Will we need lights at the silverstate? Pics of FOX internal bypass shocks

Discussion in 'Desert Racing' started by rupert14, Mar 26, 2011.

  1. rupert14

    rupert14 Raber Racing - UTVUnderground Approved

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    Jan 14, 2010
    I am trying to finish up the last couple things on my car before we go do some more testing for the silverstate. I have a question about the time of the race. I think we will leave the start line at about 6:30 am. When does the finish line close and is there a chance we will need headlights?

    I am also re-valving my fox 2.5 internal bypass shocks and I was not able to find any information about them online before I started. It appears that there are no photos of the bypass system so I decided to post some pics and explain how they work.

    There is a 2" shock body inside a 2.5" shock body. The piston is actually a standard 2" and valving on the piston is just like any other fox shock.

    The picture is of the inner 2" shock body that has the bypass ports. The left side of the tube goes in the top of the shock. There are two bleeder holes in the shock body that are always open. Just above each bleeder hole is a bypass shim. The bypass shim has two screws in it and a bypass port on outside of each screw under the shim. Basically, there are a total of four bypass ports and two bleed ports. Obviously, as the piston progresses up (toward the left) it passes the first bleed port, then two bypass ports under the first shim, then another bleed port, and two more bypass ports under the second shim. At that point, only the piston valving is affecting the shock rate.

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    I realize this is a bypass shock but it is not at all like the traditional bypass shock that has "zones" affected by a bypass tube and valve. This is more like a "progressive" shock because no matter how you valve it, the shock will get progressively stiffer. Most of us valve our traditional bypass shocks in this manner so in theory, if we get the valving right we can get the characteristics to resemble a traditional bypass shock.
     
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  2. s2k1

    s2k1 New Member

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    Nice post. Rep Points!
     
  3. dmurray

    dmurray #1917 BITD - UTVUnderground Approved

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    Last year the first MC/quads left at 6:15am and the utvs left at about 645am. I believe most of the finishers came in with enough day light (3pm to 7pm range). The cut off for MC/Quads was 700pm and trucks 11:15pm. I do not remember which cut off was ours. Lights may be needed, but unlikely. Maybe bring to install if needed. We are not going to run them.
     
  4. HDRA1

    HDRA1 old buggy dork - UTVUnderground Approved

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    you should always have 2 functioning lights on the utv at all races just in case
     
  5. rupert14

    rupert14 Raber Racing - UTVUnderground Approved

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    I agree. I think it is in the rules that there must be 2 functioning lights at all times. I have two 4" hid's behind my bumper. We have a race strategy meeting tonight and we want to be sure to plan to install the light bar if it looks like we may be running at night.

    Based on the information given, it looks like we will plan to be at the finish line before dark. The course mus be pretty fast if everyone is able to finish during the day. This is going to be a great race.
     
  6. tatum

    tatum Hans Solo - 2009 UTV Baja 500 & 1000 Winner - UTVU

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    Nice post. I need to get some rebuild kits and new oil and rebuild mine.
     
  7. rupert14

    rupert14 Raber Racing - UTVUnderground Approved

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    They are easy to rebuild but there are a couple tricks to it. I had to call Fox tech support to make sure things were going together right. If you decide to do it, let me know and I will warn you of the potential challenges. Kartek has the rebuild kits in stock as I always keep a couple on hand. If you want to rebuild them I would help if you need it. I am curious to see where your valving ended up compared to mine.

    How do you like your new motor? Did you change the internal gearing and what size did you go with? I heard you were flying at some recent desert race. What race did you do?
     
  8. tatum

    tatum Hans Solo - 2009 UTV Baja 500 & 1000 Winner - UTVU

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    I havent raced since Soboba were I had overheating issues.Also my shocks were beating me to death.You might be thinking about Nessy 2 at the San Felipe 250.They had a 2 hour issue at the beginning and came back and took the lead only to blow a belt 15 miles from the finish.

    Right now I have what I call a stock 840 which is just a bigbore with cams.I do have the brute force gears.I am working on a bigger motor and am probably going back to short course since the desert guys dont want me in there.

    I just rebuilt the King shocks on my sand car and I would think they would be similar but I am up for any info you can give me.I dont have any fox shims so I need to take them apart and see what I am working with.
    Let me know when you get yours done and how it is working.
     
  9. rupert14

    rupert14 Raber Racing - UTVUnderground Approved

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    Why can't you race BITD? If we are allowed to cut the whole front/rear of the frame off and rebuild it, why are you not allowed to race? If you need a "stock frame" weld two stock pieces of square tubing under there and you have as much frame as many of the folks racing. The suspension pick up points are in the stock location right?

