The Lotus Cars Community banner
1 - 20 of 66 Posts

·
Registered
Joined
·
184 Posts
Discussion Starter · #1 ·
I'm fairly new to autocrossing and hoping get a bit more serious about it this season. In reading through the "2009 Solo Rules" classifications an '05 Elise with BWR SC will be in the SSM class.

Page 180 Says Turbo or Supercharged engines are classified on a basis of adding 1.4L to actual displacement.

Page 181 has the minimum Weight Calcs:
Minimum Weight Calculations:
All listed weights are without driver.
FWD: 1350lbs + 125 lbs/liter
RWD: 1600 lbs + 200 lbs/liter
AWD: 1600 lbs + 300 lbs/liter
Cars with engine located behind driver: +25 lbs/liter

My math says:
Engine capacity 1.8
Super Charger addition 1.4
Engine Capacity Basis 3.2


RWD WT Basis 1,600
225lb / liter * 3.2 Liters 720
Minimum Weight 2,320
Actual Weight 1,984
Ballast Required 336

Am I figuring that right? I think 336 lbs exceeds the max capacity of both the
trunk and passenger compartment once you add a driver.

- Todd
 

·
Registered
Joined
·
184 Posts
Discussion Starter · #2 ·
Found more on Page 180:
Weight Adjustments
Cars running tires with a rated width of 275 mm or less on all four
wheels may compete at a minimum weight 200 lbs less than their
calculated weight.

Engine capacity 1.8
Super Charger addition 1.4
Engine Capacity Basis 3.2

RWD WT Basis 1,600
225lb / liter * 3.2 Liters 720
Minimum Weight 2,320
Adjusted Min Wt 2,120 For tires < 275mm
Actual Weight 1,984
Ballast Required 136

136lbs seems more do-able. I'm a ways off from being competitive enough for this to matter, but want to make sure I'm understanding the classification.

- Todd
 

·
Registered
Joined
·
203 Posts
Todd,

Yes, your calculations are correct. You could even save a pound by using the actual displacement of 1795cc. You'd need creative places for the ballast to use the weight distribution to your advantage when you plan on being competitive, but you could bold lead under the passenger seat in the meantime. Run a full tank of gas, use a heavy battery, keep a subwoofer in the car...

I think the car could be competitive in SSM with decent power, 255 or 275 at all corners, and the suspension/aero/bodywork allowances.
 

·
Registered
Joined
·
14 Posts
What SCCA class does the Elise SC run in?
How about an 06 Elise with aftermarket SC and no other mods?
All factory SC'd Elise/Exiges run in ASP (no weight rules in ASP). They're also legal in SSM subject to the weight rules which means that you'd have to add weight to make the min.

Non factory SC and you're in SSM.
 

·
Registered
Joined
·
1,269 Posts
All factory SC'd Elise/Exiges run in ASP (no weight rules in ASP). They're also legal in SSM subject to the weight rules which means that you'd have to add weight to make the min.

Non factory SC and you're in SSM.
Or XP if you'd rather subtract weight rather than add weight.
 

·
Registered
Joined
·
2,795 Posts
I would rather go to XP than deal with the Strielnicks FD RX-7.
 

·
Premium Member
Joined
·
667 Posts
136lbs seems more do-able. I'm a ways off from being competitive enough for this to matter, but want to make sure I'm understanding the classification.
Even this is questionable, because the rules are (IMHO) a bit overly specific on the positioning of Balast, apparently requiring:

Ballast may be added. Ballast must be a maximum of 50 lbs. per
segment. It must be securely mounted in either the spare tire well or
the trunk.

We don't have a spare tire well and our trunk is made of fiberglass and comes with a clear warning that it's not able to carry over 100 lbs of cargo IIRC... This raises the question of whether attaching the ballast to our fiberglass trunk structure is "secure".

It may not be possible to legally ballast the car.
 

·
Premium Member
Joined
·
667 Posts
Even this is questionable, because the rules are (IMHO) a bit overly specific on the positioning of Balast, apparently requiring:

Ballast may be added. Ballast must be a maximum of 50 lbs. per
segment. It must be securely mounted in either the spare tire well or
the trunk.

We don't have a spare tire well and our trunk is made of fiberglass and comes with a clear warning that it's not able to carry over 100 lbs of cargo IIRC... This raises the question of whether attaching the ballast to our fiberglass trunk structure is "secure".

It may not be possible to legally ballast the car.
Just the other day I noticed in this thread that some of the pics show a metal cross member that appears to run below the trunk (the one with circular cutouts). I think it would probably be legal to bolt through the fiberglass trunk to this, but I'm not sure what that does in terms of weakening this obviously structural part. Nor do I know how well that part would take jolting stresses from above if it were suddenly carrying 140lbs in a location not intended in the design....

But it does look like it *might* be stronger than just bolting to the fiberglass of the trunk.
 

·
Registered
Joined
·
226 Posts
This is one area where the extra few lbs in the Exige helps! I also assume the weight of the supercharger and options like the touring package count towards the total weight.
 

·
Premium Member
Joined
·
667 Posts
This is one area where the extra few lbs in the Exige helps! I also assume the weight of the supercharger and options like the touring package count towards the total weight.
Everything that is on the car at delivery counts and is legal.

Weight includes gasoline (or lack thereof). Full/empty tank is a 70lb swing so be careful of that. If you get weighed after the race and you burned off enough gas to be under weight, you are under weight, and forfeit whatever it was you may have won. I find that in a 6 run event race I tend to burn almost 2 bars of gas, but a good part of that is idling to keep the engine warm (and avoid early rev-limits) between runs I suspect.
 

