybar and stock 88 rear bar. Also stock front springs. I am running 33psi front cold, and 35psi rear cold.
As for the rear, the shocks have about 2.5 turns from full soft to full stiff. I have been running them at 1 turn from full stiff since the middle of last summer. When at full stiff, it was harder to tell where the traction limit was, making it harder to recover when it did break loose. I may try going to a half turn since I have been getting good at drifting the car under control when I need to.
I know that I need better alignment settings. I have slotted ball joints moved as far as possible and I did move washers on the UCA to increase the caster. When I was building the car I was debating getting the 8Shark bushings. Now I wish that I had, since I would have gotten more camber and eliminated the squeaky poly. I didn’t even install grease fitting in the poly. :cussing: I might replace the bushing next year. I will get wider tires for the rear next year. I have heard the wider tire in rear thing before, but I just like being able to rotate them since the car eats up the rear tires a lot faster. I guess I could buy two rear sets.
Any help would be appreciated. I’m going to an autocross on Sat, so I’ll try stiffening up the rear and see how that goes. –Mark
BTW I have a spinout video from two weeks ago I could post if anyone wants.
-1 is about as much camber as you'll get on slotted ball joints alone. You'll need eccentric bushings to go further.
Most people usually run between 1/2 and 1 turn from full soft on the front shocks, so you're a bit stiffer than normal there.
A good setting for the rears is usually very close to full stiff, but you have a viable reason for not being there just yet.
As Doug Chase asked... does the car push on turn-in or steady-state cornering?