school boy question
Discussion
Hi all, Darren the newbie here , now hands up i know this is a bit of a schoolboy one ( how fast mister ?) but what is the sort of spec ( bhp / gearbox 5 or 6 speed etc ) that i need ? im still on the learning curve to buying an ultima and ( im being honest ) doing the double ton is in my criteria of the many boxes the ultima ticks for me , iv got a mk 1 capri at mo thats got 330 brake of cosworth yb engine and this cracks the 150 ( 153 gps timed at bruntingthorpe ) so to move up ( big time ) and to buy a car thats not quite the right combination to crack 200 would be a bit of a mega disapointment , cheers for anyones replies and thoughts on this , cheers , Dal
Steve_D said:
IMHO you will need 700+bhp reving to 7K ish.
5 or 6 speed with the correct ratios. If you go 6 speed you could fit a taller 6th just for 200+ and motorway cruise and except that you would not normally be able to use it much.
Steve
Can't argue with that Steve. Probably worth pitching high to avoid disappointment 5 or 6 speed with the correct ratios. If you go 6 speed you could fit a taller 6th just for 200+ and motorway cruise and except that you would not normally be able to use it much.
Steve
You can either go big torque & high gears (plenty of trans/drivetrain upgrades required though)
Or extend the rpm range which calls for very careful engine parts planning and selection.
(there might be some 'very' suitable bits in the classifieds at the moment!!)
If you do go the revvy route....600-640bhp@7500rpm max, a standard 930-30 (fourspeed) or g50-50/52 will have enough stock final gearing to meet your goal.
Welcome and good luck.
Or extend the rpm range which calls for very careful engine parts planning and selection.
(there might be some 'very' suitable bits in the classifieds at the moment!!)
If you do go the revvy route....600-640bhp@7500rpm max, a standard 930-30 (fourspeed) or g50-50/52 will have enough stock final gearing to meet your goal.
Welcome and good luck.
Edited by 738 driver on Monday 10th August 23:59
738 driver said:
You can either go big torque & high gears (plenty of trans/drivetrain upgrades required though)
Or extend the rpm range which calls for very careful engine parts planning and selection.
(there might be some 'very' suitable bits in the classifieds at the moment!!
Hi,Or extend the rpm range which calls for very careful engine parts planning and selection.
(there might be some 'very' suitable bits in the classifieds at the moment!!
I was interested in the G50-01 in the classified section but when I worked out the top speed at 7500rpm it worked out at 188.85mph, is this a correct calculation?
Cheers,
David.
Dave, the popular/majority of G50's are geared very closely or the same as the one you have calculated.
The three models 930-30 and g50-50 or g50-52 as previously mentioned all have the larger crown and pinion which is not only stronger but also provides taller final drive ratios. If you can source a good example of any of these three, that would be the most economical way to go for 200 mph and relibility. The fourspeed gives 205mph at 7000 or 219 @ 7500 with the 5 speed G50-50 and G50-52 being very similar. Their stock gearsets are quite acceptable too, being designed for the extra torque of the turbo engined models means that big V8 torque is within their scope.
Alternatively you could use a standard g50, like the one you have mentioned and have it upgraded. This can run up to $14'000 by the top US transaxle companies!
As with most things, if you just enjoy spending big money there will be several options open to you.
I personally don't and nor do I see the point in carrying redundant gears along for the ride (six speeds etc)
The three models 930-30 and g50-50 or g50-52 as previously mentioned all have the larger crown and pinion which is not only stronger but also provides taller final drive ratios. If you can source a good example of any of these three, that would be the most economical way to go for 200 mph and relibility. The fourspeed gives 205mph at 7000 or 219 @ 7500 with the 5 speed G50-50 and G50-52 being very similar. Their stock gearsets are quite acceptable too, being designed for the extra torque of the turbo engined models means that big V8 torque is within their scope.
Alternatively you could use a standard g50, like the one you have mentioned and have it upgraded. This can run up to $14'000 by the top US transaxle companies!
As with most things, if you just enjoy spending big money there will be several options open to you.
