UPDATE ST4/TT4 and other for 2017

[enivid]

Don't forget the FR-S/BRZ's! I'm one of the 8 signed up for TTB this weekend in MidAtlantic and have been building my car this year with TT4/ST4 in mind. I'm already struggling to get anywhere near a 12:1 ratio and getting down to 11.3 would almost certainly require either a heavily built engine or forced induction.

 

An NA 86 should not be in TTB/TT4 anyways. You'd never be competitive as FI 86's are in that class. Even with E85 you'd be in TT5/TTC with a NA 86.

[heavychevy]

 

It's called "tech shed legal". Ask Spec Miata about that. If you applied current tech shed procedures to the nascars that won races in the 60's they'd all be illegal now. People push the envelope any way they can. It's a reason why I'm particularly against Dyno based classing. I think it lends it's self to lots of ways to "trick" the dyno. That and no two dyno's read alike. Two different dynojets here in town that are the same dynojet and i made NO changes to my car yet read nearly 15% different.

I've been working on a way of calculating engine displacement and rpm with some modifiers to figure out a way of classing cars based on an engine making the max of what it can make at a particular RPM. the bad news is it screws american V8's because their HP to Displacement is poor compared to european and japansese cars and basically requires you to either drop the rev limiter way down or build a motor. But running the numbers on existing racing and existing classes it seems to work pretty well. No dyno, no tech shed, no tear down. I'm gonna keep working on it for afew more years though.

 

 

That's not really true. My car has dyno'd within 4 whp of 2 local dynojets and the mobile one used at Nationals. 3 dynojets, same hp.

 

 

 

As for ST1/TT1, 6.0:1 its going to slow the class a bit and make more cars competitive. If you have a street car, its pretty tough and many times VERY expensive to get to 5.5:1 and run it reliably over time.. 6:1 makes more cars competitive in nearly showroom condition to develop in TT and later to ST. 100 lbs is usually not much of a challenge to add.

[Mrsideways]

 

It's called "tech shed legal". Ask Spec Miata about that. If you applied current tech shed procedures to the nascars that won races in the 60's they'd all be illegal now. People push the envelope any way they can. It's a reason why I'm particularly against Dyno based classing. I think it lends it's self to lots of ways to "trick" the dyno. That and no two dyno's read alike. Two different dynojets here in town that are the same dynojet and i made NO changes to my car yet read nearly 15% different.

I've been working on a way of calculating engine displacement and rpm with some modifiers to figure out a way of classing cars based on an engine making the max of what it can make at a particular RPM. the bad news is it screws american V8's because their HP to Displacement is poor compared to european and japansese cars and basically requires you to either drop the rev limiter way down or build a motor. But running the numbers on existing racing and existing classes it seems to work pretty well. No dyno, no tech shed, no tear down. I'm gonna keep working on it for afew more years though.

 

 

 

That's not really true. My car has dyno'd within 4 whp of 2 local dynojets and the mobile one used at Nationals. 3 dynojets, same hp.

 

 

 

As for ST1/TT1, 6.0:1 its going to slow the class a bit and make more cars competitive. If you have a street car, its pretty tough and many times VERY expensive to get to 5.5:1 and run it reliably over time.. 6:1 makes more cars competitive in nearly showroom condition to develop in TT and later to ST. 100 lbs is usually not much of a challenge to add.

 

When I went to Nationals in 09 on the calibraton day I dyno'd and tuned the car here at near sea level before I left on a Dynojet. Then at the site I rented time on a dynapak that was there and it was within 2hp of what it made on the dynojet here. So we adjusted it down a slight bit. Then put it on the mobile dyno that NASA provided and it made nearly 20% more. We went into freak out mode trying to pull hp out to account for a crazy high reading dyno. I've been on about 5 different dynojets in my area and have compiled a bit of a database on them. The worst part is they don't seem to be accurate. They just happen to randomly read basically whatever. Had a S2000 make 223whp on one, then go to another and make 237. Same two dyno's took a Mini that on the first one made 224, then went to the 2nd one and made 218. It's total BS.

[D_Eclipse9916]

 

It's called "tech shed legal". Ask Spec Miata about that. If you applied current tech shed procedures to the nascars that won races in the 60's they'd all be illegal now. People push the envelope any way they can. It's a reason why I'm particularly against Dyno based classing. I think it lends it's self to lots of ways to "trick" the dyno. That and no two dyno's read alike. Two different dynojets here in town that are the same dynojet and i made NO changes to my car yet read nearly 15% different.

