Mr Bounce
After much contemplation I finally bit the bullet and bought a new set of dampers for the MR2. The standard items were well past their best and I felt they were costing me valuable time in speed events and autotests by messing up what should be excellent handling. There was some noticeable bounce of the nearside front at Hethel, resulting in a car that was trying to switch between understeer and oversteer all the way though right-hand turns. Not good for confidence I am sure!Back to the contemplation. Standard dampers can be bought for very reasonable money and would offer superior performance as compared to the exhausted units used up until now. Up-rated dampers are available for a bit more money, or I could go the whole hog and fit adjustable inserts. Despite the extra cost I decided to go for the adjustable option because it will give me so much more scope for fine-tuning, particularly when track conditions change. Springs would remain standard to comply with the standard car class for speed events.
The dampers were ordered on Tuesday and arrived on Wednesday. Work commenced on Thursday with 6 clear days to complete the swap and any follow-up wheel alignment work before the car was used again… but things are never as simple as you expect, are they?!
The first stumbling block was the brake lines; they pass through brackets on the struts and must be disconnected from the callipers to enable removal. Having nothing around to catch brake fluid in, but with the whole car up on stands, I decided to also drain, flush and refill the cooling system. The first part that needed removing was the fuel tank under shield, to give access to the radiator pipe drain plugs. The first bolt I tried to remove was seized and it snapped. Several others came out ok and some were missing. So now I need to get under there and drill out any bolt remains. Hopefully I can just re-tap them, failing that I'll have to install rivnuts and new bolts. Next I placed a bucket under the radiator drain cock and opened the valve. Nothing. The short stubby pipe was full of dirt but a bit of poking about with a nail soon sorted that out and with the valve open again, coolant started to flow. At this point I realised it was passed 10pm and I really should stop for the night! As it was time for less than good news, I also found that the offside hanger of the exhaust had broken away from the silencer, probably during the recent autotest. Luck seems to have been on my side (?!) as no other damage appears to have been done and the rod itself stayed in its rubber mount, so I can weld it back in place, with some reinforcement to prevent a repeat of the same failure.
Sunday morning, 9:30. I started removing struts. Each corner needed the anti-roll bar drop link disconnected, the brake hose disconnected from the caliper, pulled through its support bracket and re-connected to prevent too much fluid loss. Then 2 bolts at the hub end followed by 3 (rear) or 4 (front) nuts at the top and each strut was out. Only one fixing gave me trouble and that was the front offside anti-roll bar drop link – the hex form stripped from inside the stud, so I am replacing that link rather than bodging it back on and hoping I won’t have to get it off again! I got both front struts off and dismantled them first. The dampers were showing classic failures – loose pistons and low resistance to movement of the piston in the bore. Once both struts were “componentised” I checked that the spring free lengths were the same on both sides and then cleaned up everything rusty and gave them all a lick of paint.
Whilst the paint dried I took off the rear struts and did exactly the same, then for a bit of variety, I finished draining the cooling system. Once that was all done the paint was dry enough to reassemble the front struts. First a little anti-freeze, then the new dampers were placed into the strut cases and the ring nut tightened down. The rest of the bits and pieces were then reassembled and the struts were hung straight back on the car to get them out of the way. The strut-to-hub bolts were loosely fitted too. The same process was followed with the rear struts and soon it was time to bolt things together a little more permanently. The rear camber adjustment was first, once that was done I then needed another "break" so I flushed and refilled the cooling system! The instructions in the manual seemed daunting, several air drain valves needed tubes fitted to their outlets and they had to be closed in a certain sequence, but in reality it's fairly easy. By the time I'd finished that and tidied my tools up it was about 7:30 pm… I was hungry and it was nearly live music time at the local pub. The rest could wait!
In line with traditional motorsport practice it then took me until the eve of the next event to complete the work thanks to some courier delays and some complications in refitting the fuel tank under shield (this was easier than feared) and the front exhaust hanger (another snapped bolt!) in addition to setting the camber on all four wheels. On Wednesday evening I took the car for a brief and gentle drive through the village to ensure everything was properly attached and safe. After a few checks I then set off on a longer drive to ensure the dampers had been through a full heat cycle before being put to work properly on Thursday. During this drive the car felt much more taught and controlled, soon a new setup could be developed.
Daniel Whittington