RT help

Ron Gusack · 06-13-2016, 10:09 PM

I footbrake in a 6.50 index class that uses a .400 tree. To get decent lights, I have to deep stage. This works really well as long as the starter doesn't send the tree the instant I put out the top bulb. I made 4 passes on Saturday and my worst light was .021 because he gave me time. On the 5th pass he sent the tree as soon as I put out the top bulb. I was .240. Will a transbrake allow me to stage light? Will a 2 step? I'm running a 400 trans but seriously thinking about going to a glide.

Mike Gray · 06-14-2016, 01:38 AM

Ron, there are 2 reaction times involved in leaving the line. The drivers reaction to the light on the tree and the cars reaction to the input from the throttle, trans brake etc. If your car is slow changing the transmission may not help much. A two step or trans brake may help slightly with the increased rpm over the foot brake method but until you get the car set up to cut a good light the best driver in the world may always be late on a pro tree. There are plenty of places to look to improve the cars reaction time. I would start with optimizing what you have and then make the changes needed for improvement. My vote would be to go to a tran brake and then start the sorting out process all over again, you may soon need a delay box.
Good luck

Ron Gusack · 06-14-2016, 11:24 AM

I should have posted this in the tech section. Thanks Mike. It's been a long time since I tried to stage light with a .400 tree, but I think my lights were .075-.095.

Lenny5160 · 06-14-2016, 12:20 PM

Very few 6.50 door cars will be able to go .000 on a .400 Pro tree.

I think you would be a little quicker with a transbrake/2-Step setup with a Pro Tree transbrake, but you'd still be in the .040-.050s at best.

Most of the Super Gas guys run some combination of aggressive chassis setups, small front tires, and front travel limiters to cut a light. And that is likely launching with a lot less weight and more power than you have.

Ron Gusack · 06-14-2016, 02:14 PM

Quote:

Originally Posted by Lenny5160

Very few 6.50 door cars will be able to go .000 on a .400 Pro tree.

I think you would be a little quicker with a transbrake/2-Step setup with a Pro Tree transbrake, but you'd still be in the .040-.050s at best.

Most of the Super Gas guys run some combination of aggressive chassis setups, small front tires, and front travel limiters to cut a light. And that is likely launching with a lot less weight and more power than you have.

Thanks Lenny, that's what I was afraid of. A .400 tree is kinda ridiculous for a 6.50 car, but that's what the two tracks in this area run. I guess I just have to beat my opponent to the tree and get staged first. I hate to double bulb people and look like a jerk. I've tried just rolling in and not bumping, but I'm not in the same place every time so the RT and the ET vary.

Bill Baer · 06-15-2016, 11:11 AM

Mike Gray's advice is spot on.
You might also look into a device Called a "Bump Box" which will allow you to roll in deeper while keeping the top bulb lit. (If the blue light is on)
Note this device is only NHRA legal for Pro-Mod so check with your local track before you consider buying one.

Ron Gusack · 06-16-2016, 04:45 PM

I softened the rear shocks and the car hooks better so I'm going to adjust the front shocks to limit travel. I can see that I'm running a little too much air in the slicks too. But I guess no matter what I do I won't be able to get .00 lights by footbraking. Maybe if I had a really loose converter or more gear.

rtr0id · 06-16-2016, 05:29 PM

you could try leaving a couple hundred rpm higher

Keith 944 · 06-16-2016, 06:43 PM

http://classracer.com/classforum/showthread.php?t=57448
I thought we had tried this before....
guess we don't know what we are talking about

Rich Biebel · 06-16-2016, 08:36 PM

I footbraked in S/ST on a .400 tree in the early 80's....Deep staging not allowed by then...

69 Camaro....small block...PG....

I had an ATI treemaster 8" converter and could stall it to 5000 or even a little higher....

Could get maybe .460 RT at best.....without rolling in some....

Biggest RT improver....LIMIT FRONT END TRAVEL....but you will spin the tires once you go to far...been there done that...

There were a few cars and guys that could get decent RT's shallow staged footbraking but they refined their cars and probably staged as deep as they could without knocking the top light out.....

06-13-2016, 10:09 PM	#1
Ron Gusack Member Join Date: Feb 2009 Posts: 244 Likes: 1 Liked 7 Times in 6 Posts	RT help I footbrake in a 6.50 index class that uses a .400 tree. To get decent lights, I have to deep stage. This works really well as long as the starter doesn't send the tree the instant I put out the top bulb. I made 4 passes on Saturday and my worst light was .021 because he gave me time. On the 5th pass he sent the tree as soon as I put out the top bulb. I was .240. Will a transbrake allow me to stage light? Will a 2 step? I'm running a 400 trans but seriously thinking about going to a glide.

