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RULE PROPOSAL: Add a factor for racing gearboxes


JSG1901

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NEW RULE PROPOSAL

 

Proposed change

1. Add a modification factor for dog ring gear boxes.

 

2. Add a modification factor for sequential gear boxes

 

Reason

I think we are right on the verge of seeing people spend big money for gear boxes. A sequential gear box is quite an advantage in a lower HP gts-2/3 car.

 

Proposed wording

.25 increase for dog ring gear box

 

.50 increase for sequential gear box

 

So for GTS-3 a sequential gear box car running DOT tires would be 11.5:1

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We should also include SMG/M-DCT, and other automated manual transmissions. Having a shift time of 0.10 sec vs 0.40 sec for a standard H-pattern synchro gearbox is a huge advantage.

 

There are two advantages to going with an aftermarket gearbox--better gearing and reduced shift time. I don't know about the non-BMW cars, but there are few/no options to change gearing in the stock BMW case.

 

Better gearing might be a big advantage in the slower classes, but I would argue the shift time savings are an even bigger advantage in faster classes as the time saved is a greater percentage of total lap time.

 

I've always been a big proponent of not changing the basic GTS rules, but this is a huge advantage that takes big $ to take advantage of and we need to decide if we want to go down that path.

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This actually makes sense. I wouldn't penalize factory boxes, regardless how good they are. But a true sequential or even a dog box is an advantage.

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We should also include SMG/M-DCT, and other automated manual transmissions. Having a shift time of 0.10 sec vs 0.40 sec for a standard H-pattern synchro gearbox is a huge advantage.

 

There are two advantages to going with an aftermarket gearbox--better gearing and reduced shift time. I don't know about the non-BMW cars, but there are few/no options to change gearing in the stock BMW case.

 

Better gearing might be a big advantage in the slower classes, but I would argue the shift time savings are an even bigger advantage in faster classes as the time saved is a greater percentage of total lap time.

 

I've always been a big proponent of not changing the basic GTS rules, but this is a huge advantage that takes big $ to take advantage of and we need to decide if we want to go down that path.

 

I concur

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This actually makes sense. I wouldn't penalize factory boxes, regardless how good they are. But a true sequential or even a dog box is an advantage.

 

 

Correct me if I'm wrong, Porsche Cup cars use a factory installed sequential box. Would you choose to exclude them from this proposal? I would agree that SMG is a different animal and not what we're talking about here. I use a sequential box and would agree that it's an advantage and wouldn't be opposed to proposal. It doesn't seem any different than a penalty for using slicks.

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It seems sensible to me to do something along these lines. It *is* an advantage. It is expensive. And as I suspect that few people have made such a change at this time, let's nip it in the bud.

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I agree with this rule proposal, though the penalty is not stiff enough for both boxes. I would say .5 for a dog box, and 1.0 for a sequential.

 

In addition, you should include factory electronic or pneumatic actuated gear boxes as well since they can shift the car faster than one can manually.

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This actually makes sense. I wouldn't penalize factory boxes, regardless how good they are. But a true sequential or even a dog box is an advantage.

 

 

Correct me if I'm wrong, Porsche Cup cars use a factory installed sequential box. Would you choose to exclude them from this proposal? I would agree that SMG is a different animal and not what we're talking about here. I use a sequential box and would agree that it's an advantage and wouldn't be opposed to proposal. It doesn't seem any different than a penalty for using slicks.

 

Kurt, you are right - I didn't think about late Cups. I meant SMG, DCT, DSG, PDK type of stuff.

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I agree with this rule, maybe the modification factor numbers need to be played with. A cup car or any other factory race car would NOT be exempt. They still have the advantage, correct?

 

-Tony Colicchio

GTS-3

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FandangoDrew

I would not penalize factory boxes like the SMG because there is no real advantage with these boxes and it can be argued that they are at a disadvantage; I would not use one if I didn't have to for physical reasons.

 

Even though a full box box is an advantage should it really be penalized? There are a lot of things that give an advantage that we don't penalize such as the full moton set-up or aero package. Innovations like these give an advantage on track and we don't penalize them. Unlike innovation in suspension and aerodynamics, innovations in transmissions can actually improve the driving experience not just make the cars faster. I personally am hopeful we will see more choices (hopefully cheaper) in race boxes in the future and would hate to see us penalize them.

