DIY Alignment?

[Achilles99]

Has anyone tried to align their own SRT before? Now that I'm tracking more often, I'd like to experiment with camber and toe settings. I've had it professionally aligned to:

Front:
-1.5 camber
5.5 caster
1/16 toe out

Rear:
-1.0 camber
1/8 toe in

I'd like to dial in another degree of front camber, and maybe another half degree in the rear. I bought a smartcamber gauge which should allow for easy measurement of caster and camber, but will probably use strings for the toe. Having a lift definitely helps.

I'd rather not pay $150 to align it before and after each track event. It seems simple enough looking at the factory manuals. Two eccentric camber bolts, and a tie-rod for toe. I watched two separate race shops align my car, and it seemed doable at home. I'm not looking for laser precision, and from what I've seen the "best" alignments I've ever received rarely used lasers at all (apparently lasers are off quite a bit with calibration).

Any tips from those who have done it before? I'll probably mark the bolts to make it easier to return back to the current settings. Any idea how far the cam bolts need to be turned for another degree of negative camber? Is there a trick to keep the caster roughly the same while adjusting camber?

 

[Viper X]

I've been doing this for a while and find that once I get the alignment where I want it, I just leave it there. It works fine for short rides on the street.

I bought a camber gauge too and Smart Strings for the toe. Both work well.

Adding another degree of negative camber up front and a 1/2 degree in the back should work well on the track, as a general setting.

You could add a bit more "toe in" at the rears too.

Tips would be:

1 - These adjustments are fairly easy to do, you just need a level floor or some way of achieving level

2 - Snap On makes a tool that sits on your driver's seat, presses up against the steering wheel and helps keep the steering wheel centered while adjusting toe. It really helps if you are doing this by yourself, and I usually am.

2 - To make minor adjustments to negative camber, such as those mentioned above, loosen the front eccentric bolts only and try to get where you want to be without changing the rear eccentric bolts. This shouldn't mess up your Castor setting too much but you will have to redo the toe settings.

Now, take your car to the track and see how it feels. As you get better, you can adjust your set up for each track that your drive at.

Good luck,

Dan

 

[Achilles99]

Great advice Dan. Do you have any suggestions on which wheels to do first?

EDIT: Just read factory service manuals. They recommend setting toe on rears first.

 

[Viper X]

Great advice Dan. Do you have any suggestions on which wheels to do first?

EDIT: Just read factory service manuals. They recommend setting toe on rears first.

Yes, that's what I do too, just makes sense - never read the manual.

 

[Newport Viper]

Dan

In my Gen 1 days didn't you have to sandbag (drivers weight) the drivers seat to do the alignment?

Same with the Gen 3/4?

 

[jimsmyth1]

Dan

In my Gen 1 days didn't you have to sandbag (drivers weight) the drivers seat to do the alignment?

Same with the Gen 3/4?

Just had my '04 aligned last week and needed 150 lbs in each seat and a full tank of fuel. I had 7/8 tank and me and the parts counter guy weighed 170 each so we played "sandbag" for about an hour.

 

[jk]

I remember this quote dealing with alignment:

"In a process normally performed only on race cars, an alignment machine sets caster and camber at normal ride height, and then at jounce and at rebound (upward and downward travel of suspension). The 2008 Dodge Viper SRT10 is the only U.S. production vehicle set up for such alignment at the factory; it uses a machine that aligns all four wheels off their wheel hubs, moving them up and down in their suspension travel and setting alignment in three different positions."

Which makes me wonder how you do this on your own?

 

[Achilles99]

OK, so I just finished doing my alignment with the help of ChrisGTS. We'll do his car next. Before we do, some notes and questions:

I was trying to reach -2.5 camber on the front wheels. I moved the rear eccentric bolt to it's maximum position outwards (thus decreasing camber), and was ONLY able to reach -2.0 degrees without dropping caster below 5 degrees. If I move the front eccentric outwards (also decreasing camber past -2.0), I reduce caster. Is there any other way to get more camber? I thought the Viper suspension could go more negative.

In other words:
1) Moving the rear eccentric bolt towards outside of car gives more negative camber (good) and increases caster (good). I'm maxed out here though.
2) Moving front bolt outwards gives more negative camber (good) BUT decreases caster (bad).

What would you guys do? If I bring camber down to -2.5, I'd have to move the front bolt which will bring my caster down to about 3.5 to 5 range. Which is more important, camber or caster? I'd like to hear from you guys who have actually experienced the difference.

