I've had my 2005 SRT-10 for about 2 years now and I'm wanting to do a few upgrades. First off I want to upgrade my brake system. I'm not doing any tracking, I'm just looking for some extra stoping power.
Also, I'm looking to upgrade my suspension system. Maybe lower it 1" or so. But I dont want to compromise the ride quality I have now. If anything a little softer would be nice. The roads really suck around here, lots of humps, bumps, dips, uneven road conditions, really the worst roads ever for driving a viper. I've been in moderate cornering conditions, and drive over a little bump, and the rear end will bounce out. This can be quite scary if your not ready for it. I'm hoping some suspension upgrades will help. Any suggestions would be great.
Thanks
__________________
2007 Acura MDX Sport/Ent
2005 Dodge Viper SRT10
2004 Jeep Grand Cherokee Ltd
2000 Pontiac Trans Am
1992 Dodge Stealth RT
1991 Dodge Stealth RT Turbo
Only just came to this forum to double check when I heard you guys had a live rear axle. Searched it, this post came up and I figured I could help.
Anyway, I'm gonna fly in the face of the vast majority of what people will say here, since the vast majority of people have some inaccuracies in their suspension knowledge.
First of all, hardening your suspension is going to make handling a lot worse, if you live on a bumpy road. The only advantage lowering your suspension has is to increase roll hardness without increasing lateral weight transfer. If you have a live rear axle, you shouldn't worry about rear roll hardness, since the main reason for it is nullified by the fact that your suspension geometry won't change in a bad way during roll.
Also, if you harden/add a rear roll bar, you will be making the tail come out even more easily in turns. A harder roll bar on the front may be advisable, but its almost certainly going to make front grip worse in corners and ESPECIALLY in bumps, while making only a slight difference to the rear (since again, the main purpose of roll stiffness, keeping the geometry constant, is nullified)
I would recommends progressive rate springs that are softer than your current ones in the middle, giving a good bit of soft travel, before hardening up. If you can , make them harden up to a very large extent in the last bit of travel, to avoid hitting the bump stops.
Oh, and don't lower your car any, you need as much suspension travel as you can get. If you want to tweak your cars bump-versus-G handling ability in turns, you can increase ride height and equip softer, longer springs to increase bump handling, or vice versa for Gs.
Yes your car will roll more with progressive springs, especially in the rear, which will be ever so slightly bad for steady state high g turning, but the benefit is to increase the bump handling ability of your car, since you said you live in a bumpy area.
Now, I've helped you as best I can, someone help me and tlel me if this live rear axle thing is true?
Only just came to this forum to double check when I heard you guys had a live rear axle. Searched it, this post came up and I figured I could help.
Anyway, I'm gonna fly in the face of the vast majority of what people will say here, since the vast majority of people have some inaccuracies in their suspension knowledge.
First of all, hardening your suspension is going to make handling a lot worse, if you live on a bumpy road. The only advantage lowering your suspension has is to increase roll hardness without increasing lateral weight transfer. If you have a live rear axle, you shouldn't worry about rear roll hardness, since the main reason for it is nullified by the fact that your suspension geometry won't change in a bad way during roll.
Also, if you harden/add a rear roll bar, you will be making the tail come out even more easily in turns. A harder roll bar on the front may be advisable, but its almost certainly going to make front grip worse in corners and ESPECIALLY in bumps, while making only a slight difference to the rear (since again, the main purpose of roll stiffness, keeping the geometry constant, is nullified)
I would recommends progressive rate springs that are softer than your current ones in the middle, giving a good bit of soft travel, before hardening up. If you can , make them harden up to a very large extent in the last bit of travel, to avoid hitting the bump stops.
Oh, and don't lower your car any, you need as much suspension travel as you can get. If you want to tweak your cars bump-versus-G handling ability in turns, you can increase ride height and equip softer, longer springs to increase bump handling, or vice versa for Gs.
Yes your car will roll more with progressive springs, especially in the rear, which will be ever so slightly bad for steady state high g turning, but the benefit is to increase the bump handling ability of your car, since you said you live in a bumpy area.
Now, I've helped you as best I can, someone help me and tlel me if this live rear axle thing is true?
Is this a joke? You don't know shit about how to make a car handle. Your "harder" "roll bar" might be similar to a stiffer anti sway bar but please don't try to advise someone about something you dont understand. Progressive springs always increase stiffness the more they are compressed. Nevermind, there are way too many things to correct and I have lost interest.
