WesBrooks
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Posts posted by WesBrooks
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Great videos. Interested to see no anti roll bar on your video there?
I was interested interested in this partly because I thought the efforts around caster correction etc when lifting is focused on making the road manners better for an extreme lift. So with air suspension that can lift an extra 50mm if needed I was wondering where the wise money goes to make sure the truck is well behaved in most circumstances, which in terms of hours use would be road by a long shot.
So shocks top of the pile. Check straps if there is any chance of air time. Uprated bump stops for heavy hits. Are uprated anti roll bars always bad off road or on trail? That video didn't appear to have any at the back? That said with hydrualic steering it will never sniff tarmac so I guess the equation is completely different.
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I think you'd need to rotate the mount points of the radius arms about the axle too? An appropriate degree of both clocking the hubs and rotating radius arm mounts would sort out caster and prop angle, but not cheap. You'd likely need to drill through part weld part casting to get the required degree of correction.
Interesting discussion around caster but I guess irrelevant as people have said stock-ish height which means caster should be fine.
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Yeah I hate auto correct but even with that off my thumbs and touch screens still aren't on best terms!
Cheers for the link. I guess the side effect of caster correction is it increases the angle on the prop shaft joints.
Saw the caster angle and had instant recollection on frame angles on my road bike. I got nasty wobble on my steel frame bike if I hit over 35 on a decent. Caster angle significantly out of spec may well be a significant factor in the infamous death wobble.
Edit: as in caster angle reducing or worst case going negative.
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So micky taking aside caster mainly effect self centering which is lost as suspension is raised from stock?
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8 minutes ago, Bowie69 said:
Increased faster can be preferable in a racer...
Sounds logical! 😄
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Comp Safari and Hill Rally. Hill rally looked to be closer to stock vehicles?
Bowler advertise a fast kit which merely namedrops Bilstiens (have them on my daily - skoda superb - very happy with them) and says different anti roll, stearing damper, new bushes, etc.
Tyre choice appears to be more modest in terms of diameter. I've seen 245 75 16" mentioned which would be about 30" diameter. Bigger than Disco and Range Rover but within stock range for a Defender?
Regards the Caster correction kits you see listed for lifts what is the effect of incorrect caster on the handling of the vehicle? Likewise if lowered and the caster is the other side on normal what would that cause?
Edit: Wrote before Bowie's post!
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By 'at speed' I mean a little faster where theres a enough pace for wheels not to remain permanently planted, but I'm not thinking massive pace.
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Having diverted the Grenadier topic by mistake I thought I'd spin off the suspension talk to a seperate thread!
Most talk on these forums around suspension centre around increasing articulation and low speed off roading performance. So out of curiosity what mods are made to make the typical coil landrover suspension behave well at speed?
I've seen a couple of clips of hill rallys on TV and they look great and there is a large green oval contingent which implies there must be a reasonable body of knowledge on the subject.
So stock ride height is probably preferable along with good condition/new shocks and springs and Poly bushing. What about tyre size, how large can you go before tyre size and weight becomes a hindrance? Wider track / offset rims a little?
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I did catch a few interesting articles on unsprung mass a while back including some that mentioned in some cases the weight of the axle could make the tyres work a little more at absorbing road vibrations (at some frequencys) before they are transferred to the body. I guess for us that's countered a bit by heavier duty tyres and additional vibrations from aggressive treads!
I'll look up the death wobble closer as I've seen that mentioned many times. I guess it's almost as effective as ice for one end of your vehicle sliding out if you catch it on a corner.
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He he yes, I dodged that comment. Random citations in US marketing such as peak G forces a vehicle can exert when going around a corner, rather than a far more real dynamic test.
I Apologise for dragging this off track! 😄
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Yeah, a lot of economy UK/EU front wheel drive vehicles have (not live) beam suspension at the rear too. It's the front that causes most chaos with the road manners.
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Those are essentially the point I'm making but I'm guessing you'd have a hard time doing the same with most of the 4x4 SUVs with electric aids or independent suspension?
Anyway I've diverted the topic a bit. It isn't a road car, and they are not targeting sales reps and company car fleets. All I was really wondering was if the are going in as a commercial or not.
Final question on the handling characteristics though (it does fasinate me but not had the time to find a decent affordable book to read) is beam axles do have their own perculiar handling characteristics compaired to the run of the mill road car right?
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At least with IVA you have the choice open to you. I was wondering if they'd take this route in part to force home the message that this is a commercial vehicle to potential customers with the lower speed limit adding to that inforcement.
I've been framing through this video to see if the anti roll bars were present (don't think so but video isn't exactly high resolution), but it is easy to make emotive videos like this, particually if you have no antiroll bars (/disconnect), low front tyre pressures, over correct, etc...
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Certainly looks like it's heading down the solid workhorse path. I wonder if they look at registering it as a light commercial rather than private car and take the speed limit on the chin.
