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 Post subject: Tighten your front end
PostPosted: Tue Sep 05, 2017 12:10 pm 
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Joined: Mon Sep 02, 2013 11:26 pm
Posts: 57
Location: Buderim, QLD
I've owned and seen quite a few minis over the years, and almost all had front end issues - not surprising considering that is where the weight is carried, the majority of braking and accelerative forces occur and it has to steer and ride well to boot! There's a lot going on.

On this build, I wanted to be able to drive with full confidence the front end would do it's job properly, so in addition to alloy hubs (with metro ball joints) from KAD and their 4-pot vented disc package, plus their anti-roll bars at both ends a 'new quick' rack and upper arms, adjustable lower arms from MS and rose jointed radius rods- which obviously have significant costs attached - I tried a few other small cheaper mods to encourage the whole shebang (isn't that a Ricky Martin song?) to stay firmly on the straight and curvy. Result is the quietest (no squeaks or rattles) and most precise mini front end I have driven. I have quite possibly re-invented the wheel here, and the more august members of the forum perhaps have done all this before, but for those that haven't you may consider these suggestions! (note - this is all on hydro suspension, and obviously if I have included anything risky or dangerous, feel free to put me straight)

1. Replace all rubbers/bearings/spacers etc with new - and if possible genuine parts. I prefer not to use nolothane bushes - they can be harsh and tend to emphasise misalignments, but I did use the mixed nolothane buffers on the previous front radius rods - very good!
2. Use the uprated Rover rubber/steel bushes in the steady bar on the left of the engine block (looking from the front) and seriously consider another steady at the radiator end of the head. These will transmit some buzz to the cabin, but if you insulate well and fix any loose bolts, screws, rivets it won't be a problem.
3. Buy genuine engine mounts and consider lower engine steady kits - they give the engine a better chance to get its power to the wheels, rather than wasting it just twisting the engine in the frame. Note - for 'remote' gearboxes, get a new extension mount (at the back of the housing) if the gear lever drops more than 2-3 mm under hard acceleration.
4.Bolt the lower edge of the inner wing panels to the upright edge of the font subframe in 3 - 4 places
5.Drill out the 6 subframe/body mounting bolt holes to accept larger bolts and fit front radius arm washers shaped to fit on both sides. The thick rear radius arm washers are also good. Use nylock nuts or thread lock.
6. The four 5/16 bolts that attach the subframe to the bulkhead often rust/break/strip. When you have the subframe out, give them the chuck and carefully drill and tap the holes in the 'towers' to take the longer 7/16 cylinder head studs. They will need some solid packing at the top, but these are much stronger and can be undone even if the stud rusts into the tower. Don't wind them up too tightly or you will crush the box section - but once done all flex in those mountings is gone. And the subframe is easier to install because the bolts guide it into place.
7.Nip everything up to the proper torque settings inc diff side cover bolts, output shaft nuts, universal nuts, drive flange boltsand CV nuts (replace split pin) and wheel nuts. Securely lift each side of the car and pull the wheel in all directions. It may have some free-play in turning, and should obviously steer - but there should be no jiggles, knocks or free-play in any other direction and no obvious tight spots in turning or steering. Check tyres for damage, lumps and flats. Check wheel/bearing is true (attach a piece of wire to an axle stand and position it just touching the outer corner of the wheel rim. Wheel should spin easily without moving more than 1mm away or closer to the wire in any direction, less is better). Check for anything else that is loose or could foul the wheel, brake line or any other item.
8. If you like a firmer ride, add competition bumpstops and ordinary mini shocks (need upper shock mounts) to the front arms. You will need to enlarge the bolt holes in the hydro arms and space the shocks forward to clear the subframe towers.
9. Check everything is properly tight but free to move as it should - including steering rack (may need new tie rod ends)
10. Finally, unless you know what you're doing and have the basic necessary equipment, take your car for a professional alignment. There are lots of suggestions for alignment settings available. I use:
Front. -3/4 degree camber 3/16 inch toe out +3 degree castor
Rear. -1/2 degree camber 1/8 toe in
It doesn't take much uneducated fiddling to create interesting (read dangerous) handling for a mini, but when it's right... it should feel as if the car is (quietly) reading your thoughts. Happy trails...

_________________
Min - 1970 MkII S, 119hp Dave Anton 1380, SH Engineering belt drive, 1.5 rollers, 123Tune ignition, 48 DCO SP Weber, HP Headers, MSD, Maniflow ex. Swiftune SC/CR 3.7 + ATB, all KAD front, antiroll bars and gas shocks, 6 inch Minilites with Dunlop Sports


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