Jump to content
SAU Community

Recommended Posts

Guys,

I have S1 R33 GTS-T. Suspension mods:

Front.

- Bilstein shocks (basic type, yellow colour)

- King Springs (200lb linear I think, no idea of heights)

- Offset polyurethane castor bushes

- Stock Sway Bars

- Shock tower brace in engine bay

- Tyres are 18" 235 Bridgestone S03s

Angles: -2deg camber, -12deg castor, 1mm toe in

Rear.

- Bilstein shocks (basic type, yellow colour)

- King Springs SP version (160-200lb progressive, no idea of heights, bit low though)

- Offset polyerethane camber bushes upper and lower arms

- Full R33 GTR rear bracing setup at back end of boot and across rear shock towers

- No sway bar

- Locally designed HICAS lock kit with full mechanical replacement and rose joints

- Tyres are 18" 265, very hard and 85% bald Faulkens

Angles: -1deg camber, 0mm toe in

Main problems I have:

- Very slight understeer

- Bad oversteer mid corner with or without power on

- Can really feel a change in dynamics when weight transfers to the rear

- Inside rear wheel sometimes lifts off ground, particularly slow sharp corners

Took rear sway bar off to try and fix rear wheel lift and oversteer problem but made no difference. I also need new tyres I know but it's has been like this for a long time.

Thanks in advance for any pointers.

Link to comment
https://www.sau.com.au/forums/topic/109850-inside-rear-wheel-lifting-r33/
Share on other sites

A bad handling imbalance can be due to running different tyres front & rear. I would suggest that you need to sort the tyres before making more changes as to be honest even if you fix it for the current tyres what will you have when you replace them with new rubber?

to clarify

- Very slight understeer - do you mean turn in understeer?

- Can really feel a change in dynamics when weight transfers to the rear - do you mean power on?

- Inside rear wheel sometimes lifts off ground, particularly slow sharp corners - this is a worry. Mostly when this happens it is the end of the car with stiff anti roll bars (As per say an on VW Golf GT-i) Other than that it can be due to an excessively inclined roll axis front rear. Does your car sit nose down by any chance?

Guys,

I have S1 R33 GTS-T. Suspension mods:

Front.

- Bilstein shocks (basic type, yellow colour)

- King Springs (200lb linear I think, no idea of heights)

- Offset polyurethane castor bushes

- Stock Sway Bars

- Shock tower brace in engine bay

- Tyres are 18" 235 Bridgestone S03s

Angles: -2deg camber, -12deg castor, 1mm toe in

Rear.

- Bilstein shocks (basic type, yellow colour)

- King Springs SP version (160-200lb progressive, no idea of heights, bit low though)

- Offset polyerethane camber bushes upper and lower arms

- Full R33 GTR rear bracing setup at back end of boot and across rear shock towers

- No sway bar

- Locally designed HICAS lock kit with full mechanical replacement and rose joints

- Tyres are 18" 265, very hard and 85% bald Faulkens

Angles: -1deg camber, 0mm toe in

Main problems I have:

- Very slight understeer

- Bad oversteer mid corner with or without power on

- Can really feel a change in dynamics when weight transfers to the rear

- Inside rear wheel sometimes lifts off ground, particularly slow sharp corners

Took rear sway bar off to try and fix rear wheel lift and oversteer problem but made no difference. I also need new tyres I know but it's has been like this for a long time.

Thanks in advance for any pointers.

Bascially that's a pretty good set up you have there, just a few items that need checking, changing and upgrading.

The first thing to do is to measure the heights, centre of wheel to guard on each corner. That will at least eliminate a potential problem.

The first thing I would fix would be to toe the front tyres out around 2 mm each side and toe the rear tyres in 1-2 mm per side. That will help the turn in and remove soem of the exit oversteer.

The second this I would fix;

- Stock Sway Bars

My suggestion would be a 24 mm adjustable on the front and a 22 mm adjustable on the rear. That will stop the weight transfer and make the transition more progressive. Plus increase the tyre contact patch by reducng the roll.

Third on my list, would be rear subframe alignment bushes. If it doesn't already have them, the subframe movement distrubes the tyre contact patch causing loss of traction.

Hope that was of some help

:D cheers :D

A bad handling imbalance can be due to running different tyres front & rear. I would suggest that you need to sort the tyres before making more changes as to be honest even if you fix it for the current tyres what will you have when you replace them with new rubber?

to clarify

- Very slight understeer - do you mean turn in understeer?

- Can really feel a change in dynamics when weight transfers to the rear - do you mean power on?