06-14-2016, 01:38 AM	#2
Mike Gray Senior Member Join Date: Oct 2006 Posts: 617 Likes: 311 Liked 687 Times in 198 Posts	Re: RT help Ron, there are 2 reaction times involved in leaving the line. The drivers reaction to the light on the tree and the cars reaction to the input from the throttle, trans brake etc. If your car is slow changing the transmission may not help much. A two step or trans brake may help slightly with the increased rpm over the foot brake method but until you get the car set up to cut a good light the best driver in the world may always be late on a pro tree. There are plenty of places to look to improve the cars reaction time. I would start with optimizing what you have and then make the changes needed for improvement. My vote would be to go to a tran brake and then start the sorting out process all over again, you may soon need a delay box. Good luck

06-14-2016, 11:24 AM	#3
Ron Gusack Member Join Date: Feb 2009 Posts: 244 Likes: 1 Liked 7 Times in 6 Posts	Re: RT help I should have posted this in the tech section. Thanks Mike. It's been a long time since I tried to stage light with a .400 tree, but I think my lights were .075-.095.

06-14-2016, 12:20 PM	#4
Lenny5160 Senior Member Join Date: Nov 2015 Location: Inver Grove Heights, MN Posts: 898 Likes: 604 Liked 431 Times in 224 Posts	Re: RT help Very few 6.50 door cars will be able to go .000 on a .400 Pro tree. I think you would be a little quicker with a transbrake/2-Step setup with a Pro Tree transbrake, but you'd still be in the .040-.050s at best. Most of the Super Gas guys run some combination of aggressive chassis setups, small front tires, and front travel limiters to cut a light. And that is likely launching with a lot less weight and more power than you have. __________________ S/ST 51 S/C 53

06-15-2016, 11:11 AM	#6
Bill Baer Senior Member Join Date: Jul 2007 Location: Nothern IL Posts: 596 Likes: 1 Liked 1 Time in 1 Post	Re: RT help Mike Gray's advice is spot on. You might also look into a device Called a "Bump Box" which will allow you to roll in deeper while keeping the top bulb lit. (If the blue light is on) Note this device is only NHRA legal for Pro-Mod so check with your local track before you consider buying one. __________________ Bill Baer 3391 SC, 339B SC, QR Last edited by Bill Baer; 06-15-2016 at 12:00 PM. Reason: More info

06-16-2016, 04:45 PM	#7
Ron Gusack Member Join Date: Feb 2009 Posts: 244 Likes: 1 Liked 7 Times in 6 Posts	Re: RT help I softened the rear shocks and the car hooks better so I'm going to adjust the front shocks to limit travel. I can see that I'm running a little too much air in the slicks too. But I guess no matter what I do I won't be able to get .00 lights by footbraking. Maybe if I had a really loose converter or more gear.

06-16-2016, 05:29 PM	#8
rtr0id Member Join Date: Sep 2012 Posts: 183 Likes: 1 Liked 0 Times in 0 Posts	Re: RT help you could try leaving a couple hundred rpm higher

06-16-2016, 06:43 PM	#9
Keith 944 VIP Member Join Date: Feb 2006 Location: Dela-where? Posts: 2,193 Likes: 1,161 Liked 1,877 Times in 577 Posts	Re: RT help http://classracer.com/classforum/showthread.php?t=57448 I thought we had tried this before.... guess we don't know what we are talking about __________________ KEITH MAYERS 2-1/2 X somebody Still many X nobody

06-16-2016, 08:36 PM	#10
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,314 Likes: 25 Liked 544 Times in 213 Posts	Re: RT help I footbraked in S/ST on a .400 tree in the early 80's....Deep staging not allowed by then... 69 Camaro....small block...PG.... I had an ATI treemaster 8" converter and could stall it to 5000 or even a little higher.... Could get maybe .460 RT at best.....without rolling in some.... Biggest RT improver....LIMIT FRONT END TRAVEL....but you will spin the tires once you go to far...been there done that... There were a few cars and guys that could get decent RT's shallow staged footbraking but they refined their cars and probably staged as deep as they could without knocking the top light out..... __________________ Rich Biebel S/C 1479 Stock 147R