I've been working on a way of calculating engine displacement and rpm with some modifiers to figure out a way of classing cars based on an engine making the max of what it can make at a particular RPM. the bad news is it screws american V8's because their HP to Displacement is poor compared to european and japansese cars and basically requires you to either drop the rev limiter way down or build a motor. But running the numbers on existing racing and existing classes it seems to work pretty well. No dyno, no tech shed, no tear down. I'm gonna keep working on it for afew more years though.

 

 

 

That's not really true. My car has dyno'd within 4 whp of 2 local dynojets and the mobile one used at Nationals. 3 dynojets, same hp.

 

 

 

As for ST1/TT1, 6.0:1 its going to slow the class a bit and make more cars competitive. If you have a street car, its pretty tough and many times VERY expensive to get to 5.5:1 and run it reliably over time.. 6:1 makes more cars competitive in nearly showroom condition to develop in TT and later to ST. 100 lbs is usually not much of a challenge to add.

 

When I went to Nationals in 09 on the calibraton day I dyno'd and tuned the car here at near sea level before I left on a Dynojet. Then at the site I rented time on a dynapak that was there and it was within 2hp of what it made on the dynojet here. So we adjusted it down a slight bit. Then put it on the mobile dyno that NASA provided and it made nearly 20% more. We went into freak out mode trying to pull hp out to account for a crazy high reading dyno. I've been on about 5 different dynojets in my area and have compiled a bit of a database on them. The worst part is they don't seem to be accurate. They just happen to randomly read basically whatever. Had a S2000 make 223whp on one, then go to another and make 237. Same two dyno's took a Mini that on the first one made 224, then went to the 2nd one and made 218. It's total BS.

 

At 2016 East Coast Champs, I dynoed within 15 minutes of each other the two dynos there. It was a 19rwhp difference (321rwhp vs 340rwhp)...

 

To assume there is no difference is turning a blind eye.. Thats why you always dyno on the dyno that is for compliance.

[Chase J.]

ST4 aerodynamic modification allowances:

2b Modified or replaced front fascia without canards/winglets or other aspects that function as canards/winglets to provide direct downforce.

 

could someone give an example of this?

specifically the "other aspects that function as canards/winglets to provide direct downforce."

 

does it mean any curve or bend of a replaced front bumper cover that could be considered an aspect that functions as a canard?

 

are canards allowed as long as the front bumper cover is oem and not modified?

 

thanks

 

Yes, as of this minute, they are allowed as long as the bumper cover is from the trim model of the vehicle, as manufactured. HOWEVER, I'm not sure if this will be changed this coming week or not.

 

Hi Greg- I know that it may change in the coming week, but if it doesn't, does that mean that the Honda S2000 CR lip/bumper is clear to be used by any year S2000 or only the CR models?

 

+2 Thanks

[Snowmants]

I feel like there should be a FAQ section for the new rules. I see a lot of questions being asked and sometimes there are answers and sometimes not. As this thread grows in size it will be harder for newcomers to the thread to read all of it or find answers to their questions. People will start to ask the same questions that have already been answered. I think it would make sense to have a place to submit questions, and then another place where those questions along with their answers are posted for all to see. I think it will save both those looking for clarification and those doing the clarifying time.

 

Just my 0.2......

[39088/1]

2) ST4 Aerodynamic Modification Allowances:

b) Modified or replaced front fascia without canards/winglets or other aspects that function as canards/winglets to provide a direct downward force.

 

how about we just toss this rule?

 

since we can use front splitters and air dams, both very effective devices that provide "direct downward force," canards/winglets aren't much added benefit.

 

and while it is a benefit and likely expensive to replace the front fascia with a more aerodynamic version, we are allowed rear wings, why not allow drivers to balance the rear down force?

[Chase J.]

I feel like there should be a FAQ section for the new rules. I see a lot of questions being asked and sometimes there are answers and sometimes not. As this thread grows in size it will be harder for newcomers to the thread to read all of it or find answers to their questions. People will start to ask the same questions that have already been answered. I think it would make sense to have a place to submit questions, and then another place where those questions along with their answers are posted for all to see. I think it will save both those looking for clarification and those doing the clarifying time.

 

Just my 0.2......

 

That would be great but I think that's what this thread is. I just want clarity on the OEM CR front lip for base models S2000

[slowap2]

2) ST4 Aerodynamic Modification Allowances:

b) Modified or replaced front fascia without canards/winglets or other aspects that function as canards/winglets to provide a direct downward force.

