2013 Weight Break TAD/TAFC

DRAGSTER, DRIVETRAIN: 2 TRANSMISSION (Page 5)

Transmission prohibited in non-supercharged, nitromethane burning class. OEM or OEM-modified transmissions prohibited in all classes. Aftermarket planetary transmission permitted in supercharged classes, limited to two units (three speeds). Converter equipped cars may deduct 50 pounds from minimum weight. Overdrive transmission prohibited. Final drive ratio must be 1:1. Clutch hold-down device recommended on all cars. Reverser mandatory. Automated shifters and/or timer-type shifting devices prohibited; each individual shift must be a function of the driver. Air shifter bottles must be stamped as meeting DOT-1800 pound rating and permanently mounted (hose clamps

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Brandon Booher
NHRA TAD #34

 

Hey Brandon, over on InsideCompRacing we just had a somewhat related discussion about converter drives.

http://www.insidecompracing.com/showthread.php?t=8254&page=6

You have done very well with the converter combo. Do you think that 50 lbs is "fair"?

Patrick Hale
www.DragRacingPro.com

 

T/AD & TA/FC with converter

I’ve been doing some math over at InsideCompRacing about how much HP/ET is lost when switching from a clutch to a torque converter. So how about some Motorsports Engineering applied to this question for T/AD.

We could use Champ Jim Whiteley “Outstanding Run of the Year” 5.178 ET @ 277.43 for the example . . . but instead let’s use a more realistic run as the baseline – a 5.25 ET @ 273 MPH. The engine makes about 3700 HP and the car weighs 2080 lbs.

Now we take out the clutch and replace it with a LencoDrive or B&Jdrive or BrunoDrive etc, – take your pick. It includes a fluid pump and transbrake drum and my estimate is that the converter drive will take about 22.5 HP to spin it at 10,000+ RPM.

The first case is for a standard torque converter at 3.6% slippage. That’s another 133.2 HP, for a total loss of 155.7 HP (4.2% out of 3700 HP). The “classic” cube root method from Motorsports Engineering can be used to estimate that the 155.7 HP loss will slow the T/AD down 0.076 seconds with the converter drive. A 5.25 ET becomes 5.326 seconds.

The second case takes the 50 lbs weight break into account. The minimum weight goes from 2080 lbs to 2030 lbs. The cube root of this weight ratio is 0.9919, which results in a 5.283 predicted ET.

Finally, let’s add a lock-up converter to this T/AD combination. The converter can probably only be in lock-up mode once you get into high gear, or about 50% of the run. You can’t launch the car or shift from 1st gear to 2nd gear with the converter locked up. To estimate this effect, let’s knock the torque converter slippage HP loss in half . . . to just 66.6 HP. The total loss is now 89.1 HP (a smaller 2.4% of 3700 HP) and the projected ET with a lock-up torque converter at 2030 lbs would be 5.250 seconds.

On paper, this looks like a great option! NHRA’s 50 lbs break seems just about right.

Patrick Hale
www.DragRacingPro.com

 

How does the increased torque multiplication factor into your equation? I would rather them let us run lock up converters and keep the 50 lbs. What are you basing your 22.5 hp loss on? The operation of the pump and associated drag from the bearings in the converter drive? I have run lock up converters and locked them early in the run. I have also lock and unlocked them for the shift and then relocked them. On one car it went from 7.80s locking the converter in high gear to 7.20s locking the converter around the 60' marker and leaving it locked for the entire run. 3000 lb door car over 10 years ago.

 

And it's fair that a clutch can lock 100% but not the converter? I don't think that the weight break is the answer.

 

Why now

Why should there be a weight break when you chose the combination.There used to be weight breaks for different engine combos then after people built them nhra took it away are they going to do the same here? Are pro mods going quicker with converters do they get a weight break?

 

You missed the part where he said "controlled" lock up. With a clutch you have to tune it and everything around it to lock it up and that's a lot more difficult than just telling it to lock up. But if the primary concern is % slippage through high gear, welcome to the clutch world. Yeah, I can hang more weight on it, but what is that going to do to the rest of the tune-up? And if you get the clutch too hot, it won't lock up either, just like your converter drives.

I think the bigger challenge for most people would be getting 50 lbs off the car, but I don't think lock ups or the weight break are the answer either. Clutch companies and racers have had to innovate and learn how to manage them over the years. Why should converters be treated any differently? Just because you and your manufacturers haven't figured out how yet? Neither have probably 95% of us who run clutches, and the 5% that haul ass no matter where they go are still figuring it out too, they just have horsepower to save the screw ups. I agree with Kosky on this, you made the conscious choice to run a different combination.. Part of the price you pay for being different sometimes. Personally, I think us Veney head cars should get a 50 lbs weight break too. lol.

Okay, time to flame the clutch guy for chiming in on converter stuff. Business wise, I have nothing against converter drives. I'm not looking to protect my interests against converters. If they are that much better an alternative, then we need to step our game up in the clutch world. I just don't think they should be part of an exception either and NHRA should regulate converters like they do clutches with design submissions, approval and application guidelines like our "lockup in name, staged release clutches prohibited." If you allow lock up converters, you have to allow lockup clutches.

 

I didn't ask for a weight break, in fact NHRA has not once spoken to myself or my father about our combination....interesting seeing as we run a fairly competitive car. At the US Nationals (2012) our car was 2115 lbs, 40 lbs. over our legal weight of 2075. When the car hits the track next we'll roll the scales at 2025 on the nose...but most likely 5 lbs. over for insurance. The converter technology is progressing, in the 1/8th mi. we could have a championship car. We have some new stuff for next season, will it be any better...not real sure yet. The hardest thing for us has been getting the weight off, our car is nearly brand new, and had a lot of lightweight stuff on it already. Some people think 90 lbs. will be worth "X" and some think "Z"....I suppose only time will tell. The lockup deal w/ a Lencodrive won't be coming anytime soon, and when it does it's going to be a large financial bullet to bite, new converter, new can, mgmt. equipment, trans mods., etc. etc...

