https://1drv.ms/x/s!AiSPBKa26IcchM5oxMe ... Q?e=zze30n
Inputs include choice (from drop-down lists) of engine (torque curve), gearbox (Jaguar, T5, Getrag), diff ratio. Output is revs, maximum torque and minimum torque versus road speed as you go thru the gears according to your selected driving style: “tree-hugger”, “family guy”, “who’s yr daddy” or "not a vegan”.
Maximum torque is by full throttle. Minimum torque is what is needed to keep you motoring along on a flat road at constant speed. The difference between max. and min. torque is what you use to compensate for hills and to accelerate, the bigger the difference the faster you can accelerate. So Chris, to reliably see off all the young turks, Barry would need a car configuration and driving style that maximises this difference. Hope he likes meat.
Terminal velocity is when there is no difference, when maximum torque has fallen and minimum torque has risen to the same speed. As per the following snapshot, on my car this would be around 142 mph.
Another example of using this spreadsheet: The 6 litre HE has monstrous torque however, as Phil reminds us, this falls away dramatically above 5000 rpm due to the physical impossibility of pushing 20% more flow thru similar sized exhaust valves that are restricted, recessed into the head. Net effect: if u want terminal velocity bragging rights you might need to plan yr gearbox/diff combination. With a Getrag gearbox and 2.88 diff you would max out at 145 mph, = 4000 rpm in 5th. If you held it in 4th you could reach 150 mph @ some 5500 rpm (engine choked), ie:
If instead you had a 3.54 diff, you could exceed 150 mph, in 5th.
This is assuming the Getrag 265 gear ratios used by Jaguar (6 cyl XJS) during 1983 – 1987, i.e: 3.55/2.09/1.39/1/0.76. Seems there were very many different gear ratio combinations used in Getrag 265s. People with Getrags, do you know what yr model and ratios are?
Further example of using this spreadsheet that is back on topic, Tremac gearboxes: The two types being discussed, T5 and TKO, are completely different. Phil’s Tremac is a TKO, stronger than a T5 but TKO’s are apparently too big to fit into E’s?
Imo the Drivenman T5 package is very neat, well-engineered, no structural mods req’d, includes extended drive-shaft, steel (explosion-proof) bell-housing, also hydraulic clutch release bearing (no slave cylinder req’d). This is the one that SNGB sells. I almost bought one.
One concern with the T5 was that it is not that strong. The following illustrates that, after my current engine upgrades, driving like a “who’s yr daddy” with existing diff would have the T5 overloaded every foot-to-the-floor.
I’d need to drive like a “tree-hugger”, also stay below 75 mph and definitely no power-shifting (what the young turks rely on, an option with my new ECU). So instead I’m opting for an LdN overdrive addition to my Jaguar 4-speed. Automobile-catalogue.com reports that during (’79 - ’81) XJS’s had LdN ODs on V12 engines, do we know if this is true?
I note (from Wikipedia as well as automobile-catalog.com) that 1979-92 Series 3 XJ6’s were available with Jaguar 5-speed gearboxes. I’ve included the ratios in the spreadsheet despite not knowing anything about them?
