Powerhaus II 5th Gear fitted successfully

[lvjost]

Hy guys. Implanted the Powerhauss II 5th gear into my G50 just yesterday. Everything went very easy. After a hour and 50 minutes, my Baby was already awakening from anaesthesia...Immediately made a trest drive. Awesome ! Like I calculated it (see post www.pistonheads.co.uk/gassing/topic.asp?t=309645&f=20&h=0 )it serves perfectly as both a crusin low rpm gear and a high top speed gear. No rattling, noise, difficulties with shifting. Nice to see that at least some things on a GTR work without trouble

[steve_d]

Did you fit it yourself?
If so then how is it done?

Steve

[davefiddes]

Sounds very interesting. I have a G50/03 and would really like it to have a bit longer legs for cruising on the motorway too. If it was practical to fit a new 5th gear without too many special tools or shimming and such like that would be very interesting as a mod...

[GTWayne]

I have a full set of different ratio Powerhaus gears in my G50/03 and after driving it for the first time I have to say that I am well pleased and would recommend this to anyone. I was cruising at 75 mph and the motor was turning 2300rpm (that means that at 7K rpm the GTW should do 208 mph), WOW.


If anyone is interested, or come to think of it, even if not, here are my gear ratios;

1st = 2.176 = 74.1mph
2nd = 1.579 = 102.1mph
3rd = 1.174 = 137.3mph
4th = 0.923 = 174.6mph
5th = 0.756 = 213.2mph

Ring and Pinion = 3.444

Shift point = 7200rpm

Tyre circumference = 81.41"


I do not intend to rev past 7K rpm and the motor should be safe to 7.5K rpm. I have not had the opportunity to put it through its paces yet but early indications are (not revving above 5K rpm due to having break in oil in the motor for the first 200 mls) that the ratios are perfect for my motor at least and the thing just gets up and goes whatever gear you are in but each gear has a useful length so you do not find yourself changing frantically as I have experienced whilst being a passenger in several other Ultimas.

Edited by GTWayne on Saturday 30th September 22:59

[simonbooker]

How much does a fith gear change cost sounds great and its always good to know your car is capable of 200mph

[lvjost]

hy guys. Did the change myself, but accompanied by a specialist. It can even be done with the gearbox mounted into the car. Just demount the rear clip. Demount the upper and lower gearbox mounts and open the most rear section of the G50 housing by opening the threads...then disconnect the gear linkage end....pull out the housing section so the rear part of the gear box is opened and you have access. Now take off the reversing gear by unscrewing the bolts and take out the original pair of fifth gear. Put in the PHII Gear set with the original 5th gear synchro rings on it. Everything re-assemble and done.... It jaust a bit tricky to get the bearings and gears andmounts off without shaking and pulling and hammering to much....But it can be done...
Needed 1 hour 50 minutes from taking off the rear clip until the startable car including the new 5th gear...

Gearset costs about 800 $ but in my opinion is worth every pence!!!