Re: Footbrake Race Converter experts - ? on 2 step vs Flash RPM
[Re: ultimatelenny]
#1970743
12/16/15 12:03 PM
12/16/15 12:03 PM
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Joined: Jan 2003
Posts: 9,924 Weddington, N.C.
Streetwize
OP
master
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OP
master
Joined: Jan 2003
Posts: 9,924
Weddington, N.C.
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Thanks Lenny! I was hoping you'd see this, don't know if you remember talking to me about it but what you just reiterated makes a lot of sense now. BTW, did you ever see this clip of my buddy Nat's 442" Jeep with your UCC 9 1/2" Converter? This thing drives like a stocker and runs low 12's at 3800+ pounds!! Watch it CRUSH this modded SRT-8 AWD Cherokee. https://www.youtube.com/watch?v=7bNsxJLSie0I put my 9 1/2" UCC converter behind my new 440" small block in a 66 Valiant wagon, the 3800 stall should be perfect. The motor will make just a hair more power than the jeep and be about 600 pounds lighter, it's going to be a blast!
Last edited by Streetwize; 12/16/15 12:04 PM.
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Re: Footbrake Race Converter experts - ? on 2 step vs Flash RPM
[Re: Streetwize]
#1970768
12/16/15 12:58 PM
12/16/15 12:58 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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My 2-step is triggered off the brake pedal. I have it set at 3000 and it hits the tires hard but my 60's suffer due to the short wheelbase and the (too) high rate of wheelstand. If I understand what Lenny said the higher the launch speed the less violent a light car will hit the tires. Like I said it seems counter intuitive but since you are at WOT you get no torque boost from the (secondary) pump shot.
So....I was going to try 3800 and if that helps, 4200 on a 5300 flash, brake pedal is plenty stout to keep it from rolling through at 3000.
Still hoping Lenny will chime in, I may just need to call him. Again, I'm trying to visualize the fluid dynamics of the converter in those first couple 1/10's of a second after coming off the footbrake.
It's logical that generally the lighter a car is the "tighter" a given converter will be for a given gear (torque multiplication) and the hit would be a bit softer, just trying to get my head around the FB RPM vs launch RPM vs true Flash (full pull) What he said falls in line with what I said about slapping the conv... higher launch has less of a run up to hit the conv stall point... the torque multiplication is still there but you dont end up with the free rpm slap
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Re: Footbrake Race Converter experts - ? on 2 step vs Flash RPM
[Re: MR_P_BODY]
#1970874
12/16/15 03:57 PM
12/16/15 03:57 PM
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Joined: Oct 2006
Posts: 176 NC USA
ultimatelenny
member
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member
Joined: Oct 2006
Posts: 176
NC USA
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My 2-step is triggered off the brake pedal. I have it set at 3000 and it hits the tires hard but my 60's suffer due to the short wheelbase and the (too) high rate of wheelstand. If I understand what Lenny said the higher the launch speed the less violent a light car will hit the tires. Like I said it seems counter intuitive but since you are at WOT you get no torque boost from the (secondary) pump shot.
So....I was going to try 3800 and if that helps, 4200 on a 5300 flash, brake pedal is plenty stout to keep it from rolling through at 3000.
Still hoping Lenny will chime in, I may just need to call him. Again, I'm trying to visualize the fluid dynamics of the converter in those first couple 1/10's of a second after coming off the footbrake.