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-A dog ring engagement box will shift faster than a synchro box, fact. Sequential or H-pattern? Shouldn't affect much the shift time, altho sequential might bring more confidence and consistency (easier to fit electronic power cut/downshift bleep to, but a h-pattern shifter can still get this done). Pulling from 3rd to 4th on H-pattern versus pulling down on sequential shifter should be about same time.

 

This interpretation of rules brings some problems tho :

 

-A factory synchronized box with a sequential shifter attachement -> Won't be much faster than the standard H-Pattern, might bring confidence to driver, but the synchros are bottom neck. Do you get full penalty while still using stock gearing and synchros and technicly just using an aftermarket shifter like a short shifter would be?

 

-A modified factory box with custom gearing while keeping the synchros and h-pattern shifter -> Gets no penalty but uses the gearing advantage?

 

The issue might be more about penalizing use of dog rings versus synchros and leaving all the rest alone (shifter choice and gearing), since shifter choice doesn't make as much of a difference, since reduced friction from race gearboxes doesn't count in a whp/weight system and since with the possibility to use any gearboxes and differential ratio, one can get close ratio options even if its not a race box.

 

Personally I would say no, since that would be against the "purpose" of GTS being power to weight only. I do not race in GTS right now, altho I did have plans on it and I have many special gearboxes ideas for myself (and none are out of mind expense and none include just buying an available race gearbox at crazy prices) just creativity and alot of thinking (and nice tools/contacts). Why would you be allowed to play with creativity in all other places, engine choice, aero, custom suspension, tire choice but not be able to use it for the transmission department?

 

4 speeds dogboxes are very affordable, other options are available to as faceplated factory transmission that are cheaper than alot of suspension setups out there, but affordable options aren't bolton. Is this a reason to add a factor to it and claim it will raise costs alot because there IS high end options to those?

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Some more data for the discussion from "Analysis Techniques for Racecar Data Acquisition" by Jorge Segers on pg 54, Table 6.3.

 

Typical upshift times for various racecars:

F3 car: 0.15 sec

Porsche 911 GT2 Turbo, synchro H-pattern: 0.35 sec

Dodge Viper GTS-R, synchro H-pattern: 0.32 sec

Dodge Viper GTS-R, sequential no powershift: 0.23 sec

Dodge Viper GTS-R, sequential with powershift: 0.18 sec

LMP1, sequential paddle shift: 0.10 sec

 

For current gearboxes out there, mostly from manufacturer literature and/or Wikipedia

VW DSG: 0.008 sec

BMW SMG II (E46 M3): 0.080 sec

BMW M-DCT (E92 M3): 0.080 sec

 

I think the advantages are obvious in that you are giving up .27 secs per shift assuming you shift your H-pattern synchro box perfectly and quickly every time to an SMG/M-DCT transmission. For Mid-Ohio, assuming you shift 6-8 times per lap, that's 1.62 to 2.16 secs per lap. Granted it is not straight time lost but rather time spent not accelerating, but in a quick look at my data and some conservative estimations, the time to be gained is pretty close to that.

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either have a factor for all gearboxes like SMG II, DCT, PDK, dogbox, sequential or don't have a factor for any.

 

Reasoning is to be on an even playing field with the factory quick shifting boxes one would need to move to a dogbox or a sequential. It wouldn't really be fair to penalize one and not the other.

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Having first hand experience with using factory street / stock SMG box in E46M3 can tell that there are as many disadvantages as many assumed advantages. The biggest one is reliability. Those are simply not designed and not intended for race application (at least in e46m3). The unit is the same manual gearbox with the hydraulic pump attached. It is sealed and fully enclosed sitting between the engine block and the box with no cooling or circulation with less than a quart of liquid in it. There were few attempts to fabricate the cooling mechanism to a various degrees of success, but it is still far from being reliable, and often will send the car to the limb mode or will make shifting very slow at least. After a year of experimentation we managed to get to some degree of performance by relocating the whole assembly, which is complicated and labor intense to say the least.

On another note, the E46m3 SMG doesn't offer advantages in shorter ratio or no lift shifting, unlike true race automated boxes. It will also only shift with in certain rev window, and will not switch to the fastest mode with traction control on, which helps in the rain.

I simply chose it once the suitable car became available for the project, learned a lot, but would stick to manual next time.

The bigger question is, should we single out this particular feature and ignore upgrades in brakes, suspensions, aero, wide body, etc...?

From the standpoint of documented and calculated advantage, there are many aspects to consider besides gearboxes. Also, should gearbox be part of the drive train of a given manufacturer?

Until now, we strived to protect the open rule set in GTS, and the proposed change may open a Pandora Box. I don't see how we can argue against penalties for other mods if we will accept this one.