    I have a very extensive shim kit so let me know what you have and what you need. I went from a single stack .015 six shim on compression to triple stacking the larger three with .012 and keeping the smaller 3 as .015. I will let you know how stiff it is after more testing.

    How do you like the taller gears? Any clutch mods and what is your top speed? I am also running a 10:1 840 kit but I do have ported heads and +4 valves all the way around. I just made some clutch mods that should give me a top of around 80mph. We will see.
     
  10. tatum

    tatum Hans Solo - 2009 UTV Baja 500 & 1000 Winner - UTVU

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    I have completely stock frame rails on my car but since it was originaly built for short course there is no room for a passenger seat.Since CORR went belly up before the car was done we just went to BAJA and raced there.

    The car was killing everybody in the 2008 1000 until a bad airfilter caused the motor to suck to much dirt.We won the 500 and 1000 the next year.That is probably why they dont want us.Todd was trying to race BITD then and they wouldnt allow the car then or now.

    I really havent been able to get the car out and do any top speed runs.I was doing about 68 in snowflake at altitude and with the clutch setup that was still for the stock gears I was only pulling about 7300 rpm.
     
  11. deviant_illusion

    deviant_illusion go to the UTVUnderground where there is cool SHIAT

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    If you want to get some more desert race miles BORracing.org will let you race the Unlimited class with a single seater.
     
  12. tatum

    tatum Hans Solo - 2009 UTV Baja 500 & 1000 Winner - UTVU

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    Thanks,some of the other organizations have let me know I can race.Right now I am going in a different direction,but if I do desert race it will probably be Baja.There is really nothing like it, and from what I have read on here it is about the same as far as entry fees.
     
  13. rupert14

    rupert14 Raber Racing - UTVUnderground Approved

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    I was watching your tracker in 2008 when you sucked the silt and the car stopped. We tracked it on the freeway for a while after that. If I remember right, you threw down some serious top speeds in the lake bed before the motor problems.

    Do you have any pics of how your car is set up? I have always wanted to see how it went together.

    If you need help with those shocks, let me know. I am more than willing to help. I was blowing by my compression valving with my shocks at Parker. They are set like a stock shock from the factory and having the bypass and bleed ports makes them way too soft if they are not valved up right.
     
  14. tatum

    tatum Hans Solo - 2009 UTV Baja 500 & 1000 Winner - UTVU

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    I was waiting at mile 282 in 2008 and could not see the tracker so I am not sure what kind of speeds Todd was hitting.The dry lake beds you can pretty much go as fast as you want.

    Anytime you are in the phoenix area(I believe you live in Prescott)you are welcome to come by and check out the car.I would like to see your car in person as well.
    I dont own a camera and not sure how to post pics from my phone.

    My shocks are really harsh at slower speeds.Larry Roeseler drove it and says I need to take out compression and rebound.He has said he would help me with the valving and I might take him up on the offer after I get some new oil in them.I drove his DFR kit in plaster city and he had that car dialed in perfect.
     
  15. rupert14

    rupert14 Raber Racing - UTVUnderground Approved

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    I am in prescott and I go to phoenix every week or two. I would take up Larry's offer. If you can get the specs on compression/rebound I have all the shims to re-valve them. We will have to get together and compare cars sometime.
     
  16. tatum

    tatum Hans Solo - 2009 UTV Baja 500 & 1000 Winner - UTVU

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    PM me when you are going to be in phoenix and we can meet up.I just called Foddrill and they have the kits and oil.I will take a front and rear apart to find out what I need.I will let you know if I need shims.Thanks for the help.
     
  17. Zerofield

    Zerofield Pit Junky - UTVUnderground Approved

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    Yay! Come and play in short its a lot more fun!
     
  18. the stripping shop

    the stripping shop RACER - UTVUnderground Approved

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    thers alot you can do with those shocks we had them for 3 years i changed everthing. you can make the top half like a bump stop and we changed piston that helped alot. you didnt have to valve heavy. according to a source the king shims are better hint hint.
     
  19. tatum

    tatum Hans Solo - 2009 UTV Baja 500 & 1000 Winner - UTVU

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    Thanks for the info.I have a bunch of the King shims.What pistom did you put in there?
     
  20. rupert14

    rupert14 Raber Racing - UTVUnderground Approved

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    Yeah, what shims and piston did you use? I am running a piston with only one small bleed port becaue of all the other bleed/bypass ports. I could have put thicker bypass port shims in instead of valving the piston more. I wanted it to be pretty stiff the last 1/4 of shock travel. Is that what you did? I also have a pretty good assortment of King shims/pistons but the hole in the center of the shim/piston where the shaft bolts through is larger on the King stuff so they don't fit.
     

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