Paul TVR Posted October 14, 2006 Report Share Posted October 14, 2006 I have just bought a Rover 620ti, ok bit of a come down after the TVR but I'm using it as a runabout. Question is the car feels like its a little drifting when accelerating up to 70mph, not sure if it's just me not trusting the new car but is there anything that will cause this? Car has just passed the MOT where it failed dues to brakes being out of balance but had new discs and pads all round fitted by the garage. I've yet to get it up in the air to check it out, the car has been lowered on chassis dynamics springs using standard shocks, might try and get some standard springs. Paul Quote Link to comment Share on other sites More sharing options...
Tony Posted October 14, 2006 Report Share Posted October 14, 2006 I have just bought a Rover 620ti, ok bit of a come down after the TVR but I'm using it as a runabout. Question is the car feels like its a little drifting when accelerating up to 70mph, not sure if it's just me not trusting the new car but is there anything that will cause this? Car has just passed the MOT where it failed dues to brakes being out of balance but had new discs and pads all round fitted by the garage. I've yet to get it up in the air to check it out, the car has been lowered on chassis dynamics springs using standard shocks, might try and get some standard springs. Paul Paul the 'Drifting' explanation are we talking a pull or lightness on the steering... Also is there any transition on deceleration or under braking? Quote Link to comment Share on other sites More sharing options...
Paul TVR Posted October 14, 2006 Author Report Share Posted October 14, 2006 I have just bought a Rover 620ti, ok bit of a come down after the TVR but I'm using it as a runabout. Question is the car feels like its a little drifting when accelerating up to 70mph, not sure if it's just me not trusting the new car but is there anything that will cause this? Car has just passed the MOT where it failed dues to brakes being out of balance but had new discs and pads all round fitted by the garage. I've yet to get it up in the air to check it out, the car has been lowered on chassis dynamics springs using standard shocks, might try and get some standard springs. Paul Paul the 'Drifting' explanation are we talking a pull or lightness on the steering... Also is there any transition on deceleration or under braking? Well it feel like its drifting in the lane, seems to stop when decelerating and braking. Quote Link to comment Share on other sites More sharing options...
Tony Posted October 14, 2006 Report Share Posted October 14, 2006 Reads like the car has front toe out.. assuming the drive train is intact.. The deceleration and breaking commands down force and seemingly belays the problem. The coil/damper rate is of great concern since this marriage seems to have been divorced.. The toe/coil/ damper reaction seems to be very imbalanced in my opinion. Quote Link to comment Share on other sites More sharing options...
Paul TVR Posted October 14, 2006 Author Report Share Posted October 14, 2006 I'm not a big fan of changing springs without getting dampers to match, the car is lowered but i'd guess the spring rates are higher as the car corners flat for a big car so must be stiffer. What would you say the cure is? Not sure about going back to standard springs as like the way it handles but adjustable shocks will probably cost more than I paid for the car lol Quote Link to comment Share on other sites More sharing options...
Tony Posted October 14, 2006 Report Share Posted October 14, 2006 I'm not a big fan of changing springs without getting dampers to match, the car is lowered but i'd guess the spring rates are higher as the car corners flat for a big car so must be stiffer. What would you say the cure is? Not sure about going back to standard springs as like the way it handles but adjustable shocks will probably cost more than I paid for the car lol My opinion and reasons are superseded by Sam@tdi since Sam's knowledge exceeds my own in this chassis dynamics arena... If i assumed absolute command in Geometry i would be a liar, so i have to pass this topic over to our collaborative team at tdi towers. Quote Link to comment Share on other sites More sharing options...
Paul TVR Posted October 14, 2006 Author Report Share Posted October 14, 2006 Tyres are a bit worn on the front so guess I might get them replaced and have a geometry set up too see how it can be improved. any ideas the best place to get some 215/45x17's in SE london? It's running Kumho on the rear which look like new. Quote Link to comment Share on other sites More sharing options...
