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Greg G.

TECHNICAL BULLETIN-Mazda Miata Driver Seat Floor Pan 1-29-16

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Greg G.

TECHNICAL BULLETIN 1-29-16

Mazda Miata Driver Seat Floor Pan

 

Appendix B—Technical Bulletins for Specific Models/Items

Mazda Miata ('90-'05)--PTB-PTF:

The driver’s side floor pan may be modified to accommodate larger/taller drivers. All modification shall be contained between the transmission tunnel, driver’s side rocker, rear bulkhead and no more than 24” forward of rear bulkhead. The modification shall not extend below the factory floor stiffener/frame rail. The steel used in the modification shall be no thinner than .060”. All modifications shall be welded in place. This modification shall serve no other purpose other than seating position.

The assessment for having this modification will be an additional 100 lbs of weight added to the vehicle's base weight (or 100 lbs added to a Dyno Re-class if the vehicle is using a Dyno Re-class instead of the base classing table).

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Savington

Can you explain the logic behind assessing a 100lb penalty for what is essentially a safety modification for larger drivers?

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hhdinyuma
The assessment for having this modification will be an additional 100 lbs of weight added to the vehicle's base weight (or 100 lbs added to a Dyno Re-class if the vehicle is using a Dyno Re-class instead of the base classing table).

 

Might this make this car the one to have in ST or TTU-3 since there would essentially be no penalty as there are no base classes or dyno re-classes in these groups? I realize this bulletin wasn't posted in the ST forum, but it was posted in the TT forum and doesn't specify which classes it applies to, just added to appendix A, so I assume it covers all TT classes. Since TT3=ST3 then by extension it would seem to apply to ST as well.

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Greg G.

Hal,

 

We added the designation to PTB-PTF, as it was assumed that these modifications at the higher level TT classes and ST would kick in the Non-Production Vehicle Mod Factor since there was no assessment listed for those classes. But, this should clear that up for you. We have a fair amount of crossover and Supersize competitors from SM to TT and PT, and although we (TT/PT officials) don't agree that this new SM rule was necessary or that it is "only for seat position", we don't want to automatically exclude these vehicles from PT and lower TT classes because the driver chose to make what is now a legal SM modification, but is not legal otherwise in PT or TTB-F.

 

In regard to who decided on the amount of weight assessed in this Technical Bulletin, it was the NASA National Chairman with agreement by the NASA National TT/PT/ST Director, and the NASA National Competition Director. It was also decided not to open this modification up to all vehicles, and that the 100 lbs. was enough for the large majority of competitors to agree that this modification would not be worth adding another 100 lbs. to their non-Miata vehicle.

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Greg G.
Can you explain the logic behind assessing a 100lb penalty for what is essentially a safety modification for larger drivers?

 

1) The modification is not legal under the PT/TT rules that do not permit modifications to the floor pan.

2) It was also not legal in SM until 2016.

3) We have hundreds (more like thousands) that have driven with NASA over the past 20 years without needing this modification.

4) If a SM competitor chooses to do this modification, that has not been needed for 20 years, that was not legal in PT/TT, then one would assume that the competitor doesn't care about PT/TT competition since the modification was not permitted (except as a Non-production vehicle in TT3+).

5) Regardless of what the SM rule states, if the driver seat is permitted to be dropped down, there is a potential performance advantage, especially for a vehicle weighing less than 2400 lbs. (some down to 2100 lbs in PT). In fact, it will be interesting to see how many 5'5" to 6'2" drivers decide to have this modification for SM.

6) If we don't allow this modification in PT/TT for the Miatas, we may have a significant number of drivers who won't be able to supersize (or who buy a prepped Miata and later find out that they can't run PT/TT in it).

7) This is not a modification that we agree is necessary, want to inspect (safety or compliance), or want to become a "must have" for all vehicles in PT/TT to "keep up" with the other guy. In fact, because the frame "rail" must be cut into to make this modification, if it is not done correctly, there is no doubt that this will make the car less safe, not more safe.

8) We don't want drivers of other models complaining that this is permitted for the '90-'05 Miatas, but not their car model.

9) We don't want to encourage Miata drivers in PT/TT (since there is no way to isolate this to SM cars) to make this modification.

10) 100 lbs was the number that NASA executives felt was enough to accomplish all of the above.

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Savington

Makes sense, thanks.

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tonysenese

Well done Greg, I have wondered myself how much this modification was for tall drivers, and how much was to get a lower CG. I'm 5'11" and do not need it, my seat sits almost on the floor at the back and i have no issue with the cage.

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Matt@NCM

Does this apply to massaging the tunnel with a hammer - asking for a friend....

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Greg G.
Does this apply to massaging the tunnel with a hammer - asking for a friend....

Refer your friend to the PT Rules, Section 5.3.I.h.16 (page 26 of '16 PT Rules).

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