Jump to content
SAU Community

Recommended Posts

Hello!

I want to correct the roll center on my 1998 ER34.

When looking online, all I can find is roll center corrected parts for GT-R only.

 

I know extended ball joints are a thing, would this work?

The problem here is, I can find them for the front side only.

 

Also, I know there are adjustable lower control arms available that correct the roll center but they are a bit expensive and also only for the front side I believe?

 

Can someone help me please? I can't be the only one that wants/has corrected roll center on a non-gtr R34.

Thanks

Thanks for your reply.

I cannot access the car right now to measure unfortunately. But my guess is that it dropped 5-8 cm from stock. I want to correct the roll center because I think even the slightest correction will help making the car handle better, since I want to do more track events with the car.

If not please correct me.

Suspension wise it's got coilovers, hicas delete, adjustable camber arms, adjustable pillowball tension rods, tension rod bar, sway bars, drop links, roll center corrected tie rod ends. Aero is still untouched.

My intention is to build a good handling track inspired street car. Not too much power, just really good and precise handling. So yes, it is street driven but I will do the occasional trackday.

OK, so, the question again. "What leads you to want to correct roll centre on your car?"

Have you drawn a diagram that shows that it (the roll centre) is currently too low? You do know that this is not a crappy Mac strut car and that you generally have to lower the car excessively to cause this problem, right?

If you are sure you have a problem, what you need to do is cut and reweld the inner arm mounts (upper and lower) on the subframe to be higher by the desired amount (eg 10 or 20mm, or adjustable). I guess there would be weld on kits these days or you could do it custom.

If you are running the car low enough to have a roll centre problem on a street/track car, you are running the car way too low for practical use. I guess it could be a problem if you have a dedicated superlap car or similar 

Best place to start for handling is to post up your ride heights and alignment settings. The factory geometry is pretty reasonable for most use.

  • Like 2
6 hours ago, r34.bryan said:

Suspension wise it's got coilovers, hicas delete, adjustable camber arms, adjustable pillowball tension rods, tension rod bar, sway bars, drop links, roll center corrected tie rod ends. Aero is still untouched.

My intention is to build a good handling track inspired street car. Not too much power, just really good and precise handling. So yes, it is street driven but I will do the occasional trackday.

Sounds good. As everyone else is saying, if you haven't created a roll centre problem for yourself (by over lowering the car) then I think you are imagining a problem that isn't really there. 

Why do you think there is currently an issue with the cars roll centre? 

Back to some more practical advice, you say you want a 'precise' handling car, to achieve this you delete all the rubber bushes and hard mount/rose joint everything. Strong chance you'll then hate the car on the road so I don't recommend you do this. You'll also be creating a tonne of extra work for yourself as the rose joints are high maintenance.  

I'd say at this point your biggest win is going to be by putting some real tyres on the car. 

I'm guessing you do open track days and don't race in a class that restricts your tyre size or compound. So grab yourself a second set of wheels, the widest you can fit under your current guards and pop on a set of serious tyres such as - 

https://samotorsporttyres.com.au/product/hankook-ventus-z214/

or if you want to spend a bit more

https://samotorsporttyres.com.au/product/hankook-ventus-f200/

And if your Mr money bags, there are plenty of other manufacturers eg Michelin, Pirelli or Yokohama, who make slicks that would love for you to make a donation to them. 

Your current setup on a real tyre will be much quicker round the track then whatever setup your imagining on a street tyre will ever be. 

Plus you get to keep your nice handling street car/street tyre combo for daily duties. 

  • Like 1

So if I understand your comments correctly, there is no need to correct the roll center. Thanks for letting me know. Also thank you for the extra tips!

as for my tyre setup, I already run as much tire as I can fit in the stock guards. Yokohama Advan A052. 😏

It's not my daily car so I run them on the street as well. Works perfectly good for me!

  • Like 2
1 hour ago, r34.bryan said:

So if I understand your comments correctly, there is no need to correct the roll center. Thanks for letting me know. Also thank you for the extra tips!

as for my tyre setup, I already run as much tire as I can fit in the stock guards. Yokohama Advan A052. 😏

It's not my daily car so I run them on the street as well. Works perfectly good for me!

Sounds like a pretty well setup car. 

If you remember what it was like going from street tyres to A052, you've got about that much performance again to be gained from going from A052 to a race slick. 

Edited by Murray_Calavera
17 hours ago, Murray_Calavera said:

Sounds like a pretty well setup car.

Yes that's what I'm going for. I thought maybe correcting the roll center would make it even better, but I guess I was wrong.

17 hours ago, Murray_Calavera said:

If you remember what it was like going from street tyres to A052, you've got about that much performance again to be gained from going from A052 to a race slick.

That is crazy!

2 hours ago, GTSBoy said:

Keeping in mind that a full race slick really requires completely different spring rates to extract the best from them.

True, if you want to extract everything from the slick, the suspension needs to be setup with that in mind. 

