Anyone able to diagnose this sound?

When I hit first/second gear hard I hear almost a flapping sound coming from the rear. It's sort of a snapping/smacking sound that I hear about 4 times a second until I get to about 45mph (*note this is only under HARD acceleration).

I personally think it's the tires - is this possible? It's far from a screeching sound...

 

Wheel hop maybe.. Do you feel the car shake when it happens?You'll soon find out what it is cause it isn't going to last much longer!

 

He means your diff will soon be peeking out from behind the rubber boot....

Do a search on wheel hop.

 

Ok - Definitely sounds like wheel hop then... Is this normal and just induced by the driver or what?

I saw a link on one of the threads and found this:

https://www.rx7club.com/showthread.p...hreadid=242470

Saw this posted a few days ago - would this help it or what?

 

Why do you say it wont happen much longer?

 

I do have koni shocks :\

 

you should make the shocks as soft as possible in the rear and see if that stops it. A tight suspension because of a low mileage car or aftermarket suspenion + high hp will cause wheel hop all the way until ~50mph like you said. Getting really good tires will help because they will just grip but I have DRs that I daily drive with and it still happens in my car until 55mph at high boost. At low boost where I have ~50rwhp less it doesn't hardly happen.

if you keep on the throttle when you get wheel hop you will break the rear (car not drivable after) and and wear out/break all the suspension components and the car will feel like ****

 

Because it will eventually destroy your differential and housing. Do a search on "kaaz diffs" and "trailing arms/toe links". IMO shocks won't help.

 

Don't forget about the PPF.

If the sound is anywhere near metallic banging it may already be your PPF.

 

Yeah, that too.

 

Nah it doesn't sound metallica yet. Looks like I'm going to have to stay away from accelleration all together until I get some more damn money... Now that I have enough for the PFC+commander I need to spend this on other things.

Boost is too high, need a better clutch, new tires, and now I need something that doesn't exist to stop my wheel hop. I'm going to get the differential brace, but from what you guys are saying it sounds like my car is going to be plagued with wheel hop indefinitely... Who knows maybe it's already beyond repair .. Sometimes I just hear banging around the back end of the car but haven't thought much of it until now (the bangs or whatever are seemingly random and only happen at first when the car is ice cold... usually i'll hear one or two while reversing out of my bumpy *** driveway)

 

What's a PPF btw?

 

Do NOT get a diff brace until you fix the other real problems in the rear end. If you put that diff. brace on without solving the actual real issues, you're going to transfer all of that slop/wheel oscillation to the unit-ibody mounts - which will promptly tweak on you. The load may also be overly-transfered to the PPF (power plant frame), as well.

Fix the trailing arms, toe control links, diff bushings first. Also examine all spherical bearings in the rear suspension.

 

Powerplant frame. Search, grasshoppa, search...

 

Does wheel hop necessarily imply that I have real problems in the rear end?

I'll spend a few hours each night over the next week reading up on what you said to check tonight - I really have no idea what any of those things are.. well not how to fix them at least

 

Here's what you do.

Jack up the rear end.

Grab each tire with one hand on each side of it and rock it back and forth like you're trying to pull it off. Then do the same thing for up and down.

If you hear or feel anything, you know for a fact that you need to replace things.

 

if i hear nothing? ^_^ thx btw clayne you've been damn helpful

 

Nillviod did you get your clutch fixed? Didn't you think your engine was blown, than diagnosed as a bad clutch. You can't get enough torque with a bad clutch to get wheel hop. How about rear bushings that would account for the noises when backing out of the driveway when cold.

 

I know this is from awhile ago I was ... well ... just curious :p (The clutch isn't fixed yet).