Hi All,
I really didn't know what section to post this in so apologies if it's the wrong one!
I need to source a pair of good quality front uprights but the steering arm needs to be pointing forwards (steering rack mounted in front of cross-member). They will be used between a pair of wishbones in a car with an iron block V8 so they need to be strong.
Can anyone recommend suitable uprights, preferably easily sourced in the UK.
Many thanks.
Triumphs - Spitfire or TR6.
Mazda MX5 also has a front steering rack.
Front or rear steering does not matter if you swap sides....
2nd gen rx7. Many are v8 swapped. They are strut type spindles.
bentwrench said:Front or rear steering does not matter if you swap sides....
It can, depending on where you can place the rack, if you want good Ackerman or bumpsteer.
Uprights designed for front steer tend to have the steering arms mounted as far outboard as practical. Almost grinding the tie-rod end into the rotor. Rear-steer usually has the arms following the natural line from the steering axis to the center of the rear axle.
You COULD make the Ackerman work from flipping rear-steer arms side for side, if you move the rack and pinion back far enough that the steering axis - tie rod end - tie rod angle is the same as if the tie rod was straight and the steering arm was at the "correct" angle, but this usually requires that you have the rack back around the axle centerline, which is tough to package...
I may be wrong but I think the Fiero has nice front steer spindles.
As far as I know every subaru car has them in the front.
Having the steering rack in front is actually a really nice engineering compromise, with the exception of the rotor/steering arm clearance that Knurled mentioned. During a turn, the steering forces are highest on the outer corner, obviously. With a front rack these forces are in tension, whereas a rear rack puts the highest loaded tie rod in compression, making buckling more likely. Therefore the steering rack and tie rods can be built lighter. Plus, IMO the overall packaging works better, at least with RWD cars.
In reply to freetors :
Front steer is a lot more predictable handling-wise. The steering has no deflection, while the control arms will have bushings that deflect. With front steer, side loads make a negative feedback loop where more side load causes the wheels to steer to the outside of the corner. With rear steer, you have a positive feedback loop, where side loads make the car turn in harder. Positive feedback loops are never a good thing if you want consistency and predictability. That's why we stopped using self-energizing drum brakes in the front of cars!
This is a bunch of why old 1st-gen RX-7s (which were rear-steer) get so... wandery. When the TCA bushings get sloppy, side loads due to any number of things such as road camber, bumps, a light breeze, etc. will cause the car to shift over against that load. Hard.
Fiero/Chevette/Opel Kadett/Isuzu I-Mark. Pretty much all the T-bodies.
1st gen rx7s are front steer as far as I remember. They do have a steering box, not a rack.
wvumtnbkr said:1st gen rx7s are front steer as far as I remember. They do have a steering box, not a rack.
Most certainly not front steer. They were rear steer, because there was no way to reconcile the tension rod and the tie rod trying to occupy the same space.
The RX-7 was mostly an update of the RX-3, which used the stabilizer bar as the longitudinal location, just like the contemporary Ford Escort/Capri did. (And for some dang reason, Ford kept that poor design not just from the Mk1 to the Mk2, but also through the front wheel drive Mk3. And the somewhat offshoot design the Tempo/Topaz. The Taurus, at least, got separate tension rods like the RX-7 did in 1978... and like Ford had been using in their own vehicles throughout the 1960s in the Falcon and Fairlane chassis)
The interesting thing is that the RX-7 had the caliper mounted to the rear, on the same side as the steering. Almost every other chassis puts the caliper on the opposite side as the steering for packaging reasons, but rear mounted calipers are a performance benefit so Mazda did it that way. Removing the lower caliper bolt required either unbolting the steering arm from the strut, or removing the spindle nut so you could walk the brake rotor and pad hanger away from the steering arm. The bolt was too long to be removed otherwise. Most people cut the bolt down a bit and removed the washer after the first time they fought it.
I see you posted while I was searching for pics. You are indeed (obviously) correct. Somehow i had the linkage all in front of the subframe in my mind.
Sorry for the poor info!
As usual, Knurled is right when it comes to the rx7s!
Mustangs too. SN95 spindles have proven to be good in many cases.
In terms of local availability, I would recommend checking on what the UK Locost builders are using:
https://www.locostbuilders.co.uk/
Alternatively, can you get Mustang II aftermarket spindles in the UK? They are readily available from multiple vendors here in North America.
Thanks for all the replies guys, so far the list is:
Spitfire, TR6, MX5, RX7 (2nd Gen.), Pontiac Fiero, Subaru, Chevette, Kadett, Mustang II SN95?
Time to get researching.
Hopefully none of you are too prissy about "Classic cars" but this is for an LS swap into a Rover P5B Coupe, sorry if that offends but I fancied creating my own version of a GT.
The original front end on a P5B is steering to the rear of the cross-member which gets in the way of the starter so I need to put a new rack in front for starter clearance.
Many thanks.
Does it have strut front suspension or a spindle with upper and lower ball joints? If the latter you can make spindles from almost any 70-96 rwd gm car work.
In reply to SunbeamFanatic :
One of my pet ideas is to just grab the entire crossmember/control arms/uprights mess from a Volvo 240 or 740. They are front steer, but more importantly the rack is INSIDE the crossmember, so it takes up no extra real estate.
You have come to the right place to be enabled to do silly swaps in cars.
I don't think anybody here will give you grief.
Pics must happen!
@ Patrick, originally it was a spindle with upper and lower ball joints so I'm going to keep the theme. However, originally it was a Torsion Bar so I'm converting to coil-over shocks.
@Knurled, thanks for that, it sounds a neat solution so I'll do some research, could be the perfect answer.
@wvumtnbkr, I'll start a build thread when it gets interesting, I have a couple of photos so far which I'll try and post.
wvumtnbkr said:You have come to the right place to be enabled to do silly swaps in cars.
I don't think anybody here will give you grief.
Pics must happen!
So far I have a fully rebuilt stroked LQ4 an uprated TH400 with GearVendors overdrive and a Ford 9" with uprated shafts, LSD and disk brakes. plus of course a donor car for it to go in :-)
Don't forget the early Mini Trucks for a spindle source.
This -> Coleman Racing Products is where I'd go. They also have pretty much everything else you'll need to put the front suspension together.
In reply to SunbeamFanatic :
The hot ticket used to be 77-90 fullsize gm wagon(or any fullsize buick or cadillac or caprice with police package) front spindles because a change to 5x4.75 bolt circle is 80’s camaro 1LE package rotors away. 12” discs and big calipers. I used to pay for half a $300 parts car just with the spindles.
lately the hot ticket is 98ish+ 2wd blazer fronts because they use a sealed bearing unit, slip on rotors and multi piston calipers. Both will get you a front steer spindle with upper and lower ball joints and nice sized brakes.
Another option for a front steer spindle with a sealed bearing and slip on rotor but if you’re wanting 5x4.5 circle is 2wd XJ cherokee.
This is is definitely the right place for you, we’ll never talk you out of any crazy swaps, and i do a fair bit of them myself
NC Miata seems like the easy choice.
In reply to Woody :
You are correct same spindle is used on chevettes as well. Rotors are diffrent as Fiero's got 5 lugs
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