Re: BACK TO MY NISSAN ROOTS
Posted: 01 Mar 2014 17:50
A few other things to discuss.
1: Dual Mass Flywheel. I would be very, very cautious about replacing this with a Single Mass ( Lightweight Flywheel ). Most modern engines no longer use front mounted Crankshaft Dampners, but rather a DMF to control crankshaft harmonics. Changing to a lighter SMF significantly increases NVH and can change a nice comfortable and quite cruising GT car into something that you will quickly grow tired of with the extra vibrations, droning and and possible increased shift effort.
Contrary the report in the previous magazine. DMF make shifting EASIER on the synchros by absorbing the torque spikes when shifting. And V6 engines need crankshaft dampening much more than an Inlne 4... which has balanced Primary harmonics. I would be very, very cautious about replacing the Factory DMF with a SMF. Do some research on DMF by LUK and Sachs, and it quickly becomes obvious what the advantages are.
I think that most of the Lazy throttle feeling is due to not completing the TBA and possibly also the ECU Throttle Mapping.
Personal experience. I switched my Audi A4 Quattro 1.8Turbo from the factory DMF ( approx 25 lbs ) for a 9.5 lb Aluminium flywheel. Yes the engine revs quicker and double clutches quicker. Great for Autocross. But the day to day PITA issues of more noise from transmission ( gear clatter when warm at idle), MUCH more engine vibration and noise ( particularly on freeway ), reduced synchro life and shift quality, reduced clutch life due to having to slip the clutch more from starts and especially on hills makes this one modification I would never again do to a Luxury or Sports car. Unfortunately I tossed the old DMF. I'm kicking myself over that. If I keep the Audi I will be installing a new DMF in the Spring. The lightweight aluminum SMF is such a pain for Daily Driving...
People also forget that the overall mass of a DMF can actually be less than that of a older design Front Dampener and Single Mass Flywheel because a DMF does not usually require a front dampener, or if it does, the front dampener can have much less mass.
DMF were developed for Passenger cars back in the mid-1980's. Most European and Japanese manufacturers now incorporate this design into every vehicle they produce. Here are a couple of Engineering articles showing the advantages of DMF's over standard designs. Interesting is the increase in Fuel Economy by using DMF's:
http://www.schaeffler.com/remotemedien/ ... heel_1.pdf
http://www.schaeffler.com/remotemedien/ ... DMFW_1.pdf
More links:
http://www.amsautomotive.com/dual-mass-flywheels
http://www.sachsperformance.com/product ... cts_id=459
2: Transmission fluid. GM/AC DELCO has developed a semi-synthetic " Friction Modified " fluid for modern transmissions that is like MAGIC. Every forum you go to, from Honda, Audi, Toyota, VW, Suburu, BMW, Mercedes, Nissan etc raves about this stuff. I was skeptical at first, but I was having an issue with a slightly crunchy 2nd gear Synchro on my Audi. I had previously tried Amsoil GL4 manual transmission fluid and Redline MT-90 GL 4 fluid. The Amsoil was just too darned slippery and made engagement worse. The Redline wasn't too bad. But I'd still get a crunch into 2nd when the box was cold ( 236,00KM on original 5 speed ).
Tried out the GM Friction Modified fluid and the transmission shifted like new. Literally like a hot knife through butter. I could not believe the difference that this fluid made in shift quality.
I recently serviced the transmission ( Torsen wearing out ) and for some reason decided to try the Redline MT90 again. Shift quality immediately degraded, and I have the 2nd gear crunch back again. The GM/AC DELCO fluid is going back in ASAP!!
BTW, I talked to the Parts Manager at Dueck Vancouver ( on Terminal ) . He can't keep the stuff in stock!! Local dealers from Honda, Toyota, Nissan, BMW, Mercedes, VW/Audi, Subaru all order this fluid for their " difficult" shifting transmissions and install it for warranty service on the " Hush Hush " While not an Official Technical Service Bulletin.. the use of this fluid is well documented all over North America by Dealerships of European and Japanese manufacturers.
BTW. The GM Fluid and AC DELCO are the exact same part. Just different labels. Lordco seems to have one of the best prices. $12.75 CDN per liter wholesale. AC DELCO CDN part number : 10953509.
For USA members the AC DELCO USA part number is: 88900399. GM USA part number is: 12377916
Edit: All of these part numbers are the same fluid. For some reason GM/AC Delco keeps changing the packaging and part numbers. I've just found out this morning that some Canadian GM dealers have this fluid under both the old numbers and the newer ones.
