'69 230 build w/LQ4 swap

[Benz Dr.]

Isn't 2.65 a higher gear than 3.07?

[rwd4evr]

Originally Posted by Coasttocoast

Thanks for the reply!

I need to get back under it and look at it again. With the wheels straight and the tires on the ground the rack is positioned so that the tie rods at straight and level to the steering arms. I did increase the length of the tie rod arms, don’t have exact measurement in my head.

Driving sanely on both side streets and highway everything is good. When getting on the throttle (with over 450hp) the front suspension almost fully extends, front end gets very light and the tires screech. I have 225/50/16 tires all around. So pretty good traction.

This drive train came out of a 2008 Pontiac G8. To get this car setup to run similar to the G8, rear gear/tire size wise, and need to change to a lower rear gear. 2.65 is closest, but probably better would be 3.07. I’m looking now to find one.

Anyone with experience and swapping? How difficult? Time required?

I've never heard tires screech while going in a straight line even with really bad alignment. Something sounds wrong. Sure it's not a belt squealing?

As far as diff swap it's all bolt in and you can get a 2.65 or 3.07 (or 3.08 maybe) from a 450sl. Did you swap your 6cyl diff already? If not you will need the rear section from a v8 car most likely as the guibo/flex disc is bigger. The axles are specific for the v8 diff also but 450 sl axles will bolt into your car. The diff can be a little tricky to get the studs lined up in the subframe, the angle it's sitting at is critical. When I did my swap i thought the two diffs has slightly different patterns until I wrestled it around for awhile. I'd suggest pulling the subframe and building it all to reinstall as a unit. You will need a r/c107,early w126,w123 type rear diff mount with the 2 horizontal bolts if you have the early w114 single vertical bolt to the diff cover type mount. I have all these parts. Shipping to Hawaii would be interesting and not cheap I'm sure.

An easy way to check your alignment is toe plates. You can buy or make them and just use two measuring tapes. They simply sit against the tire and have a slot on either side to put the tape through . You will be able to jack it up and see what it's doing too.

https://www.jegs.com/i/JEGS/555/81680/10002/-1?mrkgcl=1239&mrkgadid=3328194139&adpos=1o1&creative=330726016715&device=m&matchtype=&network=g&jegspromo=nonbrand&gclid=CjwKCAjw5dnmBRACEiwAmMYGOaEyjb8fI1rfTChKqPCkR414K2AxFAlrIBSgKHAFxCrOAlqt02OtWRoC7NwQAvD_BwE

[Coasttocoast]

Originally Posted by Benz Dr.

Isn't 2.65 a higher gear than 3.07?

I have a hard time visualizing gearing and terms, so I used this online calculator to spell it out for me!

Since the engine and trans is from a 2008 Pontiac G8, as a starting point I thought I would see what it would take to make my 230 match, taking into account rear gearing and my tire size.

Calculating engine RPM’s @ 65 MPH.

Stock G8;


6L80 trans in my MB;


My MB with 2.65 rear gear;


My MB with 3.07 rear gear;



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[Coasttocoast]

Originally Posted by rwd4evr

I've never heard tires screech while going in a straight line even with really bad alignment. Something sounds wrong. Sure it's not a belt squealing?

As far as diff swap it's all bolt in and you can get a 2.65 or 3.07 (or 3.08 maybe) from a 450sl. Did you swap your 6cyl diff already? If not you will need the rear section from a v8 car most likely as the guibo/flex disc is bigger. The axles are specific for the v8 diff also but 450 sl axles will bolt into your car. The diff can be a little tricky to get the studs lined up in the subframe, the angle it's sitting at is critical. When I did my swap i thought the two diffs has slightly different patterns until I wrestled it around for awhile. I'd suggest pulling the subframe and building it all to reinstall as a unit. You will need a r/c107,early w126,w123 type rear diff mount with the 2 horizontal bolts if you have the early w114 single vertical bolt to the diff cover type mount. I have all these parts. Shipping to Hawaii would be interesting and not cheap I'm sure.

An easy way to check your alignment is toe plates. You can buy or make them and just use two measuring tapes. They simply sit against the tire and have a slot on either side to put the tape through . You will be able to jack it up and see what it's doing too.

https://www.jegs.com/i/JEGS/555/81680/10002/-1?mrkgcl=1239&mrkgadid=3328194139&adpos=1o1&creative=330726016715&device=m&matchtype=&network=g&jegspromo=nonbrand&gclid=CjwKCAjw5dnmBRACEiwAmMYGOaEyjb8fI1rfTChKqPCkR414K2AxFAlrIBSgKHAFxCrOAlqt02OtWRoC7NwQAvD_BwE

So my day today is getting back into this steering issue. I’ll report back and let you know what I find.

