Author Topic: Do I need a Bumpsteer kit??? (Read 9470 times)

Glen68 · « **on:** August 01, 2010, 10:41:19 am »

Hey Guys,

So far with all the help from you guys. I have so far 68 fastback bigblock 4 speed with King Springs KFFL-0 a Shelby drop 1", Koni shocks and a negative wedge kit.

Do I need bumpsteer kit and is there anything else I should be looking into for the steering and suspension?? What are good suspension settings for hard street, some track driving?

It will soon have a Heidt's four link rear end as well.

Cheers Glen

derwin66 · « **Reply #1 on:** August 01, 2010, 12:00:40 pm »

Hey glenn watch out for the bushes i the the Heidts, I have found that transmits a bit of sound from the diff to the car.

How is the motor going or is it?

moe · « **Reply #2 on:** August 01, 2010, 12:44:22 pm »

are you running an export brace?

Glen68 · « **Reply #3 on:** August 01, 2010, 03:22:03 pm »

Yeah well the motor problems are still in the pipeline.... one thing at a time and I will stay aware of the noise transfer, thanks mate.

Yes Moe running the export brace. Is there some front end strengthening I should do??

Glen68 · « **Reply #4 on:** August 15, 2010, 09:27:40 am »

Thanks Moe for setting the wheels in motion.

Looked into front end structual supports and mods for the 68. It concerns me with the weight of the 390.

Found this guy http://home.flash.net/~sanco/mustang.htm. He has a small store on ebay usa under the name of fwsanco.

He sells the negative wedge kits, the tower wraps, template for the A arm drop and the boss back of tower reinforcement plates. The prices look okay??? So I will send him an email and see what the total cost will be landed here.

But do I still need a bumpsteer kit???

donoauto · « **Reply #5 on:** August 15, 2010, 06:32:01 pm »

http://www.mustangmonthly.com/techarticles/mump_0602_how_to_correct_bumpsteer/index.html

Told me everything I needed to know. Basically , from my interpretation , it comes down to the angle of steering arms vs angle of lower control arms. Ideally both should be parallel to avoid bump steer. It's a great pictorial!!!

Glen68 · « **Reply #6 on:** August 15, 2010, 09:33:24 pm »

Thanks Mark,

Read the article, I now understand what bumpsteer is and what the different types of bumpsteer kits on the market do. I have also found a way to make a simple jig to test it.

I already know that i need the kit but I will make the test jig just to prove it. Thank you for the info.

Cheers Glen

[Edited on 15-8-10 by Glen68]

shaunp · « **Reply #7 on:** August 16, 2010, 03:37:52 pm »

I think you will find they are not legal here, at least in QLD.

Glen68 · « **Reply #8 on:** August 16, 2010, 03:39:23 pm »

So what do you do??? Or what can you do about it??

shaunp · « **Reply #9 on:** August 16, 2010, 03:43:36 pm »

Why does it have bad bump steer or does it just have factory bumpsteer? The car in the article has bump steer because it has a Flaming river rack, they are crap and locate in the wrong place they give you bucket loads of bump steer. TCP & RRS racks give some adjustment on the inner tie rod location to improve bump steer.

Bumblebee · « **Reply #10 on:** August 17, 2010, 10:11:04 am »

I have the same set up as you Glen,

Konis, Shelby drop, negative wedge kit and I also added a bumpsteer kit when I fitted the bigger wheels, never had any bumpsteer. Later I fitter an RRS power rack and still don't have any bumpsteer.

Cheers Bee

[Edited on 17-8-10 by Bumblebee]

Glen68 · « **Reply #11 on:** August 17, 2010, 05:01:37 pm »

Thanks Bee, that is good to hear. But your car is awesome anyway!! :) But as Shaunp says they are not legal in QLD :(

I was not sure if it was going to have bumpsteer after doing the shelby drop, and lowering the front another 2" inches but what I have learned is that every mustang can be different but they are all not very good in the first place. So once I get all the front end sorted out I can jig it up and check for it.

If it does have it??? What can I do??

shaunp · « **Reply #12 on:** August 18, 2010, 02:42:27 pm »

The best way to check bump steer is with no springs in the car. So you need to know what your ride hieght is basically. With the springs out so you can move the front end up and down you just measure the change in toe around your normal ride hieght as the suspension travels. Then decide what you need to do. You can bend the steering arms, as long as you magna flux them after.

Glen68 · « **Reply #13 on:** August 18, 2010, 04:51:33 pm »

Thanks Shaunp.

I will see who I can find here in Brisvegas who can magnaflux the steering arms.

shaunp · « **Reply #14 on:** August 20, 2010, 11:03:02 am »

Any engine reco shop will have Magnaflux crack testing equipment they do it all the time on cranks, heads etc. However you could call Industrial imaging at Hemant as they are NATA certifed.

Glen68 · « **Reply #15 on:** August 22, 2010, 12:44:17 pm »

Thanks Shaunp for your help.

Just an update on what I have found.

Fatman Fabrication in the States ( http://www.fatmanfab.com/catalogpage.php?page=35 ) now has a 2 1/2" Dropped stub axles for my mustang. Thay have also revised the outer tie rod postion to reduce bumpsteer. With those stubs I would be able to keep my current springs, not have to purchase a negative wedge kit and still retain full suspension travel. I would still do the strengthening work and the Shelby drop. So save on a set of springs,a negative wedge kit, having to bend and magnaflux some steering arms and still have full suspension travel. Sounds to good?? I will keep investigating.