However only changing the tyres and nothing else, the slicks offer another crazy step up in performance. 

This is a nice video showing that - 

Funnily enough, the video shows exactly what I said above. The step from street to R comp is the same again going from R comp to slick. 

 

 

16 hours ago, blind_elk said:

What size?

F:235 R:255

I had R888R before in F:245 R:265. I kid you not, the Advans are wider than the Toyos. I think a 275 R888R would be about the same width as a 255 A052...

 

5 hours ago, r34.bryan said:

F:235 R:255

I had R888R before in F:245 R:265. I kid you not, the Advans are wider than the Toyos. I think a 275 R888R would be about the same width as a 255 A052...

 

Diameter? Aspect Ratio?

On 1/18/2023 at 6:10 AM, GTSBoy said:

OK, so, the question again. "What leads you to want to correct roll centre on your car?"

 

Actually, I don't think this question has been answered. What exactly is the car doing - handling-wise - that makes you think it needs any adjustments to the suspension setup?

Okay so first off I don't have a lot of experience driving a lot of different cars fast. My car handles great, there is nothing weird going on handling wise (maybe a bit of bump steer). All I'm trying to do is make it handle as good as it could. The problem is I don't have anything to compare it to. So since my experience is lacking I'm reading online about other peoples (track)builds. And so my thought was "oh when you lower a car the roll center is off, so it needs to be corrected in order to make it handle better." Then I saw the kits are only available for R32-33-34 GT-R. Confirming these cars might need it. Hence my question how to correct it on a non-gtr Skyline.

Perhaps my question should've been: Does my car need a roll center correction to make it handle better?

Or: How to make an ER34 coupe faster around the track? (handling wise)

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

    • For these last 7 years of ownership, I've always had to use a small scissor jack under one of the front tow hooks to raise the front just enough so my low-profile jack fits under to reach my subframe jack point. I'm beginning to get annoyed of always having to do this. Are there any lower low-profile jacks that fit under the gtr lip on a dropped car?
    • Seat of the pants assessment of the new intake: The car is way less "doughy" when hitting the loud pedal, especially off idle when stopped or in traffic, I did use a cheapo lazer thermal thingo to measure the temp around where the pod filter got its air, it was between 55 - 60°C, in saying this the car was shut off and not moving, so the OEM intake pipe was not supplying any fresh air to where the pod was when the car was at least moving A weird bonus was induction noise on the throttle in the cabin increased a bit,  I was worried that I was actually going to lose some of that induction noise I love so much, outside though, when I got the daughter to do a WOT drive by pass for me, the induction noise has increased alot when on the throttle, not quite ITB doort, but well up there I'm extremely happy with the results and have been exploring the country roads in the region  As for house mods: 1.New front fence is up and is awesome, it really upgraded how the joint looks from the street, and the added security is nice 2. Electricians have replace some interior lights, and with more lighting in the garage, a few new motion detecting lights out the front above the garage, front room, and at the front door, which I have already found heaps helpful coming and going, also now has fancy pants CCTV all round the house The only hold point for power though is the solar and batteries due to supply issues, although this will happen over the next few weeks 3. I have done a heap of landscaping out the front and I'm almost ready to do a new small retaining wall with some nice blocks to replace the brick and cemented in rocks around the raised garden beds cemented in river stone "was the fashion at the time" the house was built. I currently have a pallet of retaining wall blocks and 2 bulka bags of 20mm blue metal to replace the wood chip that is in the raised garden beds around the house 4. I now have 3 big raised garden beds for out the back to grow some vegetables, about 70cm high, 200cm long and 100cm wide 5. My 2 compost bins are already pretty full with brown, green and kitchen waste from the landscaping I'vedone so far, but they will probably take a few months to break down, so anything else that gets chopped, trimmed, and kitchen waste will just start filling the base of the raised garden beds to about 30cm before I start throwing 40cm of good compost, and stuff, for the vegetables to grow in, I'll need a few ton of compost and soil, but the local supplier can sent me bulka bags of the stuff Basically the logs, wood chips and a few strategically placed rocks for drainage, will give the beds some good organic materials down low to break down over time, and they will hold moisture during the warmer months to save the water in my big arse water tank if we don't get alot of rain So, all in all, the car and house mods are going well, and I'm really enjoying being retired, I sleep in too 0700 and slowly plod around inside until I feel like actually doing anything, and only work in the yard for as long as want, which has actually been alot over the last few weeks,  although when you look at it, it seems that not a huge amount of work has been done,  until I look at the before I started the work pics Happy days and good times indeed 
    • hahaha yeah. Plan is to get side skirts and probably just rear pods. But going to do them one-by-one. I've got a set that I really like from RHDJapen, but that one isn't shipped to AU. So need to find someone who can get it for me
    • Here's an idea, answer the questions I asked you as they are trying to work out WHY the LSD will be binding up in a straight line.
×
×
  • Create New...