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911.racer

Rule Proposal - Eliminate penalty for sequential shifters

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911.racer

1. The proposed addition or change.

Eliminate the penalty for sequential shifters

 

2. The reason behind the proposal

A sequential shifter, such as the ones found in the Porsche Cup cars have an engine cut or retard during shifting to facilitate shifting. This engine cut is actually more dramatic than a standard shift.

 

The transmissions such as the PDK are exempted from this penalty. However, the PDK actually shifts faster than any sequential and does not have the same engine cut.

 

This rule was also put in place because at the time you could not retrofit a street car with a sequential transmission, but now, there are examples of BMW models with sequential transmissions installed.

 

3. Any documentation supporting the request

Rodger from AIM, when reviewing data from the 2016 national event was able to see how the sequential transmission car actually lost more speed during the shift than the standard transmissioned car.

 

4. Proposals to be submitted and signed by GTS members to be considered. (indicate Class and Region, please).

 

Ed Baus

Northern Ohio Region

(yes, I have a 997 cup car)

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focusedintntions

If data shows it's actually slower...wouldn't it just be cheaper to put in a regular gear box then vs servicing that sequential? Oh and it'd be faster!

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daytonars4

Regardless of whether a sequential transmission provides an advantage or not, there is a perception that it does. If there wasn't a perception of an advantage my guess is Cup racers would choose to swap manual transmissions in their cars instead of spending $20-30k for sequential transmission rebuilds. If we have CC restrictions based on "perception" of an advantage (despite 6 cylinder S54 cars regularly spanking V8's in the same class), I'm sure we can all agree that a mod for a perception of a sequential advantage makes sense. You actually bring up a good point that there should be a mod for PDK's as well. Should I propose that?

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911.racer

So, why do we not have a penalty for ABS, for cockpit adjustable sway bars, for traction control, for tires beyond a certain width compared to stock, Non stock ECUs or ECU programming, headers, aftermarket suspension components, ...

 

Why do we have a rule that selectively chooses this perceived advantage.

 

To me, the greatest advantage is that it is virtually impossible to money shift the car (which would be more expensive than the maintenance cost of the transmission)

 

When did this rule go in place. Who voted it in. What were the circumstances around it and what was the data that supported it.

 

This reminds me of the rear engine rule in ST.

 

Thanks

 

Ed

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mcdonaldsracing

Eliminate the stupid CC rule and TQ mod and I could possibly go along with this. Those rules are clearly based on perception! All you have to do is look at our MA ST results to see there is no clear advantage to base those rules on. We have all been super close all year long and it always comes down to driver performance, not the car or modifications. Oh, and by the way Larry, we have not been getting spanked! Lol

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John Graber

I'd go along with this. The new "auto" transmissions like the PDK are faster and not penalized. The sequential is fast, but you still have to shift, and often use the clutch.

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daytonars4

There is no argument about a PDK being substantially faster than a manual transmission. There's also no argument that a sequential is faster than a manual transmission. So they should both carry a mod. Doesn't a sequential stay in the optimal power band better than both a manual and PDK?

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911.racer
There is no argument about a PDK being substantially faster than a manual transmission. There's also no argument that a sequential is faster than a manual transmission. So they should both carry a mod. Doesn't a sequential stay in the optimal power band better than both a manual and PDK?

 

 

I am arguing that a sequential is NOT faster than a manual and I have data to prove it. Why would you say that there is no argument for that ? No, a sequential has a 6 gear speed just like a manual. The only difference is how it shifts. If you are saying that it has a tighter gear spacing than a stock transmission, yes it probably does, but nothing you could not do to a standard transmission.

 

Ohh. Lets penalize non standard gear ratios too.

 

 

Thanks

 

Ed

Edited by Guest

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rcrescencio

Counter to the original rule suggestion, i suggest ADDING PDKs to the penalty box. The advantage is not just perceived, it's real. I would be interested in seeing data that shows sequentials to be "slower" than a regular trans.

