07 Masters, No Traction Shock???

[bullittwrench]

Hey Guys,
I've always run our Masters cars with a traction shock. I was thinking about trying just the shock/spring behind and a chain to prevent overextension. Everywhere we run, it's usually always dry slick. My driver is pretty good at trail braking so I don't think not having the hike down shock will hurt us. What does everybody think and where do you start with the 1 shock deal? 8/2, 9/3? I have a reb. adj. QA1 that I could revalve the comp. to an 8 or 9 and have 0-5 reb. Just lookin for some input from anyone who has tried this deal. Thanks

[Rocket Bonehead]

Hey Guys,
I've always run our Masters cars with a traction shock. I was thinking about trying just the shock/spring behind and a chain to prevent overextension. Everywhere we run, it's usually always dry slick. My driver is pretty good at trail braking so I don't think not having the hike down shock will hurt us. What does everybody think and where do you start with the 1 shock deal? 8/2, 9/3? I have a reb. adj. QA1 that I could revalve the comp. to an 8 or 9 and have 0-5 reb. Just lookin for some input from anyone who has tried this deal. Thanks


I don't know why everyone calls the LRF shock the "traction shock" (misnomer), but you will be fine running without it provided the driver knows how to control the car on corner entry. As far as valving in the LRR shock, I'd probably start off around a 6/3 (c/r) and adjust as needed.



RB

[2dumb2kwit]

provided the driver knows how to control the car on corner entry.



RB I need to figure out how to get me some more of that!!!

[pinionangle]

I pulled mine off at the first of the year and havent looked at it since.

My car has more movement, reacts faster and has way more forward bite without it. I dont use a chain up front and havent had any problems as of yet.


Corner entry is a bit wild if your running alot of bar angle.


Good luck.

[MasterSbilt_Racer]

I pulled mine off at the first of the year and havent looked at it since.

My car has more movement, reacts faster and has way more forward bite without it. I dont use a chain up front and havent had any problems as of yet.


Corner entry is a bit wild if your running alot of bar angle.


Good luck.

You might want to consider a chain to the axle tube. My experience has been pretty much the same as you describe, but I haven't done that for years.

[pinionangle]

Im going to put one on it this year "just in case"


Are you running a shock up front? And if so why?

[MasterSbilt_Racer]

Im going to put one on it this year "just in case"


Are you running a shock up front? And if so why?

I run one stop and go track where it is near impossible to keep the bars loaded and I'm not good enough to trail brake real well. I ran without a front shock for one full season and was lousy any time there was any chop to the track.

I was faster giving up traction for a more stable car.

[billetbirdcage]

I been meaning to write a reply on this one for a while, but there is some info that I don't want to give out and trying to explain some of this without giving that out is difficult. However this is my try:

For starters 95% of the time, the reason someone looses traction with a front shock is not due to the shock itself but to a difference in travel limit. This is a constant battle to get people to see, I don't care that with the car jacked up and the rearend hanging (against the stop -I.E. Chain, rear shock, undersling) that the front shock can still extend some. Let's say that you have a chain to the axle tube and when jacked up this is tight and holding the rearend, when the RR compressed that dips the LR down farther then when it is hanging. Depending on where the chain and shocks are this can make a huge difference. Lets also say that the front shock can extend another 1/2" when the chain is tight and holding. By compressing the RR 2 or 3" from ride hieght and the LR hanging there now could be a 1/2" or more slack in the chain because the shock is now holding the rear end NOT the chain. You have changed the travel by a fair amount and a 1/2" can completely mess a car up from where you had it.

Also take into the fact that if you add some upper bar angle, index upper bar on cage, or lessen the lower bar angle you will make the cage index faster and this will make the shock catch the rearend even faster or earlier. So you should be checking the front shock with max bar split you would ever run.

Most of the time a difference is felt because of the travel change and not so much as having the shock on the front.

If you don't think a 1/4" or 1/2" of travel can make that much difference, you need to spend some time with your race car studying it. I have seen a 1/2" difference on the front shock make 1" of rollsteer at the center of the LR hub, if that ain't a difference I don't know what is. This will vary depending on how much travel you have now and the bar angles, so you may see little difference or more then what I described. Alot of times the chain is inboard of the LRF or LRR shocks so any change of the chain length causes the shock to be lengthened/shortened more then the changed chain length. A 1/2" more chain may need an 1" more shock length to stop it with the chain and not the shock.

