Jump to content
SAU Community

Recommended Posts

Front first. But it is very important to realise that if you have a skinny stock bar at one end and a big stiff bar at the other, then there will be a significant change in the balance of the car. Assuming the car is fairly neutral to start with, a very big front bar will turn it into an understeery bitch.

Example. My R32 had factory skinny rear bar on it, and some unknown 22mm front bar. The car was always fairly understeery, and I never bothered to work out that the front bar wasn't a stocker - I just glossed over it. Then I finally worked out what was going on and put a 24mm adjustable in the rear. Set that on the soft setting. Now the car is a little bit frightening. Turn in and mid corner grip at the front is excellent - but the rear is skatey. Now it needs the 24mm adjustable on the front to fix it the other way!!

Since the whiteline's don't make a 27mm bar for BNR34's only 22mm on the front, I think I'll go with Cusco F & R 24mm. I noticed with whiteline you could have a bit of adjustment, but will it really matter?

Also, does anyone know if a BNR34 embodies; Oversteer, understeer or neutral nature?

Edited by kylieyeah

Sorry, I had sorta skipped over the fact that it was for a GTR. I guess Whiteline don't think that the GTR needs as much bar as the RWD cars do, otherwise they'd have at least a 24mm adjustable front bar available for them.

Having a look at the Whiteline catalogue, I see that they do a 24mm rear bar. That makes me think that the R34 GTR tends towards understeer. I base this purely on what the result would be if you went from typical stock bar sizes to a 24 rear/22 front combo. It would shift the grip forwards.

Yep. I completely with you on this one. Thinking that the GTR will be a understeer bias type of car. In reference to the Mine's GTR, they only upgraded the rear. But the coilovers they run are much stiffer then mine, so I think I would have to run both larger front and rear.

Going with Cusco will give me, 24mm (21mm stock) Front and 28mm (24mm stock) Rear which would in my opinion seems pretty optimal, would you agree?

The Mine's GTR is the ultimate handling and response weapon, and it made me think that maybe I should only upgraded the rears due to the understeer nature of my car.

My coilovers are 10kg/6kg compared to their Fr.12kg/Rr.10kg

Would it be a better option to upgraded front as well due to my softer coilovers?

Yes before I upgraded mine to adjustable whitelines front and back car would understeer a lot. Now on tight corners it is much better but will still understeer if pushed to hard. Its a very good upgrade though and a must in my opinion with these cars especially if running a soft street coilover

Yes before I upgraded mine to adjustable whitelines front and back car would understeer a lot. Now on tight corners it is much better but will still understeer if pushed to hard. Its a very good upgrade though and a must in my opinion with these cars especially if running a soft street coilover

What spec whitelines did you get? im also going to getting some aftermarket sway bars soon.

The Mine's GTR is the ultimate handling and response weapon, and it made me think that maybe I should only upgraded the rears due to the understeer nature of my car.

My coilovers are 10kg/6kg compared to their Fr.12kg/Rr.10kg

Would it be a better option to upgraded front as well due to my softer coilovers?

There's a big difference in the relative spring rates between the Mines car and yours. Your front springs are much stiffer than your rears. The Mines car's fronts are not a lot stiffer than their rears. That means your basic spring rates are more inclined toward causing and understeer bias.

If I were you, I would buy a set of 8kg springs for the front of the car before doing any anti-roll bar mods. That is unless you are tracking it very very hard, in which case you might be better off buying some 8kg rears.

Cool, well I just spoke with another well known mechanic from here in Sydney, IS Motor Racing.

Indy had told me not worry about the sway bars right now, and change my springs from F10kg/R6kg to F10kg/R12kg.

At first, I was feeling a bit weird when he said to go to 12kg in rear, but I know doing that it will definitely decrease the cars natural understeer feel and the extra added understeer from my 10kg/6kg coilovers at the moment.

What do you think about this?

Personally i would hate a car that stiffly sprung, and on anything but a perfectly flat track it would have hopeless roadholding. Putting heavier springs in the rear than in the front is odd. The spring rate difference should somewhat match the weight difference, and GTRs are front heavy. You then control roll, and the under/over steer balance with sway bars (mainly) and alignment.

+1 to GTSboy. Put 8kg in the front. Even then, that's a track friendly rate. If you're street only, and care about comfort, softer both ends would be better.

Please speak to a proper suspension place like Heasmans!

Just go for a drive in one first because if it's a daily might be hard to live with. I recon just go with the stiffer rear sway bar and see what it does to the balance. Might be all that's needed and the cheapest option. Cheers

To be honest, I play on making my car more track based. In which I think I will go with a stiffer rear set up, so probably buy 8kg rear springs to fit with a rear sway bar to go. I know right now the car understeers like crazy, so I'll optimise oversteer. If that becomes too oversteery, I'll take out either the rear sway or refit the 6kg springs, which I doubt I'll do the latter because I've been told 6kg is way too soft as it is now.

My car is street driven 99% of the time, but it's barely driven to start off with so I don't mind the stiffer ride.

Thanks for your help guys! Any more imput would be great in terms of decision I made above.

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

    • Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
    • No those pads are DBA too  but they have colors too. I look at the and imo the green "street" are the best.
    • I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
    • Yea - I mean I've seen my fuel pump which is decades old and uh, while I'm not saying this with real knowledge... but I sure get the ick at using anything in the fuel system that produced the state of that pump. Many years ago I went through multiple pumps (and strainers) before I dropped the tank to clean it out with extreme violence. I'm talking the car would do maybe 50km before coming to a halt, which resulted in me cleaning out the filter with some brake cleaner and going on my way. None of my stuff ever looked like what came out of your fuel tank. I don't think I'd be happy with it unless every single component was replaced (or at least checked/cleaned/confirmed to be clean here).
    • I'm not going to recommend an EBC pad. I don't like them. Just about anything else would suit me better. I've been using Intima pads for a while now.
×
×
  • Create New...