- Inside rear wheel sometimes lifts off ground, particularly slow sharp corners - this is a worry. Mostly when this happens it is the end of the car with stiff anti roll bars (As per say an on VW Golf GT-i) Other than that it can be due to an excessively inclined roll axis front rear. Does your car sit nose down by any chance?

Yep time for new rubber and I have grippy stuff in garage waiting to go on the rear.

Only slight turn-in understeer at middling speeds, OK at high speeds.

I mean weight transfer to outside rear mid corner with or with out power on.

I'm thinking the -12deg castor might be inducing the inclined roll axis so I might drop it to -7 odd deg

Edited by Freebaggin

Sydneykid.

I been advised for street use (daily drive), front toe out would be a pain due to tramlining, slight instability under braking and scuffing in inside of front tyres.

But I'll see how it goes with more toe in on rear when I put new tyres on.

I had Whiteline sway bar there but found them to make handling worse and exacerbated inside rear wheel lift, so went back to stocky on front and none on rear. I'll put the rear one back on with polyurethane bushes on both front and rear to stiffen up a bit as I sold the Whiteline sway bars.

Subframe bushes sounds good. grepin is in the process of puting them on so I'll get a idea from him.

Anyone else with +ve experiences with subframe bush replacements?

Thanks guys.

Edited by Freebaggin
Sydneykid.

I been advised for street use (daily drive), front toe out would be a pain due to tramlining, slight instability under braking and scuffing in inside of front tyres.

But I'll see how it goes with more toe in on rear when I put new tyres on.

I had Whiteline sway bar there but found them to make handling worse and exacerbated inside rear wheel lift, so went back to stocky on front and none on rear. I'll put the rear one back on with polyurethane bushes on both front and rear to stiffen up a bit as I sold the Whiteline sway bars.

Subframe bushes sounds good. grepin is in the process of puting them on so I'll get a idea from him.

Anyone else with +ve experiences with subframe bush replacements?

Thanks guys.

Freeballer,

The chief suspect in your handling woes (As seen from the other side of the country & without setting eyes on the car) is a mismatch between the front & rear roll centres. It can cause the exact behaviour you are describing. Hence the question about is the car sitting nose down on its suspension? Can you measure between the centre of the rim & the underside of the wheelarch and perhaps post a photo. This may well eliminate one candidate from the list...

Freeballer,

The chief suspect in your handling woes (As seen from the other side of the country & without setting eyes on the car) is a mismatch between the front & rear roll centres. It can cause the exact behaviour you are describing. Hence the question about is the car sitting nose down on its suspension? Can you measure between the centre of the rim & the underside of the wheelarch and perhaps post a photo. This may well eliminate one candidate from the list...

Yeah, forgot to respond to that. Have measured heights before but can't remember, will do when I get home.

The rear end does sit lower than the front for sure, so it's nose up.

Edited by Freebaggin
Sydneykid.

I been advised for street use (daily drive), front toe out would be a pain due to tramlining, slight instability under braking and scuffing in inside of front tyres.

But I'll see how it goes with more toe in on rear when I put new tyres on.

I had Whiteline sway bar there but found them to make handling worse and exacerbated inside rear wheel lift, so went back to stocky on front and none on rear. I'll put the rear one back on with polyurethane bushes on both front and rear to stiffen up a bit as I sold the Whiteline sway bars.

Subframe bushes sounds good. grepin is in the process of puting them on so I'll get a idea from him.

Anyone else with +ve experiences with subframe bush replacements?

Thanks guys.

What were the ride heights? They are very important on all Skylines but GTR's in particular. Other suggestion/comments follow;

1, The small amount of front toe out I suggested would make no difference to tyre wear, compared to the 2+ degrees of negative camber.

2. Don’t do the rear toe in without doing the front toe out. It will make the turn in understeer worse.

3. Sorry I don’t understand, a larger front stabiliser bar will reduce the roll and help keep the inside rear wheel on the track. Replacing the bushes from the standard rubber to polyurethane makes ZERO difference to the mid corner and corner exit anti roll. They only effect the initial turn in roll, once the compliance difference is taken up, the bars react according to their size.

With a 200 lbs per inch front spring rate, I can assure you that a GTR will need an upgrade in its front anti roll. To balance that, a rear anti roll upgrade will also be required. The suspension is a package, change one thing and it will affect the others.

