improving handling.

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andrew T
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improving handling.

Post by andrew T » Thu Feb 19, 2004 4:44 am

I'm wonting to lower my van to improve the handling but I dont wont to loose too much hight so dont really wont to go any lower than 3inch drop. I was planning on using uprated anitrol bars front and rear as the main improvement. But, I'm unsure on which shocks to use. I wont a comfortable ride without it being to bumpy. I am lowing to improve handling but keep it as a daily drive so rockhard I dont wont. Would a new set of standard shocks be good for this or would I need to uprate them as well? if so which do people recomend, keeping cost as an issue. I have seen a kit advertised with adjusters, uprated antiroll bars and a set of KYB gas shocks all at a fairly reasonable price. Are theas shocks recomended for what I wont, or would they be too stiff. I have a friend who has them on his stock hight bus who says they are a bit hard and bumpy and would be his first choice again.

Thanks

Andrew..........

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JC-ATL
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Post by JC-ATL » Thu Feb 19, 2004 8:37 am

The KYB GR-2 would be a good shock for this application. Also, KYB has introduced a shock for SUVs and pickups, the MonoMax, which sounds to me like it would be a good choice as well. Anyone use these?

Vanman_spud
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Post by Vanman_spud » Thu Feb 19, 2004 3:15 pm

Was it Just Kampers you saw doing the kit? cos they do one.

As far as I know loads of people are runing those shocks so they must be good,
I have been thinking about fitting the uprated anti-roll bars to my bus in the future but it's got AIR suspension so the adjusters and dampers would be of no use to me.

I haven't heard any bad things about em.

ambrose
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Post by ambrose » Thu Feb 19, 2004 3:25 pm

I am fitting adjustable shocks from LA Performance (www.laperformance.co.uk). So you can go for the soft and squidgy or hard and harsh - however you like it. Have a chat with Lee - he is a top man and is doing a lot of work on my 79 bay - uprated anti-roll bars, porsche brakes, adjustable shocks, lowering, tuned Type IV etc...

Cheers

Ambrose

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amskeptic
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Re: improving handling.

Post by amskeptic » Thu Feb 19, 2004 7:14 pm

andrew T wrote:I'm wonting to lower my van to improve the handling but I dont wont to loose too much hight so dont really wont to go any lower than 3inch drop. I was planning on using uprated anitrol bars front and rear as the main improvement.Andrew..........
Handling begins and ends at the tires. Make sure they are quality tires at the correct inflation. Remember too, if you want real handling, don't go putting on outrageous wide tires, you'll flip instead of slide.
Strangely enough, bigger anti roll bars do not improve handling just because they are there. They make the grip *less* on the axle they are used on. This neat trick is pretty obvious. They transfer the inertia to the outside wheel which then has to do the work of both the inner and the outer. Let's exaggerate so you can see how. Put on a 100mm bar on the front. The instant your car leans in a corner, I guarantee you the inner wheel will be off the ground doing no work. With a VW, the factory supplies a front bar so the front will break away before the rear, this promotes understeer, the safer choice for the average driver. The factory ride height and factory roll bar are designed with the shock settings that are intrinsic to your torsion bars' spring rates . The only way you can narrowly improve the handling is to keep the balance between the axles the same, and to stay within your actual springing. If you make the rear too stiff, you interrupt the designed weight transfer that functions with the front axle to initiate understeer. If you lower the rear, same thing. If you make the front too stiff, you'll have the slow-speed Porsche 911 plow effect, where bumps cause understeer at slow speed, and terminal understeer will limit your upper end.
I am all for a good set of rear shocks. With the engine hanging back there, you will want the shocks to absorb both big occillations in road surface and they will help tidy up your windy day tracking. The front deserves fresh shocks, of course, but there is nothing to be gained by stiffening the front any more than it is. Take your bus to a good parking lot and boot it hard in a corner at 20 mph make yourself a little skid pad free of any curbs and potholes, and go see what your handling really is.
Now rent Back To The Future and look at what that '73 Sunroof Bus does with a bunch of people hanging all over it as it gets thrown around a parking lot. . . with stock suspension.
Most every modified bus I've seen loses handling ability with major suspension changes. They are too stiff to hang on in a corner, every bump throws them outward, they can't transfer weight properly so they understeer heavily at low speed and then lose it entirely too quickly at the rear when adhesion is exceeded. If you do not drive your bus at these kinds of limits, then you are not talking about handling in the first place, you are talking about "ride." Remember, the factory knew damn well that these cars have a high c.o.g. they had to limit the handling to keep them roof side up. " Improve it " at your own risk.
Colin

