Ridetech Strong Arms and Tru Turn with Speedtech Chicane and Guldstrand Mod

[Buryingthesun]

Buryingthesun,

I read your whole build tonight. Excellent work on your build so far, but I see you haven't actually driven your Bird with the Tru Turn yet. I intend to do the G-mod for two reasons. 1) I have easy access installing new suspension parts on a separate frame while I still drive my car. 2) Rod Prouty recommends it. As best as I can tell from his build thread, ridetech is his 4th suspension system he's tried from some of the Pro-Touring's industry's best suspension manufacturers. And his car is a daily driver that was picked for OUSCI. If he's tried that many suspension systems and says the G-mod works, I'll take his word for it. But I intend to do the G-mod like Ryanator has done, so if I decide its not for me I'll still be able to install the upper arm in the stock location.

That's fine, I was just adding my $0.02

[H8rDave]

Thanks for the reply Brian. I don't doubt the performance possibilities here, as we have all seen cars with a similar set up. I have considered this, and it is a bit more expensive than I would have thought, considering that with a good steering box, pitman arm, bump steer correction, and then brakes, the total up front will be well over 6k. And that's OK if it delivers, but I'm wondering, in hind sight, do you see any advantages to buying a complete clip with new geometry?
BTW, keep up the good work, and have a Happy New Years.

For the ridetech Tru Turn, StrongArms, coilovers, swaybar and Speedtech Chicane it's $4185.00. There are cheaper parts to use, but I decided I wanted to use one company that engineered their parts to work together. I haven't factored in brakes yet, because I'm still saving for them. I'm hoping to use OEM brakes for now, but there are some fitment issues I'm working through there.

[b17brian]

That's fine, I was just adding my $0.02

Thanks for your input I can surely use everyone's advise so I don't make any mistakes. This is my largest project on my Camaro so far.

Thanks for the reply Brian. I don't doubt the performance possibilities here, as we have all seen cars with a similar set up. I have considered this, and it is a bit more expensive than I would have thought, considering that with a good steering box, pitman arm, bump steer correction, and then brakes, the total up front will be well over 6k. And that's OK if it delivers, but I'm wondering, in hind sight, do you see any advantages to buying a complete clip with new geometry?
BTW, keep up the good work, and have a Happy New Years.

When its all said and done I will be approaching what it would cost for a new re-engineered subfame complete. I don't have the resources to drop down 7k in one purchase and didn't want to go into debt. Going this route I was able to buy a little at a time. If money wasn't an issue by all means buy the whole package.

[Rod]

When its all said and done I will be approaching what it would cost for a new re-engineered subfame complete. I don't have the resources to drop down 7k in one purchase and didn't want to go into debt. Going this route I was able to buy a little at a time. If money wasn't an issue by all means buy the whole package.

Agreed.....sorta I see that some one says that a new frame is new geometry.....not necessarily...a lot of frames I have looked at simply have a modified mustang two suspension...and the ones that use corvette stuff are pretty cool, but that geometry (in my opinion) was designed to work with with Higher roll steer from and independent rear suspension, or a triangulated 3 link, like the Lateral Dynamics old design, without a higher rear roll steer they push and have slower steering rate, yes you can compensate with heavier rear sway bars and faster rack and pinion ratio, the original factory '67-'69 Camaro/Firebird and '68-'74 Nova and clones were designed with no "camber gain" into its suspension geometry....Fortunately, the stock unequal-length double A-arm front suspensions on these cars can be easily modified to achieve natural camber gain by lowering the upper arms' pivot points.....
You might be wondering how drilling four simple holes could make much difference in how your car handles:

It's all about geometry and even the smallest change to a suspension's geometry can have a profound effect on how a car handles. The roll center is the central point about which a car's body rolls under cornering forces. The amount of body roll depends on the leverage effect between the vehicle's roll center and its center of gravity height. The higher the center of gravity and the lower the roll center, the greater the body roll. On the other hand, if you can lower the center of gravity and raise the roll center, your car will have less body roll and become more stable. You could dial in lots of negative static alignment camber, but that will quickly chew up the inside edges of your tires.

A better way is to generate camber gain by raising the roll center of your car, however, don't raise it too high or you will get excess tire scrub. Like everything in life, you need a balance.

