tinner

iTrader: (2)

Just got back from Mid Ohio, where were you guys? Only two events left to prep for Nationals.

RockLobster

iTrader: (7)

That's a HAUL for us. But, we are looking to do the Aug weekend and go from there....

RockLobster

iTrader: (7)

http://benandersonracing.com/misc/9.mov

Ben Anderson in my PTD FC playing with a CMC2 camarobird...

HD HERO in car...

Brainerd International Raceway

088

iTrader: (9)

LMAO. The CMC totally blew it in the left-hander at 1:45. Must have seen that intimidating FC in his mirror. heh heh

Flaggers on vacation? two for the entire track.....

I like the position of your camera mount. Covers the side window, rear view mirror, hand position, shifter, and your fancy footwork.

s5 & RTek FTW!

BTW, what's the function of the second button on your steering wheel? Nitrous?

RockLobster

iTrader: (7)

There are 3 on the steering wheel. 2 control the Racepak IQ3 dash, 1 for the radio.

SCCAITS

iTrader: (3)

Wish I could get the left foot braking down, nice job.

RockLobster

iTrader: (7)

iRacing made me a whole lot better at left foot braking. Ben is still much better than i am, but he is much better than i am at driving in general...thats why he drives and i own/crew...

wlfpkrcn

Edit- For remembering incorrectly

088

iTrader: (9)

I'm looking through the NASA PT classification rules. I see a line item "non-oem, modified/ported, or deleted intake manifold" which gives +2 points for 12A & 13B engines.

But what about the intake ports themselves? What is the points assessment for a streetport?

And what about aux port sleeves (such as the Pineapple Racing inserts)?

I'll continue reading, but I haven't run across the section that would specifically address this yet.

088

iTrader: (9)

Ok - figured out the answer at performancetouring.com. They finally posted the correct PDF that agrees with the current PT classification form.

PT rule C.2:

"port modified rotary engines [...] engine swap rules with Dyno testing apply —- must be evaluated by the National PT Director for reclassification."

and

Appendix C:

"if there is any filler material added, non-OEM sleeves added, modification of the OEM sleeves [...] the car will need to be reclassed based on Dyno testing."


The PTE ratio of 16.5 means 169.7 max whp @ 2800 lbs, which is low hp even for a stock ported engine (properly tuned). So that means a street port, even if it makes +0 extra HP, would automatically put you in PTD base class instead of PTE.

Seems a little unfair.....

Then again, my streetported engine at 139 whp would put my car in PTF base class, heh heh.

SCCAITS

iTrader: (3)

Not really. It's an "adjusted" power to weight ratio that uses more than rwhp and weight. There is a tire adjustment and a weight adjustment to the final ratio (along with body type, transmission, drivetrain if applicable). Look at Appendix A of the rules, page 32. Good luck getting a 2nd Gen in PTE, my streetport won't even fit in PTA any more. The PT rules are not that RX-7 friendly.

088

iTrader: (9)

Ok. So...... Help me out with a couple examples. The adjusted P/W ratio limits are:
PTC 12.00:1
PTD 14.25:1
PTE 16.50:1


Example A. 2nd gen rx7, s5 engine with stock porting, making 180 whp, 2800 lbs, 245 DOT-approved tires, and 35 modification points

Using the base class method, this car starts as PTE (page 12) and the modification points move it up to PTD final competition class.


Example B. same car, but with a streetport. assume the porting didn't yield much benefit beyond stock, so whp is still at 180.

Now because of the engine porting rule this car must be classified using the adjusted weight/power ratio formula in Appendix A.

2800/180, minus 0.45 (weight = 2800), plus 0.8 (245 tire size, DOT approved)
= 15.56 - 0.45 + 0.8
= 15.91

This car starts at PTD and the modification points move it up to PTC final competition class.


So the two cars end up in two different classes, simply because the engine porting caused it to be subject to dyno classification using adj. P/W ratio, whereas the other is not.

Is this correct?

SCCAITS

iTrader: (3)

Not really. Every car has a base class as listed in the rules. If you do certain things such as port a rotary, you must get a dyno re-class for your base class. This process involves a dyno performed per the rules (Dynojet, SAE 5, etc) and the competition weight submitted to Greg and he will assign a new base class. The formula used is a secret no one really knows. If you submitted a 180rwhp and 2800lb comp weight, you might get a PTE* base class, you might get a PTD, you don't know until you submit it. With this new base class, you then take your points for aero, suspension, diff, gearbox, etc. and no engine points. Now you have your final class. Whatever your final class is, whether it be starting with the base class in the rule book or the dyno re-class base class, your final class adj power/weight can not exceed the numbers published for each class. Any car can get a dyno re-class base class whether required (for porting, engine swap, etc) or because you just feel like it. It's confusing to many, I suspect more than half the competitors don't fully understand the rules or what takes points and what does not.

