Modified Street Tire Classes - What to do?

[Anonymous]

I thought almost all new cars have variable timing?
ie Tracking it would be a nightmare.

In class one, we are already pitting NA Miatas on springs against 500hp turbo Porsches. Is variable timing that important?

In any case Kenny would be covered by bumping to the donor car clause. Which I think is important, because that would also take care of multiple class bumps from the FSP field. Like say that old school Corolla yesterday put in a Supra motor. One class bump for significant engine swap, or 2 class bump for swapping in an ASP motor.

Or another example, little crappy BMW with an e46 M3 motor, one class bump or 2 for ASP swap?

[Loren]

A lot of cars do have VVT now. Let's use my Yaris as an example. The little 1500 has VVT and makes 106 hp and 103 ft/lbs. Not too shabby for such a small displacement! Compare that to anything from my Spitfire 1500 to a pre-90's Civic 1500. Those engines don't have the technology, and they make about 60-70 hp and 80 ft/lbs on a good day.

So, taking a chassis that's already been classed "as a whole" and adding 25% more power to it... shouldn't it go up a class?

That's just one example of how an engine swap that didn't increase displacement, but DID add technology would be as effective as a larger engine... or even as effective as a low-boost turbo/supercharger.

If the car already has VVT (or some other meaningful technology), they're fine to swap to another engine that has it (or doesn't) because it's already accounted for in their base classing. But, to ADD it, it needs to be considered.

I'm not saying we need to bump cars two classes if they swap to a larger engine with a turbo or a larger engine with VVT that they didn't have before. But, we should consider bumping for a similar-displacement swap with higher tech.

[Anonymous]

IMO, it's too insignificant and too hard to track. A turbo car will see much better gains by cranking up the boost and that is legal.

Don't forgot the SP rules use update/backdate so all that adding technology stuff is already factored into the classes.

[WAFlowers]

We need more input. We're making good progress here, but it's primarily you and me working this... what does everyone else think? Other ideas? Other refinements? "This sucks, leave it as it is"?

I like where you and Jeremy are going with this: splitting based on SCCA worked well for the production street tire classes and with the allowances you are making for adding FI or engine swaps (the wording also seems to cover stroker kits -- a good thing). No suggestions to make because I think it could work.

[Charles]

-Installing forced induction on a car that did not come with it from the factory will result in a one class bump.
-Engine swaps bump to the class of the donor car.
-Engine swaps which offer a significant advantage will be bumped up one class.
--Significant advantage is defined as more than 300 cc displacement increase or addition of engine technology that wasn't present originally" (such as VTEC, 4-valve head, turbo, fuel injection, etc.)

edited per below...

I'd vote for this except my engine has no "donor car" under SCCA so 1 class bump for adding turbo I guess you'd say ?

I would just simply define "significant advantage" as something like a 20% peak HP increase or more. This rule would also cover something like mine. You could also swap to another engine with higher compression, cams etc without adding "technology"

This would be open for interpretation but I doubt we will get anyone arguing with us at our events.

I think I have a pretty fair encyclopedia of engine and HP outputs stored in my head.

Plenty of others do too so I don't think classing an occasional oddball will be that tough.

[Native]

My two cents is KISS.

Class is something that needs to be easily eyeballed at on-site registration and by drivers during events, and by someone not familiar with SCCA rules. Our stock classes are easy enough (what SCCA class am I in, and translate that to a FAST class), but people routinely screw it up.

While classing a modded car is inherently trickier, it's about to become a multistep process. Currently, it's "is my car modded by FAST rules?" If so, then I looked at displacement and tire type and done. Now it's becoming "is my car modded by FAST rules? Yes, ok then what modded SCCA class am I in? Ok, then look back at FAST rules for hp, vtec, swap, displacement, FI and determine if and how many SCCA class bumps I get and then translate that back to a FAST mod. class....whew...

We just got done debating on another thread that hp isn't that important in autocross, is the emphasis necessary? Again, classing needs to be something that can be quickly spot-checked at on-site registration and by drivers during an event, by people who don't necessarily know SCCA rules. There must be an easier way.

edit again: I vote any changes we do make waits until Sept. to go into effect.

[Anonymous]

There must be an easier way.

Doubt it. The only easier system is the one we currently have.

The new system isn't really all that different from the production class changes we made last year. The only difference is bumping for swaps or forced induction. You don't have to know anything about SCCA rules other than to find your car on a list.

[Loren]

Yeah, there is no truly easy way to do it.

If you try to do a "formula based" system, your formula gets complex in a hurry because you're going to have to include too many things as modifiers. Displacement, weight, "sports car", drive layout, engine performance enhancers. There's just no simple way to do it without being unfair to someone somewhere.

Looking up the SCCA SP class of a car isn't difficult. Many of us know about what fits in each class already. Enough to at least get close when a newbie shows up. If we don't have a cheat sheet at registration, we can look it up and verify later.

To Keep It Simple, SCCA SP classes broken into three groups as mentioned previously, bump up one class for added FI or significant engine swap or internal engine modifications.

We can leave the "significant" up to interpretation, but loosely define it as "something that could be reasonably expected to increase engine output by 20% or more". Since we're not going to be cracking open engines to check, it's all on the honor system, anyway.

I'll claim a lightweight crankshaft pulley as a significant engine modification and bump myself up a class.

[Dave-ROR]

Since the driver makes the biggest difference, I want all drivers that are better than myself to get bumped a class.

K thx bye.


On a serious note, I think you two have it covered, and I 100% agree with Jeremy on a bump to the donor car class in the case of a swap.

[Loren]

On a serious note, I think you two have it covered, and I 100% agree with Jeremy on a bump to the donor car class in the case of a swap.