1: Dual Mass Flywheel. I would be very, very cautious about replacing this with a Single Mass ( Lightweight Flywheel ). Most modern engines no longer use front mounted Crankshaft Dampners, but rather a DMF to control crankshaft harmonics. Changing to a lighter SMF significantly increases NVH and can change a nice comfortable and quite cruising GT car into something that you will quickly grow tired of with the extra vibrations, droning and and possible increased shift effort.
Contrary the report in the previous magazine. DMF make shifting EASIER on the synchros by absorbing the torque spikes when shifting. And V6 engines need crankshaft dampening much more than an Inlne 4... which has balanced Primary harmonics. I would be very, very cautious about replacing the Factory DMF with a SMF. Do some research on DMF by LUK and Sachs, and it quickly becomes obvious what the advantages are.
I think that most of the Lazy throttle feeling is due to not completing the TBA and possibly also the ECU Throttle Mapping.
Personal experience. I switched my Audi A4 Quattro 1.8Turbo from the factory DMF ( approx 25 lbs ) for a 9.5 lb Aluminium flywheel. Yes the engine revs quicker and double clutches quicker. Great for Autocross. But the day to day PITA issues of more noise from transmission ( gear clatter when warm at idle), MUCH more engine vibration and noise ( particularly on freeway ), reduced synchro life and shift quality, reduced clutch life due to having to slip the clutch more from starts and especially on hills makes this one modification I would never again do to a Luxury or Sports car. Unfortunately I tossed the old DMF. I'm kicking myself over that. If I keep the Audi I will be installing a new DMF in the Spring. The lightweight aluminum SMF is such a pain for Daily Driving...
People also forget that the overall mass of a DMF can actually be less than that of a older design Front Dampener and Single Mass Flywheel because a DMF does not usually require a front dampener, or if it does, the front dampener can have much less mass.
DMF were developed for Passenger cars back in the mid-1980's. Most European and Japanese manufacturers now incorporate this design into every vehicle they produce. Here are a couple of Engineering articles showing the advantages of DMF's over standard designs. Interesting is the increase in Fuel Economy by using DMF's:
http://www.schaeffler.com/remotemedien/ ... heel_1.pdf
http://www.schaeffler.com/remotemedien/ ... DMFW_1.pdf
More links:
http://www.amsautomotive.com/dual-mass-flywheels
http://www.sachsperformance.com/product ... cts_id=459
2: Transmission fluid. GM/AC DELCO has developed a semi-synthetic " Friction Modified " fluid for modern transmissions that is like MAGIC. Every forum you go to, from Honda, Audi, Toyota, VW, Suburu, BMW, Mercedes, Nissan etc raves about this stuff. I was skeptical at first, but I was having an issue with a slightly crunchy 2nd gear Synchro on my Audi. I had previously tried Amsoil GL4 manual transmission fluid and Redline MT-90 GL 4 fluid. The Amsoil was just too darned slippery and made engagement worse. The Redline wasn't too bad. But I'd still get a crunch into 2nd when the box was cold ( 236,00KM on original 5 speed ).
Tried out the GM Friction Modified fluid and the transmission shifted like new. Literally like a hot knife through butter. I could not believe the difference that this fluid made in shift quality.
I recently serviced the transmission ( Torsen wearing out ) and for some reason decided to try the Redline MT90 again. Shift quality immediately degraded, and I have the 2nd gear crunch back again. The GM/AC DELCO fluid is going back in ASAP!!
BTW, I talked to the Parts Manager at Dueck Vancouver ( on Terminal ) . He can't keep the stuff in stock!! Local dealers from Honda, Toyota, Nissan, BMW, Mercedes, VW/Audi, Subaru all order this fluid for their " difficult" shifting transmissions and install it for warranty service on the " Hush Hush " While not an Official Technical Service Bulletin.. the use of this fluid is well documented all over North America by Dealerships of European and Japanese manufacturers.
BTW. The GM Fluid and AC DELCO are the exact same part. Just different labels. Lordco seems to have one of the best prices. $12.75 CDN per liter wholesale. AC DELCO CDN part number : 10953509.
For USA members the AC DELCO USA part number is: 88900399. GM USA part number is: 12377916
Edit: All of these part numbers are the same fluid. For some reason GM/AC Delco keeps changing the packaging and part numbers. I've just found out this morning that some Canadian GM dealers have this fluid under both the old numbers and the newer ones.