This suspension certinally looks tough but can you make this style of suspension behave well when thrown around? Not it's target I know, but people will, and if it has and of the nasty behaviours a tall beam axle vehicle can have they will need to educate it's proapective owners or risk a few poor stories. Registered as a light commercial you'd be less likely to suffer people buying it for a status symbol as they'd soon be caught out by the lower speed limits!
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On 4/9/2020 at 11:24 AM, Turbocharger said:
The minimum length of the springs is going to be very important - I can see why Robert had those extended bump stops - there's 160mm package volume for the spring at full compression to the bump stop, and I'm keen to design it as if the 50mm bump stop was removed, or at least substantially compressed.
Have you got the minimum packing lengths for the classic and P38 bags?
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Nice, thanks for the heads up there.
There is some good information on the stock height settings on this thread:
https://www.aulro.com/afvb/p38a-range-rover/78026-eas-height-settings.html
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Interesting to read lots of different takes on the same base topic!
I have it in mind that anything thay I build for the truck will be designed to run as normal on upto 24V input, have reverse polarity protection (the MOSFET trick for low power loss), with appropriate noise, and reverse polarity protection. Beyond that I will need to take a closer look at current best practice when the time comes.
I think step one will be over-volted pots with a trim pot on the ground side to shift the signal away from 0 if needed.
Is anyone familiar enough with the EAS system to know what values are classed as fault readings?
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8 hours ago, Ed Poore said:
Why not get a pot that's double the value but only use half it's travel?
That's where I was going with the 'not insurmountable' comment. At the moment I've got a complete system from the Range, aside from this sensor and the bags. I'm thinking the best approach is to get this working, then have a crack at my own controller.
The control settings (0-255) from the youtube videos of EASUnlock indicate an 8 bit analogue to digital converter. With a single turn (but no limits) pot attached to the stock controller it would still be getting a 5V signal but the range of valid positions would be halved. The controller (probably bang-bang rather than PID) would probably be only working within a range of 60-80 bits before the swing/radius arms hit their limits. Potentially too small for decent control?
Moving it steps towards the full custom controller this is less of an issue. First less stock approach would be to break of the posative supply to the pot and over-volt it so that the range of returned values is in the 0-5V (or smaller to avoid 'fault' readings) range, with care to limit current and clip over voltage from signal to the ground.
Having said that I think as microprocessors are so plentiful and cheap now a digital signal back from each corner of the vehicle would be best, there must need to be a fair measure of signal smoothing and transient voltage suppression needed on a 5V signal wire thats 2-3m long which essentially chokes resolution and responce time of the sensors?
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Ok so I can find plenty of near 360 degree pots, but no 180 degree. That and there being very few high IP rated items make me think the most cost effective method will be to work with P38 sensors if I can. Back sensors don't look a problem, but front may need some CAD and printing to get working.
The fact that there are few 180 pots isn't insurmountable, but it reduces the resolition of sensing for body height. -
I sacraficed a knackered sensor to satisfy my curiosity. It is a custom pot. It's roughly 1.37kOhm 180 turn, but wired in such a way that it can be run on onside or the other.
I don't think there are any physical limits, rather than this one is broken as there wasn't any obvious bits inside.
As shown in thw above photo: Left wire goes to the top left two contacts on outer ring. Centre wire to the centre of the outer track. Right wire to the inner (wiper) track.
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Anyone looked into whay pots are inside the height sensors?
Look to be about 1.4kOhm track resistance. Polymer pots are recommended for low noise over carbon track but I guess these may predate polymer pots?
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I'm building this project for an IVA. Due to that I requested a chassis number - even though I could have made one up - from the DVLA and that is what Designa Chassis marked on the chassis.
The chassis was made without many of the brackets and rear cross member as I wasn't 100% sure about where things needed to mount. I want to move the engine back in the chassis, but need to confirm there is enough cabin space to do that.
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Yeah I remeber there was some funnyness around fog lights. Did get my head around it for my loom, but will need to check my notes.
I was hoping that an OEM loom would be accepted as is, but then again I guess I'll have modified it by removing sevtions and components.
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The old donor is almost completely in the tip now, so the kit build is targeting being the running gear from the range in it's entirety. It'll live on, and is still running sweetly.
Ultimately I still want to do my own loom but if the rest of the Range's Loom looks reasonable I may try to get through the IVA with the stock loom and save the rewire for a later project.
No point giving myself too much of a mountain for the IVA, and may as well not pretend it will be anything but an everlong project! 😄
Suspension Mods for Faster Off Road?
in International Forum
Posted · Edited by WesBrooks
Interesting on the anti roll bars.
Regards hydrualic steering I forgot the international aspect of the forum. As far as I'm aware it's only farm and construction vehicles that can run hydrualic steering - legally - on the road.
Edit: I'm referring to construction and use regs in the UK. Irony is up until hose failure hydrualics are probably more predictable handling.