I've had my 2005 SRT-10 for about 2 years now and I'm wanting to do a few upgrades. First off I want to upgrade my brake system. I'm not doing any tracking, I'm just looking for some extra stoping power.
Also, I'm looking to upgrade my suspension system. Maybe lower it 1" or so. But I dont want to compromise the ride quality I have now. If anything a little softer would be nice. The roads really suck around here, lots of humps, bumps, dips, uneven road conditions, really the worst roads ever for driving a viper. I've been in moderate cornering conditions, and drive over a little bump, and the rear end will bounce out. This can be quite scary if your not ready for it. I'm hoping some suspension upgrades will help. Any suggestions would be great.
Thanks
Honestly, the brakes are perhaps the last thing you need to upgrade on the Gen III Viper, particularly if you are not tracking the car. The stock brake system is truly world class. Get some braided brake lines, and some Castrol SRF brake fluid, and you really are pretty much set to go. You can improve the front brake ducting a bit as well to increase airflow across the rotors for additional cooling.
If you are truly set on upgraded rotors, the ones to get are the Stoptechs.
They won't provide a whole lot of additional stopping power, but they are significantly lighter, which will reduce your unsprung weight and improve handling.
As for suspension upgrades, you will need to spend some real money to get a significantly upgraded set up. First off, you will need a good set of double adjustable coil-over dampers. I have the Moton Club Sports. These are probably the most popular, but I have heard good things about the Penske and KW dampers as well. Match the new dampers with some slightly stiffer springs. I use Eibachs in 550 front and 750 rear. I believe that stock springs are in the range of 350 front and 550 rear.
Keep you damper settings relatively soft. My Club Sports have 7 positions, and I run the rebound at 4 all around (to offset the higher spring rates) with front bump at 4, and rear bump at 3. Ride quality is much more comfortable than the stock ride. I live at the end of a long, washboard dirt road. With the stock suspension, driving at any speed over 10mph was like being caught inside a paint shaker. With my suspension mods, I can drive at 45mph, and be perfectly comfortable. The car is less unsettled at speed by bumps, ruts, dips, etc. as well.
Tires: If you are running runflats, you should consider a change to the PS2 which is now available in sizes to fit your stock Viper wheels. These tires have more grip, give a softer ride, and are all around terrific tires. Buy a Continental emergency inflation kit for some peace of mind if you are worried about a flat tire.
Wheels: Lighter wheels will significantly reduce your unsprung weight, which will really improve your handling. Get the lightest wheels you can find. I saved over 20 pounds per corner by going with lightweight wheels and non-runflat tires. (But I went down to an 18 inch wheel in the rear, which you probably won't want to do, as it doesn't look as good as a 19.)
I installed a set of Competition Coupe sway bars on my car. They are substantially stiffer than the stock bars. If I ran the car on slicks all the time, the Comp Coupe bars might have been a good idea. However, they were just a bit too stiff for the car when driven with anything other than full race rubber. The car tended to skate and slide more than it should. If I were into drifting, it would have been a perfect set up, but for streets (and even track) use, they were overkill. I took them off, and am running the stock sway bars again. If you are going to change the sway bars, I would highly suggest a set of (expensive) adjustable bars, so you have some options in between stock and the full-on Comp Coupe stiffness, particularly in the rear of the car.
Bottom line:
I'd get the dampers and springs before I upgraded the brakes. Get stiffer springs, and run your dampers relatively soft. Get PS2 tires and lighter wheels. Don't bother with a sway bar unless you get a fully adjustable one.
__________________ 2004 SRT-10
Naturally Aspirated
609 rwhp 609 rw lb-ft tq
Last edited by Kai SRT10 : July 25th, 2007 at 11:48 PM.
No. It is not true. You hve the Viper confused with the Mustang. Maybe you should go to a Mustang forum and try to help Mustang owners.
I thought the guy had mistaken it for the vette since that had leaf springs (in a sence), but yes, the mustang too. Thanks.
Also I would like to add on to your second post (so he knows what a good setup for performance is), that he should add sway hardness to the set of wheels that DON'T break traction in a turn without bumps, and adjust so that eventually both sets of wheels break traction at around the same time, with the minimum total roll stiffness. And then maybe tweak the front sway bar down for a small amount of under steer (as its easier to control), and then tweak for your own handling preference (eg you might want to soften the rear/harden the front some if you want to accelerate harder out of a corner without oversteer).
I assume if you are having traction problems then you spend a lot of time near the limit, and you can test this out till you like it. It probably will take some time. Personally I don't see a point in sway bars in a lot of cases, but if you're gonna do it, you ought to do it right.