I personally don't and nor do I see the point in carrying redundant gears along for the ride (six speeds etc)
dwrights said:
Thanks for the replies. If I changed the 5th gear ratio in the G50-01 to the same ratio as a G50-52 would that work well or would the rev drop between the two be to much using an LS7?
the 01 has a 7.5" crown wheel and the 52 a 9" so the internals are different but some gears are generic, it would be worth finding out from an expert if it can be done.the 5th on a 01 is a.82 or .86 ratio and the 52 is a .75 so it wont be hugely different.
do you have a copy of gear calc as i could email you a copy if you wish, 19" wheels on the back would also give you a lot more top end, you can even fit 20" if your mad enough!!!
http://www.kabamus.com/garage/gears.html
I have been using this one which works well.
19" wheels, nows there's a thought.
I have been using this one which works well.
19" wheels, nows there's a thought.
dwrights said:
Or how about a G96/88 6 speed from a GT2?
1ST Gear 44mph
2nd Gear 81
3rd Gear 111
4th Gear 150
5th Gear 182
6th Gear 224mph
Based on revs at 7500rpm.
Anyone got one in there Ultima?
Not in my Ultima, but have one in my RUF GT2 and it takes 632hp and 650lb/ft of torque to push the car to 206 at Brunts. I've got 660hp in my GTR with a 7500 safe rev limit, will be interesting to see if it can make the 200 but not convinced myself at the moment1ST Gear 44mph
2nd Gear 81
3rd Gear 111
4th Gear 150
5th Gear 182
6th Gear 224mph
Based on revs at 7500rpm.
Anyone got one in there Ultima?
Dom, dont know the current costs but fifth is on the rear of the box so it's quite easy to get at both gears. A couple of new locknuts to retain them should also be on your shopping list.
Kyle-Dave the G50-50/52 and fourspeeds have larger diameter shafts and splines so I dont think their gears will interchange into the standard G50 box. I seem to recall the gears themselves are also considerably more substantial in the turbo boxes than the stock 911 G50's.
Kyle-Dave the G50-50/52 and fourspeeds have larger diameter shafts and splines so I dont think their gears will interchange into the standard G50 box. I seem to recall the gears themselves are also considerably more substantial in the turbo boxes than the stock 911 G50's.
thanks for all your advice, so the gearboxes have codes that denotes what spec they are / what they have come from , have i read that right ?? so can these be seen on the boxes when their in situ in the car ( stamped on casing somewhere i assume ??) also just a thought is the sport capable of the double ton or is the shape that much different , its just that what iv been looking at the money i save on a sport ( around 10 to 15 grand ) i could then spend on inproving the trans and engine , as i said just a thought ??? :-)
738 driver said:
Dom, dont know the current costs but fifth is on the rear of the box so it's quite easy to get at both gears. A couple of new locknuts to retain them should also be on your shopping list.
Kyle-Dave the G50-50/52 and fourspeeds have larger diameter shafts and splines so I dont think their gears will interchange into the standard G50 box. I seem to recall the gears themselves are also considerably more substantial in the turbo boxes than the stock 911 G50's.
I seem to remember reading exactly the opposite?Kyle-Dave the G50-50/52 and fourspeeds have larger diameter shafts and splines so I dont think their gears will interchange into the standard G50 box. I seem to recall the gears themselves are also considerably more substantial in the turbo boxes than the stock 911 G50's.
It was something to the effect of “The shaft spacing between the lay shaft and the pinion shaft is the same, as well as the shaft diameters” I thought that there was no difference in the actual gear box casing, its only the larger differential casing that is different and that all other parts could be swapped over? I’ve got some of the Porsche spare parts manuals at home that you can download of their site. I’ll look up that part numbers when i get home to see if there are any similarities. It’s got me wondering.
As to the Gt2 and Gt3 boxes, i don’t know of anyone that has inverted them yet. Some of the boxes have a external oil pump and cooler installed as factory components. From the tech bulletins and diagrams on the Porsche site, as best as i can make out, it looks like the design of the later boxes has a sump in the bottom of the differential housing, with a small baffle to prevent the area where the crown wheel spins from being immersed in oil when it spins, and creating a wind-age loss within the case. When the box is inverted this will no longer be able to function as a sump. You will also have to provide an alternate pick up point for the oil pump. The oil pump is configured to pump oil into the hollow input shaft from the end of it furthest from the engine. The oil pump is mechanically driven, Haven’t worked out how this will work yet if it is inverted. May need to provide an additional sump and auxiliary pump.
Im, happy to be proven wrong and learn something new.
Ryan
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