RockLobster

iTrader: (7)

A 2800lb FC with stock ports and running 245 or less tires can generate a max of 173 HP and remain in PTE. This is the max adjusted power to weight ratio rule. In addition the modification points must not exceed a total of 19... the points add up and quickly put an FC into higher classes.

The adjusted PtW ratio rule was added and is separate from the re-base class rule for ported rotaries. A ported rotary changes the base class for the car based on actual race weight and max generated power. The adjusted PtW (using the same dyno sheet) was a rule added to ensure someone didnt find some magical means of having an overpowered car in a lower class....believe me it happend...

So the basic stream of thought when classing a car is:

1. What is my base class and do i need to rebaseclass the car due to any rule requiring it to be rebaseclassed (such as a rotary with any port modifications (intake and/or exhaust).
2. What points do i accumulate for modifications vs a stock BASE model car.
3. only then do you look at your adjusted Power to Weight Ratio to see if that forces you into a higher class anyway. If it does then you are bumped up and have at least another 20 mod points to play with...

Admittedly the rules are quite complicated, but the nice thing about them is they really do allow a freadom to build what you want, there is not much in the way of set rules for the class like the spec classes and the SCCA classes.

We have a PTE and a PTD setup...the former requires a LOT of ballast.

RockLobster

iTrader: (7)

When you can't run the GTUs 5th gear (because in PT once you change one gear ratio from stock base model car you might as well change them all) it makes the gap between 4th and 5th and the gap between 2nd and third, not that much different (both are terrible). If you look at the overall acceleration curves....depending on the track you end up with more area under the curve using a short/stockish final drive ratio.

kurtf

iTrader: (3)

Since you are in Hayward...

Finish the car and bring it out! Dont sweat the difference btwn PTE/PTD. In Norcal, the fast PTE guys are faster than the PTD's anyway. I doubt anyone will care unless you blow us all away. Of course, Eric, who started this thread and is the norcal PT director and occasionally runs a 2gen, might ask to see your papers.

Big event at Infineon this weekend.

Kurt
PTE#76

RockLobster

iTrader: (7)

Heck you see that at nationals some years. PTE times are faster or right on par with PTD...

wlfpkrcn

Former PT Director with a blown up 2gen. Nobody has shown up with a proper PTD car yet that I know of.

PTE is the class to play in if you want cars to compete against. Our car is not a full prep PT car. It was built to stay within SCCA ITS rules. We were in PTD with max points before dyno reclass and it is not a maxed out IT car. A fully prepped IT car will end up in PTC. With dyno reclass we dropped some points and weight.

What mods are you doing to get 180hp to the rear wheels? Our car prior to engine going south with stock ECU was 140hp. Looks like if we add a Rtek we could get to 165-170 (and require another dyno reclass or take points on original base class).

A 4.10 is useless on these cars. Especially at 2800lbs. We installed a 4.77 and the car picked up the pace, but is not geared properly for TH, probably perfect for Infineon.

What class do you want to prep your car for? PTE? PTD?
What mods have you done already?
What mods do you plan to do?

wlfpkrcn

Just to give you an idea-

Base class PTE @ 2800

Mods you'll be doing at a minimum.
2- header
2- exhaust
1- cat conv removal
3- limited slip
3- shocks
2- springs
2- sway bar

You mentioned 245 tires so +1 on any tire. You will want to run 10 point tires..

11- tires

There is 26 points that you will be taking. That puts you in PTD. You could leave the stock exhaust on and drop to a 235 tire and stay in PTE.

088

iTrader: (9)

Ok. This is slowly beginning to make more sense. My suggestion would be to augment or change the examples given on page 33 of the PT rules. Examples with the same chassis but different internal engine mods and tire/weight combinations would be helpful in demonstrating the impact on adjusted PtW ratio and classification.

The following two statements interest me.

(there would be 25 mod points available for normally aspirated cars in a ** base class, right?)

My choices for classification at this point depend on what I do engine-wise and vice versa. I have the option to (a) keep my anemic streetported engine, making 139 whp on a good day, (b) pick up a relatively $cheap srteetported engine -- assume for the sake of argument it will make 180 whp, (c) rebuild existing engine with stock intake ports, and also assume it will make 180 whp. I may still want to participate in SCCA ITS at some point (yes, I'm aware that it's difficult to build a car to be competitive in both IT and PT), in which case I need a stock engine. On the other hand, given the attractive price of the streetported engine I have in mind, I may forego any hopes of ITS racing for a while.

That's just a little background, but what I'm after is a clear understanding of the classification rules. In the end it will be up to Greg, but I'd like to approach him with a prepared mind.

So here are the examples, based roughly on my engine selection dilemma.

