After changing tires from winter to summer, i got problems with fast acceleration. On fast acceleration strange vibration/knocking coming, also on changing from 1 to 2 gear (fast changing on red line), same vibration/knocking (few secs). Tires was checked two times, and with tire balance all ok. If i try to make something like "burnout" (or fast start with burnout) - same vibration/knocking.
hmmm (winter tires 245/40/18 & 245/40/18 and summer 235/40/18 & 255/45/18 all on Track 18" v.1 350Z Wheels).

 

wheel hop?

how long does it occur for?

 

With wheels all should be ok.
This occur on acceleration 1 gear 0-65 (km) ---> 2 Gear few secs and after it - all ok. So total ~4 secs. I not sure, may-be it's ok becouse of very FAST acceleration + 255 rear tires + not perfect weather (wet sometimes) = largeee knocking/vibration on acceleration? It is possible?

 

I am having trouble really understanding you, but I think I got it.

it sounds like axle/wheel hop. basically, under acceleration sometimes the wheels loose grip but it doesn't cause them to completely spin (like a burn out), it causes them to pop off the ground in rapid succession because of the way the suspension reacts (bumping or knocking). it can be from the rear being too soft, too stiff, sideways movement of the diff assembly... there are alot of reasons.

it is very bad for the car though so once it occurs you should back off the throttle.

 

I have the same thing. I don't do burn outs but when I punch it in second pretty hard it rips thru the RPM's then starts bouncing. I let off the gas and all is well. What mod's can be done so that it doesnt do this?

 

change the springs, solid diff bushings, adjust tire pressure, change the alignment... launch the car differently

there are alot of 'causes' of wheel hop... adding more power helps the 5.7 GTOs (stock is pretty bad from what I hear) prevent axle hop for example.

 

Thanks Motormouth, I't happens with both stock and summer wheels. It started doing this after getting the light weight flywheel. Maybe I'm launching wrong.

 

hmmm,
http://www.youtube.com/watch?v=eLBcL2NNYXo

How "same" style of driving/acceleration will be from inside of the car? With any vibration/knocking? I can feel vibration/knocking only when car tires should start (may-be they start) to slide (to burn).

P.S. May-be its because of weather? Its wet (sometimes), cold (-1 - +1 C), and some snow . So my tires wet and cold.

 

This is true as well. I had my new flywheel installed in winter. Started rite after that. I might also need a wheel alighment as I havent had that done since lowering the car.

 

here,

search for "axle hop" and "wheel hop" and you can look for solutions yourself. there is a good amount of info out there for you.

 

Thanks,
Looks like, i need SPL bushings

 

Well, update:
Today, local dealer told me, that problem with rear tires or suspension.
So there 2 possible ways to fix it: New "strong" suspension or new tires. I think, more cheap and easy will be new tires. Right now i use 235/40/18 FRONT 255/45/18 Rear (45 --- its a problem), wheels are stock 18x8.0 and 18x8.5, So best solution for me (?):
235/40/18 front 265/35 R18 rear ??
235/40/18 front 255/35 R18 rear ??
235/40/18 front 245/40 R18 rear ??
hm

 

totally diff bushings. go poly