Brandon Booher
NHRA TAD #34

 

The thing with the converter is you can't take the inspection window off and tweak it to the track. To do this you have to pull the converter completely out and take it apart to make the necessary changes. You can control how early or late in the run your clutch locks by adding and subtracting weight and/or changing gear ratios. As for the lockup controller, make the rule read that they are prohibited and that it's input must be a function of the driver as a one time deal. So basically what you guys are saying is the hell with being different and innovation? If its not the norm (aka a hemi with a clutch) we shouldn't run it? Drag racing was built on new ideas and innovation, especially the alcohol classes. If we keep going the way we are there is going to be one chassis manufacture, one engine manufacture, etc etc and all we will be doing is 'spec' racing like some other organizations out there. Not sure why everyone is so scarred of the lock up deal. Do you guys really think that it would give that much of an advantage? Thinking along the same mentality, should the clutch guys be able to use a two step because the converter guys are using one?

 

All nice technical discussion but why the weight break....its a choice to run this combo?

 

I don't see why the complaints or concern? How is this any different than a-fuel not being allowed to chill the fuel, run certain %....should they just be allowed to do whatever and it's tough luck for anyone with a blown car? The converter setup is completely different than anything else, rules to make the setup more competitive with others in the class is a good thing. Like I said before I don't know where the change actually came from, we are busy working on our own setup to catch cars that are faster than us. I suppose the weight break may be a good thing, lots of things look good on paper when equated out via physics etc..

Brandon Booher
NHRA TAD #34

 

Who said the hell with being different and innovation? I just don't think you should be an exception to the rules because you CHOSE to go a different path. Do guys running anything other than Brad stuff in blower cars get any exceptions? No? Then why should you? Part of the price you pay for being innovative and leading the pack is you fail more often than you succeed.. Which I think we can all agree happens regardless of how new or old your combination is.. But it is just part of the deal. You can't compare running a converter to running a/fuel.. That's two completely different motors on completely different fuels with different setups.. You still have the same blown engine combo as the other guys, you just chose to do something different with the driveline. I think this just starts a bad precedent for more "exceptions" and before you know it, every car that shows up to the race will get a Wally, 85 points and a winner's check. Like I said, to me the weight break sounds as silly as my car getting 50lbs lighter because we run a Veney. And for the record, no, I don't think converter cars should be able to run a two-step either if the clutch cars can't. I'm tired of socialism in heads up racing. If you want to run a way different combo than everybody else within the same confines as everyone else, go for it. I support anyone who does something different. If you want to run something completely different than everyone else in the same class but with your own set of rules, well, then there's always Comp.

 

What prompted this? Other than Brandon who else runs one in a dragster? They're already competitive in the f/c's. Anderika was #15 this year and Jirka Kaplan ran a .60 flat in Pomona on what I believe was the second race on the car.

Conspiracy theory: pro teams are having trouble getting enough clutch discs so they get nhra to push the converters in the alcohol classes?

 

Weight break

Will you cover my point that there are to many unknowns to give this weight break to .My question is how did this weight break happen ,was out of the goodness of nhra?My point again is that pro mods have proven that they can go faster with the converter did nhra give them a weight break at the same time? This did not just happen out of the clear blue sky some one pushed for it.

 

Let the whining begin!!!

Merry Christmas to All !!! Let the whining begin. First let me say when NHRA came to me and TOLD me we were getting a weight break, I probably was the first person to ever ask them not to. I said to Collins 50 lbs. isn’t worth the whining that will go on. But now that it is brought up lets look at it. As Patrick Hale pointed out 50 Lbs is probably worth .04. As Will said, we have gone .54 what he didn’t say was
Ferro went .49 next to us on that run and Frank went .47 that day. That’s .07.
Fastest run ever with a converter .54, with a clutch .41 that’s .13.
NHRA as always made adjustments to try to even the field, 100 LBS for a roots blower. Nitro adjustments. Hey Mike, how about giving back that extra overdrive you got? Maybe better yet go back to the 1990 rules and not adjust the weight break (2.80 lbs. for nitro with 100%). As for the Veney head, Gill has been 40’s with it.
With reaction times Frank and Mickey would both consider a .50 late. If 50 lbs is such an advantage maybe Frank will put a converter in his new car.
Now for some fun. I think that to improve the show is we give back the 50 lbs, but go to a 40 minute turn around at regionals, Qualify and run eliminations the same day , 12:00/ 12:40/ 1:20 /2:00 finals at 2:40. Great way to give the fans a good show.
I think NHRA is trying to encourage more sportsman racers who are more familiar with converters to come into the alcohol classes so the rest of us don’t have to buy ProMod chassis. As Bob Dylan said “ the times they are a changin “

 

overdrive

Chuck I think your missing it every blown car got that instead of droping the nitro percentage. Gee---- chuck it looks like we might have found who asked for the change.

 

I would like to point out that in a very short time as usual Les has Jirka's car flying (any car he tunes). Be interesting to see where they are in a year. On the other hand for TAFC.....screw vs roots. Jimmy Rector vs Frank Manzo's record....A 50 lb break to equalize that ??. Maybe no one will try a roots anymore. I know I'm over on the nitro side now but I'd sure like to keep seeing TAFC racing.
40 minutes between rounds....Checking for safety items wouldn't happen then. Chassis, crankshafts, bearings...hmmm don't like that idea. God forbid if you had to change a valve spring or a rearend or got delayed at the scales.
Just my opinion
Dale