Classification Assistance

[evolutionmotorsports]

Car is 08 Mitsu Evo X GSR Base Class TTB

 

1st Question:

 

If the Stock Inverted Strut has > 40mm shaft do I have to take 5 pts for modified shock and spring or 9 pts for > 40mm strut and spring when using Ohlins DFV with >40mm shaft?

 

2nd Question:

 

Can I run an Upgraded Turbo stay over 8.7:1 PTW ratio and reclass to TTA?

[obzezzed350]

Car is 08 Mitsu Evo X GSR Base Class TTB

 

1st Question:

 

If the Stock Inverted Strut has > 40mm shaft do I have to take 5 pts for modified shock and spring or 9 pts for > 40mm strut and spring when using Ohlins DFV with >40mm shaft?

 

2nd Question:

 

Can I run an Upgraded Turbo stay over 8.7:1 PTW ratio and reclass to TTA?

 

Dont quite understand your first question.

 

As far as your second question, you are going to have to send Greg, the National TT director, an email and see what numbers are possible. I can tell you though that your max whp will be nowhere near the limit. Someone here tried to do the same thing for PTA with an Evo 9. I think he was allowed 303awhp with a weight of 3200, with a baseclass of TTA. If TTA is your goal, stock turbo is probably best.

[jimbow]

Your shock question is very confusing.

Look at the rules, find your car, do the shocks on your car match the BASE model in the classification?

Yes - have you had the shocks revalved or modified?

No - then its a stock shock and no points - BE VERY careful here!

 

Otherwise lets look at your question another way:

New shocks with over 40mm dia rod - Points for over 40mm

Invert them - Points for inverting

 

Its also a REAL good idea to have your regional director and someone familiar with your brand of car go ver the classification sheets with you.

[kbrew8991]

if its what came on the car without having to check any option boxes or whatnot (ie the "base" vehicle) then whatever is there is points-free. When/if you upgrade it though...

[Greg G.]

The answer to the first question is that it doesn't matter what type of shocks come on the base trim model, if you change them out, you take points for what you are putting on the car as listed in the rules.

 

So, if your car comes stock with piggyback reservoir shocks, and you put on aftermarket piggyback reservoir shocks, you still take the +7 points for them.

 

The answer to the second question (Can I run an Upgraded Turbo stay over 8.7:1 PTW ratio and reclass to TTA?) is no. You can run in TTS with an upgraded turbo and stay over the 8.7:1 Wt/Hp ratio. Your Adjusted Wt/Hp ratio in an Evo X, which would require a Dyno re-class in TTA, will not be close to 8.7:1. If you were allowed to just do what you suggest, then we wouldn't need any base classes, and only the newest and most expensive cars with the latest technology would ever be competitive. It works in TTS and TTU because those cars are semi-unlimited with the ability for a 1980's RX-7 to have enough modifications to compete against an '06 996 Porsche.

[f1honda]

the oem front strut on Evo's are over 40mm. so if i replace the strut with after market strut that are over 40mm, then that's 7 points, is that correct?

 

if i revalve the OEM strut, is that 4 points or 7 points since the oem strut is over 40mm also?

[Greg G.]

the oem front strut on Evo's are over 40mm. so if i replace the strut with after market strut that are over 40mm, then that's 7 points, is that correct?

 

if i revalve the OEM strut, is that 4 points or 7 points since the oem strut is over 40mm also?

Yes, +7 points.

 

Yes, if you revalve a strut over 40mm, then it is no longer an OEM over 40mm strut. It is now a:

2) Non-OEM shocks/struts/dampers with a “Piggy Back” external reservoir (fixed reservoir

without a connecting hose) OR with shaft diameter 40mm or greater—must still take

additional points for the springs below +7

[wlfpkrcn1]

Greg,

Can you Clarify?