It's also worth noting that the Viper X said moving the front bolt does NOT affect caster as much. Several other cars are the same way. However, given what I experienced, I think that only applies when you are within a certain camber range (maybe -1.0 to -1.5). Once you are trying to get to -2.5, it's impossible to get to that camber without moving the rear all the way towards the outside. Or, I should say that if you move the front bolt outwards to reduce camber (without moving rear bolt), you'll decrease caster too much.

Am I missing something here? Is there another combination that I'm not seeing with the bolts?

Toe is very easy to set if you have a lift. We tied a string from the front post to the rear post (on both sides), and squared it up (on my lift, 8 feet between the two). After driving the car up, we measured the distance from the hub to the string, and adjusted the string accordingly. You MUST move the strings in opposite directions to keep the 8 foot distance consistent. IE, if you have 13" on one side and 15" on the other, you have to move them both to 14" You can't move the 13" to 15" That would destroy the parallel lines, and give you more of a trapezoid shape with the strings. Then, you measure the front of the wheel with the rear of the same wheel to get toe measurements. We found that 1 turn of the toe rod is equal to 1/8" of movement. The easy way to do this is to turn the rod until all the slack is taken up by the ball joint. THEN count the turn of the rod. Lock the nut, and twist the rod until the ball joint attachment is level again.

All in all, I'd say that doing an alignment job is worth the time invested to learn. Chris and I spent a good 10 hours doing this (which included figuring out how to setup the strings, which tools we needed, etc.). Most of the time was wasted as we tried to adjust both front wheels at the same time, and adjusting both bolts at the same time. This created a lot of confusion and unneeded measuring. It was easier to work on one bolt at a time, reducing the amount of variables AND measurements. I'm sure we'll do future alignments in an hour or less. We marked the starting positions of the bolts with whiteout, so it'll be easy to return to our previous street/track setting of -1.5 degrees, although we'll probably just drop it down to -1.0 for street driving and go to -2.0 for the track.

The rear wheels were easy. No caster setting. Just move one or both bolts to give you more negative camber. We went from -0.5 to -1.3.

We picked up some good tricks along the way. The most time saving probabably being how to measure caster:

1) You can measure caster with a smartcamber gauge by holding it up to the shock tower. That will give you a good estimate. Also, while moving the front or rear bolts you can literally see the shock tower move, telling you if the caster has decreased or increased.

2) Most people measure caster by moving the wheels left 20 degrees and right 20 degrees, and measuring camber in both situations. Then, using math you calculate caster. This is time consuming if you use the 20 degree paper template provided with most camber gauges, which involves using a straight edge and making sure the template is paralle with the car. We found it much easier to MEMORIZE the steering wheel position at 20 degrees. On the viper, I found it was easy. Just turn the wheel almost a full turn, but stop when the spoke of the steering wheel points towards 5:00 or 7:00 (depending on whether you are turning left or right). You'll know what I mean if you use the template the first few times.

Lastly, in terms of weighting the car we found that it doesn't make too much difference. If I'm in the car, camber changes by decreasing about -0.1 degrees. I'm 165 lbs. I guess I was expecting a greater difference.

 

[Viper X]

OK, so I just finished doing my alignment with the help of ChrisGTS. We'll do his car next. Before we do, some notes and questions:

I was trying to reach -2.5 camber on the front wheels. I moved the rear eccentric bolt to it's maximum position outwards (thus decreasing camber), and was ONLY able to reach -2.0 degrees without dropping caster below 5 degrees. If I move the front eccentric outwards (also decreasing camber past -2.0), I reduce caster. Is there any other way to get more camber? I thought the Viper suspension could go more negative.

It can. You must lower the ride height of the car to gain more negative camber.

In other words:
1) Moving the rear eccentric bolt towards outside of car gives more negative camber (good) and increases caster (good). I'm maxed out here though.
2) Moving front bolt outwards gives more negative camber (good) BUT decreases caster (bad).

What would you guys do? If I bring camber down to -2.5, I'd have to move the front bolt which will bring my caster down to about 3.5 to 5 range. Which is more important, camber or caster? I'd like to hear from you guys who have actually experienced the difference.

Caster should stay above 5, again lower the car.

It's also worth noting that the Viper X said moving the front bolt does NOT affect caster as much. Several other cars are the same way. However, given what I experienced, I think that only applies when you are within a certain camber range (maybe -1.0 to -1.5). Once you are trying to get to -2.5, it's impossible to get to that camber without moving the rear all the way towards the outside. Or, I should say that if you move the front bolt outwards to reduce camber (without moving rear bolt), you'll decrease caster too much.