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doclouns

Disagree. In fact I have been pondering a proposal to increase the penalty. In my research, I have found that PCA penalizes a 3000 lb car in GTB w/pdk 100 lbs and 125lbs if it is a GT4 or 981. That is a higher penalty than we current assess. Other comparable numbers I can find are 100 lbs in SCCA T1 and Trans Am T3 for a true sequential. BMW CCA bumps you from mod into supermod.

In NASA GTS4, a 3000 lb car is only penalized 70lbs by my math.

Therefore, at the very least no change if not an increase based on other well-known series' as a comparison. The math for a 3000lb car would be between .3 and .35 to get to 100-125 lbs penalty.

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911.racer
Disagree. In fact I have been pondering a proposal to increase the penalty. In my research, I have found that PCA penalizes a 3000 lb car in GTB w/pdk 100 lbs and 125lbs if it is a GT4 or 981. That is a higher penalty than we current assess. Other comparable numbers I can find are 100 lbs in SCCA T1 and Trans Am T3 for a true sequential. BMW CCA bumps you from mod into supermod.

In NASA GTS4, a 3000 lb car is only penalized 70lbs by my math.

Therefore, at the very least no change if not an increase based on other well-known series' as a comparison. The math for a 3000lb car would be between .3 and .35 to get to 100-125 lbs penalty.

 

 

Conversely, in PCA I run in GT2 which is a power to weight class, unlike GTB, and there is no penalty. GTB is more of a BOP like ST while GT is more simple power to weight like GTS.

 

Again, what is GTS, power to weight or anther ST series.

 

In BMW, running a DCT transmission would bump you into supermod if the car came with it ?

 

At the same time, are you running in a region where there are PDK Caymans and Boxsters doing well in GTS ? We have so few already. One in the region I run. Does well on occasion, but not dominating.

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mikew968

Pro's would not run a sequential if they were actually slower. No empirical evidence. i guess we could ask Patrick Long!!! lol

 

As far as a PDK goes they are definitely easier to drive. But, they add weight, they "use" some HP, and currently the fastest Porsche club racers are running 6 sp's.

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doclouns

I will be the first to admit I am not a Porsche guy, but, there is a weight penalty, regardless of the class. So there is at least a perceived BOP advantage with pdk. As far as DCT, that would not put you in Mod or SM in BMW ( it comes as a stock tranny), just a true sequential as well as a dogbox. But in BMW, airjacks put you in SM, so go figure. So as far as pdk/dct etc... one can argue that point since they are stock configurations. The proposal specifically specifies "sequentials" which I interpret as aftermarket.

We have no Porsches running in NE so I have no comparison there. But I would suggest that that is a poor way to argue the point. You need the same driver in car a vs car b to make any comparisons as far as results. Flat shifting is clearly faster than a manual. Period. The only debate is the effect on actual lap times. The data is sparse. I argue that other series penalize and we should be consistent with them. Somebody smarter than me came up with the idea so I would argue that it is not whether, but how much. If the calculated range is .3-.35 in those series, then I propose those higher numbers.

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911.racer
Flat shifting is clearly faster than a manual. Period. .

 

Again, this is incorrect. I have evidence that it is not. Your position is perceived, not fact. How fast one shifts does not need to be compared with the same driver with same aero. With the AIM data you can clearly see the shifts and you can clearly see that the sequential looses more time in a shift.

 

As I stated originally, since most do not know, a true sequential with a dog box, cuts the throttle when you shift. If it did not it would tear up the transmission in a day. This cut is to allow the gears to mesh. With a standard box pushing the clutch in accomplishes the same thing (plus the standard transmission has syncros which ease the pain). The difference is that with a sequential there is engine braking while with a standard box there is not. This engine cut can be seen with the AIM data and is more pronounced than a shift with a clutch and H pattern.

 

You also state that it is OK for the DCT or the PDK event thought they are faster than a sequential.

 

I understand that I am in a minority. And, because of this EVERYONE else is against this rule because they do not understand, have a perceived position, or would like to have this advantage against a car with a sequential. That is a shame.

