Roll Centre Adjustment On R32 Gtr

[STATUS]

No having much luck....

i dont like doing this but if you get stuck i will try bring em in for you.

[djr81]

i dont like doing this but if you get stuck i will try bring em in for you.

Thanks for the offer, Trent. He has some bits & I have enquired about some others. So will give Costa first bite.

Cheers

Richard

[T04GTR]

coooool. well as soon as i can unsieze my rear driveshfts so i can get the arm off wel be in action

[Beer Baron]

well I've enquired in japan and can get the MFR bits quite reasonably priced, and most of the BNR32 gear is currently in stock so I just need to decide which bits I want and add it to my next order. Dave, if you want me to grab you a set too let me know, then we can play with them together. lol that sounds wrong.

[Sydneykid]

to be honest the whiteline ones worked very well with my old set-up which was bilstein shocks with eibach springs. the fairly light springs were complemented nicely by the big bars (rear on full hard, front on medium), but with the new ultra high srping rates I feel it's a bit too stiff, and some lighter bars will bring it back into balance. if it's no good I'll just put the rears in the front and buy some 7kgs or 8kgs for the rear.

Be careful, it will almost certainly be faster with softer springs and harder bars, than the other way around. This is due to the loss of traction from the higher spring rates. Plus you increase the braking and acceleration (straight line) traction with more compliant spring rates.

cheers

[Beer Baron]

Thanks gary, it is hard to ignore your advice. especially for me after a number of seasons in state champs sitting in the pits watching a number of the cars you work on or consult on winning their classes... thankfully you don't work on any cars in prod sports or Grp Nc historics... or do you?? :scared:

btw spencer, chris and I won the Group NC champs with the white car, and only our second year since we finished building it.

[Beer Baron]

gary, I do have one quick question for you actually (I know this is off topic, but it's all related, and it's my thread!!!)

to refresh your memory. I'm currently running the ohlins 4 way adjustable, remote canister alloy shocks with 10kg front springs and 8kg rears. you previously suggested a cheap way out of my rock solid set-up would be to try the rears in the front, and get some new rears. the only problem I can see is my fronts are 190mm long and the rears are 250mm. Although I guess I can adjust this out with the spring platform, and also the lower mount is adjustable up or down the shock shaft. but I would have to check that I have enough adjustment for 60mm. Assuming I do, is there any downside with doing things this way? The spring will be fairly heavily compressed with 60mm taken out of it.

on the other hand springs are only around $150 a pair so perhaps I should buy some different ones to try.

I'm thinking I will try the cusco bars anyway as I like the idea of a lighter bar, but I'll hang on to my whiteline ones (and my stock ones for that matter) for the time being.

[djr81]

Well the rear roll centre adjusters are in a bag somewhere over the nullaboar at about 50,000 feet.

Question I have is this:

Should I try a pre emptive lower front ride height (355 doen to the next lowest setting on the SK Bilsteins) to increase the rake angle & turn tte car in better?

Also, the bloke I bought them off is now on the business traders as drift motorsport. Has some nice stuff.

Edited February 16, 2007 by djr81

[Beer Baron]

which ones did you go for djr81? I am tossing up between 3 different rear ones. the sleave which they just call roll centre "adapter" and then roll centre adjuster and pro roll centre adjuster (about $40 difference between those two). At this stage either going the cheap one, then if it's good buy the pro one. or just go straight for the pro one.

the front there is just one kit afaik with the spacers. I'll grab that as they are quite cheap.

[djr81]

which ones did you go for djr81? I am tossing up between 3 different rear ones. the sleave which they just call roll centre "adapter" and then roll centre adjuster and pro roll centre adjuster (about $40 difference between those two). At this stage either going the cheap one, then if it's good buy the pro one. or just go straight for the pro one.

the front there is just one kit afaik with the spacers. I'll grab that as they are quite cheap.

He only had the conical type so unsurprisingly I went for that one. He only had one set of them so they were probably a sample.

The bonus is installation is cheap & easy so if I don't like it I can just drop the lower arm back off & bin 'em.

He didn't have any front ones, so I can't presently source any of them at all.

Do you have any thoughts on the rake question?

[Beer Baron]

well I think since you are correcting the roll centre anyway then perhaps a little front lowering could be worthwhile.

I'm going to order some rears, and 2 sets of the front kit next week. dave and I are going to take the plunge and see what happens. it's a pretty cheap mod, so if it improves the handling even slightly I'll be happy.