 

Yes, if you revalve a strut over 40mm, then it is no longer an OEM over 40mm strut. It is now a:

2) Non-OEM shocks/struts/dampers with a “Piggy Back” external reservoir (fixed reservoir

without a connecting hose) OR with shaft diameter 40mm or greater—must still take

additional points for the springs below +7

 

Rule E.3

Non OEM OR modified/re-valved shocks/struts/dampers +3 (all others) (springs not included)

 

If the OP re-valves his OEM strut that should be +3

 

Rule E.3 does not stipulate that re-valving OEM struts for +3 has a shaft diameter maximum. If the OP is using his OEM strut and having it re-valved, it does not fall into E.2 except for shaft diameter.

 

HOWEVER

 

E.2 is specifically for Non-OEM strut/shocks/damper. They can be piggy back resivor struts/shocks OR with a 40mm+ shaft.

 

If you believe that re-valving a OEM 40mm+ strut is +7, then rule E.2 should be written differently i.e

Non-OEM shocks/struts/dampers with a “Piggy Back” external reservoir (fixed reservoir

without a connecting hose) OR with shaft diameter 40mm or greater. This includes re-valved 40mm+ OEM strut—must still take

additional points for the springs below +7

[hired wrench]

what about a Mugen hardtop?

[Greg G.]

Eric,

 

I think we have a bit of a sticking point. I agree with what you have said, except, that once an OEM part has been modified (re-valving), under our rules, it is no longer an OEM part.

 

5.5 OEM Definition, Updating and Backdating Rules

For the purposes of NASA PT points assessments, the term OEM will be defined as follows:

Any part that is identical in size, shape, and functional characteristics compared to the part that

originally came on the vehicle, from the manufacturer, as a standard feature of the base model as

it is listed in section 5.2 Base Classifications (factory options and specialty model parts are

considered non-OEM) or is listed as a standard replacement part by the OEM manufacturer.

 

So, once the OEM shock has been modified, it is no longer an "OEM" shock, making it a "Non-OEM" shock, and once again subject to the higher assessment here instead of the +3 assessment for "(all others)":

2) Non-OEM shocks/struts/dampers with a “Piggy Back” external reservoir (fixed reservoir

without a connecting hose) OR with shaft diameter 40mm or greater—must still take

additional points for the springs below +7

 

I believe that the discussions in the past had to do with taking an OEM shock housing, and then introducing internals from a high end shock, creating the high end shock replica with just a different housing, and thereby attempting to avoid the correct assessment.

 

I guess what is important is whether two competing cars running identical shocks (that are not as they came on the vehicle "OEM") should take the same points assessment for a modified or "Non-OEM" shock. My opinion would be that they should, even if the shocks used were greater than 40mm shocks taken from some production vehicle and loaded with high end internals that require a +7 point assessment. While the base classing of cars does in part take into account advanced suspension systems, it generally does not come down to the level of adding an asterisk or such because of just the shock type. Do you agree?

 

I suppose we could just add the wording in E.2 and E.1 to "Non OEM OR modified/re-valved shocks...." for clarity. It sounds like we need to take a look at this at the National level to make sure we are all on the same page.

 

Thanks.

[wlfpkrcn1]

So E.3 be reworded to any Non-OEM Or re-valved OEM under 39.99mm +3

 

And E.2

Any Non-OEM / re-valved OEM over 40mm or piggy back +7

 

Editing after re-reading and digesting

 

I understand the theory behind your explanation. One could argue that a re-valved shock falls under your OEM definition. It is the same size and shape because the strut housing and piston are stock/OEM. I guess the "sticking point" is functional characteristic. I could argue that the OEM or re-valved have the same characteristic. They both control compression and rebound. Obviously a re-valved strut does it at a different rate. That change of rate as the rules are currently written falls into E.3 Any modification other than valving (i.e shortening piston, adding adjusters etc.) would jump to non OEM.

