Jump to content
SAU Community

Recommended Posts

When you go over a bump and the G's force your foot down further on the throttle, the car speeds up/lurches, foot comes up, then down in this horrible lurchy/jerky acceleration/deceleration of repeat, repeat, until to lift your foot off. Some sort of positive feedback or something going on?

I'm finding this happens more now I've stiffened up my suspension and put stiffer sway bars on.

It tends to happen at certain intersections in 1st or 2nd gear.

Kind of embarrassing.

Anything I can do?

Link to comment
https://www.sau.com.au/forums/topic/294013-what-do-you-call-it-when/
Share on other sites

  • Replies 50
  • Created
  • Last Reply

Top Posters In This Topic

Lol how fast are you going over said bumps? Because if you are going fast enough for the G-forces to push your foot down, i really wouldn't be worried about the embarrassment of lurching lol...

Lol how fast are you going over said bumps? Because if you are going fast enough for the G-forces to push your foot down, i really wouldn't be worried about the embarrassment of lurching lol...

Hmm not that fast, but I've been driving a bit more 'uninhibited' now I've got some mild mods.

I've had my foot totally on the floor a few times lately just to test the car out. :( Within the speed limit of course and with no loss of traction. :rofl:

I don't think he means speed bump, just any bump... I can't say i have experienced this though lol. Maybe i have, but i wouldn't describe it the same way as you haha. Don't really understand

Yeah not speed bumps as such, I don't go over them fast. I mean just the bumpy/poor surfaces of intersections etc.

We've got some real cr@p roads here in Perth that is for sure.

Yeah taking your foot off the gas until the car settles seems to work, but this seems to mean that with some traffic lights/intersections you just can't do a 'hero' type launch....er hypothetically that is. :( I guess that is the prices of stiff suspension for good cornering?

hehe, i know wat you mean, my aristo has fairly stiff suspension and this happens to me wen i drive over bumps n stuff, i have found letting off the gas until the car settles is your best bet!!

You just answered your own comment there, your aristo (read barge) is so bloody heavy it NEEDS stiff suspension to eliminate all the commodore like bodyroll.

As for the lurching, what sort of clutch do you have? How much play do you have with your release point etc? Might just want to give it a few move revs before you engage the clutch. Your suspension doesn't have anything to do with how you're using the clutch :(

Fair dinkum guys, he's not talking about jerky clutch take offs.

He's talking about going over a bump and that bump translates into his foot moving slightly on the throttle.

Rysies, why would you clutch in when rolling through an intersection? if anything you'd just lift off the gas or just raise your heel off the floor.. that's what I do, especially over railway tracks.

Hmmm i think i get it, seem to remember this happening when i was first on my L's... No offense intended with that lol. Just that in my first car i learned to do what these guys are saying, balance your foot on the accelerator and make sure your heel isn't on the floor.

In the Skyline it doesn't happen to me anymore because i make sure to not go over said bumps lol, ive replaced one rim already from Perth's sweet road surfaces, making sure it doesn't happen again

He's not talking about speed bumps, he's talking about shitty roads with holes and bumps. Don't worry mate, it is a normal by-product of stiff suspension. All your controls become extra sensitive as a result. Bumps make you lose traction very easily too. As for taking off from the lights, you can either:

A. Wedge your foot against the kick panel so that it is less likely to move when going over bumps

B. Lift off throttle and just coast in gear or use a bit of clutch over the shitty parts of the road to turn power on/off. Or if in a drag race...

C. Foot flat to the floor and let an LSD take the blame.

With my coilovers I don't bother with traffic light heroism on shitty roads, particularly uphill...you'll just get messed up in 1st gear.

I've read this thread a few times for shits and giggles - the guy can't drive his car.

I've got stiff suspension, a monster clutch and the roads around here are f**ked, maybe I'm just used to it but I have no drama's, my driveway is even worse and I can reverse up that without spitting gravel. I didnt get my license from the bottom of a Fruit Loops box..so I dunno.

I've read this thread a few times for shits and giggles - the guy can't drive his car.

I've got stiff suspension, a monster clutch and the roads around here are f**ked, maybe I'm just used to it but I have no drama's, my driveway is even worse and I can reverse up that without spitting gravel. I didnt get my license from the bottom of a Fruit Loops box..so I dunno.

You've read it a few times and still didn't know what he was talking about?

How about you shut up now.

Edited by bubba

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

    • Consider a 35 too...
    • He's right ~ there is no 'magic' with stuff like this ... it is more likely that in the process of looking for the short, the loom/wire 'incidentally' got moved in the process, thus removing the short ~ now, that maybe a wire (in a loom) rubbing against the edge of some grounded metal, that's worn through the insulation, causing the (now intermittent) short to ground. If one wire in a loom has been damaged in this fashion, it's reasonable to presume that other wires beside it may have also be damaged, and now exposed...you can bet the green crusty copper corrosion will start... ...that'd be a pisser, Murphy's Law steps right in as GTS observes...but worse, something like that is easier to find when shorted...ie; unplug bulb and fuse, and put multimeter in continuity mode so you get constant beep, and carefully poke about hoping to find if some movemet of the harness stop the beeping.... ...it's still all a bit Arnie tho' ..It'll be back... 馃槂
    • Yeah, but knowledge of one wire's insulation worn through to short on earth implies the possibility of other wires doing the same. I had my power steering die, because the wire that runs to the solenoid valve on the rack runs in the same loom as the power wire for the O2 sensor. And when the O2 sensor/wire did something stupid and burnt part of that loom to death, the only indication was the shit(ter) fuel economy and the heavy steering. It took deep excavation of the looms in the bay to find the problem. Not wear through in that case, but similar shit.
    • Ah, I thought he'd wired it to one of the spare ECU inputs! Too long ago since I read that post, ha ha. I've been arguing with radiators, harmonic balancers, alternators and rust since reading it.
    • Correct. The ECU cannot read oil temp. (Well, I think it probably can in some situations. I did have the thought of potentially repinning the ECU when I was doing oil pressure). I am using this into the MPVI dongle, so that the MPVI dongle can read oil temperature. It is attached to a VDO gauge which is obviously calibrated to whatever curve the sender actually is using. This would be easy if I could setup a table of voltage to temperature like many sensors, but it appears I cannot do this and can only setup the transform rule which appears to be Input (voltage) x Multiplier, and add an offset. This to me means it MUST be linear. So it may be a complete waste of time wiring this into the ECU. The idea was that the MPVI3 has standalone logging. I wanted to use this instead of a laptop with serial cable (for wideband) for long datalogs. Given the wideband also has electric interference, I may never trust this either in a world where the serial wideband and the analog output wideband do not agree. Last time I did a trace I could see the two wideband traces follow each other, but one was a little leaner than the other. I plan on playing with voltage offsets and actually driving the thing to see how close they correlate. If they never correlate... then, well, maybe I'll never use either. Ideally I'd like to have the Analog wideband read ever so slightly leaner than the serial one, because the serial one is 'correct'. Tuning the car to be ever so slightly too-rich would be the aim. Not needing to have a laptop flying around in the footwell connected with cables is... an advantage. About the only one from the forced upgrade to MPVI3.
  • Create New...