SLS 2018 - End of year thoughts/discussion

[David Long]

Being perfectly honest, I'm running in pro because the car went through a major engine and aero development. Pro just gave the freedom to do that (and use up my stock of Kumhos). At the start of the year I had no intention of winning it, but in terms of p/w I have been in Pro earlier this year, but an engine and gearbox issue meant a little more caution over the last few rounds.

I also think a knowledge of how to make a reliable car is every bit as much of a championship winner as someone who can make big BHP.

If Andy is saying that the current Pro Class P/W is not achievable over 6 rounds, then I rest my case.
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[AK]

so lower capture for PRO to ~400, raise B from whatever is is to 400 and Chop A out?
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Impreza Race Car - SLS/SMRC
Mini Race Car - SMRC
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
Toureg 262 RLine
Track Scotland

[Steviej]

Why keep beating on class A and pro ? The reasons for staying under the p/w for pro is so you don’t have the extra cost of ards, race licence, race fuel, in date belts, 1c Tyres etc its not just a simple case of moving up a class to go into pro as it is moving up through the lower classes, changing the class p/w limits is very unfair on people competing in those classes, it doesn’t seem to happen anywhere else in sprints, hillclimbs etc

[AK]

Stevie - Nothing has changed.... this is just a discussion

We need to throw ideas about, take on board feedback etc, give feedback to KMSC/Organisors then see where we are. If anything... SLS has been very stable over the last few years. The first 2 or 3 years needed changes to account for the extra numbers (i.e you couldn't have 7 classes and 12 cars)

The P/W limits dont change in sprints and hills because they dont have those classes

From the meeting at last round I cannot see any changes to Classes - maybe the tweak required to numbers to convert to engine/flywheel HP fihures but that'll only really effect 4x4 cars near the top of the classes I think.
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Impreza Race Car - SLS/SMRC
Mini Race Car - SMRC
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
Toureg 262 RLine
Track Scotland

[Steviej]

Adam, I realise that but “lowering Pro to 400, raising B and chopping out A “ is not stability across the classes, people have developed cars to compete in their chosen class, SLS has been very stable in the class structures which is a good thing so let’s keep it that way, as they do in other forms of motorsport.

I think you only need to look at how close the times are at the top end of all the classes to see that it’s very well structured the way it is 😀

[AK]

yup, again that line was a question to David to verify that was his suggestion?

I.e the discussion at end of year meeting had a few mins focused on the sustainability of PRO class, and PRO class cars. There needs to be more, more regularly. Its a bit of a weak class compared to the rest. One chain of thought was to do away with PRO and remove cap on A. (Again.... this is discussion.... NOT a regs change)

I personally would leave as is, but I am not the majority

We purposefully dont run PRO power levels as we dont want the ballache of keeping the thing going! For about £1500 we'd be in PRO.... but gearbox, clutch, engine, brakes, tyres etc wouldnt like it.
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Impreza Race Car - SLS/SMRC
Mini Race Car - SMRC
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
Toureg 262 RLine
Track Scotland

[AK]

Re: Change to flywheel HP over WHP.

What are folks opinions on the following recommendation to KMSC/SLS?


Existing structure (with G added)

Pro: Unlimited
A: 350-450
B: 270-350
C: 210-270
D: 160-210
E: 135-160
F: 110-135
G: < 110


Suggestion based on a generic 15% drivetrain loss. Reverse % used... (final no (flywheelHP)*100 / 100-% (15). So using 350whp as example...

to get flywheel from 350whp with blanket 15% losses. (350*100)/(100-15) = 35000/85 = 412

Pro: Unlimited
A: 412-529
B: 318-412
C: 247-318
D: 188-247
E: 159-188
F: 129-159
G: < 129

Some worked examples using stuff I know.

Mini = 127bhp, 107whp (16% losses) @ 1075 = 100whp/ton OR 118 engine hp/ton - Still in G
Impreza = 490bhp, 420whp (14% losses) @ 1230kg = 341whp/ton OR 398 engine hp/ton - Still in B


The figures dont exactly lend themselves to being memorable...so maybe some rounding is needed
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Impreza Race Car - SLS/SMRC
Mini Race Car - SMRC
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
Toureg 262 RLine
Track Scotland

[Steviej]

Totally agree, one of the main reasons I bought my car was that it wasn’t a ‘pro’ class car and didn’t demand the running costs of one ... questionable!
Likewise Eric came down to class A from pro for similar reasons, it has been a great class with 3 cars consistently within a second, one fast improving newcomer and more hopefully joining in next year, so A is a keeper 😃
It would also be a shame to lose pro as there are cars out there and everyone loves to see them, maybe this just wasn’t their year to appear in enough numbers ?
The whp/flywheel suggestion seems complicated

[AK]

The conversion may be complicated.... but once agree'd upon (class structure that doesnt change too much) it'll work exactly the same. Just using the bigger of the 2 numbers from the dyno print out
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Impreza Race Car - SLS/SMRC
Mini Race Car - SMRC
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
Toureg 262 RLine
Track Scotland

[AK]

a second example of the revised FLYWHEEL HP bands suggested above

Driver X 672 engine / 570 wheels / 1295kg (15% losses)
Driver Y 714 engine / 573 wheels / 1300kg (20% losses)

Driver X = 672bhp/1.295ton = 519hp/ton (engine) - Class A
Driver Y = 714bhp/1.3ton = 549hp/ton (engine) - Pro, with 50kg needed to get to Class A.
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Impreza Race Car - SLS/SMRC
Mini Race Car - SMRC
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
Toureg 262 RLine
Track Scotland

[s2t]

When we did the power runs this year at RA on the printout there is both whp and bhp. If we move to bhp am I to assume the current bhp figure will be the same or is there a different process for pure bhp measurement

[AK]

nope, same test... just the SLS power to weight band would have to be adjusted to keep the majority of folk in the same classes... as the calculated power to weight ratio will of course be higher (engine hp > wheel hp)

Can only see a change for a few cars that were right at the peak of their class.
_________________
Impreza Race Car - SLS/SMRC
Mini Race Car - SMRC
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
Toureg 262 RLine
Track Scotland

[AK]

Spoke with Rory, and SLS/KMSC are hoping to firm up the structure for 2019 soon
_________________
Impreza Race Car - SLS/SMRC
Mini Race Car - SMRC
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
Toureg 262 RLine
Track Scotland

[Steve H]

[AK]

so a little rounding up perhaps...

Pro: Unlimited
A: 412-529
B: 318-412
C: 247-318
D: 188-247
E: 159-188
F: 129-159
G: < 129

would become

Pro: Unlimited
A: 415-530 = 115bhp band
B: 320-415 = 95bhp band
C: 250-320 = 70bhp band
D: 190-250 = 60bhp band
E: 160-190 = 30bhp band
F: 130-160 = 30bhp band
G: < 130
_________________
Impreza Race Car - SLS/SMRC
Mini Race Car - SMRC
911 - 1981 Air Cooled 3.0
500 - 1969 Fiat 500 L
Toureg 262 RLine
Track Scotland