Cheers Glen

shaunp · « **Reply #16 on:** August 22, 2010, 05:21:22 pm »

Castmaine rod shop used to do drop axles as well, not sure if they do ford ones. I'd still run the wedge kit if you do the Shelby drop. But the rest is all good. What brakes does your car run?
Not cheap though.

donoauto · « **Reply #17 on:** August 22, 2010, 05:46:20 pm »

Let's go back to the beginning , do you actually suffer bump steer?? Wasted money otherwise. I think my RHD setup is XD-XF falcon - everythings parallel & if I have bump steer , I can't feel it at all. I'm doing the shelby drop soon & will be using wedge kit for sure. I'm also running kffl-0's.

Glen68 · « **Reply #18 on:** August 23, 2010, 12:17:52 am »

Okay guys,

Late night working on the old girl, and YES the standard suspension as it stands with no mods and standard height has bumpsteer BAD!!!! 5mm + to 6mm-

The negative wedge kit I thought on the later 67-68s was only required if you did the big shelby drop 1 1/2" ...1 3/4" or you lowered it alot?? I might be wrong??? I unbolted the top arm moved it down about an inch and clamped it. Moved the suspension (less spring and shock ) through full travel and the top ball joint still had clearance and was not binding??

Maybe I was doing something wrong?

Shaunp I will be running 12" Wilwoods on the front with a matching rear set with the internal hand brake hat. I have a good friend here who has the Wilwood deal for Aus.
CRS "Castlemaine Rod Shop" are on hold at the momemt with dropped stubs and Stub Tech are in the process of research and developement of dropped stubs for Fords.
I am not in any hurry as I can only do what I can afford as the money comes in (SLOWLY). So I will wait and see but the Fatman setup does have the adapters for Wilwoods so I am leaning that way.

shaunp · « **Reply #19 on:** August 23, 2010, 09:56:38 am »

Ok, then. 5mm bumpsteer is ok on an old car, some have up to 10mm which still doesn't worry them too much. Personally I'd run a wedge kit on any drop, You have a very heavy engine and top ford joints are prone to fail regarless. When you do the Shelby drop, drop the rear holes any extra 1/8 to add some anti-drive under hard brakes. You have good brakes on the back I assume so you may as well keep some extra weight on the rear wheels. Makes a big differeance to the braking of any car. Jag started doing this with XJ6s in 68. Makes the whole car squat rather than just standing on it's nose.

Glen68 · « **Reply #20 on:** August 23, 2010, 02:48:22 pm »

Thanks Shaunp

You are the man so I will go along with your advice and negative wedge kit anyway. I will do the extra drop to the rear holes as well for the anti dive. You are a fountain of good advice.

I have emailed Fatman about the costs and brake options. So things have stopped at the front of the car so now the rear end is comming out for the fitting of the four link and I found some rust comming out in a rear gaurd today.... more money......more time off the road......joy joy joy !! :(

shaunp · « **Reply #21 on:** August 23, 2010, 07:52:40 pm »

Personally I'd stick a Jag rear end in it, but then I'm a Jag ,man. It's hard to get an S type or 420 compact rear now, which would be a good width for a mustang, they are all in hot rods. But you get a full indepenant rear, inboard brakes, 4 coil overs and a rear that runs on roller bearings not bushes. Cheap to buy the whole rear for few $100. pleanty of Xj rears about cheap, but depending on the wheels you'd need to shorten the 1/2 shafts and lower arms to fit them in. But the late cradles line right up with the rear rails in a mustang so mounting would be no issue. It would hook up then. and corner superbly I reckon. I'm still thinking about one for my car as it is in bitts. With a Jag in the rear it would sit down like a Border collie rounding up a sheep and then leap. You get a choice of a Dana, or salisbury diff centre.

Glen68 · « **Reply #22 on:** August 23, 2010, 10:06:04 pm »

Love the idea of a jag rear end!!! The best of all worlds!! you should do it!!

Oh, word from Fatman "’65-’73 Mustang 2” dropped spindles (require the use of ’75-’80 Granada disc brakes) - $580.00/pair ’75-’80 Granada disc brakes - $450.00/set
Wilwood does not make a Granada-type brake kit that will mount to this spindle.
Note: This is a fabricated (welded) spindle and is not street legal in Australia and NZ.
Philip Snyder

So back to square one. maybe I can push Stub tech a little harder???

shaunp · « **Reply #23 on:** August 24, 2010, 09:45:20 am »

You can still bend the standard steering arms on the stub if all other options fail. John green does this to falcon stubs on pre 67 cars to make them correct.

Glen68 · « **Reply #24 on:** August 24, 2010, 05:00:24 pm »

Thanks Shaunp....if it comes down to it I will contact John Green.. Do you have his contact details mate?

I flicked off an email to stub tech today pushing the point of dropped spindles, but still waiting a reply. :(

I went on to Vintage Mustang forum in the US and they had nothing to offer either.

Do I need a Bumpsteer kit???

News:

Author Topic: Do I need a Bumpsteer kit??? (Read 9470 times)