 

Since E.3 is the only rule that allows re-valving of the stock shock, it is the one he would take points for. I stick by my original post that E.2 is for non OEM only until worded differently. Of course you have final say, and hopefully that will be clarified in the rules

[evolutionmotorsports]

So E.3 be reworded to any Non-OEM Or re-valved OEM under 39.99mm +3

 

And E.2

Any Non-OEM / re-valved OEM over 40mm or piggy back +7

 

Editing after re-reading and digesting

 

I understand the theory behind your explanation. One could argue that a re-valved shock falls under your OEM definition. It is the same size and shape because the strut housing and piston are stock/OEM. I guess the "sticking point" is functional characteristic. I could argue that the OEM or re-valved have the same characteristic. They both control compression and rebound. Obviously a re-valved strut does it at a different rate. That change of rate as the rules are currently written falls into E.3 Any modification other than valving (i.e shortening piston, adding adjusters etc.) would jump to non OEM.

 

Since E.3 is the only rule that allows re-valving of the stock shock, it is the one he would take points for. I stick by my original post that E.2 is for non OEM only until worded differently. Of course you have final say, and hopefully that will be clarified in the rules

 

Is the Jury still out on this or is it final?

 

Ok so to get this all straight:

 

+7 For Single Adjustable Non-OEM Non Piggyback Strut over 40 mm Shaft

+2 For Coil Springs

+1 For Inverted

 

+10 Total

 

Does it matter if its Single or Double Adjustable? These are not mentioned in the rules at all

[Greg G.]

 

Is the Jury still out on this or is it final?

 

Ok so to get this all straight:

 

+7 For Single Adjustable Non-OEM Non Piggyback Strut over 40 mm Shaft

+2 For Coil Springs

+1 For Inverted

 

+10 Total

 

Does it matter if its Single or Double Adjustable? These are not mentioned in the rules at all

Yes, that is correct. No, it does not matter if they are single or double adjustable (two ranges of adjustment)--same number of points. If you go up to three ranges of adjustment, though, you bump up to the +10 point shocks/struts.

[clydesdale]

 

Is the Jury still out on this or is it final?

 

Ok so to get this all straight:

 

+7 For Single Adjustable Non-OEM Non Piggyback Strut over 40 mm Shaft

+2 For Coil Springs

+1 For Inverted

 

+10 Total

 

Does it matter if its Single or Double Adjustable? These are not mentioned in the rules at all

Yes, that is correct. No, it does not matter if they are single or double adjustable (two ranges of adjustment)--same number of points. If you go up to three ranges of adjustment, though, you bump up to the +10 point shocks/struts.

 

 

Why would rule E4. applies in this case? I read the rule as meaning a change in installation orientation of a non-OEM or OEM shock from it's original design e.g. if I buy an inverted or non-inverted shock and install it upside down I take an additional point. The usage of "invert" in rule E4 is different as an inverted shock isn't the same as an upside-down shock (which technically could be an inverted or non-inverted shock design). In general this wouldn't be possible or beneficial in a strut anyway would it?

 

My opinion on the re-valving question: re-valved OEM shocks should be exposed to only additional points associated with re-valving i.e +3. It seems clear that rule E3 does not refer to OEM re-valved struts even if the shaft happened to be over 40mm. If you were to assume that changing the valving makes a strut non-OEM, you'd need to use the same conclusion for changing the springs from rule E5. Using this logic, a spring change on an inverted OEM strut with >40mm shaft diameter (just about every inverted strut OEM or otherwise is this large) would be +9? That would be terribly unfair.

[Greg G.]

 

 

Why would rule E4. applies in this case? I read the rule as meaning a change in installation orientation of a non-OEM or OEM shock from it's original design e.g. if I buy an inverted or non-inverted shock and install it upside down I take an additional point. The usage of "invert" in rule E4 is different as an inverted shock isn't the same as an upside-down shock (which technically could be an inverted or non-inverted shock design). In general this wouldn't be possible or beneficial in a strut anyway would it?