It's logical that generally the lighter a car is the "tighter" a given converter will be for a given gear (torque multiplication) and the hit would be a bit softer, just trying to get my head around the FB RPM vs launch RPM vs true Flash (full pull) What he said falls in line with what I said about slapping the conv... higher launch has less of a run up to hit the conv stall point... the torque multiplication is still there but you dont end up with the free rpm slap I agree with you completely Mr. P Body
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Re: Footbrake Race Converter experts - ? on 2 step vs Flash RPM
[Re: MR_P_BODY]
#1970890
12/16/15 04:28 PM
12/16/15 04:28 PM
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Joined: Sep 2014
Posts: 4,457 Washington
madscientist
master
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master
Joined: Sep 2014
Posts: 4,457
Washington
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I'm curious about hooking my 2 step so I can have a little more consistency and focus more on the light.if I leave higher than 3200 my 60ft is crap so I leave about 2900 with converter flashing to 5400 When you go up n rpm.. what else are you changing.. your changing the torque point and the slap of the conv.. when I go lower on rpm I have to raise the tire pressure to compensate.. if I go up I lower the pressure.. being a 4 link I dont have to change that part.. but if a ladder bar I did have to change the front of the bars While raising the tire pressure is easier, you could accomplish the same thing by stiffining the shock in rebound. Not as easy as a tire pressure change, but it accomplishes the same thing. Well kind of.
Last edited by madscientist; 12/16/15 04:31 PM.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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Re: Footbrake Race Converter experts - ? on 2 step vs Flash RPM
[Re: MR_P_BODY]
#1971064
12/16/15 09:13 PM
12/16/15 09:13 PM
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Joined: Oct 2009
Posts: 1,267 North, Alabama
D-50
pro stock
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pro stock
Joined: Oct 2009
Posts: 1,267
North, Alabama
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There are tracks that allow a trans brake in the foot brake class, I race at 2 of them. Never understood why. They both have a electronic class which I guess just lets the racer add a crossover/delay box. That does not make sense. Why call it a foot brake class and allow a trans brake? Because its called no box and box.. thats the way division 3 is.. thats why I have a trans brake because its legal even in no box Down here there is 2 classes, Footbrake, Any ET.(No delay box,No 2 step,No trans brake, foot brake only) The other class is Pro,Any ET (You can have all the above)
1.33 60 ft,6.21 at 110.59 in the 1/8, pump gas small block,2950lbs,drag radials,mufflers and driven to track ...
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Re: Footbrake Race Converter experts - ? on 2 step vs Flash RPM
[Re: MR_P_BODY]
#1971094
12/16/15 10:00 PM
12/16/15 10:00 PM
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Joined: May 2005
Posts: 1,031 ohio
67mprfan
super stock
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super stock
Joined: May 2005
Posts: 1,031
ohio
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I'm curious about hooking my 2 step so I can have a little more consistency and focus more on the light.if I leave higher than 3200 my 60ft is crap so I leave about 2900 with converter flashing to 5400 When you go up n rpm.. what else are you changing.. your changing the torque point and the slap of the conv.. when I go lower on rpm I have to raise the tire pressure to compensate.. if I go up I lower the pressure.. being a 4 link I dont have to change that part.. but if a ladder bar I did have to change the front of the bars Mine is a ladder bar car it's set in the bottom hole it was in the middle but pinion angle was off..I set tire pressure to track conditions that day. Here we have Pro and Super Pro classes, 1 allows delay boxes both will let you run trans brakes
71 demon stock stroke 440/indy ez-1 running 10.10 @ 132.14 mph in the 1/4 and 6.36 @ 107.46 mph in the 1/8 not in the same weekend but It did it then I sold it. 67 Belvedere that worked it's way in the 10's
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Re: Footbrake Race Converter experts - ? on 2 step vs Flash RPM
[Re: Streetwize]
#1971148
12/16/15 11:19 PM
12/16/15 11:19 PM
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crabman173
Unregistered
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crabman173
Unregistered
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I foot braked a Duster running 6.90-7.0 for years What I found was --looser converter made car faster but.... I could cut way better lights with tighter converter Stalling it hard as possible also enabled better lights Once I quit caring about ET and tuned car for best reaction times and best lights it started winning! Two steps and Transbrakes in footbrake is just like mixing chocolate and [censored]--it is silly--either footbrake the car or put a box in it! You are fighting city hall Drum front brakes on footbrake car are a MUST--they are self energizing--they HOLD the car 10 times better than disc--most winning footbrake cars have drums--there are ways are lighten them--been around for decades Toss the brake or get a box Brakes are the secret to Foot Braking Loose super fast converters sink the whole set up Leave RPM has to be consistent to cut good lights and win races--Period. I am always amazed that folks are never seeking ways to WIN more races-- rather they fiddle with the mechanical aspects of the game Those have to be understood for sure so your basic questions are super valid but if you want to win races study the guys and ask the guys that win lots of races --same ole guys win all the darn time and many can't even adjust a shifter--they just have learned How to Win! Get the car where it will hook in a plowed field and is not so sensitive to track conditions--keep converter on tight side --work with all the things you have available like front tire pressure, shocks, big mirrors, staging technique--never forget the psych game--use it like you have a truckload of it to get rid of fast--Polite drivers do not win-- Then go win a race--amazing thing is after you get one they start to come easier and easier--pretty soon you are the guy they don't want to get beside--then they start beating themselves and you are da Man!