Thanks for your time and information.


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[fonzi]

I think you want to always have a slight toe-in. If there’s any slop in your suspension, think about what forces are going to be on those front wheels whenever braking or accelerating hard. The front wheels are getting pushed backwards. So even though they are in a straight line when you are aligning it, when braking or under hard acceleration, the car is pushing forward on those front wheels, toe-ing them out.


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[97 SL320]

Originally Posted by fonzi

I think you want to always have a slight toe-in. If there’s any slop in your suspension, think about what forces are going to be on those front wheels whenever braking or accelerating hard. The front wheels are getting pushed backwards. So even though they are in a straight line when you are aligning it, when braking or under hard acceleration, the car is pushing forward on those front wheels, toe-ing them out.


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Our guy added a steering rack so the bump steer is going to be off. Way back in this thread I stated that the front springs need to be removed and suspension cycled to measure / correct bump steer.

This is accomplished by bolting a plate to the hub and using two measuring devices, even a a pair of rulers works.
~~~~
https://www.youtube.com/watch?v=7VuvPicStY4

The Gray Area With Brian Gray Season 2 Episode 1 Bump Steer

On the channel The DRC
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Technical Articles

[97 SL320]

Also see Ackerman for going around a corner, this is dictated by steering arm angle relative to the hub.

https://www.youtube.com/watch?v=ghZZp3t7bbc

Steering Ackermann | Hot Rod Garage Tech Tips (Ep. 46)

On the chennel Lincoln Tech

[rwd4evr]

Originally Posted by 97 SL320

Also see Ackerman for going around a corner, this is dictated by steering arm angle relative to the hub.

https://www.youtube.com/watch?v=ghZZp3t7bbc

Steering Ackermann | Hot Rod Garage Tech Tips (Ep. 46)

On the chennel Lincoln Tech

I don't think he messed with the steering arms mounted to the spindles. Ackerman should be ok unless the rack is way off position. Is not really super critical anyway. Parking lot tire squealing is the only issue unless it's really far off. Many production cars have horrible Ackerman geometry. These cars are dead on from factory. I'm actually dialing it out for my drift car.

[Coasttocoast]

Hey guys, thanks for all your time reading and posting to help me out! Much appreciated.

Made some positive improvements today. Let me explain where I’m at and where I started.

Because of the huge MB steering box I wouldn’t be able to snake the exhaust by it. I also wanted intermittent wipers and electric washer pump. Since the stock steering box has about 8” of travel and virtually all rack and pinions only have 6” of travel, every piece from the wheel hub to my hands is new.

I shorted the stock steering arms the correct ratio so that 6” does what 8” did.

I purchased a Flaming River rack and pinion and fabricated a “travel bar” to interface between the attachment points on the rack and the mounting points of the tie rods.

Then with the use of a pair of steering joints everything is controlled by a newer model MB steering column that looks about the same as the original, but no shifter and had the arm/switch for intermittent wipers and electric washer pump.

The “travel bar” runs almost exactly in the same space as the original steering arms. I took Ackerman into account when I shortened and modified the steering arms.

So this morning I set a pair of gloss painted pieces of wood under each front tire so that I could take measurements with the full weight yet turn the tires side to side by hand.

I took a bunch of measurements and then jacked the body of the car up from the forward lift point and dropped down onto jackstands with about a 1/2” load. And took another round of measurements.

It stands to reason that under load you would want some more toe in to add stability with less weight. But how much is the question.

From center to center of the bottom of the ball joints, on the ground, I measured 46 3/4”. Before today’s changes I had 44 7/8” in the raised position. So under acceleration toe in was too much and the tires would squeal. To put in perspective, I have tuning hardware/software and while driving and monitoring all engine/transmission sensors the tires would start to make noise right at 50% throttle. So if this number is linear that would be about 220HP. So no stock 230 would be able to duplicate this condition.

So where to start? I determined that a good place would be to make the tie rods the same length as the lower A-arms, which is 16 1/4” (between pivot points). To make the changes I had to move the threaded points on the “travel bar” and shorten the tie rods. Basically by 1 1/4” on all parts.

Put everything back together, adjusted the alignment back to where I started this morning, and took for a test drive.

Feels oh so good to lay into the throttle with no noise!

Got dinner date here in a few, so no time for extended testing.

I at least got to about 75% throttle.

After these changes the ball joint to ball joint obviously remained the same on the ground 46 3/4” but in the raised position the toe in was reduced by 5/8”, now center to center is 45 1/2”

What would help is if anyone knows or can measure what the stock measurements are, both on the ground and raised.