 

My opinion on the re-valving question: re-valved OEM shocks should be exposed to only additional points associated with re-valving i.e +3. It seems clear that rule E3 does not refer to OEM re-valved struts even if the shaft happened to be over 40mm. If you were to assume that changing the valving makes a strut non-OEM, you'd need to use the same conclusion for changing the springs from rule E5. Using this logic, a spring change on an inverted OEM strut with >40mm shaft diameter (just about every inverted strut OEM or otherwise is this large) would be +9? That would be terribly unfair.

E.4. applies because it says this:

(includes non-OEM inverted shocks/struts)

 

Your analogy does not hold water because springs are considered a completely different part from shocks. So, changing the springs would not effect the points assessed regarding the shocks at all.

[wlfpkrcn1]

Just so I can see each rule number in question

 

E. SUSPENSION:

1) Non-OEM shocks/struts/dampers with an external reservoir or more than two ranges of adjustment—must still take

points for springs below +10 (example: compression (bump) and both high & low rebound adjustments).

2) Non-OEM shocks/struts/dampers with a “Piggy Back” external reservoir (fixed reservoir without a connecting hose) OR

with shaft diameter 40mm or greater—must still take additional points for the springs below +7

3) Non-OEM or modified/re-valved shocks/struts/dampers +3 (all others) (springs not included)

4) Changing the mounting orientation/design of the OEM shock and/or spring perch in order to invert the shocks/struts

(includes non-OEM inverted shocks/struts) +1

5) Non-OEM or modified coil springs, leaf springs/spacers/brackets, or torsion bars +2

 

Randy- One of the main advantages of inverted shocks is to reduce unsprung weight. Your opinion is kind of confusing but i will attempt to understand it.

 

My opinion on the re-valving question: re-valved OEM shocks should be exposed to only additional points associated with re-valving i.e +3. It seems clear that rule E3 does not refer to OEM re-valved struts even if the shaft happened to be over 40mm.

 

I agree with this as the rules currently are written. I assume that will soon change and a re-valve will constitute a non OEM shock/strut. Greg has given us his intent when he wrote the rule, and you can anticipate those re-valve 40mm to be +7

 

If you were to assume that changing the valving makes a strut non-OEM, you'd need to use the same conclusion for changing the springs from rule E5.

 

Seems clear that any spring change is +2

 

Using this logic, a spring change on an inverted OEM strut with >40mm shaft diameter (just about every inverted strut OEM or otherwise is this large) would be +9?

 

per E.5 Non-OEM or modified coil springs, leaf springs/spacers/brackets, or torsion bars +2 Why would you take points for a OEM strut if you are just doing a spring change?

 

Just to add fuel to the fire (sorry Greg)

If a car come stock with inverted struts and the car is being assesed a base class on having an inverted strut. Why would someone replacing a stock OEM inverted strut take an additional +1 for a Non OEM inverted

 

4) Changing the mounting orientation/design of the OEM shock and/or spring perch in order to invert the shocks/struts

(includes non-OEM inverted shocks/struts) +1

 

This +1 should only be for conventional struts switching to inverted. Not an OEM inverted staying inverted with a Non OEM. The key phrase being in order to invert the shocks/struts

[Greg G.]

 

Just to add fuel to the fire (sorry Greg)

If a car come stock with inverted struts and the car is being assesed a base class on having an inverted strut. Why would someone replacing a stock OEM inverted strut take an additional +1 for a Non OEM inverted

 

4) Changing the mounting orientation/design of the OEM shock and/or spring perch in order to invert the shocks/struts

(includes non-OEM inverted shocks/struts) +1

 

This +1 should only be for conventional struts switching to inverted. Not an OEM inverted staying inverted with a Non OEM. The key phrase being in order to invert the shocks/struts

Eric, using that logic, if one starts with OEM inverted shocks, and then puts on aftermarket non-inverted shocks (which are then inverted compared to the OEM configuration, one would have to take the +1 point.

 

No, I don't think it is the same thing as taking off an OEM wing and having to take the +4 points

 

Actually, I tried to get rid of the inverted strut rule last year but it was not approved.

