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Discussion Starter #1
As you may know, MSM MT IS300 contacted us about the possiblity of setting up an IS300 Challenge Series for you guys, and as an IS300 owner myself, I'm excited to do it. The first step is we need to figure out how to class IS300's according to the common modifications you guys are doing to your cars, in order to create a structure so differently-modded IS can compete fairly with one another.

First of all, we need to decide how the classing should be done. There are two basic ways: 1) The way the Corvette guys decided to do theirs is a very simple, "net effect" classing, where cars are basically grouped by HP and certain suspension/non-hp, mods are allowed in certain classes. This is the easy way to do it, though the less accurate I'd say. See thier example below. 2) The second way is the S2000/WRX method. This is a points-based system, where we assign points to each mod (exp: springs = 20pts, race tires = 60pts), and you have a certain number of points you can spend per class. This is more accurate, but more complicated, obviously. I'll post the S2000 classing below, to give you an idea.

So, in this first step, just let me know which method you prefer, and we'll go from there. Thanks to all who participate!

Corvette Classing Method:

A note on weight reduction: Any weight reduction will be normalized based upon the weight of a stock coupe. For instance, a modified coupe at standard weight may weigh 3200lbs w/375hp, giving it a ratio of 8.53lbs per hp. This is the limit for the stock classes. If you have a Vette with 345hp which weighs 2700lbs, your ratio is 7.8lbs / hp. This places you squarely in Mod 1 at the least, despite the fact you have only 345hp. Incidentally, the weight difference between a stock convertible and a stock coupe is not great enough to warrant a hp exemption for the vert.
This classification system is subject to change at any time.

STOCK 1
The idea of the Stock 1 class is to provide a class where stock C5's can be competitive. Though the class is fairly liberal about modifications, if you were to show up with a full-race suspension, etc, we would reserve the right to bump you into another class.

Tires: Street tires of any width/size, but limited to a treadwear rating of 100+.
HP: 375 at the flywheel or less Alignment: any setting
Lowering springs
Any brake pad
Any modification to stock rotor
Any brake fluid
Brake ducting allowed
Brake dust shields can be removed
Brakelines
Any air filter
No appreciable weight reduction allowed
etc...

STOCK 2
Stock 2 is the same as Stock 1, with the addition of race tires

Tires: Any tire, slicks included.
HP: 375 at the flywheel or less Alignment: any setting
Lowering springs
Any brake pad
Any modification to stock rotor
Any brake fluid
Brake ducting allowed
Brake dust shields can be removed
Brakelines
Any air filter
No appreciable weight reduction allowed
etc...

Mod 1
Mod 1 is designed for those with mildly-modified cars.

Tires: Any tire, slicks included.
HP: 450 at the flywheel or less Alignment: any setting
Any suspension mods
Any brake pad
Any modification to stock rotor
Any brake fluid
Brake ducting allowed
Brake dust shields can be removed
Brakelines
Any air filter
etc...

Mod 2
Mod 2 could effectively be called an "Open" class. Almost anything is allowed.

Tires: Any tire, slicks included.
HP: 450 at the flywheel or more Alignment: any setting
Any suspension mods
Any brake pad
Any modification to stock rotor
Any brake fluid
Brake ducting allowed
Brake dust shields can be removed
Brakelines
Any air filter
Weight reduction
No tube-frames, etc. These classes are for production-based cars.




S2000 Classing Method:

S2000 Challenge Series Classification

No changes are allowed to a car unless they are listed below. If a component or other modification is listed below, any type (or size) of that component is allowed, unless otherwise noted (ie. "sway bar" means adjustable or non-adjustable allowed).


STOCK
Tires: up to 275 width rear tire, 120+ treadwear
Stock wheels only
Alignment – any setting
Any brake pad
Any modification to stock rotors (cross-drilling, cryotreating, etc.)
Any brake fluid
Brake ducting allowed
Brakelines
Any air filter
Any cat-back exhaust
X-brace
Modified stock throttle body
Strut-tower brace
Rear brace
Thermostat
Radiator cap
Heat Shield
Rollbars, seats, or any other safety equipment allowed
Removal of any part not listed above is allowed, as long as it is not replaced with an aftermarket or modified stock version.


