Cradle bush (pineapple) query

[Dale FZ1]

Having done the forum search, I'm still not much more enlightened about the value of either urethane or alloy cradle bushes.

It is evident that the harder materials will transmit more vibrations, and they will also locate the whole cradle assembly more "tightly" to the chassis, but beyond this is where I'm lost.

Draggers talk about a traction setting which is no good for drifters, while there isn't a lot said about the benefit for track work.

I can understand that under torque loadings the whole assembly should rock if the bushes are compliant, but how do the harder bushes prevent (or encourage) squat? Is it the case that you do not replace all the bushes depending on the desired handling outcome?

Do pineapples produce good results for circuit work?

[someonestolecc]

I'm no expert but I'll give it a shot from my limited understanding.

More vibration and cradle assembly being tighter is spot on - sounds like you got it in one.

There are 3 'settings' that I'm aware of. Drift, drag and normal. For drag, I would assume the harder than stock but still compliant polyurethane bushes would flex somewhat. My understanding is that it wouldn't be as bouncy as stockers so helping to combat axle tramp (I could be waaaay off here).

For drift, the setting essentially as you probably guessed is the opposite, allowing for easier wheel spins because it's not very compliant at all.

The normal setting (which is what I have on my car) is a balance of both, but make the rear end feel firmer, more predictable and generally makes it feel ... more trustworthy. These are my "by seat" feelings.

You would always replace the set of 4 - the settings are dependant on where and how you place them rather than leaving some on as stock (I think this would result in undesirable rear end characteristics). There was a slip of paper with mine - I'm sure someone can post that picture up it will give you a good idea of how the placements differ.

I believe if you put the setting on natural it would help you with circuit work with all other supporting suspension bits. I reckon it was $60 well spent for me.

[Dale FZ1]

The gut feeling is that it has to be a good thing, just haven't seen any pics of the job.

I must have balls-ed up how the assembly goes together - thought there may be an upper and lower bush for each mounting point? As far as where the bushes are installed, can you be more specific please?

[NZM.031]

i have pinapples set up for drift. what happens is....

for all round performance and general tightening up of the diff cradle, you put all 8 pinapples in. this keeps the diff in its orginal position but stiffens it up..

for drag, you put four in, 2 at the top on the front and 2 at the back underneath the cradle. this changes the angle of the cradle so when you stomp on it, the cradle which would normally move around is now held in position, different but at a different angle, encouraging squat.

drift is the opposite. and sets the cradle up the opposite way...

they do work, and it takes a bit to get used to. you can feel the diff is tighter, the wheels spin easier and for longer.

i have alloy ones, which transmit a bit of noise and vibrations, polyurethane ones shouldnt do that though.

cheers

Linton

[Dale FZ1]

Top Stuff.

Thanks Linton, you've made it much easier to understand, using plain English.

I'm a big believer in car speed from chassis tuning, and this seems to be one of the easier and cheaper options to improving the Skyline - provided you can live with some of the original NVH refinements being removed.

cheers

[Sydneykid]

Linton has done pretty well in his description. The concept is to change the angle of the rear cradle for the same, more or less anti squat. The tightening up of the movements of the rear sub frame in relation to the chassis is a separate but very worthwhile advantage.

For drag applications you want as much squat as you can get to maximise the weight transfer to the rear. The trade off is making sure you don't get too much or the camber change will overcome any weight transfer advantage.

For drift applications you want as much anti squat as you can get, by reducing the weight transfer to the rear it minimises the rear grip. At the same time it maximises the front grip for better steering response.

Circuit racing is a bit of both, I tend to go for a fair bit of rear squat in high powered rear drive Skylines. GTR's being 4wd don't need quite as much, so I run a bit of anti squat.

The postition of the polyurethane bushes (above or below) determines how much angle there is on the sub frame (in relation to the chassis). The Whiteline kit has a table with the applicable settings.

Hope that was of some help:cheers:

[|PRESA|]

Very good discriptions, Linton and again SK!

What would be most suitable for drag set up? Polyurethane bushes or Alloy bushes?

[Sydneykid]

Very good discriptions, Linton and again SK!

What would be most suitable for drag set up? Polyurethane bushes or Alloy bushes?

Clarification first, there are polyurethane pineapples that supplement (not replace) the standard bushes. They also allow subframe angle changes. There are polyurethane bushes that replace the standard bushes. There are alloy bushes that replace the standard bushes. I haven't seen any alloy pineapples.

