Torsional Vibration of Biturbo series
- Thread starter Enz0
- Start date
324662340, the flywheel used in some of Ghibli 2 and Quattroporte 4, seems like dual-mass.
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Maserati introduced the dual-mass flywheel for later Ghibli 2 and pre-Evo Quattroporte 4 (both V6 and V8), and continued to use it for Quattroporte 4 Evoluzione V6. However, they ditched it for Quattroporte 4 Evoluzione V8 and 3200 GT. Maybe, they thought the Biturbo V8 was smooth enough.
It makes much more sense to use crank/torque dampers of any kind on an odd-firing v6 than on an odd-firing v8. So not surprising they did not use a dual-mass on v8 (which has the same flywheel as the QP4/GT 2.0/2.8 engines). Maserati equipped late QP4 2.8 engines with dual-mass flywheels. Other engines have quite heavy 8-9kg flywheels (except for 2.24 that had a lighter one) + 4-5kg for the clutch mechanism. v6 cranks have the same weight on 2.0 and 2.8 (at least those I could weigh): 16 kg I think.
Having driven few biturbo/Ghibli/QP4 I don't find these engine vibrate that much. May be a bit too much around 2-2.5k rpm.
I made modify the stock 18v flywheel to reduce its weight down to 5.4kg and did not notice any excessive vibration. While the throttle response is clearly faster (for gear changes).
Seems like the 24/32v flywheels are steel (and not cast iron) made, so my next 2.0 flywheel will be even lighter.
BTW, some 18/2.24 flywheels I've got were not balanced at all, there are no traces of balancing. May be this could be a source of vibrations. Additionally it's known that many engines were assembled with not matched pistons. People reported weight differences of up to 10gr. The 2.8 18v engine I've just rebuilt had 15gr of difference and was vibrating around 3k rpm, but it has already been rebuilt once, just one bank
.
The clutch mechanism I made balance had 20gr of unbalance, it's huge.
Having driven few biturbo/Ghibli/QP4 I don't find these engine vibrate that much. May be a bit too much around 2-2.5k rpm.
I made modify the stock 18v flywheel to reduce its weight down to 5.4kg and did not notice any excessive vibration. While the throttle response is clearly faster (for gear changes).
Seems like the 24/32v flywheels are steel (and not cast iron) made, so my next 2.0 flywheel will be even lighter.
BTW, some 18/2.24 flywheels I've got were not balanced at all, there are no traces of balancing. May be this could be a source of vibrations. Additionally it's known that many engines were assembled with not matched pistons. People reported weight differences of up to 10gr. The 2.8 18v engine I've just rebuilt had 15gr of difference and was vibrating around 3k rpm, but it has already been rebuilt once, just one bank
.The clutch mechanism I made balance had 20gr of unbalance, it's huge.