Quote:
Originally Posted by redlineviper
Is this a joke? You don't know shit about how to make a car handle. Your "harder" "roll bar" might be similar to a stiffer anti sway bar but please don't try to advise someone about something you dont understand. Progressive springs always increase stiffness the more they are compressed. Nevermind, there are way too many things to correct and I have lost interest.
Yes, I meant anti sway bar. I always call them roll bars, and call what you probably think of when I said roll bar, as a roll cage.
Also, yes, progressive springs increase stiffness as they travel, but I was specifying that they should be softer than his current springs at rest. If they were harder than his current ones at rest, it would make things worse.
Would you like to correct the rest? I've just nullified your first two so unless you can pull some more errors out, I wont agree that I don't know what I'm talking about.
since the vast majority of people have some inaccuracies in their suspension knowledge.
Ya think?
First of all, hardening your suspension is going to make handling a lot worse, if you live on a bumpy road. The only advantage lowering your suspension has is to increase roll hardness without increasing lateral weight transfer. If you have a live rear axle, you shouldn't worry about rear roll hardness, since the main reason for it is nullified by the fact that your suspension geometry won't change in a bad way during roll.
No its to help all four corners stay planted and do their part as all weight above center of gravity shifts. Solid rear axle cars need sway bars just as much. Try taking a camaro or mustang out with no sway bar. Have fun.
Also, if you harden/add a rear roll bar, you will be making the tail come out even more easily in turns. A harder roll bar on the front may be advisable, but its almost certainly going to make front grip worse in corners and ESPECIALLY in bumps, while making only a slight difference to the rear (since again, the main purpose of roll stiffness, keeping the geometry constant, is nullified)
A stiffer front sway bar will not "almost certainly" make it grip worse in corners. Depending on tire compound, air presure, and size it may understeer at limit.
I would recommends progressive rate springs that are softer than your current ones in the middle, giving a good bit of soft travel, before hardening up. If you can , make them harden up to a very large extent in the last bit of travel, to avoid hitting the bump stops[/font].
Oh, and don't lower your car any, you need as much suspension travel as you can get. If you want to tweak your cars bump-versus-G handling ability in turns, you can increase ride height and equip softer, longer springs to increase bump handling, or vice versa for Gs.
You are suggesting to raise the car? Good plan.
Yes your car will roll more with progressive springs, especially in the rear, which will be ever so slightly bad for steady state high g turning, but the benefit is to increase the bump handling ability of your car, since you said you live in a bumpy area.
No, it wont.
Now, I've helped you as best I can, someone help me and tlel me if this live rear axle thing is true?
Since you didn't even know this you obviously just picked up a Car Craft mag and thought you are a racing pro.
Last edited by redlineviper : July 26th, 2007 at 09:16 AM.
No its to help all four corners stay planted and do their part as all weight above center of gravity shifts. Solid rear axle cars need sway bars just as much. Try taking a camaro or mustang out with no sway bar. Have fun.
How will it help keep them planted? Thats what soft suspension is for. The inside wheel will still lift off the ground at the same total weight transfer, so it doesn't actually keep the inside wheel down any longer. You know what the roll bar is gonna do? Hes gonna hit a bump and BOTH tires will lose traction, because BOTH will be lifted off the ground.
Quote:
A stiffer front sway bar will not "almost certainly" make it grip worse in corners. Depending on tire compound, air presure, and size it may understeer at limit.
It *will* almost certainly make the *front* grip worse in corners, and will probably cause both limit and pre-limit understeer. Seems to me you agreed with me directly after disagreeing with me, there.
Quote:
You are suggesting to raise the car? Good plan.
No, I'm suggesting to leave it the same unless he has bump stop problems. Why? Are you suggesting he reduce his suspension travel when even a 'little' bump makes him lose control?
Quote:
No, it wont.
You will recall I told him to get springs wound to have a softer than stock rate at rest. Are you sugesting that wont decrease roll stiffness?
Your problem is you know very little about the stock Viper suspension. You are trying to answer the question without knowing the reasons why he is having handling issues.
Bone stock, the Viper is set up for a smooth track, and performs very well in that environment. However, it works poorly on rough roads. It is a combination of springs, dampers, and tires. As delivered from the factory, all three of these suspension components have very narrow margins in which they perform well.
