Jump to content
SAU Community

Recommended Posts

Hard to get in 3rd gear when lose traction on 2nd gear. r34 gtr

Hi. I got this change gear problem from my last happy lap.

My car is 660hp r34 gtr, I lose traction badly everytime when I floor it on 2nd gear from 5000rpm. At the same time the gear stick shaking very bad.  It's AWD OMG:(

The gear shift and car drive all good normally but if I floor it 2nd to 3rd is hard to get in gear and sometime I miss shift to 5. I know it's about my skill. But it's really hard get the right position when the gear stick shake like crazy. 

I already got nismo engine and gearbox mount.  So my question is what I can do to make the gear stick stable on 2nd gear? And it wasn't that bad before maybe I got bad traction this time?

i think change better tyre will help (I have nitto invo)any other idea?

 

 

Axle tramp occurs when the combination of spring + damper + tyre sidewall stiffness + tyre grip + bush deflection + chassis twist all add up to cause the rear suspension to compress as the tyre grips under power and then as the tyre reaches the point of breaking traction the sudden reduction in compressive force in the suspension causes it to pogo upwards.  As it comes back down it loads the tyre over and above the load it gets just from weight + torque reaction, increasing grip.  So it hooks up, loading the suspension more until it pogos again.  Rinse and repeat.

The R32 rear end is particularly prone to it due to the geometry.  The 33s and 34s less so, but they're not immune.  2 cars that seem to be set up identical will have one do it while the other one doesn't.

It ultimately comes down to springs and dampers, getting them right.  If really stiff then it never grips properly and just breaks traction.  If really soft, it compresses heaps and doesn't rebound (drag style).  Somewhere in the middle is better performance overall, but also somewhere in the middle is axle tramp territory.  And then all those other factors I listed at the top stick their beaks in too.

Fixing it is hard.  My car axle tramps like a bitch and I've never been able to fix it, through 3 different sets of dampers and springs.  Different tyres have affected it more than anything else.

thank

4 minutes ago, GTSBoy said:

Axle tramp occurs when the combination of spring + damper + tyre sidewall stiffness + tyre grip + bush deflection + chassis twist all add up to cause the rear suspension to compress as the tyre grips under power and then as the tyre reaches the point of breaking traction the sudden reduction in compressive force in the suspension causes it to pogo upwards.  As it comes back down it loads the tyre over and above the load it gets just from weight + torque reaction, increasing grip.  So it hooks up, loading the suspension more until it pogos again.  Rinse and repeat.

The R32 rear end is particularly prone to it due to the geometry.  The 33s and 34s less so, but they're not immune.  2 cars that seem to be set up identical will have one do it while the other one doesn't.

It ultimately comes down to springs and dampers, getting them right.  If really stiff then it never grips properly and just breaks traction.  If really soft, it compresses heaps and doesn't rebound (drag style).  Somewhere in the middle is better performance overall, but also somewhere in the middle is axle tramp territory.  And then all those other factors I listed at the top stick their beaks in too.

Fixing it is hard.  My car axle tramps like a bitch and I've never been able to fix it, through 3 different sets of dampers and springs.  Different tyres have affected it more than anything else.

great info!! thanks a lot! i will get the suspension checked one day, but i don't think anything wrong with it. if they are all good, I will get better tire, but i worried some better tire will make it even worse.  because the day without too much axle tramp the tire feel normal, but the day with a lot axle tramp the tire feel a little sticky. both day i run same setup. 

maybe some really sticky tire will fix this problem. 

 

I don't really feel the car shake  , but the gear knob shake badly. i just worried i will damage the gearbox one day cause the axle tramp:(

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

    • Yes that’s what im trying to decide. Should I do stock gtt box or enclosed or open pod. 
    • Also, I note OP is in Melbourne, which begs the question... are you aware of how illegal your car will be with a turbo, and intercooler and any sort of filter change? I don't know how you can get past the "2 intake mods" "rule" that seems to exist in Vic. Fully engineered might or might not get you there.
    • If you have a turbo... then the ducting holes I used to feed the pod are not available because your intercooler likely uses them. If you have an intercooler, your IAT's are going to be goverened by how good your intercooler setup is. I'm yet to really see anyone check IAT with a snorkel/boxed pod/proper CAI versus and unshielded pod. It would be interesting! But I suspect that the differences would not be so noticeable as if you were N/A as the intercooler is where the air is being cooled.. and out in front where the FMIC would be is a pretty good spot for it.. When I was turbo I pushed the stock GTT box as far as I could and made some pretty good power out of it, and noticed on the street I never made the same power/boost. Then I did a before and after run with a pod filter versus the box and picked up about 9PSI from the same boost duty cycle and about 50KW instantly. I never ran the stock box again, and recently removed it for my N/A setup. The box is restrictive to a degree - Even with the V8 setup I noticed I picked up power by removing the box completely, so punching holes from the bottom of it to get air from the passenger guard *helps* but the most effective one in my case was simply having the ducts, a pod, and no box around it. In my experience, *more* air was better than cold air. The air (with ducts) will be cooled off as you start moving, and especially if you start moving fast (a race track). It actually moves around quite a bit as you can see.  
    • Well you could certainly buy or build an enclosure for a pod in that corner of the bay. It is absolutely vital that there is a nice big opening to let cold air in to it from the front or underside, otherwise it will just pull air in around the edges from the bay, and if that air is hot, you gain nothing from enclosing the pod. There is lots of good evidence around (including on here, see posts by @Kinkstaah for example) showing that pods pulling hot air from the bay is only a problem when you're static or slow in traffic, and that as soon as you get the car up and moving the air being grabbed by the pod cools down. Although that will obviously vary from car to car, whether there is a flow of cold air to the pod or if it all has to come through the radiator area, etc etc. Obviously, the whole exercise requires as much thought as anything else does. Doing the lazy thing will often end up being the dumb thing. The stock GTT airbox has a cold air snorkel to feed it from over the radiator. Shows that Nissan were thinking. The GT airbox is upside down compared to the turbo one, yeah? Inlet at the bottom, AFM/exit on the lid? That might make it harder to route the turbo inlet pipe using the GT airbox than a turbo one. That would probably be the main reason I'd consider not using it, not that it is too small and restrictive. I'm looking at a photo of one now and the inlet opening seems nice and large. Also seems to have the same type of snorkel that the turbo one has. Maybe all that's required is to make a less restrictive snorkel/cold air inlet, perhaps by punching down through the guard like I did.
    • Also seen this as an option 
×
×
  • Create New...