...and there are cases of cars with and without PSon different speclines due to trim or body type (think civic) with the same publsihed hp ratings, the ability to underdrive a parasitic system that is an effective gain over the cars without it, etc... no argument, and it's not the CRB. 'nuff said. you know where the letter form is.
The manufacturers did not publish two different horsepower specs based on the type of steering installed in the car and I’m sure we do not have that level of resolution in IT classing. How many cars came with manual and power steering racks? How many of those cars are racing? Wondering about ITS since I know some of those cars…
240,240,260,280Z – all manual
RX7 – manual and power available
TR8 – power only
Mustang – power only
300ZX – power only
Miata – power only I think for ITS years
240SX – power only?
E36 BMW 325 – power only?
FWIW NOTHING matches the process anyhow. E.G. all the popular ITS stuff is 5% or more above expected power, big motor cars like Jeff's TR8 and the mustangs are well above process weight and power (by how much I do not know, but they do allow that they are well over both). we're just lucky everythign has found a good relative balance due to all the hard work by the competitors
The process greatly underestimates gains for a variety of reasons:
*The level of R&D that would be done on IT cars that encompasses many, many facets of the engine development program.
*No distinction between two valve and four valve motors.
*Ignores what modern EFI can do for engine output compared to carbs, or even compared to early EFI.
*Largely ignores displacement and factors only peak power, although there is a "torque adder" that we know when to use when we see it.
With respect to the last point, earlier this week I got interested in area under the horsepower curve and performed some calculations based on my own dyno data. Back in the day, a version of my 260Z engine and a version of the Mustang engine were making the exact same peak power, 169 rwhp. However, the area under the horsepower curve in the best 2000 RPM wide power band for each motor was considerably different with the Mustang having a 16% advantage. Both of these engines exceed their IT process power. The 260Z was rated at 138hp from the factory and went on to make as much as 176-180hp at the wheel when everything was perfect. Parity with these two cars or engines was, as you say, by blind luck. The Z can make its 2480 lb process weight, the Mustang can't and races at about 13% heavier than the Z which is within spitting distance of the 16% horsepower area under the curve advantage.
As stated, most cars are above their 25% process power, but given how things shake out on track I’m not sure any “IT approved” formula or correction could improve things. I do think a new process using a max cam duration, a max lift, factoring displacement, and valve curtain area could create a very interesting and level class, but that’s another topic.
. It's time to open up the rule books for simple changes and start having deeper fields.
Back to this, so what is needed for SMs to come in droves to IT?
1. PS elimination allowance
2. Ability to run a larger torsen/rear end