There are three basic ways to gain camber on your front double A-arm suspension.
1) You can shorten the upper control arms
2) install a taller spindle
3) or change the pivot points of your control arms.
In this case, relocating the arms is the cheapest option (since you can't pay less than zero). Using the template designed by Guldstrand (for First Generation Camaros and Firebirds) will let you lower the upper control arm pivot points by .75 inch. This raises the front suspension roll center from below ground level, to a point well above the road. This will reduce the angle of the lower control arms and make them more parallel to the ground, giving you a more favorable camber curve. The new holes will also move the top of the spindle rearward .25 inch from stock. This will create more positive caster, which will make the steering feel more "snappy.

hope that helps

[eric1967]

Do the G mod. I did it last year after talking to Rodney. It changes the feel of the car for the better. I am short on time. But I can give more details tomorrow if you want.

[kirt70camaro]

Hey Rod what if any front clip would you suggest?

[b17brian]

Agreed.....sorta I see that some one says that a new frame is new geometry.....not necessarily...a lot of frames I have looked at simply have a modified mustang two suspension...and the ones that use corvette stuff are pretty cool, but that geometry (in my opinion) was designed to work with with Higher roll steer from and independent rear suspension, or a triangulated 3 link, like the Lateral Dynamics old design, without a higher rear roll steer they push and have slower steering rate, yes you can compensate with heavier rear sway bars and faster rack and pinion ratio, the original factory '67-'69 Camaro/Firebird and '68-'74 Nova and clones were designed with no "camber gain" into its suspension geometry....Fortunately, the stock unequal-length double A-arm front suspensions on these cars can be easily modified to achieve natural camber gain by lowering the upper arms' pivot points.....
You might be wondering how drilling four simple holes could make much difference in how your car handles:

It's all about geometry and even the smallest change to a suspension's geometry can have a profound effect on how a car handles. The roll center is the central point about which a car's body rolls under cornering forces. The amount of body roll depends on the leverage effect between the vehicle's roll center and its center of gravity height. The higher the center of gravity and the lower the roll center, the greater the body roll. On the other hand, if you can lower the center of gravity and raise the roll center, your car will have less body roll and become more stable. You could dial in lots of negative static alignment camber, but that will quickly chew up the inside edges of your tires.

A better way is to generate camber gain by raising the roll center of your car, however, don't raise it too high or you will get excess tire scrub. Like everything in life, you need a balance.

There are three basic ways to gain camber on your front double A-arm suspension.
1) You can shorten the upper control arms
2) install a taller spindle
3) or change the pivot points of your control arms.
In this case, relocating the arms is the cheapest option (since you can't pay less than zero). Using the template designed by Guldstrand (for First Generation Camaros and Firebirds) will let you lower the upper control arm pivot points by .75 inch. This raises the front suspension roll center from below ground level, to a point well above the road. This will reduce the angle of the lower control arms and make them more parallel to the ground, giving you a more favorable camber curve. The new holes will also move the top of the spindle rearward .25 inch from stock. This will create more positive caster, which will make the steering feel more "snappy.

hope that helps

Rod,
That answer made me pull out my chassis engineering book out. One follow up question though. When you say it levels the lower control arm, do you mean the lower ball joint and the lower arm pivot point are level? With the lower arm having such a large curve in it I don't know how else you would make it level.

Do the G mod. I did it last year after talking to Rodney. It changes the feel of the car for the better. I am short on time. But I can give more details tomorrow if you want.

eric1967,
Would love to hear more on your opinion of the G Mod and Tru Turn. Im looking for real world reviews from those already driving their Camaro in that configuration.

[eric1967]

I put the whole ridetech package with arms, single adjustable shocks, sway bar, & Tru Trun. I also went from a 225 front tire to a 275. That was a major game changer. I was very pleased with the improvements on the autocross. The Tru Turn is really noticeable on the street. Sometimes when you drive an older car over a small hill they feel kind of twitchy. All of that drama is gone after the Tru Turn. As far as the G mod. I really notice when braking. The nose of the car does not fall as much & the car stops much better with less pedal effort. I drive my car all over. Most of the time drive to local autocross events about an hour away. Run it all day & drive it home. Usually put about 5000 miles on it thru the summer. I have went to triple adjustable shock now. They are a great tuning tool. If you are just starting to autocross the single adjustable shock work great. Hope this help
Thank Eric

[b17brian]

Thanks Eric. My front end is so loose and twitchy right now. I blasted my frame and will be taking it to the welder to get all the welds re-welded. I'm starting off with the triple adjustable shocks. I'm looking forward to getting my ridetech parts on and feeling the improvement.

