rickya

iTrader: (18)

My latest mods & remap produced 350bhp & 405 ft/lb of torque (from right down the rev range all the way up to 6500rpm & still over 300ft/lb torque!)

But I have noticed that in speeds in excess of 80mph (on track/prvt road) in 5th or 6th gear, if I come off the throttle too suddenly the drive shaft knocks into floorpan quite loudly! If I come off throttle gently it does not happen & it does not happen on any other occassion. Obviously it is due to increased torque and in 5th or 6th at those speeds the revs are quite high in the 2 litre/ 6 speed engine.

Is there anyway to stop this happening with some kind of stronger/stiffer driveshaft mounts/bolts or something???

JonMc

iTrader: (51)

Is it the rear drive shafts rather than the propshaft Ricky. If so possibly look at a perrin subframe lock down kit, includes poly bushes and a couple of locking bolts to remove any play in the rear subframe. If it's torque, then the propshaft may be excerting torsional forces on the subframe creating enough rotating movement for the knocking.

rickya

iTrader: (18)

Im not sure if its Propshaft instead John?? How can I tell?

Jam Performance

iTrader: (3)

Perrin subframe lockdown kit definately needed, have the same problem with mine, the perrin kit will stop the diff banging

JonMc

iTrader: (51)

You'll need to get underneath and look for where it's been knocking.

The lock-down kit will stop any movement, just need to take your time with the locking bolts. The first one of mine ripped the captive nut off it's weld. It's buried inside some box section and the only fix is to cut open the box section, re-weld the nut and weld the ection back up, so I've got a lock-down bolt hanging half out of my subframe.

rickya

iTrader: (18)

Am I right in thinking the subframe lockdown kit will only stop driveshaft knocking? What if its the propshaft knocking?

Also Whiteline seem to do some subframe lockdown bolts, what are they & are the same as Perrin?

Jam Performance

iTrader: (3)

Ricky have a read of this :

DIY Perrin Rear Differential / Subframe Lockdown System - ClubWRX Forum - Subaru Impreza WRX and STi Community and Forums

JonMc

iTrader: (51)

Perrin do the bolts and bushes (in the same kit I think). I have all of the bushes fitted and it's a really easy job to do, even for you

If it's the torsional forces that a causing something to knock, the lock down kit will eliminate that movement and should therefore stop any knocking.

rickya

iTrader: (18)

Cheersn John & Killer

Will get it ordered asap.

ps You off to MSOC meet John? I dont think Im gon a be able to make this one

JonMc

iTrader: (51)

Yes mate, I'll be heading off in about an hour or so.

I'll drop you a text about next Saturday. I might have a volunteer driver for the evening, so I can get completely smashed watching the football