Rollout at SGMP

65Shoebox · 03-07-2011, 06:35 PM

For those there, can you explain to me why theheck they changed the rollout so dramatically from testing on Thursday to Friday. I made 6 hits on Thursday all with decent rts. On Friday I couldn't get less than .040 with my normal delay in the box.

Took out all the delay Saturday AM and went .015. Unfortunately I kept it out and then went red in first round when the heart rate was way up...

What gives with NHRA changing the rollout like that??

63corvette · 03-07-2011, 07:10 PM

Quote:

Originally Posted by 65Shoebox

For those there, can you explain to me why theheck they changed the rollout so dramatically from testing on Thursday to Friday. I made 6 hits on Thursday all with decent rts. On Friday I couldn't get less than .040 with my normal delay in the box.

Took out all the delay Saturday AM and went .015. Unfortunately I kept it out and then went red in first round when the heart rate was way up...

What gives with NHRA changing the rollout like that??

NHRA does that quite often at the National Events and you can bet on it happening when the Pro Stock Motorcycles are there.
You just have to plan on it happening and talk to the track personnel to get a heads up when it does. That way you know when it changes.
Its a crap shoot.
Just The NHRA Way....
My 2 Cents
Rick Cates

Rollins_2241 · 03-08-2011, 09:18 AM

NHRA resets to their specs before every event. Whether it's done prior to the test day or just prior to qualifying I can't tell you, that may also vary by track.

SGMP is the loosest track on tour in Division 2 and always has been. I think it's the way the track is built, with very little crown and grooves in the middle of each lane rather than toward the inside (e.g. Gainesville). Do a little geometry and you'll see that's a recipe for dumped delay boxes and small front tires.

65Shoebox · 03-08-2011, 02:51 PM

Quote:

Originally Posted by Rollins_2241

NHRA resets to their specs before every event. Whether it's done prior to the test day or just prior to qualifying I can't tell you, that may also vary by track.

SGMP is the loosest track on tour in Division 2 and always has been. I think it's the way the track is built, with very little crown and grooves in the middle of each lane rather than toward the inside (e.g. Gainesville). Do a little geometry and you'll see that's a recipe for dumped delay boxes and small front tires.

Can you please ellaborate a bit futher? I am not sure I understand the connection to the down-track surface and the the rollout.

Rollins_2241 · 03-08-2011, 04:03 PM

Downtrack doesn't matter, it's the crown and position of the groove at the starting line.

NHRA sets the beam height the same everywhere (1 + 9/16" I think.) and tests it with a 22" front tire template so that the "on paper" rollout of about 11" is established. Exactly how they do that is better explained by Jeff Foster.

But that doesn't account for where your car is in a real time trial. You should stage "in the groove" but the groove is not the same distance from the infrareds at each track, nor is it the same throughout a weekend. None of this matters if the track is perfectly level relative to the beams, but most tracks are built with varying degrees of "crown" for drainage.

The bottom line is that where you stage "east to west" as well as "north to south" when staging can have an impact on rollout and reaction time, and it is impossible to standardize conditions totally from track to track. And of course, we haven't even talked about the human element.

65Shoebox · 03-08-2011, 05:57 PM

Got it. That makes perfcet sense. I learned a valuable lesson this time.

Another racer told me that NHRA may, from time to time, stretch the rollout a bit to help the stock/SS and comp guys with record runs.

Frustrating for those of us that just want to get a good light, but I understand the polictics both with NHRA and the track...

I also need some more practice hitting a good consistent light... and I understand that.

Thanks for the replies

Regan Wilson · 03-14-2011, 06:09 PM

It may not be the rollout . They changed our tree in D4 to the National type tree . In other words .500 is more like .470 . Supposedly it was to keep every thing consistant from National to Division races . I can do a track operated test session on thursday and the lights are 30 slower on friday with NHRA . MY PROBLEM IS IF YOU RUN THIS STUFF WITH COMPUTERS WHY SCREW WITH US !!!!!!! 500 should be 500 not 470 and if Pro Stock MC has a redlight problem give em a dang 300 tree . Ok I'm gettin off my soapbox now ! Thanks for listening .