That works sometimes... and sometimes not.

We have DSP and ESP combined. That's a pretty big spread of cars.

Let's take a nice lightweight DSP Nissan 240SX. If our donor car is an ESP Camaro, we can get a nice 350 V8 with anywhere from 300-600 hp depending on what's done to it. Donor is in the same class. No class bump???

IF we were keeping the SP classes separated, that would work a little better. But, combining DSP and ESP makes that a little funky.

Regarding "driver based classing", I've been thinking about that. I designed a driver indexing system many years ago and we ran it for a couple years when I was in KS. It was pretty cool, but not perfect. I'll try to see if I can remember what I did and find a way to improve on it. Basically, what it did was index everyone against FTD. Each driver had their own "PAX-like" score based on their average from the last 3 events. So, FTD times their index was their "target" and they were scored against that. It rewarded consistency, but fell apart if you let a novice run in it because they're always improving and staying ahead of their index. It also got a little weird if someone really fast showed up randomly and skewed the FTD trend. Anyway, I think we have enough "experienced drivers" to do something like that. Pull us out of the regular classes and let us compete against each other in some way. I'll work on it.

[impalanut]

We could do our own pax. Use last years events. Pick out all the people who made at least six or seven (pick a number) Make the pax by class. A would probably be the 1.0 time and all the other would be something less than 1. You could make individual paxes for people with enough events and just assign the average pax number by class to people without enough events.

[Dave-ROR]

On a serious note, I think you two have it covered, and I 100% agree with Jeremy on a bump to the donor car class in the case of a swap.

That works sometimes... and sometimes not.

We have DSP and ESP combined. That's a pretty big spread of cars.

Let's take a nice lightweight DSP Nissan 240SX. If our donor car is an ESP Camaro, we can get a nice 350 V8 with anywhere from 300-600 hp depending on what's done to it. Donor is in the same class. No class bump???

That would still get caught under "significant" no? Jeremy listed two penalties for engine swaps.

[Loren]

Yes, that would be caught by the "significant" rule.

I guess what I'm saying is that we want, if at all possible, ONE rule. The "significant" rule covers it. We don't really need the "bump to the donor class" verbiage.

If it's an engine swap that a reasonable person would expect to provide more than 20% increase in HP, bump up 1 class. Simple.

[Miata GT]

Way back in the day it seems to me there was a formula that was based on a point system. The cars themselves were classed in categories as stock then you would add a number of points for FI (on a normally NA car), sway bars, shocks, springs, race tires, etc. Why not do that?

[Charles]

Way back in the day it seems to me there was a formula that was based on a point system. The cars themselves were classed in categories as stock then you would add a number of points for FI (on a normally NA car), sway bars, shocks, springs, race tires, etc. Why not do that?

If you are referring to the NASA classing it sucked because R-comp cars regularly ran against street tire cars. Ignoring everything else in the equation, R-comps are worth 1.5-2 secs on our typical course.

It took a LOT of driver to make up for that gap if you ran street tires....

[Loren]

Yeah, the NASA system was pretty complex. It relied on the competitors to be open and honest about EVERY mod that they did, and the points for race tires were not enough of a hit.

[Alizarin]

After reading the responses from this afternoon and this evening, I want to state that the F in FAST stands for FUN. Regardless of where I end up (this has nothing to do with that, I assure you), these proposed classing changes to handle engine swaps, etc etc are not, in my opinion, in the spirit of that F.

You guys are talking about situations that probably will not happen with our group [referring to V8 swapped BMWs and such], and if it ever does, we should address it then. Since we're a Fun club, hopefully that situation will resolve itself at that juncture by somebody being "cool" and running with a higher class. Splitting by SP classes, that's fine. Talking about what to do about engine swaps, class bumps (and the associated ceiling you have to consider if we continue using letters) for said swaps, etc... jeeze.

All to accommodate a few swapped 240s and a swapped WRX? I think I proved at Brooksville in Dec that having all the power I do does not make me a better driver. And I will confess I have no idea how I did so at the Jan SPC event, but it wasn't the power. I did my fastest run in 1st gear, on the rev limiter for half the straights.

[Loren]

Don't get us wrong, Kenny. We're all about Fun. But, autocross, even with FAST, is a sport full of ana... er... very particular people. It just goes with the territory. The personality type that is into precision driving is usually a pretty finicky person on some level.

The time we spend now in hammering out a well-considered and simple set of rules will pay off later.

Take a look at that ridiculous "what is stock" thread. We're Fun, man... but people still want some sense of order. We can't leave too many questions unanswered.

Think about the engine swaps that we actually HAVE seen at our events. I can tell you that I've seen V8's in a lot of cars. Fiero, Miata, RX-7... just because we haven't seen a BMW with an American V8 yet doesn't mean that we won't. 80's vintage 325's are dirt cheap these days, and BMW 6's, while pretty stout and fun, aren't cheap.

I'm surprised nobody mentioned rotary swaps yet.

[Anonymous]

Just trying to make it consistent. If we are going to do it, why not do it right the first time?

Example:
STi is in BSP - Class 1
WRX is in ESP - Class 2
Impreza L is in FSP - Class 3

If we didn't penalize swaps then you could have a STi clone in every class. I think that is kinda silly, and if you bumped to donor class they would all be together in Class 1 with the STi, where they should be.

I mean an Impreza L with an STi swap is going to be the fastest car, but if you only bump one class for significant swap, it's going to run in a lower class than an STi?

[Loren]

Okay, good point. I really didn't think there was a good example of a car that would need to bump more than one class.

How's this:
Base SP classing, grouped as stated.
Bump one class for adding forced induction
Bump to donor class OR up one class (whichever is higher) for a significant (+20%) engine swap.

Will that cover it?