 

how about we just toss this rule?

 

since we can use front splitters and air dams, both very effective devices that provide "direct downward force," canards/winglets aren't much added benefit.

 

and while it is a benefit and likely expensive to replace the front fascia with a more aerodynamic version, we are allowed rear wings, why not allow drivers to balance the rear down force?

I think they are trying to avoid cars like that M3 with the giant front wing happening in S/TT4

[Mrsideways]

2) ST4 Aerodynamic Modification Allowances:

b) Modified or replaced front fascia without canards/winglets or other aspects that function as canards/winglets to provide a direct downward force.

 

how about we just toss this rule?

 

since we can use front splitters and air dams, both very effective devices that provide "direct downward force," canards/winglets aren't much added benefit.

 

and while it is a benefit and likely expensive to replace the front fascia with a more aerodynamic version, we are allowed rear wings, why not allow drivers to balance the rear down force?

 

 

I agree 100% especially since this leaves all kinds of grey area that a lot of OEM bumpers could fall into. Hell the Stock Bumper on my daily driver Volvo would be illegal the way this reads.

[Chase J.]

2) ST4 Aerodynamic Modification Allowances:

b) Modified or replaced front fascia without canards/winglets or other aspects that function as canards/winglets to provide a direct downward force.

 

how about we just toss this rule?

 

since we can use front splitters and air dams, both very effective devices that provide "direct downward force," canards/winglets aren't much added benefit.

 

and while it is a benefit and likely expensive to replace the front fascia with a more aerodynamic version, we are allowed rear wings, why not allow drivers to balance the rear down force?

I think they are trying to avoid cars like that M3 with the giant front wing happening in S/TT4

 

Couldn't they say no giant front wings then? I mean, just hit the nail with the hammer. Don't beat around it.

[ja1217]

2) ST4 Aerodynamic Modification Allowances:

b) Modified or replaced front fascia without canards/winglets or other aspects that function as canards/winglets to provide a direct downward force.

 

how about we just toss this rule?

 

since we can use front splitters and air dams, both very effective devices that provide "direct downward force," canards/winglets aren't much added benefit.

 

and while it is a benefit and likely expensive to replace the front fascia with a more aerodynamic version, we are allowed rear wings, why not allow drivers to balance the rear down force?

 

Agreed. I know this rule would effect a lot of GTS2/3 cars that might want to supersize since a lot of them run more than just a simple splitter for front aero.

[39088/1]

I agree 100% especially since this leaves all kinds of grey area that a lot of OEM bumpers could fall into. Hell the Stock Bumper on my daily driver Volvo would be illegal the way this reads.

 

good point, a current model mini van has better front aero than my 20yr old track car's oem front fascia.

this rule keeps me from changing to a front bumper cover with "aspects that function as canards," but a late model car might already have a bumper cover with those aspects.

same weight/hp and tires, but the newer car comes with better aero and the older can't update.

this rule punishes older cars and is an incentive to buy newer cars for competition.

[Mrsideways]

Walking through a grocery store parking lot the other day I counted at least 5 cars that were stock that looking at them just right you could call the front bumper shape a "canard of sorts".

[heavychevy]

 

 

 

That's not really true. My car has dyno'd within 4 whp of 2 local dynojets and the mobile one used at Nationals. 3 dynojets, same hp.

 

 

 

As for ST1/TT1, 6.0:1 its going to slow the class a bit and make more cars competitive. If you have a street car, its pretty tough and many times VERY expensive to get to 5.5:1 and run it reliably over time.. 6:1 makes more cars competitive in nearly showroom condition to develop in TT and later to ST. 100 lbs is usually not much of a challenge to add.

 

When I went to Nationals in 09 on the calibraton day I dyno'd and tuned the car here at near sea level before I left on a Dynojet. Then at the site I rented time on a dynapak that was there and it was within 2hp of what it made on the dynojet here. So we adjusted it down a slight bit. Then put it on the mobile dyno that NASA provided and it made nearly 20% more. We went into freak out mode trying to pull hp out to account for a crazy high reading dyno. I've been on about 5 different dynojets in my area and have compiled a bit of a database on them. The worst part is they don't seem to be accurate. They just happen to randomly read basically whatever. Had a S2000 make 223whp on one, then go to another and make 237. Same two dyno's took a Mini that on the first one made 224, then went to the 2nd one and made 218. It's total BS.

 

At 2016 East Coast Champs, I dynoed within 15 minutes of each other the two dynos there. It was a 19rwhp difference (321rwhp vs 340rwhp)...

