December Fastrack Prelims

[PamRichardson]

If you haven't checked these on scca.com, today, the preliminary minutes and tech bulletin are up.

Lots of changes for 2021 in the tech bulletin and proposed rule changes for 2022.

Be good to check them out as you work on your cars over the winter. Lots of changes.

Pam

[jimwheeler]

The restrictor plate and rev limiter Recommended Rule changes are no longer TBs, but are REC for next year. Item 29826. If you wrote in before, you probably should write in again to www.crbscca.com and tell them what you think about the Recommended Rule change. Not sure if they will count your earlier input since it is no longer a TB. Also, How the hell would you "demonstrate by the competitor upon request of SCCA official", Floor it in neutral and see if it blows up or hits a 7600 rev limiter? This rule is nuts.

[PamRichardson]

Jim --

All good points! Please everyone, send in your view on these topics. This decision will be made at the Convention in January by the BOD, and, if approved, will be applicable 3/1/2021.

I agree about how do they police it? Does it mean I need to show the a 7600 chip? MSD ignitions start to cut power somewhere between 100 and 200 RPM below the chip number, meaning, a 7600 chip will work for full power AT MOST to 7500. I'm also not sure that Tech has been given any guidance or tools to check this at this point.

Both the restrictor and the rev limiter seem like a "shoot from the hip" plan with no real guidance on any implementation or compliance checking.

Pam

[jimwheeler]

I see the restrictor as a way to make quick restrictor changes to cut the performance of the current full prep cars, to make them slower than the new restricted prep cars. If the rule change goes through, the CRB can put any size restrictor on us without any input from the members. They just write a Tech Bulletin and we are done.

[DHRMX5]

Really Jim? I am not exactly dancing a jig about the +2mm restrictor size that is going to get me in the neighborhood of 365rwhp. Why would you think the AS rules are about killing off the FP cars?

How much power do you make? McDermid?

I know of 5 potential cars that are awaiting the results of this silly season to decide whether to run Touring or AS. None of them are interested in FP cars.

If anything, AS clings to a ruleset that accommodates the FP cars and that is fine. They were here first. It's just silly to run cars that create their own set of problems.

It cost me less to build my 2011 Mustang than what I have been told a new front running engine for FP engine costs. Take my restrictor off and my car would kick the living crap out of AS at any track. At the current level of power I am allowed I will never have to worry about spares...

[MarkMuddiman]

Shine up them dancing shoes, 'cause you're there!

425 at the crank is about all that be squeezed out of a FP motor in race trim.
Estimate around 15% losses thru the trans and diff, and you get 361 rwhp.

[Scott Sanda]

We getting into this discussion again? All numbers from a new, in ground Dynojet at Blackdog speed shop.

LS2 with dry sump, 351.8 @ 5700 rpm, max Tq 365

LS6 with dry sump, 369 @ 5800 rpm, max tq 360

LS2 was faster at short tacks, LS6 had higher top speed at RA. Andy does not pull me in a straight line, and last spring neither did Thomas Ellis at Sebring.

Back when I was on the Ad hoc and we had access to data, Andy vs Me at RA for the Sprints showed identical lap time and speeds, with me a little faster on the front straight, from turn 14 to the entrance to the carousel.

They just out drive me.

I would think a car with similar HP and a close ratio gear box would do quite well.

[DHRMX5]

And this is why no one believes the numbers in AS.

From your previous post: "My AS V does not have a restrictor. On blackdogs brand new dynojet, in November, it made 373hp and 385T."

I'd be happy to be allowed that HP level.

[Scott Sanda]

I’m sure I have a sheet that says that. 4hp is statistical noise. Could be air temp, tire inflation, any number of things.

I’m sure I can find a dyno that says more or less for your motor as well. From pull to pull even.

That does not invalidate the point.

If you are in the 360’s, you are going to be competitive. Or at least have a competitive car.

Driving it that way is another thing.

Scott

[mlanglin2007]

Jim Wheeler makes good points. While it is my opinion that rev limit is way overdue, both rev limit and restrictor plate should not be done at the same time. No way to assess impact of one vs the other.

Pam makes a great point about where MSD rev limiter begins to cut power.

Also, as Jim said, how do you enforce rev limit? How hard would it be to put a "7600" sticker on whatever rev limiter you wish to use? There are ways to deal with this, but all of them involve people time (i.e., stamped/certified rev limiter chip).