Which Rear Beam
#1
Posted 10 July 2018 - 08:33 PM
Without a full thread of hate and moaning
I am going to be fitting a rear beam and coilovers to my estate soon
The whole car is lightened and having a tonne of body mods done to it
I will be tubbing and turreting the rear arches for the Coilovers
But my question is
Which rear beam is the best?
I’ve seen the kad/ Force racing ones
I don’t mind spending £400 on a beam if it is going to be worth it over the minispares alternative
Also Coilovers
Which ones do you guys recommend?
Offset tops or not?
Gaz/ protech/ Spax?
#2
Posted 10 July 2018 - 08:53 PM
make your own.
dont expect to be able to put anything in the back of the estate though.
offset tops why ask if you are tubbing and turreting it. they are a total bodge with make then fit is a space not designed for them why would you thing about it when it is putting bending loads into the shockbody.
i have AVO on the rear.
#3
Posted 10 July 2018 - 09:15 PM
What type of 'beam' axle were you considering?
There's a pseudo beam that still uses trailing arms or the proper beam axle type.
#4
Posted 10 July 2018 - 09:18 PM
it will be a trailing arm beam as no one makes a proper beam anymore.
#5
Posted 10 July 2018 - 09:22 PM
make your own.
dont expect to be able to put anything in the back of the estate though.
offset tops why ask if you are tubbing and turreting it. they are a total bodge with make then fit is a space not designed for them why would you thing about it when it is putting bending loads into the shockbody.
i have AVO on the rear.
The huge list of things to make and source etc is getting out of hand. I’d rather buy one that is tried and tested to save me a lot of hassle and time
#6
Posted 10 July 2018 - 09:29 PM
#7
Posted 10 July 2018 - 10:21 PM
make your own.
dont expect to be able to put anything in the back of the estate though.
offset tops why ask if you are tubbing and turreting it. they are a total bodge with make then fit is a space not designed for them why would you thing about it when it is putting bending loads into the shockbody.
i have AVO on the rear.
The huge list of things to make and source etc is getting out of hand. I’d rather buy one that is tried and tested to save me a lot of hassle and time
well there is no way i would splash 500 on one.
#8
Posted 10 July 2018 - 10:50 PM
other things to thing about. do the rules and regs limit the amount the wheel base can change from original? can you change the track width do you want to.
if it is a road car them i see no point in the cost of the KAD one.
#9
Posted 11 July 2018 - 09:08 PM
It will still have an interior as I want some sort of comfort with it
But will only ever be used to drive to track or shows
Not every day use
The tank will be relocated etc
And wanted the beam and Coilovers to go with it
#10
Posted 11 July 2018 - 10:28 PM
If it was a track only then you could get away with it. But as I said in my first post the right springs will mean no load in the back.
Run a subframe and some decent new rubber dounuts and no problems as the spring rate will be suitable with maybe a small adjustment to the damper rate.
The issues are linear Spring rate and no wheel movement. Just because it us on a race car or a modern car does not mean it is any good.
And yes I have coils on my race car. Would I build a track and road car with them? No fing way. A set up on rubbers for the road is way way good enough for the track and will out perform most coil set ups as the fitter has no idea.
#11
Posted 11 July 2018 - 10:46 PM
I get that you are setting out to do something a bit different, and a bit of an eye grabber in certain ways.
In regards to your proposed rear suspension set up, in all honestly and sorry for the bluntness with which I put this, but what is it going to achieve?
To explain myself and the question here, here's what I see and why I ask that;- The stock year suspension is swing arm and if I'm not mistaken this proposed set up will also be swing arm and in fact, use the same swing arms, so, there's no geometry gain (that I can see).
There is obviously a springing medium change and the question here is 'will it be better for my application?' I gotta agree with Nick on this. Yes, the rubber cones are what every other Mini has and yes they sag with time, but will coil overs give any advantage? I'd say no.
I'm sure you've read the same drum beat page after page about the rising rate of the rubber cones. They are also largely self damping and very tunable, where as a coil spring set up is not, or only to very very limited degree.