 

To assume there is no difference is turning a blind eye.. Thats why you always dyno on the dyno that is for compliance.

I wouldnt say ever, probably more cases of similar hp as there are far apart or we certainly would have a lot more DQ's at nationals and around the country in general. There are always anomalys though and I agree that one should dyno on the actual compliance dyno.

[countryboyshane]

Greg,

 

For the A-tire modification factor in 2017 TT4, what value should we all assume it will be in the final rules? I plan on running Hoosier A7 tires, and will probably have to re-tune my as I'm almost at 12:1 adjusted wt/hp already.

 

Thanks!

[Jon B.]

Greg,

 

For the A-tire modification factor in 2017 TT4, what value should we all assume it will be in the final rules? I plan on running Hoosier A7 tires, and will probably have to re-tune my as I'm almost at 12:1 adjusted wt/hp already.

 

Thanks!

 

The rules are posted for 2017 and it shows the A7 having a 1 mod factor. Greg, correct me if i'm wrong, but I think with the exception of smaller items like clarifying canards/fascias with protrusions that may act like canards, the rules as posted are official and should not be expected to change much from what is is written?

https://nasa-assets.s3.amazonaws.com/document/document/4272/ST_Rules_2017--v11.1--10-31-16.pdf

 

Size 245 or smaller (DOT-approved) = +0.7

Size 275 to 250 (DOT- approved) = +0.3

Size 9.5” (241mm) or smaller (non-DOT approved) = +0.7

Size 10.5” (267mm) to 9.6” (244mm) (non-DOT approved) = +0.3

 

Tire Type: Non-DOT approved tires (ST1, ST2, ST3 Only) = -0.5

ST4 Only: DOT-approved R-comp Autocross tires = -1.0

[zigspeed10]

2) ST4 Aerodynamic Modification Allowances:

b) Modified or replaced front fascia without canards/winglets or other aspects that function as canards/winglets to provide a direct downward force.

 

how about we just toss this rule?

 

since we can use front splitters and air dams, both very effective devices that provide "direct downward force," canards/winglets aren't much added benefit.

 

and while it is a benefit and likely expensive to replace the front fascia with a more aerodynamic version, we are allowed rear wings, why not allow drivers to balance the rear down force?

 

I agree we should toss this rule. It's making something that should be simple and making it complicated. This rule essentially rules out all of the cheap common off the shelf lips/splitters because they almost always have some type of curve or angle to them. Not to mention the issue with some of the cars with factory aero elements as opposed to the base trim models. The rules should level the playing field and promote close competition and this rule doesn't seem to do that. Maybe Greg could help us understand why he wrote this rule to begin with. I currently don't see any benefit to having it.

 

Thanks

[Greg G.]

2) ST4 Aerodynamic Modification Allowances:

b) Modified or replaced front fascia without canards/winglets or other aspects that function as canards/winglets to provide a direct downward force.

 

how about we just toss this rule?

 

since we can use front splitters and air dams, both very effective devices that provide "direct downward force," canards/winglets aren't much added benefit.

 

and while it is a benefit and likely expensive to replace the front fascia with a more aerodynamic version, we are allowed rear wings, why not allow drivers to balance the rear down force?

 

I agree we should toss this rule. It's making something that should be simple and making it complicated. This rule essentially rules out all of the cheap common off the shelf lips/splitters because they almost always have some type of curve or angle to them. Not to mention the issue with some of the cars with factory aero elements as opposed to the base trim models. The rules should level the playing field and promote close competition and this rule doesn't seem to do that. Maybe Greg could help us understand why he wrote this rule to begin with. I currently don't see any benefit to having it.

 

Thanks

 

Well, if we "toss" the rule, then anyone running a stock E36 M3 front fascia on a 325 or 330 would not be legal for the class. If we allow canards/winglets, then it opens up Pandora's box to the aero mods and costs that we don't want in ST4/TT4.

 

We will have a ruling on this issue by Thursday. I think there needs to be a better way to define what we don't want to see in the class. Also, if I had a CR2000, I'd start looking for a stock S2000 front fascia, as I think that this is going to be one result of this. Of course, we haven't actually had anyone that I'm aware of racing a CR2000 with us, and only less than a handful in TT over the past many years.

[Greg G.]