Car modification specs:
2800 lbs
+8 Suspension (delete rear swaybar, coilovers, fronts inverted)
+3 Drivetrain (LSD)
= +11 so far

+7 Engine/exhaust (air intake, replaced drive pulley, aftermarket header, aftermarket exhaust, cat deleted)

+n Tires (points depend on class, treadwear, tire size)

+0 (zero points in all other categories)

Example A: stock ported engine making 180 whp
starts as PTE (page 12): +11 (susp/drivetr), +7 (engine), +7 (treadwear 100), +1 (size 245) = +26
bumped up to PTD so far
Check adj. PtW ratio = 15.91 > 14.25 : ok to stay in PTD
Final Class = PTD

Example B: streetported engine making 180 whp
dyno-reclassed to PTE* due to porting
starts as PTE*: *means +7, +11 (susp/drivetr), +0 (engine, dyno re-classed), +7 (treadwear 100), +1 (size 245) = +26
bumped up to PTD so far
Check adj. PtW ratio = 15.91 > 14.25 : ok to stay in PTD
Final Class = PTD

Example C: streetported engine making 139 whp (my car, actual peak hp number)
Dyno tested due to non-stock porting. Found to have zero power advantage over stock porting, ok to start with PTE base class
starts as PTE: +11 (susp/drivetr), +7 (engine), +2 (treadwear 120), -1 (size 225) = +19
stays in PTE so far
Check adj. PtW ratio = 20.49 > 16.50 : ok to stay in PTE
Final class = PTE

And the following dyno-reclassification would not be allowed:

Example D: streetported engine making 139 whp
dyno reclassed to PTF
starts as PTF: +11, +0 (engine, dyno re-classed), +7 (treadwear 100), +1 (size 225) = +19
stays in PTF so far
Check adj. PtW ratio = 20.49 > 19.50 : ok to stay in PTF
Final class = PTF


Have I got this right?

088

iTrader: (9)

wlpkcrn --

looks like I was working on my long post before seeing yours

180 hp is just a theoretical example. I'm just trying to decide which way to go and understand the classification rules.

wlfpkrcn

What I can tell you that is known

Tinner is dyno classed in PTD with 185 & 2850 . If you make 180 you will be in PTD base clase

My dyno reclass is PTE with 140 @ ITS weight (2680?)

Here is where the problem lies. HP sells cars. Torques wins races. A rotary has no torque. This is not accounted for in classing the cars. My dyno sheet is on the previous page for a bone stock S5.

Now for my opinion

I think for a FC to be competitive (nationally not regionally) in PTD it would need an engine swap. A stock rotary just doesn't make the torque to go play in PTD.

If you are starting with a clean slate and want to run a stock S5 engine or end up in PTD, then here is what I think. You should plan on the car finishing at 2800 lb. You are allowed a max of 250 of ballast. That leaves the car and driver at 2550.

Completely strip and seam weld chassis and sub frames- 0 points.
Install a fancy 1.75 x .120 roll cage (6 point with lots of bars.. no NASCAR)- 0 points
Lexan front and rear glass- 0
Stock windows down in door (unless you can make 2550 without the glass. remove glass if taking WR points below) 0
Relocate that big battery - 0
Aluminum hood or composite- 0
Mazda comp oil cooler- 0 (other wise you will run 2 oil cooler and need an air dam to get the air to them. that would add 3 points)
Aluminum Radiator- 0
Rtek ECU- 0
Build engine with lightened rotors, have balanced with lightest flywheel you can find- 0
Remove AC, PS, AIR Injection
Lightest wheels you can find- 0
5.12 rear end- 0
Camber plates- 0
Delrin bushing through out car- 0
Stainless Brake lines- 0
Proportioning valve-0
brake ducts- 0
Strut tower braces- 0
PS steering rack has better ratio- 0
Remove headlights- 0

So at this juncture we have not added points. Lets get to it!

Tires- (My opinion on 15" wheels is 225 on 10 point tires)- 9
Shocks- Custom valved double adjustable non inverted- 3
Sway bar- Speedway bar- 2
Springs- 2
Limited slip- 3
Brakes- You will want at least the 4 pistons if not some AM wilwoods etc- 2
under drive pulley-1
header-2
exhaust-2
cat conv removal-1

27 points... 12 more to go this is where you need to work

170 weight reduction- 12
Splitter, air dam, Wing- 10 then take 20lb WR for 2= 12
Increase tire points and not as much WR-12

RockLobster

iTrader: (7)

Gulping extra air to the radiator and oil coolers is free...as long as that is the only purpose it serves.

Hmm learned something new with that post, when did they up max range of adjustment for 3pt shocks to 2?! At some point in the past 3pts limited a guy to single way adjustable shocks.

Also for D we are starting to move towards the opinion that A6s are worth the 45lbs in additional weight....

wlfpkrcn

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)

Rule E.1- More than 2 ranges of adjustment
E.2- Ext. Res., Piggyback or over 40mm

RockLobster

iTrader: (7)

Yeah i saw it but i do recall a previous year rulset stating "greater than one range of adjustment"