Busguy71
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Post by Busguy71 » Thu Feb 19, 2004 11:24 pm

with that said, what if you get an adjustable beam in the front, or dropped spindles for that matter, and drop it in the rear by installing bus-boys boomerang, would that keep the stock handling and also lower the ride height?

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jloh
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Post by jloh » Fri Feb 20, 2004 6:54 am

people just assume because a bus sits up high that it doesn't "handle."

why dont people just come out and say i like/want the "look" of a lowered bus. why try to pin it on "handling?!"

like colin said...buses were desinged to "handle" at the factory. if you've driven a properly setup bus, good shocks and properly inflated LIGHT TRUCK tires. you'll find that they handle quite nicely indeed!

case in point: my brother has driven my bus several times. when he started looking he drove one that had gone through some of the steps the poster mentioned, LOOKEd really cool. drove like shiate!!! he said he couldn't beleive how GREAT my bus ahandled complared to the one that LOOKED really cool

ambrose
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Post by ambrose » Fri Feb 20, 2004 7:25 am

I want a bus that handles.

I also like the look of a lowered bus.

The two may or may not be connected.

As you state a properly setup bus, with good shocks and properly inflated light truck tires will handle quite nicely.

How do you properly setup a bus? What is a 'good' shock?

No doubt the factory was a great setup - but surely with modern technology there may be some room for improvement - such as good modern shocks?

Also did the factory not have to consider that the bus may be used to carry loads close to or maybe even in excess of the capacity of the bus? I surely do not intend to do so and so maybe there are some compromises that the factory made that I can remove?

Why light truck tires? My Audi weighs the same as my bus yet it has low profile tires. So maybe we come back to the load carrying capacity of the bus?

I entirely take your point that some people are just after the look of a lowered bus and so do horrible things that destroy ride quality and handling - frequently two different things of course - and racing car handles superbly on a nice flat race track but the ride is shiate.

Straying from the factory default may improve handling and/or ride if done properly. But it is very easy to do quite the opposite and I think you are quite right to point that out.

Cheers

Ambrose

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aircooledtechguy
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Post by aircooledtechguy » Fri Feb 20, 2004 8:43 am

I TOTALLY agree with the tires comments. The #1 best $$$ EVER spent on improving the handling and overall drivability of my bus was the addition of a set of LT195/75R14 Load range "C" tires. Yeah, I wish they were load Range "D", but the tires I bought didn't come in a D. The instant I drove away from the Garage, I thought somone had installed the "Ferrari Upgrade" on the suspension. OK, maybe that's a stretch, but it handled like a brand new bus. The difference was truly unbelievable!!

Only those who have gone from plain-jane passanger tires to LT tires can understand the change in handling I'm talking about. I've had those tires now for over 5 years and 45K miles and the tread is still more than half that of new.

ambrose
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Post by ambrose » Fri Feb 20, 2004 9:13 am

I can see that being the case if you stick with the same wheels and do not go for low profile tires. The walls of 'normal' tires aren't going to cope with the weight of the bus.

Surely if you changed the wheels and went for lower profile tyres - by definition they have less tire wall and so will not flex?

I just can't see how my Audi that weighs 2 tonnes can handle as it does on low profile tires and yet my bus that weighs the same would need LT tires - assuming of course I have appropriate wheels.

The BIG downside of low profile tires is that you have much much heavier steering I guess?