Am I missing something here? Is there another combination that I'm not seeing with the bolts?

I am at -3.0 camber front, caster 5.7 at smooth track ride height or about 4.0 inches from the ground to the frame between the lower A arms.

Toe is very easy to set if you have a lift. We tied a string from the front post to the rear post (on both sides), and squared it up (on my lift, 8 feet between the two). After driving the car up, we measured the distance from the hub to the string, and adjusted the string accordingly. You MUST move the strings in opposite directions to keep the 8 foot distance consistent. IE, if you have 13" on one side and 15" on the other, you have to move them both to 14" You can't move the 13" to 15" That would destroy the parallel lines, and give you more of a trapezoid shape with the strings. Then, you measure the front of the wheel with the rear of the same wheel to get toe measurements. We found that 1 turn of the toe rod is equal to 1/8" of movement. The easy way to do this is to turn the rod until all the slack is taken up by the ball joint. THEN count the turn of the rod. Lock the nut, and twist the rod until the ball joint attachment is level again.

All in all, I'd say that doing an alignment job is worth the time invested to learn. Chris and I spent a good 10 hours doing this (which included figuring out how to setup the strings, which tools we needed, etc.). Most of the time was wasted as we tried to adjust both front wheels at the same time, and adjusting both bolts at the same time. This created a lot of confusion and unneeded measuring. It was easier to work on one bolt at a time, reducing the amount of variables AND measurements. I'm sure we'll do future alignments in an hour or less. We marked the starting positions of the bolts with whiteout, so it'll be easy to return to our previous street/track setting of -1.5 degrees, although we'll probably just drop it down to -1.0 for street driving and go to -2.0 for the track.

-1.5 front and 1.0 rear is fine for the street.

The rear wheels were easy. No caster setting. Just move one or both bolts to give you more negative camber. We went from -0.5 to -1.3.

We picked up some good tricks along the way. The most time saving probabably being how to measure caster:

1) You can measure caster with a smartcamber gauge by holding it up to the shock tower. That will give you a good estimate. Also, while moving the front or rear bolts you can literally see the shock tower move, telling you if the caster has decreased or increased.

2) Most people measure caster by moving the wheels left 20 degrees and right 20 degrees, and measuring camber in both situations. Then, using math you calculate caster. This is time consuming if you use the 20 degree paper template provided with most camber gauges, which involves using a straight edge and making sure the template is paralle with the car. We found it much easier to MEMORIZE the steering wheel position at 20 degrees. On the viper, I found it was easy. Just turn the wheel almost a full turn, but stop when the spoke of the steering wheel points towards 5:00 or 7:00 (depending on whether you are turning left or right). You'll know what I mean if you use the template the first few times.

Lastly, in terms of weighting the car we found that it doesn't make too much difference. If I'm in the car, camber changes by decreasing about -0.1 degrees. I'm 165 lbs. I guess I was expecting a greater difference.

Cross or corner weights won't change much with you in the car either.

You can also measure camber with the wheel off of the ground as it relates to having the wheel on the ground and get very close with a little practice using the camber gauge, eliminating a bunch of time raising and lowering the car, settling the springs and measuring.

Good luck,

Dan

 

[Achilles99]

Dan, is there an easy way to lower the ride height? I know Corvette guys add washers somehow to their a-arms to get more camber without adjusting ride height, not sure if this is a possibility on our cars?

We adjusted everything while the car was on my 4-post lift. Never lifted the wheels. We were worried that the suspension wouldn't settle after making adjustments to get accurate measurements. To address this, we turned the steering wheel left/right several times after making adjustments, and then measured camber/caster. Much better results this way.

 

[Viper X]

Price is the main factor.

Best way is to buy a set of Moton Club Sports which are adjustable.

Second best way is to buy a set of KW Variant 2s, which are adjustable.

JonB at Partsrack also has lowering caps along with the above items. Call Jon.

Shorter tires, like track tires in 18's, will also give you a bit more negative camber because they lower the car. Installing a set of Kumho Ecsta V700's will give you some additional negative camber.

On the settling of the springs, which you must do, most of us roll the car back and forth a bit. I also rock the car by standing on each side sill. Turning the steering wheel a bit will help up front.

Good luck,

Dan

 

[j-rho]

Shorter tires will lower your CG but they aren't going to change suspension geometry, including camber.