[Sydneykid]

gary, I do have one quick question for you actually (I know this is off topic, but it's all related, and it's my thread!!!)

to refresh your memory. I'm currently running the ohlins 4 way adjustable, remote canister alloy shocks with 10kg front springs and 8kg rears. you previously suggested a cheap way out of my rock solid set-up would be to try the rears in the front, and get some new rears. the only problem I can see is my fronts are 190mm long and the rears are 250mm. Although I guess I can adjust this out with the spring platform, and also the lower mount is adjustable up or down the shock shaft. but I would have to check that I have enough adjustment for 60mm. Assuming I do, is there any downside with doing things this way? The spring will be fairly heavily compressed with 60mm taken out of it.

on the other hand springs are only around $150 a pair so perhaps I should buy some different ones to try.

I'm thinking I will try the cusco bars anyway as I like the idea of a lighter bar, but I'll hang on to my whiteline ones (and my stock ones for that matter) for the time being.

The 8kg/mm springs will compress more than the 10 kg/mm springs to hold up the weight of the car.

R32GTR usually weighs around 950 kgs on the front

So 950 /2 = 475 kgs

10 kg/mm = 47 mm to hold up 475 kgs

8 kg/mm = 60 mm to hold up 475 kgs

So ~13 mm of the 60 mm will be needed for the softer spring to hold up the car.

Hence you only need 47.5 mm of adjustment

It's a cheap test, $150 for softer rear springs

cheers

[Sydneykid]

Question I have is this:

Should I try a pre emptive lower front ride height (355 doen to the next lowest setting on the SK Bilsteins) to increase the rake angle & turn tte car in better?

You could try 345 mm, but it depends on how much travel you are using. If that 10 mm reduction results in excessive bump stop contact, then it will have a negative effect. Have you checked the travel with the "old cable tie on the shock shaft" trick?

cheers

[Ronin 09]

gary, I do have one quick question for you actually (I know this is off topic, but it's all related, and it's my thread!!!)

to refresh your memory. I'm currently running the ohlins 4 way adjustable, remote canister alloy shocks with 10kg front springs and 8kg rears. you previously suggested a cheap way out of my rock solid set-up would be to try the rears in the front, and get some new rears. the only problem I can see is my fronts are 190mm long and the rears are 250mm. Although I guess I can adjust this out with the spring platform, and also the lower mount is adjustable up or down the shock shaft. but I would have to check that I have enough adjustment for 60mm. Assuming I do, is there any downside with doing things this way? The spring will be fairly heavily compressed with 60mm taken out of it.

on the other hand springs are only around $150 a pair so perhaps I should buy some different ones to try.

I'm thinking I will try the cusco bars anyway as I like the idea of a lighter bar, but I'll hang on to my whiteline ones (and my stock ones for that matter) for the time being.

get me a set of springs too Baron! (seriously)

[Beer Baron]

no prob. we'll talk when you're up here

[Andrw Le Lievre]

I have got front roll centre adjuster spacers coming from Japan soon as well. I got the ones from ESP-SPORTS NET SHOP (espoirsp2002) on yahoo.jp for ¥13,800 a set. They have rear units as well but it is a ball joint replacement, so like many of you I am going to try the rear Moonface spacer first.

Andrew

well I think since you are correcting the roll centre anyway then perhaps a little front lowering could be worthwhile.

I'm going to order some rears, and 2 sets of the front kit next week. dave and I are going to take the plunge and see what happens. it's a pretty cheap mod, so if it improves the handling even slightly I'll be happy.

[Andrw Le Lievre]

Tried to fit the front roll-centre spacers when I was swapping over to 356mm G4 brakes. The two bolts fastening the hub to the lower arm seem to be pressed in, as I could not get them out even with a drift and big hammer on the loosened nut. Has anyone had success in getting these out?

Andrew

[djr81]

Mmm, the bolts in the Moonface kit for the front end didn't look anything special. Maybe I need to look again.

The manual does have a cryptic note on page CH-228. See attachment.

Oh and Andrew if you are after some rear spacers I have a pair at home (2nd hand) for sale.

Edited April 5, 2007 by djr81

[T04GTR]

they bang out like wheel studs. and from the look of them they are wheel studs lol.

[Andrw Le Lievre]

Thanks.

Looks like I need a bigger hammer!

Andrew