You're gonna lose more than 15% 'drivetrain losses'. More like 30% when you consider a stock 165kW motor puts out about 115kW at the rears. I'm not trying to split hairs or anything.

+1

RAPTOR's fairmont made 108rwkw on Crescent motors mainland dyno

i'm at 137 rwkw's (stock motor,full exhaust, cai & underdrive's)
to go on are gt40p's, performer efi manifold, xe 270 cam with matching 1.7 rocker's & spring's, 70mm t/body, te 50 maf, 24 lb injector's, chip & tune after all's installed
any thoughts on what i'll gain ?

Depending on the tune, I'd have a guess anywhere between 195 to 210kW at the rears, exactly the ballpark figure that I'm aiming for my station wagon.

Drivetrain losses are not linear wrt rpm, but "general" figures are well established and range from 12% - 20%. Manual transmissions are slightly better than automatics for obvious reasons. Low viscosity oils are better than higher viscosity oils. Hypoid action gears are worse then normal action gears. etc

If your drivetrain loss was truely 30% you would need a radiator 1/3 the surface area (this is fin surface area, not overall width x height of radiator) of your engine radiator just to disapate the heat generated by these losses. Case surface area would definately be completely insufficient. But how many vehicles making good HP have these coolers fitted to their manual transmissions and differentials?

If you are truely calculating a 30% loss, either the net flywheel HP was over-stated, the RWHP figure was under-stated or a gross flywheel HP figure was used instead of a net figure.

The calculation I summarised above was only intended to give a rough estimate of potential for some basic upgrades. All the figures are approximate. A "tune" is the most dodgy figure. It does not mean new plugs and air filter, it means new fuel & timing curves to optimise engine operation. Remember that WOT is open loop so fuel & timing is calculated via TP, ACT, ECT tables so the old figures the ecu uses are no longer relevant. A bump up in fuel pressure and a twist of the distributor will get you some of the potential, but not all.

reference:i worked at hp dyno tuning (hprace engines) in wagga wagga and people showed dyno certificats that were 10-30 rwk differnt to our print outs these were usually people from the nsw coast and old wa ect entries can be affected by air conditions eg-humidity ect... and also things like operator dyno type make these kinds off gains or loses

Another dyno error is down to how well the dyno operator straps the rear end down - if not done properly you can get an extra 30 - 40kw, giving some outrageous dyno figures as a result. Some unscrupulous dyno operators do this deliberately.

I cant believe how little the gains are from the stroker kit, rip out the 5 litre and put a 351 f150 bottom end and put all the AU3 top end with maybe a minor stroke to a 378 with j3 ecu, exhaust, extractors. The stroker kits for the 351 are roughly the same price as the 302. Not sure if missing anything else but with those mods with the same kind of money will get that power no problem but also depends on who builds it, puts it together...Time, labour can equal alot of money...

no ones mentioned figures for a 347 in this thread.

Not refering to this thread in regards to 347 stroker but have spoken to plenty of people in regards to the same thing cause i have an eb ghia 5 litre and am looking for the same power if not a little more... Im going to go the 351 route formy car thats why i mentioned it...

heads are the limitation.
even a 351-based stroker isn't going to make much more power then a 347 if both have GT40s.
alot of torque, but you won't be able to rev it hard enough to make any decent power!

Just a daft question, can you use old school 351W heads on efi? don't shoot me i don't know too much about EFI (i'm old school myself)

I know you can use gt40p,s on carby motors.

Yes you can, but in my opinion its a step backwards. Mind you all the SA design books i have read state the E7's are a good upgrade for an old school windsor.

Brett