 

[ACRBruce]

I used to use the Smart Camber gauge to do the alignment changes at home as my GT3 and EVO both have adjustable camber plates. I have monkey around with the Viper yet but will probably do so in the not so distant future. I discovered a cheap way to measure camber using the iPhone a while back and you may want to try that first if you don't want to spend the money on the Smart Camber gauge AND have an iPhone. There's a free app called the iHandy Carpenter, there's a paid version but even the free version has a bubble level with digital readout and I am able to get fairly close results by first measuring the slope of the ground with the edge of the iPhone and then measure the wheel's angle by putting the iPhone against a straight edge rest against the wheel, then add or substract the angle of the wheel, depending which way the ground is sloping away. Be sure to follow the instructions to calibrate the level of the app first.

 

[Achilles99]

Dan - Exactly when do you settle the springs (ie, after which adjustment?). Chris and I found that if we move the steering wheel back and forth after each adjustment, the measurements we made were the same before and after a test drive. When we didn't move the steering wheel, the adjustments were a little off. We didn't settle anything on the rears, and they are still holding steady knock on wood!

Bruce - good call on the iPhone. I plan to take my wife's with me to the track, there's a great app on it called Hal's GPS laptimer which automatically records your lap times. Since I'll have it with me, I'll use the level on it to check my camber!

Price is the main factor.

Best way is to buy a set of Moton Club Sports which are adjustable.

Second best way is to buy a set of KW Variant 2s, which are adjustable.

JonB at Partsrack also has lowering caps along with the above items. Call Jon.

Shorter tires, like track tires in 18's, will also give you a bit more negative camber because they lower the car. Installing a set of Kumho Ecsta V700's will give you some additional negative camber.

On the settling of the springs, which you must do, most of us roll the car back and forth a bit. I also rock the car by standing on each side sill. Turning the steering wheel a bit will help up front.

Good luck,

Dan

 

[GTS Dean]

A little late to the party - so apologies in advance.

When adjusting the alignment, you should move BOTH lower wishbone cams together by the same amount. This keeps caster angle close to the same, and gives maximum adjustment for camber. After adjusting, you should roll the car a couple of feet front/rear to relieve the lateral stiction in the tires & suspension bushings, or place slip plates under the tires and jounce a few times before measuring the camber & toe. The track width changes as the wheels move through their travel arcs. If you lower the car after adjustment and don't relieve the stiction, the car will not be at its natural ride height (it will be higher) and the readings will be slightly off.

 

[ViperGeorge]

I remember this quote dealing with alignment:

"In a process normally performed only on race cars, an alignment machine sets caster and camber at normal ride height, and then at jounce and at rebound (upward and downward travel of suspension). The 2008 Dodge Viper SRT10 is the only U.S. production vehicle set up for such alignment at the factory; it uses a machine that aligns all four wheels off their wheel hubs, moving them up and down in their suspension travel and setting alignment in three different positions."

Which makes me wonder how you do this on your own?

Yea I remember the same thing. My Viper tech took like 6 hours to do a track alignment on my Gen 3 but then he followed the procedure to the letter. Its awesome now but it cost quite a bit more than $150. The tech was very good and I never have had any issues with his work or price. Unfortunately his dealership was one of those closed by Chrysler Corp.

 

[Achilles99]

Does the lateral stiction still apply if I'm doing the alignment on a 4 post lift? IE, my wheels never leave the "ground" since the wheels are on the ramps the entire time. I do find that I have to move the steering wheel left and right to settle something, though. Just not sure what exactly. I assumed it was the bolts and eccentric nuts.

You are correct about caster, though. The rear adjustment increases caster, and the front decreases it. Moving them both should in theory keep caster the same. However, I found that past -1.5 camber, they aren't 1:1. I pushed rear out all the way, and front almost out all the way, and I still lost caster.

I went from about 5.5 down to 4.2 After a quick test drive, car still turned without noticeable change. After talking with a few racers, they said that they would sacrifice a little caster for more camber. So, I set camber at -2.7 and caster had to be at 4.2 (couldn't change it without messing up camber). I'll report back after my next track event (next weekend).

A little late to the party - so apologies in advance.

When adjusting the alignment, you should move BOTH lower wishbone cams together by the same amount. This keeps caster angle close to the same, and gives maximum adjustment for camber. After adjusting, you should roll the car a couple of feet front/rear to relieve the lateral stiction in the tires & suspension bushings, or place slip plates under the tires and jounce a few times before measuring the camber & toe. The track width changes as the wheels move through their travel arcs. If you lower the car after adjustment and don't relieve the stiction, the car will not be at its natural ride height (it will be higher) and the readings will be slightly off.

 

[GTS Dean]

Does the lateral stiction still apply if I'm doing the alignment on a 4 post lift? IE, my wheels never leave the "ground" since the wheels are on the ramps the entire time.