I probably lost everyone already!

On to the shock itself: Any 0 rebound shock has seal and piston drag and has some resistance to it to extend it. A #0 rebound at 4.7" a sec is 16# to 18# of force to move it at that speed, so by installing a front shock you have added 16/18# of resistance to let the car climb the bars. If you have a gas pressure shock by adding pressure to it you can make that go to a true 0 pound of resistance or actually have several pounds of force pushing up on the LR. This is the reason gas shocks (traction/pop up shock) is popular. Say you have a shock with 250 PSI of gas and it has a tremendious amount of rod pressure (say 50# of force at 4.7" per second trying to extend the shock) you will have 50 pounds of force trying to lift the LR corner ofthe car (will have more then 50# if traveling less then the 4.7" a second). I think people get overboard as with most things and have the some is good so more has to be better attitude.

So when you look at this, how can a gas shock with alot of rod pressure not make the car get up faster????? Kind of blows holes in peoples statements that the car gets up faster with out a front shock.

Now don't take this as you should always run a front shock, I just discribing some things here.

By my definition a traction shock and a hike down shock are not the same, period. A hike down shock is just controling some of the violet droping of the car on the LR. A tracion shock (bad word in my opinion) is generally a shock that can have high rod pressure and 0/or little rebound, so it has a high amount of poundage trying to extend the shock even at higher speeds thus allowing the car to come up faster/easier. However adding rod pressure increases the effective compression that the car sees, this is a by product in my opinion and should be considered seperate and more along the lines of a hike shock in terms of what you want.

You need to seperate compression and rebound when looking at these things, you could have a twin tube hike down shock that had more compression then a high charged gas traction shock depending on how they are valved on the compression side, so treat this item seperately.

There are reasons some don't like front shocks, alot of GRT's don't. Some of this is due to they typically run more bar angle then any other car out there. This increases the travel needed on the front shock to get the same travel without one and the speed is higher then a car that doesn't have those extreme bar angles. A 9" stroke shock can be extremely borderline on having enough travel to actually allow this to work. Alot of times (with alot of total travel and extreme bar angles and splits) to get enough extensions on the shock, the shock is almost bottomed out at ride height (1/2" to 1 1/2" shaft showing) which is going to cause problems if the car compresses from ride height.

Like I said most of the time it is do to travel limitations and not so much that there is a shock on the front as to why people loose traction with a front shock. When done correctly you can have more instant and more traction down the straight with a shock on front but the rest of the set-up needs to change to compliment this and make it work like I described. Some set-ups or styles of car (because of their set-up) aren't going to be able to make it work very well. This is getting into a part I don't wish to get into so I'm stopping here.

I'm just pointing out that before you blame the shock or having a shock on front or what removing it does, you need to be sure that you haven't changed the total travel available at the LR as it will have a HUGE effect of the car.

[MasterSbilt_Racer]

I been meaning to write a reply on this one for a while, but there is some info that I don't want to give out and trying to explain some of this without giving that out is difficult. However this is my try:

For starters 95% of the time, the reason someone looses traction with a front shock is not due to the shock itself but to a difference in travel limit. This is a constant battle to get people to see, I don't care that with the car jacked up and the rearend hanging (against the stop -I.E. Chain, rear shock, undersling) that the front shock can still extend some. Let's say that you have a chain to the axle tube and when jacked up this is tight and holding the rearend, when the RR compressed that dips the LR down farther then when it is hanging. Depending on where the chain and shocks are this can make a huge difference. Lets also say that the front shock can extend another 1/2" when the chain is tight and holding. By compressing the RR 2 or 3" from ride hieght and the LR hanging there now could be a 1/2" or more slack in the chain because the shock is now holding the rear end NOT the chain. You have changed the travel by a fair amount and a 1/2" can completely mess a car up from where you had it.

Also take into the fact that if you add some upper bar angle, index upper bar on cage, or lessen the lower bar angle you will make the cage index faster and this will make the shock catch the rearend even faster or earlier. So you should be checking the front shock with max bar split you would ever run.

Most of the time a difference is felt because of the travel change and not so much as having the shock on the front.