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doclouns

Well, Ill just say I was privy to AIM data at the same event that showed the opposite for me vs a certain true sequential car. A significant straight line advantage. Thats my point of reference, all mechanical engineering aside. I guess I could be a slow shifter.......So I go back to my original point. I think GTS should mimic other well-known series' and actually increase the penalty rather than eliminate it.

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cstreit911

Ed,

 

Can you post the graphs of this data you are referring to? This would help a lot with the discussion. Otherwise its just one opinion over another.

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911.racer

Chris,

 

I can not since it was compliance data, not my own.

 

I will save my breath and see what kind of data I can put together to support my position for the future.

 

Thanks

 

Ed

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mjmccoy

If you have a sequential that is slower to shift than a conventional h pattern, then you have a calibration problem.

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gjkasten
Flat shifting is clearly faster than a manual. Period. .

 

Again, this is incorrect. I have evidence that it is not. Your position is perceived, not fact. How fast one shifts does not need to be compared with the same driver with same aero. With the AIM data you can clearly see the shifts and you can clearly see that the sequential looses more time in a shift.

 

 

This rule doesn't impact me at all (E36 M3 in GTS2), but if there is data available that supports one side of the argument, please post it here for everyone to see. It would probably be helpful to provide an explanation of what we are looking at, as well.

 

Cheers.

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daytonars4

Just because the calibration in a Cup can’t be adjusted doesn’t mean that’s the case for all the other sequential’s being run by non-Porsche race cars. Or even Porsche’s with aftermarket ecu’s. I think for there to be a rule change would require data from multiple sequential cars, not just Cups. Maybe present data from manual E46 M3’s compared to E46’s with Samsonas and Drenth sequential’s?

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mjmccoy
If you have a sequential that is slower to shift than a conventional h pattern, then you have a calibration problem.

 

FYI,

 

Factory set. No calibration or adjustment

 

https://rennlist.com/forums/porsche-cup-cars/1026290-ignition-cut-retard-for-up-shifts-on-a-997-a.html

How does that make it not a calibration issue?

 

We want to make this change for what purpose? Based on data of one car? (Probably compared to a dog box which gets the same penalty and not to a standard box.)

 

Also, still a calibration issue. And with an easy fix that could include a good bump in total performance.... and without moving where it would be in GTS to boot...

 

http://www.bosch-motorsport.de/content/downloads/Products/9007212707846411.html

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911.racer
If you have a sequential that is slower to shift than a conventional h pattern, then you have a calibration problem.

 

FYI,

 

Factory set. No calibration or adjustment

 

https://rennlist.com/forums/porsche-cup-cars/1026290-ignition-cut-retard-for-up-shifts-on-a-997-a.html

How does that make it not a calibration issue?

 

We want to make this change for what purpose? Based on data of one car? (Probably compared to a dog box which gets the same penalty and not to a standard box.)

 

Also, still a calibration issue. And with an easy fix that could include a good bump in total performance.... and without moving where it would be in GTS to boot...

 

http://www.bosch-motorsport.de/content/downloads/Products/9007212707846411.html

 

 

This will be my last post to this thread. You are making an assumption that it is out of adjustment. Why would Porsche make a fuel cut too long on a dedicated race car. And, even if I were to spend $7k and the tuning cost to buy the aftermarket box that it would do a lick of good. (or potentially blow up the transmission because of lack of cut)

 

The fuel cut is there for a purpose.

 

You have not provided me any data to show that normally a cup car would not have a drop in performance from shifts.

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mjmccoy

Let me simplify.

 

Fact 1. If you do not have a torque reduction, you will not cleanly get it out of gear with a dog box. (H pattern or sequential).

 

Fact 2. If you can do it as fast or faster with your feet and hand with an h pattern and no ecu assistance, there is something massively wrong with the calibration. (Or, to un-bunch your panties, it is completely correct and working as intended, there just happens to be massive room for improvement.)

 

 

Typically you have enough access to enable burst logging on shifts. I suggest posting that log or email it to me. Or if you don't like me, there are plenty of other qualified race engineers with calibration experience to whom I can refer you.

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