MODIFIED (same as Stock + up to 100 points from Points Listing provided below)

PRODUCTION (up to 200 points allowed)

UNLIMITED (Anything goes, including any tire, no points limitations)


NOTE: please bear in mind that the points below do not strictly reflect the performance value of each modification on the track, they also reflect the cost of the modification.

Modifications & Points
Turbocharger 100
Supercharger 100
Internal Mods to stock motor 100
Non-spec Competition Tires* 100
Transmission Mods/replacement 75
Shocks & Springs 75
Spec Competition Tires* 50
Shocks (w/stock springs only) 25
ECU/Ignition Control 25
Remove Catalytic Converter 25
Piggy Backing 25
Final Drive gear change 25
Differential 25
Any wheels 20
Hardtop 20
Springs (w/stock shocks only) 15
Any Intake 15
Calipers & Rotors 15
V-TEC Controller 15
Front swaybar 15
Aerodynamic additions 10 (all other than hardtop)
Hood (carbon fiber, etc.) 10
Rear swaybar 10
Flywheel 10
Header 10
Clutch 5


* Spec Competition tires are any of the four make/models listed here, no others. Allowed make/models are: Kumho Victoracer/V700; Toyo RA-1; Yokohama A032r, Micheline Pilot Cup Sport (???). Max width rear for all tires = 275.



Now I know I just gave you a whole lot of text to read through, and I apologize, but it's important that we make the right choice from the beginning :)

What do you think?
 

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The S2k/WRX classing system makes more sense to me...it's very similar to the way SCCA classifies cars for their SoloII Autocrosses (Stock, ST, and SP).
 

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The S2K/WRX method will work.

I'm assuming the Falken Azenis Sport is considered a non-competion tire (no point added at all) for its treadwear rating of 200? :p
 

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Discussion Starter #6
Off-TRAC said:
The S2K/WRX method will work.

I'm assuming the Falken Azenis Sport is considered a non-competion tire (no point added at all) for its treadwear rating of 200? :p
Ok, I think it's unanimous that the points-based system is the way to go. I'll post again with a first draft based upon the S2000 classing, and we'll adjust it to fit the IS.

And yes, as I think is noted in the above classing, tires over a certain wear rating are non-competition tires :)
 

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Discussion Starter #7
IS300 Challenge Series Classification Draft #1:

No changes are allowed to a car unless they are listed below. If a component or other modification is listed below, any type (or size) of that component is allowed, unless otherwise noted (ie. "sway bar" means adjustable or non-adjustable allowed).


STOCK
Tires: up to 255 width rear tire, 120+ treadwear
Stock wheels only
Alignment – any setting
Any brake pad
Any modification to stock rotors (cross-drilling, cryotreating, etc.)
Any brake fluid
Brake ducting allowed
Brakelines
Any air filter
Any cat-back exhaust
X-brace
Modified stock throttle body
Strut-tower brace
Rear brace
Thermostat
Radiator cap
Heat Shield
Rollbars, seats, or any other safety equipment allowed
Removal of any part not listed above is allowed, as long as it is not replaced with an aftermarket or modified stock version.


MODIFIED (same as Stock + up to 100 points from Points Listing provided below)

PRODUCTION (up to 200 points allowed)

UNLIMITED (Anything goes, including any tire, no points limitations)


NOTE: please bear in mind that the points below do not strictly reflect the performance value of each modification on the track, they also reflect the cost of the modification.

Modifications & Points
Turbocharger 100
Supercharger 100
Internal Mods to stock motor 100
Non-spec Competition Tires* 100
Transmission Mods/replacement 75
Shocks & Springs 75
Spec Competition Tires* 50
Shocks (w/stock springs only) 25
Springs (w/stock shocks only) 15
ECU/Ignition Control 25
Remove Catalytic Converter 25
Piggy Backing 25
Final Drive gear change 25
Differential 25
Any wheels 20
Any Intake 15
Calipers & Rotors 15
Front swaybar 15
Aerodynamic additions 10
Hood (carbon fiber, etc.) 10
Rear swaybar 10
Flywheel 10
Header 10
Clutch 5


* Spec Competition tires are any of the four make/models listed here, no others. Allowed make/models are: Kumho Victoracer/V700; Toyo RA-1; Yokohama A032r, Micheline Pilot Cup Sport (???). Max width rear for all tires = 275.