Now that I have before and after measurements I could calculate a next move to get to stock numbers.

Well off for Mother’s Day dinner,

Thanks again!








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[rwd4evr]

When you say "ball joints" are you referring to the outer tie rods? Meaning the measurements you are taking are between the outer tierods? Getting the tie rods close to the lower a arm pivot to pivot is a good start, but remember that the upper is shorter so there is a difference in the geometry of where their arc follows. Depending on how high the tie rod is in the space between the upper and lower arms and pivots tells you how long the ideal length will be to reduce bump steer to a minimum. Think of it this way. If you have the tie rod the same length as the lower arm they follow the same arc during suspension travel. then the shorter upper arm follows a tighter arc causing the spindle to lean over toward the center of the car(negative camber). So when that happens the steering toes in since the tie rod is behind the axle. If the tie rod was at exactly the same height(and following the same arc) as the lower a arm you wouldn't have a problem but since it's not you do.

This drawing g is crude but I think the piont comes across. Imagine this is the driver suspension looking at it from the front of the car.
Black is the spindle and axle.
Green is upper
Blue is the tie rod
Red is the lower
Yellow is the imaginary line between inner and outer pivots.

As the upper and lower go through their different arcs, the tie rod needs to be the right length to follow in the line between them. It's height in relation to them determines that. So ideally the yellow lines pass through all three joints top to bottom. What I was saying in my other post about the tie rod being offset from the upper and lower joints is that the as long as the tie rod is the correct length for its height in relation to the upper and lower arms, it can be out of the path of the yellow line but still follow the same arc and cause no toe in or out through the suspension travel.


The tricky part is that the a arms don't travel in the same plane as each other in this suspension ssysten, which causes the anti dive geometry to work, so that arc is traveling in an unatural way. I don't think that is causing the issues though.

The next bit you need to look at is the rack and outer tie rod relation looking from the side of the car. You want your inner tie rod to be halfway between the furthest the outer tierods pivot travels forward and rearward during it's steering swing.

You also want the tierod to be level when the a arms are level so they are on the same arc. If the a arms are level at rest and the tie rod is angled upwards, when the suspension droops they travel on different arcs and throw the toe out.

[Coasttocoast]

Originally Posted by rwd4evr

When you say "ball joints" are you referring to the outer tie rods? Meaning the measurements you are taking are between the outer tierods? Getting the tie rods close to the lower a arm pivot to pivot is a good start, but remember that the upper is shorter so there is a difference in the geometry of where their arc follows. Depending on how high the tie rod is in the space between the upper and lower arms and pivots tells you how long the ideal length will be to reduce bump steer to a minimum. Think of it this way. If you have the tie rod the same length as the lower arm they follow the same arc during suspension travel. then the shorter upper arm follows a tighter arc causing the spindle to lean over toward the center of the car(negative camber). So when that happens the steering toes in since the tie rod is behind the axle. If the tie rod was at exactly the same height(and following the same arc) as the lower a arm you wouldn't have a problem but since it's not you do.



This drawing g is crude but I think the piont comes across. Imagine this is the driver suspension looking at it from the front of the car.

Black is the spindle and axle.

Green is upper

Blue is the tie rod

Red is the lower

Yellow is the imaginary line between inner and outer pivots.



As the upper and lower go through their different arcs, the tie rod needs to be the right length to follow in the line between them. It's height in relation to them determines that. So ideally the yellow lines pass through all three joints top to bottom. What I was saying in my other post about the tie rod being offset from the upper and lower joints is that the as long as the tie rod is the correct length for its height in relation to the upper and lower arms, it can be out of the path of the yellow line but still follow the same arc and cause no toe in or out through the suspension travel.





The tricky part is that the a arms don't travel in the same plane as each other in this suspension ssysten, which causes the anti dive geometry to work, so that arc is traveling in an unatural way. I don't think that is causing the issues though.



The next bit you need to look at is the rack and outer tie rod relation looking from the side of the car. You want your inner tie rod to be halfway between the furthest the outer tierods pivot travels forward and rearward during it's steering swing.



You also want the tierod to be level when the a arms are level so they are on the same arc. If the a arms are level at rest and the tie rod is angled upwards, when the suspension droops they travel on different arcs and throw the toe out.

Thanks for all your effort and replies.