Regan Wilson · 03-15-2011, 07:18 AM

Maybe I was wrong about the tree and maybe it is the rollout . The bad thing is I could never get an answer about it from an NHRA official as to what and why this was going on .Thanks Rollins

03-07-2011, 06:35 PM	#1
65Shoebox Junior Member Join Date: Oct 2009 Posts: 32 Likes: 0 Liked 0 Times in 0 Posts	Rollout at SGMP For those there, can you explain to me why theheck they changed the rollout so dramatically from testing on Thursday to Friday. I made 6 hits on Thursday all with decent rts. On Friday I couldn't get less than .040 with my normal delay in the box. Took out all the delay Saturday AM and went .015. Unfortunately I kept it out and then went red in first round when the heart rate was way up... What gives with NHRA changing the rollout like that??

03-08-2011, 09:18 AM	#3
Rollins_2241 Member Join Date: Nov 2007 Location: Tallahassee, FL Posts: 170 Likes: 0 Liked 0 Times in 0 Posts	Re: Rollout at SGMP NHRA resets to their specs before every event. Whether it's done prior to the test day or just prior to qualifying I can't tell you, that may also vary by track. SGMP is the loosest track on tour in Division 2 and always has been. I think it's the way the track is built, with very little crown and grooves in the middle of each lane rather than toward the inside (e.g. Gainesville). Do a little geometry and you'll see that's a recipe for dumped delay boxes and small front tires.

03-08-2011, 04:03 PM	#5
Rollins_2241 Member Join Date: Nov 2007 Location: Tallahassee, FL Posts: 170 Likes: 0 Liked 0 Times in 0 Posts	Re: Rollout at SGMP Downtrack doesn't matter, it's the crown and position of the groove at the starting line. NHRA sets the beam height the same everywhere (1 + 9/16" I think.) and tests it with a 22" front tire template so that the "on paper" rollout of about 11" is established. Exactly how they do that is better explained by Jeff Foster. But that doesn't account for where your car is in a real time trial. You should stage "in the groove" but the groove is not the same distance from the infrareds at each track, nor is it the same throughout a weekend. None of this matters if the track is perfectly level relative to the beams, but most tracks are built with varying degrees of "crown" for drainage. The bottom line is that where you stage "east to west" as well as "north to south" when staging can have an impact on rollout and reaction time, and it is impossible to standardize conditions totally from track to track. And of course, we haven't even talked about the human element.

03-08-2011, 05:57 PM	#6
65Shoebox Junior Member Join Date: Oct 2009 Posts: 32 Likes: 0 Liked 0 Times in 0 Posts	Re: Rollout at SGMP Got it. That makes perfcet sense. I learned a valuable lesson this time. Another racer told me that NHRA may, from time to time, stretch the rollout a bit to help the stock/SS and comp guys with record runs. Frustrating for those of us that just want to get a good light, but I understand the polictics both with NHRA and the track... I also need some more practice hitting a good consistent light... and I understand that. Thanks for the replies

03-14-2011, 06:09 PM	#7
Regan Wilson Member Join Date: Nov 2007 Posts: 245 Likes: 141 Liked 125 Times in 65 Posts	Re: Rollout at SGMP It may not be the rollout . They changed our tree in D4 to the National type tree . In other words .500 is more like .470 . Supposedly it was to keep every thing consistant from National to Division races . I can do a track operated test session on thursday and the lights are 30 slower on friday with NHRA . MY PROBLEM IS IF YOU RUN THIS STUFF WITH COMPUTERS WHY SCREW WITH US !!!!!!! 500 should be 500 not 470 and if Pro Stock MC has a redlight problem give em a dang 300 tree . Ok I'm gettin off my soapbox now ! Thanks for listening .

03-15-2011, 07:18 AM	#8
Regan Wilson Member Join Date: Nov 2007 Posts: 245 Likes: 141 Liked 125 Times in 65 Posts	Re: Rollout at SGMP Maybe I was wrong about the tree and maybe it is the rollout . The bad thing is I could never get an answer about it from an NHRA official as to what and why this was going on .Thanks Rollins