All right, that's about it. Let me know what mods I don't have listed, or what mods don't apply for whatever reason to the IS300. Remember, I have a totally stock IS (it's mostly my wife's car), so I have no idea what mods are common. Thanks!
 

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:D This is what I like to see leadership & determination = SUCESS.

Count me in, good choices. Can we patition some other tire brands ? by any wild chance just for the IS Class ?
 

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fluxen said:
All right, that's about it. Let me know what mods I don't have listed, or what mods don't apply for whatever reason to the IS300. Remember, I have a totally stock IS (it's mostly my wife's car), so I have no idea what mods are common. Thanks!
Some issues to consider:

* ECUs - so far, there are no tuned ECUs or chips for the IS300. There are fully programmable ECUs that can be adapted for the IS300, but that is usually in combination with a F/I kit. You may want to consider removing the ECU from the point penalty guide and add a F/I kit penalty.

* F/I kits - due to the nature of the current F/I kits available, there should be two penalty classes: <270rwhp, which is the realm of the CARB-legal SC kits and entry-level turbo kits, and >270rwhp, which is the realm of the outlaw class. It would help promote vehicle longevity if it was specified that the >270rwhp class have no limits to engine or tranny internal mods, except for the fact that stock block and crank should be used. Policing the outlaw class will be difficult, but fortunately there should be few if any participants.

* Intakes - one of the most popular intake kits is the SRT intake, which is a combination intake + MAF signal modifier. This also applies to the Area 51 intake + BlackBox. The Apex'I S-AFC is just a MAF signal modifier. You may want to consider adding a MAF signal modifier point penalty.

* Wheels & tires - in SCCA autocrossing (if your entrants are motorsports junkies, they might also be autocrossers) the three classes that the IS is often found competing in are DS, STS, and STX. The effective (not literal, details available) tire limit and what you will find most IS competitors there running for all three classes is 225 width, mounted on either stock or 7.5" rims. My suggestion is to replace the stock rim stipulation add a =<225 tire width stipulation, wear =>120. A small penalty should be added for >225 tire width, and continue with the penalty for R-compound tires. You may want to tweak penalty values for both to ensure greatest fairness.

* Chassis braces - even though it is stipulated that the X-brace is stock-legal, there are other braces for this car that do not fall under the current wording. These braces don't do much if anything for the car when other aspects of the suspension are stock. However, they help ensure that the car stays tight and doesn't wear by an accelerated rate via excessive flex when upgraded suspension and tires are installed. Many people already have them. I think we should promote them for the greater good if people are already putting suspension components/tires on the car. I think the wording should be broadened to include all such braces that do not intrude into the passenger compartment. Any performance enhancement they provide in conjunction with upgraded suspension should be weighted/penalized through the suspension/tire upgrade.

* Removal of parts - do we really want to promote stripped Lexuses? Or consider it this way: do we really want to dissuade everyone else with a full-interior Lexus from participating if the series is dominated by the lone stripped Lexus? Maybe we should re-word that to "any item not permanently fastened", which would be interpreted to mean the spare tire, jacks, headrests, floor mats, etc. Within that should include a stipulation that these refer to things withing the passenger compartment and trunk, because many people have had to remove the cosmetic engine cover to fit a front strut tower bar.
 

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Off-TRAC said:
fluxen said:
All right, that's about it. Let me know what mods I don't have listed, or what mods don't apply for whatever reason to the IS300. Remember, I have a totally stock IS (it's mostly my wife's car), so I have no idea what mods are common. Thanks!
Some issues to consider:

* ECUs - so far, there are no tuned ECUs or chips for the IS300. There are fully programmable ECUs that can be adapted for the IS300, but that is usually in combination with a F/I kit. You may want to consider removing the ECU from the point penalty guide and add a F/I kit penalty.

* F/I kits - due to the nature of the current F/I kits available, there should be two penalty classes: <270rwhp, which is the realm of the CARB-legal SC kits and entry-level turbo kits, and >270rwhp, which is the realm of the outlaw class. It would help promote vehicle longevity if it was specified that the >270rwhp class have no limits to engine or tranny internal mods, except for the fact that stock block and crank should be used. Policing the outlaw class will be difficult, but fortunately there should be few if any participants.