If you don't think a 1/4" or 1/2" of travel can make that much difference, you need to spend some time with your race car studying it. I have seen a 1/2" difference on the front shock make 1" of rollsteer at the center of the LR hub, if that ain't a difference I don't know what is. This will vary depending on how much travel you have now and the bar angles, so you may see little difference or more then what I described. Alot of times the chain is inboard of the LRF or LRR shocks so any change of the chain length causes the shock to be lengthened/shortened more then the changed chain length. A 1/2" more chain may need an 1" more shock length to stop it with the chain and not the shock.

I probably lost everyone already!

On to the shock itself: Any 0 rebound shock has seal and piston drag and has some resistance to it to extend it. A #0 rebound at 4.7" a sec is 16# to 18# of force to move it at that speed, so by installing a front shock you have added 16/18# of resistance to let the car climb the bars. If you have a gas pressure shock by adding pressure to it you can make that go to a true 0 pound of resistance or actually have several pounds of force pushing up on the LR. This is the reason gas shocks (traction/pop up shock) is popular. Say you have a shock with 250 PSI of gas and it has a tremendious amount of rod pressure (say 50# of force at 4.7" per second trying to extend the shock) you will have 50 pounds of force trying to lift the LR corner ofthe car (will have more then 50# if traveling less then the 4.7" a second). I think people get overboard as with most things and have the some is good so more has to be better attitude.

So when you look at this, how can a gas shock with alot of rod pressure not make the car get up faster????? Kind of blows holes in peoples statements that the car gets up faster with out a front shock.

Now don't take this as you should always run a front shock, I just discribing some things here.

By my definition a traction shock and a hike down shock are not the same, period. A hike down shock is just controling some of the violet droping of the car on the LR. A tracion shock (bad word in my opinion) is generally a shock that can have high rod pressure and 0/or little rebound, so it has a high amount of poundage trying to extend the shock even at higher speeds thus allowing the car to come up faster/easier. However adding rod pressure increases the effective compression that the car sees, this is a by product in my opinion and should be considered seperate and more along the lines of a hike shock in terms of what you want.

You need to seperate compression and rebound when looking at these things, you could have a twin tube hike down shock that had more compression then a high charged gas traction shock depending on how they are valved on the compression side, so treat this item seperately.

There are reasons some don't like front shocks, alot of GRT's don't. Some of this is due to they typically run more bar angle then any other car out there. This increases the travel needed on the front shock to get the same travel without one and the speed is higher then a car that doesn't have those extreme bar angles. A 9" stroke shock can be extremely borderline on having enough travel to actually allow this to work. Alot of times (with alot of total travel and extreme bar angles and splits) to get enough extensions on the shock, the shock is almost bottomed out at ride height (1/2" to 1 1/2" shaft showing) which is going to cause problems if the car compresses from ride height.

Like I said most of the time it is do to travel limitations and not so much that there is a shock on the front as to why people loose traction with a front shock. When done correctly you can have more instant and more traction down the straight with a shock on front but the rest of the set-up needs to change to compliment this and make it work like I described. Some set-ups or styles of car (because of their set-up) aren't going to be able to make it work very well. This is getting into a part I don't wish to get into so I'm stopping here.

I'm just pointing out that before you blame the shock or having a shock on front or what removing it does, you need to be sure that you haven't changed the total travel available at the LR as it will have a HUGE effect of the car.

Very good post. I guess I should have stated that my experience was a twin tube vs no shock. As you said, a twin tube always adds resistance to hike. A gas shock can slow or speed up hike. This is another reason why I think you should always run a front shock. If you know what you are doing, it allows you to keep the car's attitude pretty constant over a variety of racing surfaces.

[pinionangle]

Thanks Billet.

All things being equal on my car, I prefer not to run a shock up front. My car just works better with it off and my results prove this.









I been meaning to write a reply on this one for a while, but there is some info that I don't want to give out and trying to explain some of this without giving that out is difficult. However this is my try:




This is getting into a part I don't wish to get into so I'm stopping here.

I'm just pointing out that before you blame the shock or having a shock on front or what removing it does, you need to be sure that you haven't changed the total travel available at the LR as it will have a HUGE effect of the car.



Always so secretive. Such a shame.

