Jump to content
SAU Community

Recommended Posts

I recently drove my friend's R32 gtst which has coilovers and a roll cage but is otherwise stock. It sits perfectly flat through corners without absolutley no body roll. I want this handling.

I'm currently running bilstein shocks with Apexi springs (which are a progressive rate spring). I've also have ARC swaybars and front and rear strut braces. Judging by pushing down on the corners of each car, my suspension is pretty much as stiff as his.

My issue is that when I put the car into a corner (on a racetrack of course), I initially get a small amount of body roll before the suspension stiffens up, which I find a bit unsettling. It makes it hard to judge where the car's limit is.

Do you think this is caused by:

a) lack of roll cage; or

b.) progressive rate springs; or

c) all of the above; or

d) other... please explain.

My current theory is that the "soft" coils of the springs are initially being compressed as I enter the corner, allowing the small amount of body roll, before load is placed onto the "harder" coils - will a linear rate springs be much of an improvement?

Cheers,

Greg

Edited by Greg
Link to comment
https://www.sau.com.au/forums/topic/85664-spot-the-difference-handling/
Share on other sites

Rather then thinking about body roll etc, throw the same rubber on each car and look at corner speed. What feels quick isnt always, and sitting perfectly flat may not be the quickest way thru a corner?!?!?!

This is just conjecture but a darty pointy car with firm suspension could feel great and resposnive, but when you load the thing up through a quick corner with undulations like most australian roads and tracks for that matter, you may find the actual corner speed is down a little.

Then again it could be a lot higher...guess im just saying dont let the seat of the pants deceive you .

And it comes back to driver comfort as well, nand how you liek th ecar to feel. Im starting to lean towards liking a slightyl firmer setup then what i currently have, though odds are i wont be able to ride kerbs etc meaning that i will be wanting to make up a lot of time elsewhere, because at the moment my cars ability to really ride kerbs means i am able to make time on soem quicker cars then me.

I've found from riding in peoples cars with roll cages it adds much more of a firm feel. But as Roy said what feels doesn't always mean faster (lap times). Are all your other stiffening bits the same? (struts/sway bars/bushes etc?)

Could it be your wheel/tyre setup too? (i.e. lower profile tyres on your mates car?) There have been a few people around that complain about having the tyre compress before their suspension does (when they have hard suspension but high profile tyres).

As Roy posted, the feel is irrelevant, it's how much grip it has that determines how fast it is. Generally speaking a softer spring rate gives more grip. That said, we don't use progressive rate springs in the race cars. We do use tender/helper springs to keep the main coils trapped.

I have never seen progressive front springs in a Skyline, it is quite common in the rear though. But mostly to soak up the travel in the shock. The progression is there to keep the coil trapped, not to have an initial softer spring rate.

You should check this before you jump to the conclusion that it is the progressive rate that is causing the initial vagueness. Firstly check that you actually have progressive springs in the front (unlikely). Then have a look under the car (on ramps with the weight on the wheels) and see if there are any of the progressive coils not sitting on top of one another. That will tell you if there is in fact any progression at all in the dynamic spring rate.

:huh: cheers :)

The roll cage will also add weight...

And the other thing, potentially your subconsous could make you think you can go round coners safer because you have a cage around you, like, even if you come off, you wont die kinda thing, strange how the mind works.

Thanks for the replies everyone :)

I am going purely off the in seat feel, not corner speed. In some ways the feel is more important to me as my car rarely sees the track.

The tyres I'm running are 205/60/15 so there is a distinct possibility that the sidewalls are flexing before the suspension. I'll borrow some lower profile rubber to test this theory.

My front springs are definitely progressive. I will check if any of the progressive coils aren't touching each other tomorrow in the light. Thanks for your help :D

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

    • Hello, everyone. I'm new to the forum. I have a 1989 Nissan Skyline R32 GTR. I have lost all power to the interior, including AC controls, the gauge cluster, turn signals, and windows. Stuff that still works includes the horn, brake lights, radio, and headlights. All fuses, in the interior and exterior boxes, tested good.  It starts and runs fine, just with no gauge power or anything stated above. No warning lights either. Things that I have tested: - Fusable link tested fine - No other fuses blown - Alternator good - IGN switch tested fine - With my power probe, I can backfeed power through the IGN pin to the plug on the back of the gauge cluster, and everything comes back on.    So my theory is something on the control side that sends the ignition power through the system isn't doing its job, or a wire is broken. (I would think that it is the ignition switch that would do that, but who knows?). The ignition relays don't fire (all relays tested good). So what tells them to fire other than the IGN switch?  I would really appreciate it if someone had some insight on this. I have tons of hours into this; I don't want to give up in defeat! I have the HD wiring diagram, but having all those wires laid out like that on one sheet of paper makes things pretty hard to follow.  Thanks for reading, and thanks for the replies.  Where should I look next? Thanks.
    • Install a MAP sensor pre and post throttle. Best data you could have for NA, then play with the bends and/or air box and see how much of inflection is created at WOT on the plot.
    • And gone to a new home  
    • The car remains in paint jail. I am now pretty convinced that the whole "RB25 Airboxes are kinda limiting to ~300kw" could be a thing. Also saw a good video from Engine Masters: (Sorry for FB link) (https://www.facebook.com/watch/?ref=search&v=761771519471924&external_log_id=c10bcbb6-2c39-4ff3-9240-287e9921fde6&q=Cold Air Considerations) Where they tested Pod Filter sizes and kept adding bends to a LS3 on an Engine Dyno to find if bends caused power loss. It's a good video worth watching - They did lose ~25hp from making an intake which had 3x90's and a 120 degree. They only lost maybe 1hp with a basic 90. I feel that by sealing up my airbox I have: 1) Created the same restriction a stock airbox would have. 2) Created a very convoluted set of intake 'pipes' by forcing all the air through the ducts. So I am pretty confident I'll be going full circle and have a huge hot air intake pod and actually see a benefit. The air does *not* stay hot once it gets flowing, aided by the ducts, and the pod can then pull air from anywhere. All the posts of yore talk about the stock airbox costing 10-15kw at 300kw+ but you know what? I f**king would very much like that 10-15kw and I remember my own pod filter in engine bay experiences. Turns out the GTT Reo and Headlight brackets really don't allow you to mount GTR items, no matter what the internet says. Various brackets have had to be made up to actually make it fit right for the front bar. Also some idiot mounted a 3L Accusump right where the bumper wants to go, so that has had to be 'relocated' To where, I am still not sure, but it's supposedly mounted in the pictures and I can't see it.
    • Sounds like the oil pressure light is wired into the oil temp sensor... As it warms up, resistance on temp sensor reduces, hence more current can flow and the dash light gets brighter.
×
×
  • Create New...