Good practice is to jounce and/or roll the car every time you make an adjustment so that your tire treads don't have any lateral deflection bound up. Generally speaking, the widest your track width will be is near static ride height. If you jounce the car it comes in, and if you droop the tires it comes in. Specifically speaking, it depends on where you have your ride height set.

I don't adjust my wishbones with load on them - it leads to bent cam stops.

 

[Achilles99]

What is jouncing and drooping a tire, and what exactly "comes in"? At first I thought it was some kind of European term, but then I see you are in TX

Good practice is to jounce and/or roll the car every time you make an adjustment so that your tire treads don't have any lateral deflection bound up. Generally speaking, the widest your track width will be is near static ride height. If you jounce the car it comes in, and if you droop the tires it comes in. Specifically speaking, it depends on where you have your ride height set.

I don't adjust my wishbones with load on them - it leads to bent cam stops.

 

[GTS Dean]

I'm gonna overlook that and assume you're a neophyte. "Comes in" means track width gets narrower. Jounce is bump and droop is rebound.

 

[Achilles99]

Thanks Dean. I'm absolutely a neophyte when it comes to alignment, I always relied on the shop for that. Just trying to learn how to do it myself, and since there isn't a guide on the VCA forums I was hoping to start one up. This thread has been great thanks to everyone's input.

After driving the car around a little, I didn't measure any change in camber, caster or toe. I didn't jounce or droop the tires after each adjustment, but maybe I got lucky. I'll be sure to bounce the car around a little after each adjustment, since rolling it back and forth on the lift will be too time consuming between each adjustment.

 

[Viper X]

Achilles,

Dean is right that you need to get the suspension settled after each adjustment and before you measure it. Also, you should not be making adjustments with your wheels on the ground or on the lift with weight on them unless you have your wheels on a plate that will allow it to move without binding, like a skid plate of some sort.

You can buy or build "skid plates". A simple skid plate can be made with two 26 gauge metal sheets about 12 inches long and 8 inches wide. You can usually buy these already cut at Home Depot. Put the two pieces together with oil or grease between the two sheets of metal on each side of the car, then let the tires down on top of them. Jounce the car a bit and you'll get pretty good readings as the tires will be able to slide back to their correct position without binding. The jouncing will help settle the springs.

For a final measurement, I'd want to drive the car around the block, but the above procedure will help you get very close, very quickly.

Good luck,

Dan

 

[Viper X]

Shorter tires will lower your CG but they aren't going to change suspension geometry, including camber.

My camber gauge says otherwise.....

 

[j-rho]

My camber gauge says otherwise.....

If you have found repeated negative camber "gains" from shorer tires, it speaks only to an error in measurement technique. Think about it - how are you getting that camber change without a toe change? Or do the shorter tires also change toe somehow?

Tire diameter does not affect suspension geometry including camber, caster, or toe. All three alignment parameters interact and you can't change one without changing the other two.

Shorter tires will allow you to lower the car more before you run into a tire-rub situation, and that additional lowering (done at the spring perch), if performed, would beget additional negative camber.

 

[Achilles99]

I'm getting skid plates tomorrow, thanks for the advice!

Achilles,

Dean is right that you need to get the suspension settled after each adjustment and before you measure it. Also, you should not be making adjustments with your wheels on the ground or on the lift with weight on them unless you have your wheels on a plate that will allow it to move without binding, like a skid plate of some sort.

You can buy or build "skid plates". A simple skid plate can be made with two 26 gauge metal sheets about 12 inches long and 8 inches wide. You can usually buy these already cut at Home Depot. Put the two pieces together with oil or grease between the two sheets of metal on each side of the car, then let the tires down on top of them. Jounce the car a bit and you'll get pretty good readings as the tires will be able to slide back to their correct position without binding. The jouncing will help settle the springs.

For a final measurement, I'd want to drive the car around the block, but the above procedure will help you get very close, very quickly.

Good luck,

Dan

 

[GTS Dean]

Tire diameter does not affect suspension geometry including camber, caster, or toe. All three alignment parameters interact and you can't change one without changing the other two.

Tire diameter DOES affect the Roll Center Height. Tire loaded radius, along with static ride height are the primary user adjustments for RCH.

 

[j-rho]

Tire diameter DOES affect the Roll Center Height. Tire loaded radius, along with static ride height are the primary user adjustments for RCH.

Yes true, but you should also agree it does not affect camber, caster, or toe. I figure the audience should try to swallow that bit before introducing further confusion via RCH, FVSA lengths, etc.