I don't think the material is the issue if it is a 100% drag application (ie; no road use). The angle of the sub frame is the important tuning item. So by default you may have to use the polyurethane pineapples. You should also replace the standard rubber bushes with alloy bushes and then change the angles with the polurethane pineapples.

For a road car that does a lot of drag work, the best would be polyurethane bushes and pineapples. For a road car that sees only a little drag work, the standard rubber bushes and pineapples would be my choice.

Hope that makes sense:cheers:

[|PRESA|]

Your a champ! I now see light...

[Greg]

Some very good info in here...

Just how much do the pineapples affect NVH?

[Sydneykid]

Some very good info in here...

Just how much do the pineapples affect NVH?

Not a lot, that's why they are such a good idea and popular.

[siksII]

this cleared things up a lot for me, i was worried about NVH but for my needs i now know i should get 4 soft pineapples to set up for grip...and it shouldnt affect nvh too much as mentioned.

i hope they make 1st gear a bit more useable

[GTaaargh]

The suspension shop who tested my shocks pointed out that my Cradle Bushes were on the way out. Apparently they should be oil filled, and mine aren't

They thought the replacements for an R32 GTR would be around $1500.

Does that sound about right?

[|PRESA|]

Planning to buy a set of pineapples tomorrow. I sure hope they have instructions on how to fit.

[gts4diehard]

Hi, in relation to cradle bushes, Noltec in Sydney make them and you can buy the from http://www.uniqueautosports.com/ for $195 a set.

it will take around 10 hours for a suspension shop to drop the subframe, pull out the old bushes ( - I used a carpenter holesaw to cut bush out and hacksaw outer case to release pressure and they will just pop out!) and press in new bushes, refit subframe and hook everything up, I did it by myself at home - didnt take 10 hours.. , but biggest hassle was working out how to drop subframe without damaging stuff.

2 hours - subframe removal - dont need to disconnect hicas or calipers - just remove bolts and support somewhere

2-4 hours - bush removal and refit

rest hooking things back up, bleeding attessa - easy see manual.

so around $800 to $1000 to fit. while you are at it you should check diff mount bushes, Nismo only supplier and around $400 for these bushes - not sure on fitting.

tightens up the rear a bit, but not as much as I expereincec from replacing bushes in rear hubs and rear tierod & arms

cost breakdown to do bushes on GTR or GTS4

1) -subframe bushes $200 (Noltec)

2)-diff support bushes $400 (Nismo) $800- 1100 to fit 1 & 2

3)-hub bushes (Nissan) $150

4) -rear tierods and balljoints $375 ( nissan) $300 to fit 3 & 4

5)- rear links new bushes - non - adj. $300 (super pro) need press to do $300 to fit

labour may be a bit cheaper if you do all the rear subframe bushes at once - I didnt.

then your GTR rear will be brand new

Stephen

[Taso84]

Sorrry im bringing up an old thread, but what is NVH and what is the best setting to have the pineapples on if u wanna eliminate axel tramp but still be able to drift?

[andylaurel]

NVH stands for "Noise Vibration Harshness"

basically changing the pinion angle of the diff allows you to transfer the power to the road better, or worse.

It is similar to the concept of a live axle 4 link rear end, where one might point the pinion up to slippery up the rear end, or vica versa.

because of the design of the multilink IRS rear end, you have to change the entire angle of the crade to change the pinion angle...

actually disregard all this information, the pinion angle in a multilink wont change with squat cos its sprung weight.

[ls1ben]

I have heard some people saying that the drift setting can be a bit to slippery and that its better to use the normal position with the pineapples. Can anyone comment on that?

[Sydneykid]

I have heard some people saying that the drift setting can be a bit to slippery and that its better to use the normal position with the pineapples. Can anyone comment on that?

Drift postion is good for drifting

All round position is good for normal driving

Max grip position is good for drags

cheers

[NickR33]

this cleared things up a lot for me, i was worried about NVH but for my needs i now know i should get 4 soft pineapples to set up for grip...and it shouldnt affect nvh too much as mentioned.

i hope they make 1st gear a bit more useable

with the Bilstein shocks, the whiteline camber adjustment bushes, pineapples set to squat and 255 semi comps, if you stomp it in 1st it snaps your head off backwards! I still get a little wheelspin but MUCH more forward momentum to go with it... only have 200kw at the wheels tho...