The other advantage of retaining the rubber cones and the rear subframe for them is that it spreads the loads the rear end of the car sees over a large area as well as stiffening up that rear end of the shell - more so with a Van / Estate as they loose a lot of torsional strength due to the big opening in the back, so retaining a full rear subframe will reduce some of the twisting the shell will see.
The ride of good quality and condition rubber cones, on suitable trumpets / flanges along with applicable dampers just cannot be compared. Some guys here no doubt will recommend red spot cones, but I think they'd be too stiff, I'd be inclined to go to standard ones, but again, this is one item you can easily tinker with to tune it to how you'd like it to feel and handle.
You could too if looking for something different, go to a hybrid of rubber cones and coil overs, though you'd only need springs in order of the rate around 30 - 50 lb/in and these won't require any rear shock tower modifications. Likewise, with this set up, you could easily has a set of say 30 lb'er for the street, then when going to the track, slip is some 50 or 70 lb'ers for a stiffer set up. Would take all of 15 minutes to swap from one to the other. Many guys who tour in their Mokes have these 'hybrid' set ups. I have tried these set ups and still have a set on the wife's Moke, I actually run Air these days.
I'll also advise if you do go down the route of a 'beam' to be sure all the mods are easily 'reversible' and what ever way you go, keep an open mind about it all.
#12
Posted 11 July 2018 - 11:26 PM
I have to agree with Nick and Spider on this
You will loose some weight, primarily from your wallet....
Consider that you are adding a big lump in the front in the form of a non A series engine further lightning the rear is not advised
it will make the front / rear weight distribution worse which will have more negative effects than the gain of loosing 15kg
Ideal weight distribution is 50/50, adding lighter rear to a car with a heavy front end will make it nearer 70/30
Another consideration is triangulation...the turret tops should really be braced to a full welded in cage
and have a K frame across between the arches, this spreads the load and stresses, reducing flex.
The rear of a van is a bit like a matchbox on a skateboard and needs bracing as much as possible
#13
Posted 12 July 2018 - 09:56 AM
A B16 shouldn't be that much heavier with its alloy block. BMW adverts like to tell us 50:50 distribution is everything, that may be so on a uniform curve at neutral speed. Not so sure when you chuck in bumps, braking and other things that make driving a Mini so entertaining. Then there's the different characteristics of your front and rear suspension. Offset coilovers do look like a bit of a bodge, but if you were to design suspension for them you wouldn't come up with a Mini radius arm (they weren't really intended for their dampers either). To my mind the offset bush at the bottom is less of a compromise for the radius arm pin than a generic coilover. The coilover still fits between the same two points on rubber bushes that will flex more easily than the assembly between them. Although the upper point isn't central it is inboard of the spring coils carrying the weight of the rear end and closer to the vertical part of the arch that will take most of the transferred load. The upper (axial) bushes already have more of a job to do coping with the designed (radial) displacement of the arm. Mine is homespun from stock steel section, similar to the KAD offering. It wasn't that much work, I'd think you could certainly get one fab'd for less than £400. Theirs does look to be better at keeping the wheel centred in the arch, but I note they recommend lopping off yer knuckle joint lugs - a consideration if you want to keep the option to revert.
http://midasownerscl...php?f=54&t=1960 There were some plans for a beam kicking about on one of the Midas sites too - seriously "industrial" but useful dimensions.
#14
Posted 12 July 2018 - 11:33 AM
From what I can find the B16 unit is about 30kg than an A Series unit
Add to that that a B16 will be further forward
I neither know nor care what BMW say, 50:50 is what to aim for, its balance
Try sticking 30 KG+ forward of the driveshafts and taking the same from the rear, it is not an improvement
Handling will be worse and with increased control difficulty ie inclined to swap ends...exactly what you don't want
They did a test at Curborough Sprint comparing A series / Vtec / Red top
Anyone care to guess which came out fastest ?
#15
Posted 12 July 2018 - 12:50 PM
Because I like to "Think outside the box" (who thinks up these crazy expressions?), I recon that you should go ahead, pick a beam axle and fit it.
It will be very interesting to read your track day description of how it handles, ........... if you survive.
Edited by DeadSquare, 12 July 2018 - 01:08 PM.
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