* Intakes - one of the most popular intake kits is the SRT intake, which is a combination intake + MAF signal modifier. This also applies to the Area 51 intake + BlackBox. The Apex'I S-AFC is just a MAF signal modifier. You may want to consider adding a MAF signal modifier point penalty.

* Wheels & tires - in SCCA autocrossing (if your entrants are motorsports junkies, they might also be autocrossers) the three classes that the IS is often found competing in are DS, STS, and STX. The effective (not literal, details available) tire limit and what you will find most IS competitors there running for all three classes is 225 width, mounted on either stock or 7.5" rims. My suggestion is to replace the stock rim stipulation add a =<225 tire width stipulation, wear =>120. A small penalty should be added for >225 tire width, and continue with the penalty for R-compound tires. You may want to tweak penalty values for both to ensure greatest fairness.

* Chassis braces - even though it is stipulated that the X-brace is stock-legal, there are other braces for this car that do not fall under the current wording. These braces don't do much if anything for the car when other aspects of the suspension are stock. However, they help ensure that the car stays tight and doesn't wear by an accelerated rate via excessive flex when upgraded suspension and tires are installed. Many people already have them. I think we should promote them for the greater good if people are already putting suspension components/tires on the car. I think the wording should be broadened to include all such braces that do not intrude into the passenger compartment. Any performance enhancement they provide in conjunction with upgraded suspension should be weighted/penalized through the suspension/tire upgrade.

* Removal of parts - do we really want to promote stripped Lexuses? Or consider it this way: do we really want to dissuade everyone else with a full-interior Lexus from participating if the series is dominated by the lone stripped Lexus? Maybe we should re-word that to "any item not permanently fastened", which would be interpreted to mean the spare tire, jacks, headrests, floor mats, etc. Within that should include a stipulation that these refer to things withing the passenger compartment and trunk, because many people have had to remove the cosmetic engine cover to fit a front strut tower bar.
all very true!
 

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Discussion Starter #13
IS300 Challenge Series Classification Draft #2:

No changes are allowed to a car unless they are listed below. If a component or other modification is listed below, any type (or size) of that component is allowed, unless otherwise noted (ie. "sway bar" means adjustable or non-adjustable allowed).


STOCK
Tires: up to 225 width tires, 120+ treadwear
Stock wheels only
Alignment – any setting
Any brake pad
Any modification to stock rotors (cross-drilling, cryotreating, etc.)
Any brake fluid
Brake ducting allowed
Brakelines
Any air filter
Any cat-back exhaust
X-Brace, A-Brace, V-Brace
Tower Braces
Modified stock throttle body
Thermostat
Radiator cap
Heat Shield
Rollbars, seats, or any other safety equipment allowed
Weight reduction is not allowed in the Stock class

MODIFIED (same as Stock + up to 100 points from Points Listing provided below)

PRODUCTION (up to 200 points allowed)

UNLIMITED (Anything goes, including any tire, no points limitations)


NOTE: please bear in mind that the points below do not strictly reflect the performance value of each modification on the track, they also reflect the cost of the modification.

Modifications & Points
CARB-Legal Forced Induction 100
Non CARB-Legal Forced Induction 150
Internal Mods to stock motor 100
Non-spec Competition Tires* 100
Transmission Mods/replacement 75
Shocks & Springs 75
Spec Competition Tires* 50
Shocks (w/stock springs only) 25
Springs (w/stock shocks only) 15
ECU/Ignition Control 25
Remove Catalytic Converter 25
AFC/MAF Mods 25
Final Drive gear change 25
Differential 25
Any wheels 20
Any Intake 15
Calipers & Rotors 15
Front swaybar 15
Aerodynamic additions 10
Hood (carbon fiber, etc.) 10
Rear swaybar 10
Flywheel 10
Header 10
Clutch 5


* Spec Competition tires are any of the four make/models listed here, no others. Allowed make/models are: Kumho Victoracer/V700; Toyo RA-1; Yokohama A032r, Micheline Pilot Cup Sport (???). Max width rear for all tires = 275.

**Updated with some of the proposed changes OffTrac brought up.
 

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Discussion Starter #14
* Chassis braces - What other Chassis braces are there, other than strut tower bars and X braces?
 