Converter choice should be about tuning car for best lights in a footbrake car--nothing else. ET should be just a result not the goal.
Nothing helps like trying several and just see what happens--you will find a favorite and win like crazy until it blows up--then you will have to buy several more to get another one like it--they are like cakes --same recipe from same baker--top looks different on every one!
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Re: Footbrake Race Converter experts - ? on 2 step vs Flash RPM
[Re: Streetwize]
#1971149
12/16/15 11:21 PM
12/16/15 11:21 PM
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crabman173
Unregistered
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crabman173
Unregistered
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I said [censored] like sourkraut how did That get censored--really???
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Re: Footbrake Race Converter experts - ? on 2 step vs Flash RPM
[Re: Streetwize]
#1971152
12/16/15 11:24 PM
12/16/15 11:24 PM
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crabman173
Unregistered
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crabman173
Unregistered
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Your little wagon is super duper COOL!!!!
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Re: Footbrake Race Converter experts - ? on 2 step vs Flash RPM
[Re: ]
#1971372
12/17/15 12:13 PM
12/17/15 12:13 PM
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Joined: Jan 2004
Posts: 8,637 fredericksburg,va
cudaman1969
master
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master
Joined: Jan 2004
Posts: 8,637
fredericksburg,va
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I foot braked a Duster running 6.90-7.0 for years What I found was --looser converter made car faster but.... I could cut way better lights with tighter converter Stalling it hard as possible also enabled better lights Once I quit caring about ET and tuned car for best reaction times and best lights it started winning! Two steps and Transbrakes in footbrake is just like mixing chocolate and [censored]--it is silly--either footbrake the car or put a box in it! You are fighting city hall Drum front brakes on footbrake car are a MUST--they are self energizing--they HOLD the car 10 times better than disc--most winning footbrake cars have drums--there are ways are lighten them--been around for decades Toss the brake or get a box Brakes are the secret to Foot Braking Loose super fast converters sink the whole set up Leave RPM has to be consistent to cut good lights and win races--Period. I am always amazed that folks are never seeking ways to WIN more races-- rather they fiddle with the mechanical aspects of the game Those have to be understood for sure so your basic questions are super valid but if you want to win races study the guys and ask the guys that win lots of races --same ole guys win all the darn time and many can't even adjust a shifter--they just have learned How to Win! Get the car where it will hook in a plowed field and is not so sensitive to track conditions--keep converter on tight side --work with all the things you have available like front tire pressure, shocks, big mirrors, staging technique--never forget the psych game--use it like you have a truckload of it to get rid of fast--Polite drivers do not win-- Then go win a race--amazing thing is after you get one they start to come easier and easier--pretty soon you are the guy they don't want to get beside--then they start beating themselves and you are da Man!
Converter choice should be about tuning car for best lights in a footbrake car--nothing else. ET should be just a result not the goal.
Nothing helps like trying several and just see what happens--you will find a favorite and win like crazy until it blows up--then you will have to buy several more to get another one like it--they are like cakes --same recipe from same baker--top looks different on every one! Couldn't have said it better.
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