Well I FINALLY got the damn center tie rod section reworked to Pete's suggestions there, and in a short test drive, I THINK there is a good improvement.....will take time to see.....
finally got a chance to get that steel adaptor block over to my buddy's place for him to weld YET AGAIN on this ....he said this was the last time for this piece of steel, as he was concerned about it being brittle after this....

at any rate, it's DONE...and I will pix the silly thing if anyone is interested....

post on my 'site' there....in place of the other one....

I do say this, the toe in change is a whole lot differant when jacking the car up....less...

GENE

 

Gene this bump steer issue is really getting to me. Honestly I just came in now from lying under the car planning how it improve my bump steer. I am replacing the outer tie rods with heim joints on a stud with spacers to raise of lower the outer tie rod. I am also going to make a new center link so I can increase the length of my tie rods. They are too short stock.
I have 1/2 inch of toe out when jacking the body 3 inches.That is 1/2 inch on the toe gage on the front of the tire. That means the back is moving in 1/2 inch also for a total toe out of 1 inch.
I like running at high speed. At 100mph the car is dead calm but at 110 things start to fall apart. The motor is still smooth but your grip on the steering wheel increases and hitting the brakes at this speed seems to throw you around. Why?
I assume you are address ackerman's and I haven't even begun to go there. While running at 100mph hopefully I am pointed straight ahead so ackerman's doesn't come into play but bump steer does as the wind gets under the car and starts to lift.
I am going to your web site and look at what you have done.
Gene I am interested in hearing anything you tried. My pet pev for this year is bump steer and ackermans.

I do say this, the toe in change is a whole lot differant when jacking the car up....less...

GENE

What are some numbers. For 1 inch lift I can't detect anything. 2 inches it is starting to move but at 3 inches 1/2 inch front and back for a total of 1 inch toe out at 3 inches body rise.


[Modified by norvalwilhelm, 3:14 PM 6/13/2003]

 

Gene I have just been reading more on bump steer and they are talking about maximum bump steer of .010-.015. I have 1 inch. I know what part of my problem is and that is the stock tie rods are about 2 inches too short and I have to lengthen them. Really an easy fix but the center link is then too long and must be shortened or the mounting points for the inner tie rods moved the corresponging 2 inches per side in. Alot more work. I will make new tie rod blocks and weld them to the center link at the proper distance. I really want the bump steer to come down to the .010 range and will work towards that.
There is no reason at over 100 mph our vets need to become a white knuckle affair.
George might have the right idea and tie the car down with the 550 springs but I still want a smooth bump free ride. I am using long travel 280 pound morosso springs. Very nice ride and I will raise the roll center to help with the flat cornering.

 

NOrval, all I can do is laugh my butt off....change ONE thing on any design, and man what a mess....what started out as a simple pimple rack install has all of a sudden takne on a whole new life with me here....the damn thing goes on and on like Topsey...you know, the song without end....

I do know the steering was a LOT like yours before this last FINAL change the other day, and so its not so bad as it was...but I have NO numbers...
all I know is to follow Pete's advice there and raise the center links on MY initial install 1.5 inches...which I pretty nearly did....

NOW here's the clunker....

the ONE example (I can't imagine much variation) of a Steeroids installation their rack was ever further off center to the driver's side than mine...in this work, that's a LOT, and if was ME I"d want that puppy even more centered than my one inch offset....making the drivers tie rod TWO inches shorter than the pass side....and the differances in toe are noticeable with car in the air...
in my case it's still toe in....but then again, don't forget that lower arm is only about 17 inches some odd long on that rear length from pivot center to pivot center....so therefore my longer tie rods are not really what's wanted...so many compromises....and not many NICE solutions...except maybe Steeroids munting plate....I have to photo and post my new install...and take the thing all apart for painting pretty for a photo shoot, and specs....right NOW, I"m driving the damn thing and seeing....I know at this point the front tires make mucho grande less noise around corners...so something is happier....

just wish my hands didn't hurt so freakng BAD from handling even a simple couple of tools for a freaking hour or so...sux...

at any rate,...the system is about as far as I think I need to go in the steering department....I have not bothered to address Ackerman yet, as I figgered if the rack was about closely to the drag link in placement, it would be fine...maybe a rong assumption....dunno....

I AM highly interested in increasing the overall height of the spindles though...I know some years ago was done on a GTO.Lemans convertible I had, and it was amazing....but that was junkyard parts, and who knows what, I sure don't remember anymore....
some kind of voodoo majic involving love potion #9 or some such other drug...

OH yeh....that's it....Viagra, yes...stiffened it up right away!!!!

no that's another topic...for the OT forum here....

SO if you can give me a hint on some way of doing that other than welding a ton of stuff on the spindles....it woud be nice....
I"m kinda looking for a junkyard spindle to do what I want...

GENE

 

Gene you have been busy. For one thing you do not want TOE IN.. Toe out is alot better. If you have to bump steer let it be toe out.
I will not spend alot of time this summer on the bump steer issue. I am ordering parts Monday to work on the outer tie rods but nothing major.
I saw a set of welded spindles and you can not tell. All welds were ground smooth and generous radius. I know that I can add a length to a spindle and other then the very smooth surface you could not tell. I will work on that as next winter's project. I will just add the adjustable outer tie rod bump steer studs and make a bump steer gage with twin dial indicators and get ready for next winter.
To properly check pump steer you need to remove the springs, install the plates instead of wheels and use dial gages. I will go this route in future. PeteL82 already told us that is the route we have to go a few months ago ,it finally sunk in that Pete knows alot more then us.