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fluxen said:
* Chassis braces - What other Chassis braces are there, other than strut tower bars and X braces?
Well, by "X brace" I'm reading it to mean the classic X-shaped underbrace that some high-performance vehicles (M3 comes to mind) employ to laterally locate the rear subframe. Tom's and TRD used to offer that classic design, but these days every manufacturer except Tom's have moved to a variant design that offers both better ground and resonator clearance. It meets the spirit of the rule but might be excluded by the wording.

For the IS300, the other major brace is an "A" or "V" (depending on the design) underbrace that triangulates between the firewall and the front subframe.



Quite a few people have these braces, as we just had a group buy on these not too long ago.

There are also subframe closers (Tom's), eyelet reinforcements (Tom's), tranny tunnel closers (Tanabe) and some other stuff that defies description. The only common theme to them is that they reinforce the vehicle but does not affect the utility and daily liveability of the vehicle at all, in contrast to a full cage or even just a roll bar.

The point is that they offer more of a long-term durability advantage than a real performance advantage. Most people have these for that very reason. And whatever performance advantage they offer really only comes in conjunction with serious suspension tuning. So the suggestion is to allow them and only penalize the serious suspension tuning, in effect *mildy* promoting them. But those that don't have it won't suffer any real competitive disadvantage relative to, say, stock vs. coilovers.
 

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Discussion Starter #17
Ok, I did modify the draft above to read "X brace, V brace, A brace" as legal in stock. Perhaps it should be worded as "under-body braces" but I don't want to open it up to where wild bracing becomes legal in stock.

We're kind of stalled on this discussion I see (present posters excluded)...either 1) we've got classing everyone likes or 2) No one cares or 3) there are a lot of mute spectators just seeing what happens.

No one else has anything to suggest on classing??
 

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wow, looks like most of us would run into the modified class.

maybe we should create a larger gap between the n/a mods versus the turbo charged mods. i know that roadcourse/autox is about handling, however the turboed cars still pose an advantage.

to keep it competitive, maybe the f/i penalty should be higher? or the cutoff points raised a little?
 

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I don't think that most people are posting because this is going to be such an expensive way to race. There is no way I could afford to race in this group, along with Autox. Also If I spec my car out for autox, I can't fit into any of the proposed classes here and still be competitive.

You should REALLY change the stock rim requirement. I have two sets of rims, and both are the stock rims but that is just because I was too cheap to buy a nice set of racing rims (which I will do at some point unless I find another car to race). The problem with stock rims is that a lot of people have gone with aftermarket rims. I think just adding the 225 limit or a =<225 penalty and a >225 penalty would be better. If someone wants to race on 18" rims, let them. They are just going to weigh more and any advantage that comes with such a massive rim will not do much good because of the added unsprung-weight.

Another reason not many people are posting.... not that many people really want to race their cars. On this board there are 15-20 people who are dedicated to racing or at least claim to be. On the west coast there are only 7, maybe 10? That is 7 people who show up at nearly every possible event. Then if you break that down into do-able travel areas... you end up with 3 or 4 people in northern cal, then 3-5 down here.

No matter what you decide to do with the classifications the rules will change after one season. You'll find out that people with some mods will dominate their class, while cars with other mods are still at a stock level. With such a low level of competitors I think the best option is to go with time penalitys. Meaning that if someone has F/I they automaticly get 5.0 seconds added to their lap times. Then if someone is using race tires, they get 3.0 seconds added. Something like that so that everyone can kinda be in the same class. Otherwise you'll end up with one or two cars in each class per event.
 

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I just wanted to say that I'm watching these discusions but I think that most all of my concerns/questions are being covered. Off-TRAC and christobal have basically covered everything that I had questions about.


Most all of us who either track or autocross tend to think along the same lines so someone invariably brings up what others are thinking.



fluxen said:
Ok, I did modify the draft above to read "X brace, V brace, A brace" as legal in stock. Perhaps it should be worded as "under-body braces" but I don't want to open it up to where wild bracing becomes legal in stock.

We're kind of stalled on this discussion I see (present posters excluded)...either 1) we've got classing everyone likes or 2) No one cares or 3) there are a lot of mute spectators just seeing what happens.

No one else has anything to suggest on classing??
 
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