But thanks for the knowledge you do share. We all soak it up like a sponge!

[billetbirdcage]

Pinion, my point was that most likely your car does NOT have the same amount of travel with the shock on front then it does with nothing (especially since you have no chain or anything limiting travel.

Not saying your wrong but some of the change you felt is likely due to the limit travel change, if in fact there is a travel difference on your car with or without a chock on front. I would be willing to bet that if you installed a chain bewteen front shock mounts the same length as the shock you had been using (just as a limiter same as what the shock is doing but no valving) that your result would be similar to having the shock on the front.

That is what I wanted to point out. Just alot of people miss diagnos the front shock deal as the shock itself when the travel change had the most effect. Without knowing exactly what you all did, I can't say for sure that you had a travel change or not, but it seems likely to me.

Let me make this clear: One way isn't wrong or right just different, there is plenty of ways to make a car do what you want and work with your driving habits/style.

[bullittwrench]

I hope this ? makes sense. If you have a gas LRF shock @ 250 psi, does the lower front shock mount drop faster than the rod comes out of the shock when the car climbs the bars? I guess what i'm asking is how does the rate of shock extension compare to the rate at which the lower mount drops? I guess this would also depend on the reb. valving on the rear shock, wouldn't it?
Also since everywhere we run usually gets smooth and slick and we have a small budget, I'm staying on the QA1 twin tubes with good oil in them. What causes a twin tube to fade, heat or cavitation....or both? I have a temp gun. Do guys take their shock temps? At what temp should I be concerned about them giving up? Sorry about rambling on, I get a lot of time to think during the day while i'm staring out the windshield.

[billetbirdcage]

I hope this ? makes sense. If you have a gas LRF shock @ 250 psi, does the lower front shock mount drop faster than the rod comes out of the shock when the car climbs the bars? I guess what i'm asking is how does the rate of shock extension compare to the rate at which the lower mount drops? I guess this would also depend on the reb. valving on the rear shock, wouldn't it?

I guess you didn't completely follow my posts about the speeds and poundage on the shock!

I'll try again:

I'm going to simplify here or try to: Picture a shock on a shock dyno, this shock is standing straight up and down and moves the lower shaft up and down at a certain speed measured in "INCHES PER SECOND". The top of the shock is mount to what looks like a solid mount and the bottom of the shock is what moves, however the top of the shock is actually hooked to a load cell that measures poundage that is pulling on it or pushing on it (body of shock).

When the shock is dynoed and the shock is in compression the top of the shock pushes up on the load cell and gives a number in pounds of force pushing on the shock body upwards. In rebound the opposite is true, it pulls down on the shock body and gives a number in pounds to how much it is puling down on the shock. These numbers are considered a POSITVE number.

Say the number for compression was 160# and the number for rebound was 160# also. Say that the speed in which it was tested was at 4.7 inches a second (industry std for rating shocks -have other speed as well), you would look at the chart for that speed and see what 160# means in terms of the number rating system. I don't have my chart here, but say that is a #5 compression and a #5 rebound.

A #0 rebound will read 16 to 18 pounds on the rebound, this means that to move the shaft out at 4.7" a second it takes 16 to 18# of force to move it at that speed (it was pulling down on the load cell that much).

If I took that #0 rebound shock and put 90PSI of gas in it and redynoed it, the dyno would read around MINUS 18 to 20#. This means with the shaft coming out at 4.7" per second it was still pushing up on the body against the load cell 18 to 20# instead of pulling on it 16 to 18# (<< POSITIVE number) without gas pressure.

If you crammed 250 PSI in the shock it may read MINUS 50 or more pounds. This means that with the shaft coming out at a rate of 4.7" per second that it still has 50# pushing up on the shock body.

As the speed increases the MINUS number will go down and if the speed slows the MINUS number will go up. Lets say that shock (with 250 PSI) is compressed and you release it that the shaft will extend on it's own at 7" per second. If when on the car the shaft gets going that fast there will be no force required to move it and therefore no pressure trying to lift or slowing the car from lifting. Then anything faster then that speed will actually have force slowing it or back to a actually positive rebound rating (actually having some rebound value.)

If that don't make sense, you'll likely need to call me so I can explain better and make sure you follow as we go step by step. If you don't follow one part it makes it hard to understand the rest.