For those questioning whether you will be permitted to just use the Max HP from your regional pre-competition Dyno for your Car Classification Form, the answer is "yes". We'll put that in as a revision. And, it is a nice way to build in a buffer for Dyno variance. We will still hold you to Avg HP during a compliance inspection either way. However, if you choose to use Max HP, you are still held to the Minimum Competition Weight on the Car Classification Form.

[Greg G.]

Greg, correct me if i'm wrong, but I think with the exception of smaller items like clarifying canards/fascias with protrusions that may act like canards, the rules as posted are official and should not be expected to change much from what is is written?

https://nasa-assets.s3.amazonaws.com/document/document/4272/ST_Rules_2017--v11.1--10-31-16.pdf

 

That is correct. We will be doing something with the canard/Fascia/OEM rule, adding the above regarding the ability to use Max HP if one does not want to deal with Avg HP or for whatever other reason, and there will likely be an additional bump in the Mod Factor for ST2/TT2 sports racers. Those seem to be the current issues to deal with.

 

If possible, I'd like to see these all published by Thursday, along with the PT Rules that will have just a few revisions (PTC Adjusted Wt/HP Ratio, and maybe a few tire points changes, along with additional vehicles from the lists sent to ST1,2,3,4)

[Mrsideways]

2) ST4 Aerodynamic Modification Allowances:

b) Modified or replaced front fascia without canards/winglets or other aspects that function as canards/winglets to provide a direct downward force.

 

how about we just toss this rule?

 

since we can use front splitters and air dams, both very effective devices that provide "direct downward force," canards/winglets aren't much added benefit.

 

and while it is a benefit and likely expensive to replace the front fascia with a more aerodynamic version, we are allowed rear wings, why not allow drivers to balance the rear down force?

 

I agree we should toss this rule. It's making something that should be simple and making it complicated. This rule essentially rules out all of the cheap common off the shelf lips/splitters because they almost always have some type of curve or angle to them. Not to mention the issue with some of the cars with factory aero elements as opposed to the base trim models. The rules should level the playing field and promote close competition and this rule doesn't seem to do that. Maybe Greg could help us understand why he wrote this rule to begin with. I currently don't see any benefit to having it.

 

Thanks

 

Well, if we "toss" the rule, then anyone running a stock E36 M3 front fascia on a 325 or 330 would not be legal for the class. If we allow canards/winglets, then it opens up Pandora's box to the aero mods and costs that we don't want in ST4/TT4.

 

We will have a ruling on this issue by Thursday. I think there needs to be a better way to define what we don't want to see in the class. Also, if I had a CR2000, I'd start looking for a stock S2000 front fascia, as I think that this is going to be one result of this. Of course, we haven't actually had anyone that I'm aware of racing a CR2000 with us, and only less than a handful in TT over the past many years.

 

I don't see why swapping OEM front facias around is an issue. Practically every 325 BMW in town has a M3 bumper on it driving around town and I can say nearly the same with S2000's and CR front ends. Nearly everyone did it because it "looks" better.

 

Greg, why the big hate towards people doing this. Seems simple to me, allow Factory upgraded front fascia but no aftermarket. If it's OEM and bolts up. Have at it.

[39088/1]

Well, if we "toss" the rule, then anyone running a stock E36 M3 front fascia on a 325 or 330 would not be legal for the class. If we allow canards/winglets, then it opens up Pandora's box to the aero mods and costs that we don't want in ST4/TT4.

 

wouldn't anyone running a stock e36 m3 front fascia on a 325 or 330 be illegal with the rule in place?

seems like that would be a perfect example of a replaced front fascia with aspects that function as canards/winglets.

 

I understand how allowing canards/winglets opens the box to aero mods, but costs?

canards are much cheaper than a front splitter and about 1/10 the cost of a rear wing.

 

how do we reconcile

legal-a legal late model car with an oem bumper cover that has aspects that function as canards/winglets

vs

illegal-an old car that has a replaced front fascia with the same aspects?

 

thanks

[Mrsideways]

Just started looking online. Finding a new replica front bumper for an S2000 isn't easy like it was years ago when Keystone made them. What a PITA this has turned into.

[Roundel]

I think the A7/autocross tire 1.0 mod factor is extreme. With a mod of 0.5, it's a competitive option, though probably not the fastest setup.

 

If it was 0.5 it would give a competitive, cheaper option to allow people to run in ST/TT4, without requiring engine work to get to the limit. For E36 M3 and S2000 guys, a ratio of 11.3 (245 tires) is tough to get to, coming from ST/TTB. 11.8 (245, A7 tires) would be a bit easier without dumping a bunch of money in a motor build.