[b17brian]

I have a question about the Guldstrand Mod for those that have done it. I am still not 100% sure if I'm doing the G Mod yet, but I'm drilling the holes so I have the option. When I mock up the upper A arm in the G Mod holes, my A arm hits on the mount and won't mount flush. My question is, do the shims installed during alignment take up enough space to prevent it from hitting the mount or do I have to dimple the mount where it curves out? In the pictures you can see it hits where the "X" mark is and I marked where it curves out.

Question 2, what side of the ridetech A arm shaft faces the mount? Do I have the A arm shaft in the correct position in the picture?

[Ryanater]

Hey guys,

I know I am beating a dead horse here, but the whole Guldstrand mod with the ridetech tall spindles has been killing me. So, after losing sleep for the last 2 years, I finally decided to measure the suspension points with the stock pickup points and then with the Guldstrand mod. Then I created an Excel spreadsheet that models camber curve.

While my measurements probably aren't EXACTLY perfect, I did test my calculated results by actually measuring the camber throughout the suspension travel (1" rebound through 2" of compression is all I could get because my gauge only goes from 0 to -6 degrees of camber). Turns out the calculated curve and the points I measured were within .1 degree, so I'm confident that I'm in the ballpark. The other thing to consider is that using the Guldstrand mod raises the roll center. ridetech has a pretty balanced setup, and their 1.5" front sway bar might be too much when the roll center is raised.

Anyway, I found that it really depends on what ride height you are running.... My car is very low, and the lower control arms are actually pointing upward about 1 degree. In this case, the Guldstrand + tall spindle camber curve seemed too aggressive with around 1.7 degrees of camber gain per inch at static ride height. At 1" of compression, the camber gain was over 2 degrees per inch. However, with the stock suspension points, the camber gain was about 1 degree per inch at static, then increased from there. This seemed like a much better camber curve to use.

However, if the car is raised so that the lower control arms are sloping down about 4-5 degrees towards the wheels, using the Guldstrand mod seemed like the better option.

Below are a few screenshots of what I found. (keep in mind that this only takes into account camber gain. I'm not considering caster, anti dive, roll center, etc etc....)



Stock Control Arm Pickup Points: (-1 degree of static camber)




With Guldstrand Mod: (-1 degree of static camber)

[Rod]

Hey guys,

I know I am beating a dead horse here, but the whole Guldstrand mod with the ridetech tall spindles has been killing me. So, after losing sleep for the last 2 years, I finally decided to measure the suspension points with the stock pickup points and then with the Guldstrand mod. Then I created an Excel spreadsheet that models camber curve.

While my measurements probably aren't EXACTLY perfect, I did test my calculated results by actually measuring the camber throughout the suspension travel (1" rebound through 2" of compression is all I could get because my gauge only goes from 0 to -6 degrees of camber). Turns out the calculated curve and the points I measured were within .1 degree, so I'm confident that I'm in the ballpark. The other thing to consider is that using the Guldstrand mod raises the roll center. ridetech has a pretty balanced setup, and their 1.5" front sway bar might be too much when the roll center is raised.

Anyway, I found that it really depends on what ride height you are running.... My car is very low, and the lower control arms are actually pointing upward about 1 degree. In this case, the Guldstrand + tall spindle camber curve seemed too aggressive with around 1.7 degrees of camber gain per inch at static ride height. At 1" of compression, the camber gain was over 2 degrees per inch. However, with the stock suspension points, the camber gain was about 1 degree per inch at static, then increased from there. This seemed like a much better camber curve to use.

However, if the car is raised so that the lower control arms are sloping down about 4-5 degrees towards the wheels, using the Guldstrand mod seemed like the better option.

Below are a few screenshots of what I found. (keep in mind that this only takes into account camber gain. I'm not considering caster, anti dive, roll center, etc etc....)

good stuff ...I think that aggressive camber gain is necessary the wider the tires become

[Ryanater]

That may be true. I'm running 275/35/18s in the front.