 

Michael G. NE GTS Dir.

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No matter what argument you make about "shift time" a factory paddle shift like SMG should not be in any way considered similar to a dogbox or sequential. Mike is right in many regards there.

 

But a dogbox or sequential should be penalized. Anyone that has one would agree that it's an advantage. Personally I think any car with a non-OEM gearbox should be penalized. The exception to the rule would be a Cup with the factory dogbox and a line item could be written to include that car.

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. The biggest one is reliability.

 

Michael-

I dont think reliabilty has relevance to the proposal. But maybe i should re-phrase though, when I mean electronic I meant to include the race stuff, sequential etc... too. Maybe you dont penalize smg since it comes installed as original equipment. Again, I leave the details to those with way more knowledge than me (obviously, lol). But if a "race" gearbox provides a significant mechanical performance advantage, then it worth considering, as dont we try and level the mechanical performance by classing?

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Again, my bigger concern is opening rules to the factors of mods outside of hp, weight and tire compound. The next will be brakes, aero, suspension, etc...

As long as everyone agrees on changing direction, fine with me.

I can tell that triple adjustable external reservoir is much better than stock, the same for big brake kit and 6 piston calipers, the same is for the big wings and flat bottoms...

 

Michael G. NE GTS Dir.

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FandangoDrew

I have to agree with Michael on both fronts here:

 

1/ SMG is not an advantage, I have been running it for 5 years now and when you take into account the limited rear end ratio that will work with SMG, the weight of the equipment needed to make it work as well as the factors Michael already quoted it is a distinct disadvantage.

 

2/ we have not added factors for things like suspension, brakes, aerodynamics or engine management why do it for gear boxes?

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This idea that the GTS rule book is hp/wt pure as the driven snow is a red herring, IMHO. We already make allowances for tires, tube-frame, and torque. This is merely consideration of whether it makes sense to add one more category that could get very expensive very quickly. It is not a precedent...

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I can appreciate the slight advantage that a dog face box or true sequential box can give. But I intuitively (and I may be way wrong on this) I think that the advantage is a rather small one.

 

Seems to me the tires and the car setup are more of a dominating factor in terms of car capability.

 

I'd by lying if I didn't say the idea of a true race box being penalized irks me. Street gearboxes are challenged to withstand the abuse of racing. Synchros get wasted by all those high rpm shifts. If someone can afford a dog face box, great, go for it. I'd love dog faced gears that would increase the durability of my old gearbox. Rebuilds would be a lot simpler (less parts to look after/inspect for replacement) and the gearbox would run cooler. Synchros generate a good bit of heat, especially in an old 915 box.

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In all practical terms there is an open "spirit" to GTS but rules used are to create fair competition. Byproducts like controlling cost and creating accessibility are also heavily considered. A race gearbox is an advantage pure and simple. Basically unlimited gear ratio selection and ease/speed of shifting.

 

Making an argument that a racebox makes racing more practical is sort of ridiculous. My crappy OEM gearbox has lasted 6 years? How many Porsche and BMW drivers are swapping transmissions every couple of events??? I honestly can't name one.

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In all practical terms there is an open "spirit" to GTS but rules used are to create fair competition. Byproducts like controlling cost and creating accessibility are also heavily considered. A race gearbox is an advantage pure and simple. Basically unlimited gear ratio selection and ease/speed of shifting.

 

Making an argument that a racebox makes racing more practical is sort of ridiculous. My crappy OEM gearbox has lasted 6 years? How many Porsche and BMW drivers are swapping transmissions every couple of events??? I honestly can't name one.

 

How would you treat a factory gear box with a custom gear set then, gear ratio selection but still synchro shifted (slow), but also a short rear end drive can lead to "close" ratio for some people with factory gear box to.

 

How would you treat a factory gearbox with a sequential shifter attachement? (Which is similar to swapping for a short shifter in the end...) is that considered "race box" or no penalty? Because in fact it problem would be only a very small advantage.

 

What if one combined both of those but kept synchro and factory casing... technicly it still not a race gear box but does it gets penalized versus the high end race gear box stuff?

 

A brand new 4 speed dogbox is under 4000$, all over the place at 1500-2000$ used from nascar resellers.... is that considered expensive? Yes the very high end stuff is pricy and better, but most of their advantage over cheaper units = weight reduction and (less rotating weight so of course) less drivetrain loss. But in a whp/weight scenario neither of these 2 factor makes much of a difference.

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