:D cheers :D

Edited by Sydneykid

OK so let's review current setup after I had a proper look:

Front end:

- Camber -1°45'

- Castor +7°40'

- Total Toe +0°8'

- ride height = 337mm

Rear end:

- Camber -0°42'

- Total Toe +0°6'

- ride height = 325mm

Edited by Freebaggin
OK so let's review current setup after I had a proper look:

Front end:

- Camber -1°45'

- Castor +7°40'

- Total Toe +0°8'

- ride height = 337mm

Rear end:

- Camber -0°42'

- Total Toe +0°6'

- ride height = 325mm

Well, let's start of with its too low, far too low. The roll centre is now too close to the CoG ie; the roll couple is too small. The lower control arms are pointing upwards to the wheel, not parrallel to the ground, so the dynamic camber change angles are reversed ie; it's going posititive camber under compression. Plus there will be noticeable bump steer. Hence the oversteer/understeer balance changes due to the roll couple inbalance and tyre contact patch issues. The front height should be 350 to 355 mm and the rear should be 340 to 345 mm.

The front should be toe out a little, as discussed previously.

The rear toe is OK, but if it is still reluctant to tuirn in, then try some toe out as discussed previously.

It doesn't have enough camber, front or rear for the circuit and R type tyres. It needs another 1 degree negative both ends.

Then do the stabiliser bar upgrades as per the previous posts.

Hope that helps

:P Cheers :P

Edited by Sydneykid
Thanks all and SK.

Can I have clarification on what some terms mean?

- Roll Centre

- Roll Couple

- Bump Steer (sounds obvious but I want to be sure)

Thanks again.

Broadly (ie the abridged explanation so please don't flame me for not including everything or for being a little generalised).

Roll centre - this is the geometric point about which the car rolls. It is dependent on the suspension geometry eg with wishbones the angle of inclination of both suspension members goes a long way to determining where the roll centre is located & also how it migrates (ie moves) when the car rolls. Note that the front & rear roll centres are commonly at different heights which in turn allows the balance of the car to be modified to give more or less understeer/oversteer.

Roll couple - the couple (ie torque) produced by the product of the mass of the car acting through the centre of gravity multiplied by the distance between the centre of gravity and the roll centre. The roll couple is the quantified torque that makes the car roll or lean through a corner.

Bump steer - when a suspension is compressed (or unloaded, bumps go down too!) the toe of the wheel changes. The outcome of this is known as bump steer. Most manufacturers use toe in for their front suspension because it makes the car more stable when one wheel hits a bump.

Thanks all and SK.

Can I have clarification on what some terms mean?

- Roll Centre

- Roll Couple

- Bump Steer (sounds obvious but I want to be sure)

Thanks again.

Roll Centre = the point around which the chassis rolls. There is a front and a rear roll centre, determined by the location of the control arms in relation to each other.

Roll Couple = the distance between the roll centre and the centre of gravity (both front and rear).

Bump Steer = the amount the toe angles change when the suspension is compressed and extended fully. There is bump steer both front and rear.