I did notice that Detroit Speed publishes their hydroformed subframe camber curve on their website. It appears to have less than 1 degree per inch. Obviously there are a lot of other factors there, and who knows what their static ride height is.

[MonzaRacer]

Ok so as a 30+ yr tech, alignment specialist, and lifelong hot rodder lets under sta d if you want performance handling your ride heght should be closer to having lower arms closer to level. If you set lower then you not closest to zero bumpsteer zone. While ridetech put the kit together to eliminate bumpsteer but that low puts you farther out of optimum running range. Too low is as bad as too hogh, bumpsteer or no neg camber gain. Set a 69 fbody up for friend except he used shockwaves, but was trying to push hard with shock close to bottomed out. Ride height needs to leave shock travel in 60/40 range. Britt and Rod made good points over on latg site better than I can, but my findings show the ore level the lower arm the closer you are. But a faster neg camber curve NEVER hurts. Few years back set up ACR Neon, the next year I had 28 to setup cause my customer and wife had ran on same set of Hoosier race tires for full season, and other drivers were eating 2--3 sets. With one driver.
Listen to Rod guys the guy has even figured out wheel offset can tighten or loosen the car and cost near nothing.

[Ryanater]

I agree that the 0 degree control arm angle is a good rule of thumb. I'm sure there are exceptions, but it seems accurate in this case. As I said earlier, I'm pretty close, with about 1 degree of slope (which is about .25" lower than 0 degrees).

The camber gain is what is in question here. Sure, more camber gain is better to a point. However, there is a point where there is too much. From everything I've read, the target camber gain is around 1 degree per inch. But that is what I've read... I don't have a lot of experience myself. (I did autocross the car last year with the more aggressive camber curve with some success.) I'm just curious if the Guldstrand mod with the ridetech spindles is too much?

I am going to try running the stock pickup points this year and see how I like it. Who knows, maybe I will end up eating the outside of my tires up.

[Rod]

I am going to try running the stock pickup points this year and see how I like it. Who knows, maybe I will end up eating the outside of my tires up.

I like the fact your trying it yourself...that's how everything I have done started...... take pictures let us know....how you come along...I'm pretty sure I will know the result...but it will be good

[Ryanater]

Rod, are you running Delrin bushings?

[b17brian]

Ryanater,

Why do you think the camber gain is too much? You have been using the G-mod since you've installed the ridetech parts, is that correct? Are you getting tire wear, front end not gripping, or is your steering performance not good?

I have mine set to use the G-mod, but I'm still a few months away from driving mine. This project has taken so much longer than I expected.

[Ryanater]

First of all, I don’t mean to disagree with Rod or anyone else. (Especially since they have more experience than me). I was just surprised on how much camber gain the Guldstrand + tall spindles provides. I thought it would be worth posting my findings. And from everything I have read, .7-1.0 degrees per inch seems like a good rule of thumb. But again, I don’t have enough real world experience to have a large opinion one way or another.

And yes, I have been running the ridetech tall spindles with the Guldstrand mod. The car did push on corner entry, but that could be any number of things. Overall though, the car did really well. Plus, that is my baseline setup, so I don't have a lot of comparison.
So I will try moving back to the stock mounting points and see what happens. I will make sure to post my findings.

[Ryanater]

Ok I'm bringing this one back from the dead. I've been playing with this all year over the course of about 8 events. I've tried identical setups (other than static camber) with and without the G-mod and here are my findings...

With the G-mod, the front of the car seemed to grip better on turn entry. It was hard to tell if there was much of a difference mid corner. Maybe it helped the front stick a little, but it's hard to tell. The problem was that I picked up a corner exit push when I added the g-mod. This was probably do to the more aggressive camber curve. First of all, I ran less static camber with the g-mod because I didn't need as much to keep the tire flat mid corner (which is a nice bonus). That combined with the fact that more camber gain on compression means more camber loss on rebound. Which probably means the tire was not an optimal angle when I was on the throttle exiting the corner.

Overall, my car was more competitive when I was using the stock inner pickup points. But if I could get rid of the corner exit push, I think that the g-mod might have more potential. I'm going to try a smaller front swaybar next year to see if that helps.