I took the car out for an extended drive today, which included some highway driving also.

Major improvements from the last iteration. I think this move almost got the steering back to the original feeling. The power steering pressure reducer is dialed in now and feels perfect.

The steering arms I started with yesterday were about 3 1/2” longer than stock. Yesterday I shortened them by 1 1/4” and I can tell I need to go some more. But now going in the right direction.

Today I ordered another set of stock tie rods. When they arrive I’m going to weld in another set of bolting point to my travel bar and see what happens.

Based on measurements yesterday, with this length the toe in change from ride height to almost full extension will be just proud of 1”, as measured at the tie rod ends/steering arm location.

Since the car originally had a type of “travel bar” and in the same location I have now, this should actually be the correct solution.


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[rwd4evr]

That's good. If you go too short you will know it because it will start to toe out with suspension travel. When you remade the steering arms in the spindles did you follow the pivot to the center of the rear axle? That would keep Ackerman geometry the same. These are my shortened versions where I decreased my Ackerman slightly and shortened the arms to get more steering angle from the same amount of pitman arm travel.

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[Coasttocoast]

Originally Posted by Coasttocoast

Thanks for all your effort and replies.

I took the car out for an extended drive today, which included some highway driving also.

Major improvements from the last iteration. I think this move almost got the steering back to the original feeling. The power steering pressure reducer is dialed in now and feels perfect.

The steering arms I started with yesterday were about 3 1/2” longer than stock. Yesterday I shortened them by 1 1/4” and I can tell I need to go some more. But now going in the right direction.

Today I ordered another set of stock tie rods. When they arrive I’m going to weld in another set of bolting point to my travel bar and see what happens.

Based on measurements yesterday, with this length the toe in change from ride height to almost full extension will be just proud of 1”, as measured at the tie rod ends/steering arm location.

Since the car originally had a type of “travel bar” and in the same location I have now, this should actually be the correct solution.


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Steering geometry is important, but not fun to talk about!

So as an intermission, here some interior upgrades.

This is a pic of the current engine compartment. I finally found a new washer bottle. Used a new lid and have the washer motor just to the rear side of it



I am 5’8” tall and the sagging seat was making me feel like a 10 year old driving the car. So I took the seats out, used the horsehair pad to make a template, and used a 1” layer of heavy foam (actually a kneed pad from a local hardware store ) and 1” of softer foam. Put everything back together, great feel! Can’t think of anything better.









I mounted the new engine ECU and related fuse panel in front of the new A/C blower unit on the passenger side. Made a couple panels from aluminum, covered with the same vinyl as the dash and center console, with shaping to keep from blocking the added speakers. I think turned out pretty good. USB port on passenger side, flasher button on drivers side.

The 6L80 trans is a little over 2” taller than the 4L80, plus I raised it some this time around. So I had to raise the trans tunnel from 0” at the rear seat to over 2” at the shifter. This required remaking the center console to cover. Just about finished with it. Need to stain and clear coat the wood insert, and finish the shifter boot. BTW, this 6L80 trans and shifter have Tap-up, Tap-down, Sport mode shifting!

The original seat belts were a pain, buckle getting caught in the dood or wedged in the seat back, can’t find the other end, etc. so I bought a pair of universal seat belts off of eBay and installed. Requires welding in 2 new anchor points for each seat, but oh so nice to have everything right where you expect it.






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[Coasttocoast]

On my test drive today I took it back to the local truck scales to have it weighed again.

Before I started this journey, both times with 1/2 tank of fuel

3140 lbs Total
1740 lbs Front
1400 lbs Rear
55% Front, 45% Rear

Today

3360 lbs
1820 lbs Front
1540lbs Rear
54% Front, 46% Rear

I porked it up 220 lbs, but did better the front/rear balance in the process.


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[Coasttocoast]

Originally Posted by rwd4evr

That's good. If you go too short you will know it because it will start to toe out with suspension travel. When you remade the steering arms in the spindles did you follow the pivot to the center of the rear axle? That would keep Ackerman geometry the same. These are my shortened versions where I decreased my Ackerman slightly and shortened the arms to get more steering angle from the same amount of pitman arm travel.

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Yes I did, very similar to yours.

After I get the new arms installed I can remeasure and test drive to see if I went too far. Hope not, takes 4-5 hours to modify!


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