IT should really think about welcoming Older SM's....... Without a new class..

[Ron Earp]

The Miata example isn't a good one as that car just got a weight adjustment using the 'what we know' theory. The most fair way to do it would be to determine a % gain factor...say 1 or 2% (based on actual research, could be more, could be non-existent based on results) and simply add it to all cars with power steering, and then allow them to remove it.

The problem is that PS loss research is very hard to do. Some of it is methodology, but it's also that the loss is probably about the same absolute value as the noise of the measurement. First we'd need to establish a Limit of Detection for the dyno, LOD, which is the lowest value that can be distinguished from noise. But statistically we can't quantitate values at the LOD, we'd need to work at the Limit of Quantitation, the LOQ, which is about three times higher.

http://en.wikipedia.org/wiki/Detection_limit

Where I'm going with this is if we have two measurements, A and B, and we determine that the LOD of our measurement is 2hp, then we can't statistically say with greater than 95% confidence that A is different from B unless the difference is around 6hp (I'm estimating based on LOD = 3*stdev blank / m, compared to LOQ = 10*Stdev blank / m).

This PS stuff is going to be lost in the noise, and probably the reason why manufacturers do not consider it when stating hp numbers.

Still, I'd be happy to try and measure it and I have the skills to get it done.

[Ron Earp]

Or they could be running in IT.

[Chip42]

but SM2 can still be illegal for IT even if the PS rules were changed. allowing comparable speed classes into IT? the line for the slippery slope starts over there...

[Dano77]

Or they could be running in IT.

Thats the point, They are running IT and they are noncompliant. In NER you can run an SM in 4 race groups. We made it that way so there was a NON SMish group in between every one. So in NER you can run Group 1,3,5,7 or SM, SM2, STL, ITA.

The issue at hand is not JUST Power Steering. But unfortunatly thats what the world is hung up on today, for this discussion. It was a rear diff the last time this came up. Non-Compliant is NON COMPLIANT..... we dont need to change the rules to fit ONE make of car. Slippery slope and all.

[Flyinglizard]

1) Can anyone here give a valid reason not to allow depowering the racks? other than " we cant do that? "
2) Does the updated SM diff go faster or just go more often?? More often is the answer. I think that the entire class/group should allow bigger more modern diffs. They wil go slower but race more often. We had the same discussion with a Datsun a little while ago.

It is true that the Miata has plenty of places to play already. The IT ranks could pick up the 1.6 cars with a little thought before they all go to prod/Chump/NASA.
See a market- make a product.

[Chip42]

mike - I know I'm feeding bears here but:

1) depowering rack has the knock-on request to remove the PS pump. I know, crazy talk! anyhow, with that little power sapper removed, the output of the engines is thuss made different from the number we are starting with in the calculations that are generally referred to as "the process". WHAT WE KNOW (tm) is an often used mechanism to adjust the weight of car where the HP output is documented well enough for us to adjust to that number rather than a theoretical gain percentage over stock advertised hp. we do this on a handful of cars but theres a lot of cars we know diddly about in the ITCS so this isn't a practical way to overcome the issue. As stated above, the process is imperfect, but allowances that change that initial hp number and aren't 100% to all cars (some don't have power steering to start with, everything has an exhaust and all of them are restrictive to some degree) "unblance" the output. yes, I know the "noise" of the system is enough to hide this influence.

2) upDated diffs are currently not part of the class philosophy of improving what was found in showrooms of the USA. we allow alternates or modifications to stock units to keep the one wheel peel to a minimum but do nto allow replacments of the pumkins, transaxles, etc... which is what is needed in the case of the 1.6 - 1.8L NA miata diff swap. you are correct, it doesn't make the car go faster, only more often. but it is a significant change from current philosophy and THATS where the line is being drawn. it's a classic case of be careful what you wish for, and all you have to do is look at the current "max build" in IT vs. the letter of the rules and it' seasy to see that "these cast manifolds are cracking, let the guys run headers" turns into "lets send the car to a specialist fabricator to mock up a set of stainless steel 1-off headers based loosely on calculations from one of two software models or straight mathematics then tune the lengths to suit the motor on a dyno. when we're done we'll go back and try a bunch more configurations with different length between stepped primary pipes, relocating collectors, tr-Y and 4-1, mergine both sides of the V, ...." as the popular adage goes, you get the IT you want.

[gran racing]

Or they could be running in IT.

Is this the direction or where IT has reached? They have a place that makes perfect sense for them to run, has been proven at least in some regions to be a success WITHOUT changing multiple rules to IT just to accommodate them... SRF cars are going to be required several updates and eventually will be phased out of that category. Are we desperate enough to go after them too?