[clydesdale]

 

Just to add fuel to the fire (sorry Greg)

If a car come stock with inverted struts and the car is being assesed a base class on having an inverted strut. Why would someone replacing a stock OEM inverted strut take an additional +1 for a Non OEM inverted

 

4) Changing the mounting orientation/design of the OEM shock and/or spring perch in order to invert the shocks/struts

(includes non-OEM inverted shocks/struts) +1

 

This +1 should only be for conventional struts switching to inverted. Not an OEM inverted staying inverted with a Non OEM. The key phrase being in order to invert the shocks/struts

 

Amen, Eric.

 

To address my earlier point about springs, given that an OEM strut part number typically comes with a spring, I considered the spring an integral part of the strut-- hence the basis of my argument that both a re-valve and a spring change make a strut non-OEM. That a spring is not a strut is fine by me. That an STI or an Evo doing a re-valve take +8 points and an S2000 or and Elise doing a re-valve take +3 is just foolish in my opinion. Fortunately Mugen doesn't offer a top for the STI so that topic won't come up.

 

To the OP evolutionmotorsports, you made the same mistake I did and purchased a suspension that is a black hole for points. Thankfully money can correct the problem. Look for non-inverted single adjustable dampers, same lap times, fewer points. Please, can someone name a single brand of inverted strut that isn't greater than 40mm?

[kbrew8991]

given that an OEM strut part number typically comes with a spring, I considered the spring an integral part of the strut

nothing I've ever worked on does that... really??!?

[clydesdale]

No, not really.

[wlfpkrcn1]

A strut is a replaceable part. Your are confusing strut and strut assembly. A strut assembly consists of a strut, perch, spring, strut top ( for us camber plate) each one of those is adressed in the rules.

 

Greg,

 

I agree with my logic. A strut that changes direction should be +1. If your strut remains in the same direction as stock it should be free.

[clydesdale]

A strut is a replaceable part. Your are confusing strut and strut assembly. A strut assembly consists of a strut, perch, spring, strut top ( for us camber plate) each one of those is adressed in the rules.

 

Excellent piece of nomenclature explanation. I've been wrong on more than a few occasions.

[evolutionmotorsports]

The Evo comes with OEM Inverted Struts. The Coilovers in question are the Ohlins R&T for 2008 Evo X and 2006 Evo. They are inverted and have an inner shaft size of 12mm and outer shaft size of 40mm.

 

First why are there shaft size rules and not number of adjustments because clearly the adjustments are better then shaft size?

Advantages?

 

The rules do not state which shaft is the measured shaft.

 

The rules do say shaft size >40mm in which the outer shaft is 40mm and not greater then 40mm so these should only be 3pts not 7pts.

 

The major issue is that there is alot of people running these in TT and were told that they are a 3pts and 2pts not 7 + 2 + 1 so the big question is how are all the Regions scoring this and are they all doing the same thing?

[TurboShortBus]

given that an OEM strut part number typically comes with a spring, I considered the spring an integral part of the strut--

For your car, maybe. Have you ever looked under, say, a 1979-2004 Mustang? There are probably a couple of them still on the road and on tracks if you look hard enough. The springs are completely separate from the shocks and struts by a distance of several inches, and one can be changed without affecting the other. This also applies to the rear of 2005-current Mustangs.

 

Mark

[f1honda]

I contacted Andrew from GTWorx to ask about shaft size of AST strut. He said that in an inverted strut, the top part that looks like the shaft is not the shaft. since the strut is inverted, the shaft is in the bottom portion inside strut body. so it can't really be measured unless the manufacture give the specs for the shaft size.

 

so i thought i was measuring the shaft on my inverted Ohlins but it was the body.

 

the strut on the left of the picture is the inverted strut for Evo. the top part of the strut is not the shaft since it's inverted. the shaft is inside the housing of the strut.

so which part does Nasa consider to be the shaft in an inverted strut.

 

Edited April 29, 2011 by Guest