Tony Posted October 14, 2006 Report Share Posted October 14, 2006 Tyres are a bit worn on the front so guess I might get them replaced and have a geometry set up too see how it can be improved. any ideas the best place to get some 215/45x17's in SE london? It's running Kumho on the rear which look like new. Lets invite the higher powers from tdi with the pro-drive knowledge a chance to resolve this issue before wim comments...... At the end of the day we all want the best result. Quote Link to comment Share on other sites More sharing options...
Paul TVR Posted October 15, 2006 Author Report Share Posted October 15, 2006 Well woke up this morning to find the front tyre was flat, I had check th tyres before leaving the house yesterday so looks like i probably picked up a slow puncture along the way, I'll see what if feels like with the front tyres replaced/repaired depending on where the leak is from. Quote Link to comment Share on other sites More sharing options...
Tony Posted October 15, 2006 Report Share Posted October 15, 2006 Well woke up this morning to find the front tyre was flat, I had check th tyres before leaving the house yesterday so looks like i probably picked up a slow puncture along the way, I'll see what if feels like with the front tyres replaced/repaired depending on where the leak is from. The simplest reasons are the most ignored Keep us aware of how thing go after the tyre issue is sorted. Quote Link to comment Share on other sites More sharing options...
Paul TVR Posted October 15, 2006 Author Report Share Posted October 15, 2006 Well after a hunt around my local tyre fitters not many had any in my size, the ones that did wanted a fortune or tried to flog my some second-hand ones for more than I can pay online for a new pair, so I guess a call to black circles in the morning will be in order. Gave it a squirt of the dreaded tyre weld to seal it up until I can get them here, it seems to be holding pressure fine for now. The car has a wheel wobble too so thinking the new balanced tyres should sort it out, if not then I'll be buying new bushes as well lol. Quote Link to comment Share on other sites More sharing options...
Sam@TDi Posted October 16, 2006 Report Share Posted October 16, 2006 Hi Paul sorry I’ve only just caught up with this thread, ok firstly I think it's entirely possible that there could be more than one problem at play here. I think that with the car being lowered it's likely to be running some "tow out" on the front axle unless it's been checked and corrected recently. This as Tony rightly says will have the effect of dulling the front axle's response to steering inputs and may give rise to a "drifting" feeling. I can't give you exact figures without corner weight results but I would estimate this cars dynamic index at around 1.22 whilst this isn't actually too bad compared to most of rovers creations it would indicate to me that the chassis is a bit of a slug by design so having good front end grip will be absolutely crucial in order to provide good feel & disturbance rejection whilst the vehicle is at speed (you’d feel this effect more as you go faster). The cure for this could be as simple as making sure that you invest in some quality sport rubber for the front axle or even better, all round. PS. I wouldn't assume that the shock absorbers are "good" simply because they passed an mot, the bump test is notoriously un-reliable Quote Link to comment Share on other sites More sharing options...
Paul TVR Posted October 16, 2006 Author Report Share Posted October 16, 2006 What sort of tyre wear will I see if the wheels are toeing out? If I remember from years ago toe out causes insides of the tyres to wear? it seems to turn in ok when going into roundabouts but it's still a huge car compared with what I am used to. Quote Link to comment Share on other sites More sharing options...
Tony Posted October 17, 2006 Report Share Posted October 17, 2006 What sort of tyre wear will I see if the wheels are toeing out? If I remember from years ago toe out causes insides of the tyres to wear? it seems to turn in ok when going into roundabouts but it's still a huge car compared with what I am used to. I will post an image for you tomorrow Paul. Quote Link to comment Share on other sites More sharing options...
Tony Posted October 18, 2006 Report Share Posted October 18, 2006 What sort of tyre wear will I see if the wheels are toeing out? If I remember from years ago toe out causes insides of the tyres to wear? it seems to turn in ok when going into roundabouts but it's still a huge car compared with what I am used to. I will post an image for you tomorrow Paul. Here we go... Remember toe wear is lateral (scrubs sideways) this example is extreme... so subject to this type of force? Quote Link to comment Share on other sites More sharing options...
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