:) cheers :(

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • My experience with Rising Sun Exports Before agreeing to the sale I tried to do as much research as I could (obviously), his Facebook reviews are 98% and he goes Live at least once or twice a week. I contacted 2 people in the UK who had used him for their imports, both had positive feedback. His explanation and talk through of the import process was thorough, answering any query no matter how stupid it was. It felt as soon as the money was sent, communication dropped off. I asked for shipping updates every 2 weeks or so, not wanting to pester him, he never had any updates. I wasn't informed the car had been dropped off at the port, I only found out by his Facebook story. I asked for the photos taken at the port, knowing he would need some for insurance purposes. I received a few 5 second clips and that's it. When asked again, he said his staff had them. Weeks later I asked again, he tells me he doesn't have any, but does have 50 photos from the original advert. I never received them. I eventually got the documents sent via WhatsApp after I mentioned the port was requesting them. I purchased a CarVX report, to find out the vehicle is a Grade R with recorded accident damage, first recorded in 2017 when it was first auctioned. He never told me the grade, then again I didn't ask. His response was "Grade R means nothing, it wasn't chassis damage". Still, I would have liked to have been informed about it. Jon prides himself on being open and honest when it comes to inspecting cars, it's his main job doing so at the auctions for customers. When the vehicle arrived in the UK I noticed a few little cosmetic issues. It's a 21 year old car so it wasn't going to be mint condition. The side skirts are cracked on each corner and the sealant is failing. The front grill on the bonnet/hood isn't secured very well, mounting studs are missing. Both minor things, but again, it would have been nice to be told. During a Facebook Live walk around video of the vehicle, he mentioned it has a front Whiteline anti roll bar/sway bar. While on the inspection ramp, I noticed the stock item has been installed. When first questioned, his response was "the ARB? Switched? Since when, it never had them". Since sending video and photo evidence I've not received a response. I'm probably being over critical of the overall condition of an old car, but all I wanted was honesty (which he claims to have). I'm aware I wasn't his only customer, he's busy doing XYZ but other reviews praise him for great communication with regular updates and photos, I felt I didn't receive the same treatment. 
    • I was able to get some underside photos while the car was on the ramp The suspension is all Altezza/IS200/IS300 so getting part's will hopefully be less of a headache
    • Welcome to my 2004 Toyota Mark ii IR-V Fortuna (series 2) With a 1JZ-GTE powerplant under the bonnet (hood) it'll give me plenty of scope for power upgrades. For those who aren't familiar with imports, the 1JZ-GTE is a 2.5L 6 cylinder VVTi engine with a single turbocharger. This has the factory R154 5 speed gearbox, along with a aftermarket 2 way LSD differential (brand unknown). Under the arches are a set of CST Zero 1 alloys, 18x9 +30 225/40 up front and 18x9.5 +15 265/35 on the rear. The car was quite low in Japan and there's evidence of the wheels catching the rolled arches/fenders. The tyre's aren't great so I'm in two minds whether to replace both or just the tyres and put up with the wider wheels on the rear. The car still uses stock brakes with the addition of some braided hoses. The exterior is stock with the exception of a BN Sports front bumper and a replacement Fortuna grill  Moving to the interior, the steering wheel has been replaced with a dished MOMO steering wheel (which will get swapped for my Momo Tuner for the time being) Defi Link Gauges are mounted above the climate controls and on the A pillar, the Oil Temp,Oil Pressure,Water Temp and Boost gauges should help with spirited and track driving  The stock seats have been replaced with some retrimmed Recaro bucket seats. Being a larger build these are a little snug, unfortunately the orange isn't for me so I'll look into replacing these down the line. Other modifications include a twin plate clutch, Blitz intercooler, Evolve alloy radiator, a stainless exhaust with decat, HKS EVC-S boost controller and coil overs
    • Apologies for the long read My R34 GTT was up for sale at the beginning of spring due to a few repairs creeping up. The strut tops needed replacing, roof and bonnet (hood) painting (yay for 3 stage pearl) and the underside stripped and treated. I sold the car which allowed me to be in a much better place financially. Leading up to the sale I was already thinking about the replacement. In an ideal world it needed to be a good all-rounder. Something I can mess around with, modify, do track days, do the school run, go on long drives etc.  Options included but not limited to... Laurel C35, Evo 8/9, Civic FD2, Impreza Hawkeye, Aristo and even an Audi S4 Avant (I've already got the Mazda 6 wagon). But there was always one car at the top of the list The Toyota Mark ii JZX110 I found an advert on a Facebook group for an example in Japan, from a seller called Jon at Rising Sun Exports. A few messages back and forth and Jon calls me from Yokohama one morning (or afternoon in his case). He briefly explained the import process, the costs involved and a repeat of the advert. After much deliberation, the price was agreed and the sale was locked in. I've never imported a vehicle so I jumped into the unknown head first. The money transfer was completed through wise.com (fees apply), very easy to use and the money was with him within a day or two.  The car suspension was raised for the vessel and the car dropped off at the port. It was 7 weeks later when the bill of lading was received and the freight invoice sent to me, followed by the export certificate a couple of days after (both digital copies) In the mean time the port had been in contact. I needed an agent to deal with the NOVA (notification of vehicle arrival) along with the tax/duty invoice, this was £75.00. The port also had a fee of £100, I'm guessing to cover the cost of the 10 day 'free storage' and for moving the car off the boat etc. They need a copy of the vehicle invoice, freight invoice and export certificate to allow the vehicle to pass through customs. The vessel arrived on Tuesday 5th August, the tax/duty invoice was generated and sent over. This is generally tax 20% and duty 10% of the vehicle value. Although the invoice came in at a higher amount than I had calculated. Once HMRC had received the payment the vehicle could be released from customs. I thought once the tax/duty was paid you could collect at any point, that's not the case. Your agent will need to book a collection slot, I requested Thursday 7th which was accepted, with a 9:00am slot allocated. It was a 5:00am start from Norfolk heading to Southampton. We eventually found the compound, upon presenting the bill of lading and some ID they released the car (they drove it out of the compound to the front ready for us to load up). The email from the port stated each slot had a 10 minute window, which seemed abit farfetched but the staff said it's not a strict rule. We were there for approx. 30-40 mins in total. A week prior to collecting I contacted my garage and explained the situation, I was able to get an inspection slot that afternoon. For the registration, DVLA require the car to be insured, for this I used a company called Adrian Flux who can insure the vehicle using the VIN number. 
    • Hey guys, looking for these side skirts if anyone can help me out. 
×
×
  • Create New...