The reason he is losing control over bumps is not overall lack of suspension travel, it has to do with the way that the stock springs and shocks are set up. The stock springs have non-linear resistance. They are soft initially, but when compressed, they get really really hard very fast. The resistance curve is not progressive, it is exponential.
So, when he hits a big bump, it's not quite as bad as bottoming out, but close, as resistance goes from reasonable to crazy in a very short amount of spring compression. This is what is causing his loss of control over bumps. The stock dampers exacerbate the problem, as they are set up very stiff in terms of high speed bump control.
The answer is not softer springs. The answer is stiffer springs (stiffer to provide better overall support for the car) that have linear compression, so they don't feel like they are bottoming out when they get compressed. Even though the springs are stiffer, they are actually more comfortable and forgiving, because their linear response makes them better at reacting to big bumps.
With these stiffer springs, you can run dampers with reasonable bump settings, without losing overall crisp response. This combination gives you more usable suspension travel and better compliance over bumps, while still supporting the car in turns. As for lowering the car, it can be lowered an inch or so without having to worry much about bottoming out.
If you soften everything up, the car is going to wallow like a pig in mud.
Quote:
Originally Posted by Nereth
How will it help keep them planted? Thats what soft suspension is for. The inside wheel will still lift off the ground at the same total weight transfer, so it doesn't actually keep the inside wheel down any longer. You know what the roll bar is gonna do? Hes gonna hit a bump and BOTH tires will lose traction, because BOTH will be lifted off the ground.
It *will* almost certainly make the *front* grip worse in corners, and will probably cause both limit and pre-limit understeer. Seems to me you agreed with me directly after disagreeing with me, there.
No, I'm suggesting to leave it the same unless he has bump stop problems. Why? Are you suggesting he reduce his suspension travel when even a 'little' bump makes him lose control?
You will recall I told him to get springs wound to have a softer than stock rate at rest. Are you sugesting that wont decrease roll stiffness?
Your problem is you know very little about the stock Viper suspension. You are trying to answer the question without knowing the reasons why he is having handling issues.
Bone stock, the Viper is set up for a smooth track, and performs very well in that environment. However, it works poorly on rough roads. It is a combination of springs, dampers, and tires. As delivered from the factory, all three of these suspension components have very narrow margins in which they perform well.
The reason he is losing control over bumps is not overall lack of suspension travel, it has to do with the way that the stock springs and shocks are set up. The stock springs have non-linear resistance. They are soft initially, but when compressed, they get really really hard very fast. The resistance curve is not progressive, it is exponential.
So, when he hits a big bump, it's not quite as bad as bottoming out, but close, as resistance goes from reasonable to crazy in a very short amount of spring compression. This is what is causing his loss of control over bumps. The stock dampers exacerbate the problem, as they are set up very stiff in terms of high speed bump control.
The answer is not softer springs. The answer is stiffer springs (stiffer to provide better overall support for the car) that have linear compression, so they don't feel like they are bottoming out when they get compressed. Even though the springs are stiffer, they are actually more comfortable and forgiving, because their linear response makes them better at reacting to big bumps.
With these stiffer springs, you can run dampers with reasonable bump settings, without losing overall crisp response. This combination gives you more usable suspension travel and better compliance over bumps, while still supporting the car in turns. As for lowering the car, it can be lowered an inch or so without having to worry much about bottoming out.
If you soften everything up, the car is going to wallow like a pig in mud.
This is true. I know nothing about the stock viper suspension. I had assumed non progressive springs, so I figured by using progressives I could leave the center softer, for bumps, while having the ends of the springs harder, so as to avoid the bump stops. Obviously if I wanted to do this and they already had progressive springs running a very high spring rate gain, my gain would have to be even higher, and yes, the non linearity of the response would be horrible.
The new springs and shocks however should still be as soft as possible without needing an excessive hardness gain at the ends of the travel. Needlessly hardening the entire suspension package (as a lot of people do) leads to the chassis bouncing instead of the tires, which leads, obviously to a whole lot of not fun.
As for you, I believe you had the patience but not the knowledge. Judging by your previous replies you don't even know that sway bars increase weight transfer, they don't decrease it. They do quite the opposite of 'help all four corners stay planted'. In upwards bumps they also do the opposite, by removing load from a tire that would otherwise not be effected.
Similarly, you merely contradict all of my points, rather than tell me why my reasoning is wrong. This leads me to believe that you don't even understand my reasoning, due to your own lack of knowledge. In short, don't '[pick] up a Car Craft mag and [think] you are a racing pro.'
Good plan.
Nice explanation. Didn't have the patiance.
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