·
Registered
Joined
·
226 Posts
Everything that is on the car at delivery counts and is legal.

Weight includes gasoline (or lack thereof). Full/empty tank is a 70lb swing so be careful of that. If you get weighed after the race and you burned off enough gas to be under weight, you are under weight, and forfeit whatever it was you may have won. I find that in a 6 run event race I tend to burn almost 2 bars of gas, but a good part of that is idling to keep the engine warm (and avoid early rev-limits) between runs I suspect.
What is the difference between adding ballast and adding equipment that increases weight? If you get weighed after an event, I don't see how anyone can work out what weight to use if they need to subtract aftermarket add-ons that are not legal ballast.
 

·
Premium Member
Joined
·
667 Posts
It's simple :)

Any modification not explicitly allowed by the rules is forbidden and you get DQ'd if they find it regardless of what it weighs.

In the case of SSM the cockpit must retain all road going equipment and the only modifications allowed in the in cockpit are cosmetic parts with no intrinsic performance benefit (inherited from ST rules). Stretching that you *might* justify heavy cosmetics except that I think that adding significant weight _can_ be called a performance benefit as it may change the front-rear weight bias and mess with the corner weights. So if someone specifically protests you use of a lead trimmed dash board you might have an issue, even if you honestly can say you think lead looks way better than carbon fibre or leather.

So if it's an allowed modification that is slightly heavier nobody can complain. If it's rediculously heavier (lead dash board), you can probably get in trouble. There are folks that are quite certain that one of the ST rules about seats & their brackets must be at least 25lbs, justifies seat brackets of any weight over 25lbs. (The owner of this forum holds that belief last I heard, whereas I find it to be unclear ).

The foregoing of course is just *my* interpretation of the 2010 rules and may change in 2011, or may not be perfectly correct. YMMV. See your friendly rulebook for the exact answers :).
 

·
Registered
Joined
·
226 Posts
OK, so it is just the total weight of the car that matters with no distinction on what came from the factory as long as everything is legal for the class.

The nominal weight of the Exige is 2015 plus, I think, 12 lbs for the touring pack. How close is the real weight of these cars with all fluids to the nominal weight from Lotus? Add 42lbs for 7 gallons of gas and it is within 51lbs of the target. The weight of the supercharger brings it a bit closer. What is the best way of closing this gap to run SSM? e.g. I have a fire extinguisher that adds a little.
 

·
Vendor
Joined
·
3,466 Posts
I am going to do an SSM car with our other Elise so I have struggled with this as well. YOu can add for "comfort" and "convenience" i.e. my JL audio Sub and Amp. Full tank and hard top(not ideal too high but its an 80% car). Then you can add ballast to the trunk. The trunk can handle the weigh if it is secured properly. You can also replace with heavier items. I don't know about you but my car needs a depleted Uranium passenger seat bracket!

My plan is 275s my Sub, amp, probably some sound deadening material ala Dave T. Stewart. Full gas, BOE/BWR Revolution S/C system
 

·
Registered
Joined
·
181 Posts
Depleted uranium may not be so good for the nuts and bolts!
 

·
Registered
Joined
·
1,269 Posts
I am going to do an SSM car with our other Elise so I have struggled with this as well. YOu can add for "comfort" and "convenience" i.e. my JL audio Sub and Amp. Full tank and hard top(not ideal too high but its an 80% car). Then you can add ballast to the trunk. The trunk can handle the weigh if it is secured properly. You can also replace with heavier items. I don't know about you but my car needs a depleted Uranium passenger seat bracket!

My plan is 275s my Sub, amp, probably some sound deadening material ala Dave T. Stewart. Full gas, BOE/BWR Revolution S/C system
Damn it, Fred! Isn't 3 National Championships enough for you!?!? Leave a few classes for the rest of us!;)

I assume you will you will be running the TVS, not the M62.

Could you add a sand bag for ballast?
 

·
Registered
Joined
·
1,269 Posts
Modified Classes Rule 18.A.6 Page 133
"Ballast may be added to obtain minimum weight requirements.
However, it must be attached and secured in a safe manner."

Seems plates or even properly secured sandbags would do the trick. I understand that a stereo system serves an obvious benefit besides adding weight, but it is limited in where you add the weight and is more expensive and harder to remove if you ever want to lighten the car in the future. But I understand, Fred, that as you said you are shooting for an 80% car.

I'm just thinking out loud since I'm trying to decide between TVS in SSM or M62 in ASP.
 

·
Premium Member
Joined
·
667 Posts
Modified Classes Rule 18.A.6 Page 133
"Ballast may be added to obtain minimum weight requirements.
However, it must be attached and secured in a safe manner."

Seems plates or even properly secured sandbags would do the trick. I understand that a stereo system serves an obvious benefit besides adding weight, but it is limited in where you add the weight and is more expensive and harder to remove if you ever want to lighten the car in the future. But I understand, Fred, that as you said you are shooting for an 80% car.

I'm just thinking out loud since I'm trying to decide between TVS in SSM or M62 in ASP.
Street modifed (section 16) does not inherit rules from Modified classes (section 18).

Street modified has it's own specific rule for ballast.

16.1.Q. Ballast may be added. Ballast must be a maximum of 50 lbs. per
segment. It must be securely mounted in either the spare tire well or
the trunk​
 
1 - 20 of 66 Posts
Top