My goal is soft front springs, a 1 1/8th sway bar , a roll center about 4 inches off the ground in the center of the car and zero bump steer through 3 inches of travel up and 3 inches down.
That is my winter project next year.
Wait Gene until you see the spindles I want to build. They will be 1 - 2inches longer then stock with no sign of welding and powder coated black. They will look stock. I will build the proper jigs for alignment and welding.
Look luck Gene, stay alive to comment on my work and keep taking that Viagra :) :) :)

 

:lurk:

 

Mrvette,
Love to see the pix,
You show me yours and I will dig out mine, I have non digital photos of the job I did with the ETO rack, Just have to get them scanned at work. Short on time at the moment, Fly out to LA on thursday.
Or I could bring them to the 50th.
Very fond of KISS principle, am I.
I measured my Bump steer over entire travel and "0" except for when the car is in the air, now I want more Caster and longer Spindles.
Website address to look at pix?
:cheers:
James

 

Guys, I haven't done the pix of the center block yet, and at this point, frankly I"m too lazy to remove the front springs and check for how it all reacts through the travel, I should, and you know, maybe that's not a bad idea, get some stock springs again, and put the original sway bar back too, this rough riding stiff springs/bars in front and rear is getting to be a bit much....
maybe I"ll just make a cruiser out of it again...just what I need, another project.....
right now, I"m pissed at the brakes again, having some issues with continual loss of pedal..for the longest time it's ok, then back down agai...and thing is, there is no pumping issues, can't be, on account of O ring pistons and no springs....rotors are pretty good anyway...can't figger...I wonder about calipers in rear now....getting a LOT of vibration noise from rear end when brakes are applied and car goes slow...pads are good, and rotors are smooth...

GENE

 

Gene: sorry I didn't reponsed sooner. I have been swamped at work. I have got to get 3 motors finished up today to go racing. A 402, a 421, and an all aluminum 433. All small blocks. Long stroke small blocks take forever to fit everything.

Glad to see you got your spacer made and it helps. Eventually we will need to put a bump steer gauge on it to make sure it is right.

Norval: I am not sure that having to bump steer toe out is correct on a street car. Race cars are set up wih initial toe-out and you set bump steer to toe-out. A street car is set with initial toe-in and my first response would be to set bump steer to toe-in. Going from toe-in to toe-out during suspension travel is generally not a good set-up. I will have to think that over a bit.

Here is a good artical from Woodward steering. They make a great rack for race cars. A lot of the information is for race cars but you might pick up some pointers from it. http://www.woodwardsteering.com/rpi.htm

Norval: if you are fabricating your own bump steer gauge let me know. I can take some pictures of mine if it will help you. They are pretty basic except for the plate that mounts to the spindle. That has to be very flat and very ridgid. Nothing I sure you can't handle easily.


[Modified by Pete79L82, 6:48 AM 6/14/2003]

 

Norval: if you are fabricating your own bump steer gauge let me know. I can take some pictures of mine if it will help you. They are pretty basic except for the plate that mounts to the spindle. That has to be very flat and very ridgid. Nothing I sure you can't handle easily.

Thanks Pete for the offer but my friend Roger has a nice gage, which I could borrow but it is something I think I would like in my own shop. As for the spindle plate I have lots of 1/4 or 1/2 inch aluminum plates lying around and with the mill I can bore the center hole and drill the 5 mounting studs. I can also fabricate the rest. Thanks.
As for bumping out , sure the toe is initially set to toe in but under bump steer toe out makes the car less darty then toe in. I don't want any bump steer but if I have my choice I thought toe out was the better of the two.

 

Guys, I took the vette across my favorite bridge today, nice burst up to 110, car stable and really SCHWEEEEET!!!!!.....top down of course, handles wonderful on ridged out roads locallly here, changes lanes with just barely noticeable through the grooves....just the way God intended....

the amount of bump steer I notices throug the jacking up at aroud 4 this morning was a LOT less than I thought I noticed before....so really the suspension has to be off the floor before any steering is noticeable at all....
not that's not a gauge for sure, but...well as an observation it's sure a hell of a lot more comforting to see than that silliness it had before, which was REALLY noticeable.....
Thanks Pete and you too Norval, for holding my hand throug this ordeal....

I will pay in pain for the next step which is taking the springs out,...damn tools kill my hands these daze, not fun....just take more damn Advil and Vioxx and it's better.....drink a few beers....

GENE

 

RHD 68L89 Did you do an accurate measurement of bump steer? Our stock systems have Tie rods that are about 1 inch too short plus the inner mounting is too high.
I was once again under the car this morning measuring and just looking and thinking about how to increase the tie rod length, raise/lower the tie rod ends and how to make a new center link.
All these things need to be addressed if I want to achieve zero pump steer.
You got lucky or did alot of work.

 

Norval, Pete, well in my home page there is a new pix of the completed assy in the CTO rack...and i'ts to stay this way for a while, I think.....

GENE

 

Pete, that Woodward steering site there looks for all the world like the racks on the race cars the folks down the road, who sold me the headers shown in the rack install there....they had those racks on a bench...why have enough throw to satisfy our needs here with C3's we measured one of his cars...
any ratio wanted, power assist even yet....amazing....
and only 3-400 bux.....

NOW, I went there this week to job their memory and see what they said about those header....

they are Schoenfeld....Number 151 more properly 151v....in the 1.75 size...

one and 5/8 is what I would order to do it next time....have to get them replaced as these are very tired used/burnt out headers as you see, and so they were a test set, and now to spend yet more money I do not have....
wonderful....

at any rate, they give lotsa clearance for wires, sending units, plugs, steering, anything you want in a vette.....much better than other designs I have seen on our cars....

only about 130 bux too....nice....3/8 flange too....no bending...no leakage...

GENE