Originally Posted by: HK1837 
It will work within reason. I don't care about the consistency of the driver reaction or the 1/4 mile times, they are irrelevant to power. It is the 1/4 mile trap speed that matters. Not interested in understanding diff ratios or gearbox ratios, they have no bearing on power. All that matters is the consistency of testing with regards to two people, throttle lifts between shifts and no missed shifts, and the tests I'm looking at are mostly done by the same people. Primarily Mel Nichols, Rob Luck and a few other key players. Yes the tune of the engine matters, and I have road tests and trap speeds for properly tuned examples of some cars, others I'm looking for, one being that initial LX SS 5.0L test. So far the examples I've played with appear spot on, even down to the driveline losses in these manual dual exhaust cars appearing to be awful close across the board, ie calculated rwhp from the tap speed versus known SAE gross engine power. With this consistent loss factor it is easy to spot fudged claimed hp figures, like the XY GT-HO's claimed 300hp cannot be correct given the 1/4 mile trap speeds obtained. It also becomes easy to spot cars that are down on power compared to the known factory hp figures, like the initial road tests of the GTS327 and GTS350M. Yes I know rear wheel dynos vary, but they also show figures from the day and what people achieved out of stock properly tuned examples.
The best XY GT-HO Dynoed was 350HP.
The Max HP has got bugger all to do with total performance.
I could build a 350hp engine and a 300hp engine could out perform it with the same ratios diff or box especially on 1/4 mile rubbish, 1000m will tell another story as to the ability of the 2 engines, there are horses for courses.
One engine set up for the drags and one setup for the race track, we are not interested in max HP but in how it performs.
If we are into testing stock production cars and to take a stock red 202 powered Holden for example every one knows that such should make 160KM/H top speed, now no one would argue with that really, but what if I said that they can do 185KM/H well then comes the line of total disbelief, but but but they can with a 3.08 diff I have seen it for a fact, take a VB SL auto 3.3L with a 3.08 diff and one with a 3.36 ratio and you will see where the 3.08 eats the 3.36 ratio, sure the 3.36 is quicker just off the line, but by does the 3.08 go ! it's just unbelievable how the ratios work to it's advantage in many ways. I am amazed at the difference. it's like wow the car has been transformed into a rocket ship. it's like come on bring out the 4.1L Falcon bro and we will see how ya go with a big smile.
Like having a dual exhaust stock HQ 308 with a 3.36 diff vs a 3.08 ratio the 3.36 ratio is stupid over all for a road going car, it will not be faster over the 1/4 and you will be limited to about 185KM/H and a 3.55 would be even slower on the 1/4 and limited to 160KM/H and why is that so, well it's mainly about understanding what part torque plays in all this.
Look at the HT 350 and the XY GT-HO on the race track, the HT 350 torque that counted very well on the track, it did not have the HP of the XW GT-HO, so HP is not always everything it's cracked up to be all the time.
Take this example a stock HQ dual exhaust 308 3.08 diff has about 204hp net and a XU-1 202 say 190hp, now at 180km/h both flatten it ? you will see the XU-I take off from the HQ like a shot. weight aside, it's the way that the HP is made at high rev that make this difference, they take off but the 308 has dropped out of it's power curve and is dying when the XU-1 is just getting it all together.
You are not going to tow a van behind a XU-1 would you,because it would be a bucket of, to drive but the 308 HQ would be magic with towing a van and a XY GT-HO would be a bucket of to drive with towing a van behind it as well.
Look at a stock dual exh LH 308 VS a HQ 308 stock dual exh with the same gearing, it power to weight that comes into it directly and then the test can point out the rest of such things.