Of course everything I write is opinion - I have no real world knowledge so please take everything I write with a pinch of salt :-)

Cheers

Ambrose

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jloh
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Post by jloh » Fri Feb 20, 2004 11:02 am

good shocks= KYB gas-adjust {they are stiffer than the gr-2s}


drop spindles are great for the front becase they dont alter the geometry/weight dist, but i question the torsion adjust necessary to lower the rear.

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amskeptic
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Post by amskeptic » Fri Feb 20, 2004 2:05 pm

ambrose wrote: I just can't see how my Audi that weighs 2 tonnes can handle as it does on low profile tires and yet my bus that weighs the same would need LT tires - assuming of course I have appropriate wheels.
Ambrose
You are right about the weight issues, the bus doesn't have some gross obesity issues that necessitate special tires. . . . . except that it needs special tires to remain within compliance with its Gross Vehicle Weight capability. My '73 bus is 3032 lbs. That is svelte in comparison to my portly BMW 5 Series. But while the BMW takes on an additional 880 lbs to max out, the bus takes on a potential 1979 additional lbs. Low profile tires are lovely on a BMW, the alacrity with which they respond to steering inputs is what the car is all about. A bus, on the other hand, has dizzying numbness through the center pin pivot, it has a huge polar moment of inertia, and you are wasting low profile tires on that car, sort of like paying for a stereo system with .0005% THD, and then putting it in a Kombi with a Baja exhaust. Duh?
Colin

andrew T
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Post by andrew T » Fri Feb 20, 2004 3:25 pm

ok so to answer my question, how would a bus handle with a 3inch drop, uprated antiroll bars and KYB gas shocks?

If I was saying I wonted the look of a lowered bus then I would have not said that I dont wont to compromise on hight keeping to a maximum of 3inch drop. I said I wonted to improve the handaling as thats what I wont to do. It seems though that what people are saying is thats not possible. Or if thats not what they are saying then they arent answering the question by saying how it can be done. If the handling can get no better then thats fine I dont need to do anything. If anyone feels it is possible then give advice on ways how, I'm sure there are maney people wonting to know the same. You guys seem very knowledgable and it is all usefull.

I have followed a bus that took a corner at 60mph that in the standard van we were following could only take at 35 and that was pushing it, he would also leave us for dust at roundabouts. He had a 6inch drop uprated antiroll bars and AVO coil over shocks. Granted theas shocks are not cheap but this shows the handling can be improved, I've experienced it. I dont wont to race it and I'm certainly not after a 6inch drop, just wont to see what improvement people think are possible. If I can then improve it by anyway then that has to be a bonus.

Oh and I'm using 185R14 Comertial with a load rating of 102/100.


Andrew...............

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JC-ATL
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Post by JC-ATL » Fri Feb 20, 2004 4:19 pm

jloh73busT4 wrote:good shocks= KYB gas-adjust {they are stiffer than the gr-2s}
Too stiff for what he wants, though. IMHO, too stiff for anything but a pure performance car - autocrosser, something like that. They will make your car handle, but they ride like a freakin' buckboard.

CLH
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Post by CLH » Sat Feb 21, 2004 2:35 am

Here's my list of improvements in order of effectiveness and happiness from personal experience: 1- LT tires, this is the same effect you get from low profile tires, less sidewall flex, much better resistance to sidewinds, better turn in, the increased load carrying capacity is not the issue for most of us. 2- larger front sway bar, add rear sway bar, this makes a huge difference in the amount of lean you get thru the twisties, with a small effect on the stiffness of the ride, also a huge improvement to sidewinds if you have a bus with none, i.e. an older splitty. 3- stiffer shocks, helps all of the above, while sacrificing ride smoothness. Running stiff shocks in the rear is not as noticable as the front, which is why many of us run the stiffer KYBs in the rear, softer in front. 4- I don't have any experience with lowering a bus, so I won't spout off about that, although if done properly I would expect the same benefits/drawbacks you get with any vehicle. I have never flipped my bus or rolled it, but I'm sure it's more likely to happen with these modifications, although maybe not, because I might avoid an accident with my vastly improved handling :D

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