How big of a FOX by-pass on a 1 car???

joe1369

Well-Known Member
How big of a FOX BYPASS are the 3000 to 3500 lb 1 cars running, and what is more important bypass diameter or number of by-pass tubes, if you are considering cost. Eg. a 3.0 5 way or a 3.5 3 way???? Not a 2.5 RIGHT???????:D
 

sickdayz

Well-Known Member
As you know, I’m no professional expert, but I’ll give you my thoughts anyway… :)

I’m running the 3.0 4-tube on my car and it weighs 3000lbs (Rear). I don’t think the diameter needs to be any larger, because the oil temp isn’t getting too hot. I think the only advantage to a larger diameter shock is the added volume, which helps keep the oil cooler, reducing fade. Note, I’m running 2.5 4-tube in the front.

I would go for the added tubes. I like having the added adjustability. If I were doing it all over, I would get the 3.0 4-tube plus a gold (Free Bleed) tube. I would also cycle my suspension and decide the tube locations for optimal performance.

Are you looking to change your suspension? Or building a new car, or???
 

joe1369

Well-Known Member
As you know, I’m no professional expert, but I’ll give you my thoughts anyway… :)

I’m running the 3.0 4-tube on my car and it weighs 3000lbs (Rear). I don’t think the diameter needs to be any larger, because the oil temp isn’t getting too hot. I think the only advantage to a larger diameter shock is the added volume, which helps keep the oil cooler, reducing fade. Note, I’m running 2.5 4-tube in the front.

I would go for the added tubes. I like having the added adjustability. If I were doing it all over, I would get the 3.0 4-tube plus a gold (Free Bleed) tube. I would also cycle my suspension and decide the tube locations for optimal performance.

Are you looking to change your suspension? Or building a new car, or???
I have 2.5 triples by-pass in the rear, with a lot of re-bound valving, which creates a lot of heat, I think all the 1 cars have something bigger than 2.5's, WHY, can they just afford a bigger shock package, or is a 3.0 or bigger what you need to make these cars much more driveable/FASTER, through the CRAP WE RACE THROUGH. Learning, upgrading, dialing in the car with the V6 HONDA before switching to the V8 package, or maybe not??? Just maybe need another gear, 5 speed option.
 

Superfab

Well-Known Member
3.0 3tube w/ gold valve in 4th tube in front and 3.4 4 tube w/ gold valve in 5th tube. This was the standard set-up on a class 1 Jimco.
 

joe1369

Well-Known Member
3.0 3tube w/ gold valve in 4th tube in front and 3.4 4 tube w/ gold valve in 5th tube. This was the standard set-up on a class 1 Jimco.
I assume that was a 3.5 4 tube or was it a 4.4, (you said 3.4, could go either way?) Thanks
 

joe1369

Well-Known Member
I guess what I am really after is finding out what everyone is using in the rear or this type of car. There is a fine line between spring rate, and being able to control it without packing in the woops, via the rebound adjustments and valving, I think I,m on the edge with the 2.5's triples because after 100+ miles everything seems to change.:D
 
I think you should try backing off a bit on the rebound dampening. Are you working your coilovers or just using them as spring carriers?
 

joe1369

Well-Known Member
I think you should try backing off a bit on the rebound dampening. Are you working your coilovers or just using them as spring carriers?
If by working them do you mean having valving inside, yes we have valving inside of the coil over, but only a 2.5 coil over.

Packing is not really the issue, I would like to get rid of all that tail fling in Barstow through those drop ins, some 1 cars have it dialed, some not so much, i'm thinking less spring, more compression dampening, then backing off of the rebound dampening.
 
Yes, I meant valving. I think you are heading in the right direction. Lee Finke died have some used bypass bodies in various diameters, you might want to try him at 602/493/3700 if you decide to trade up.
 

sickdayz

Well-Known Member
Mine is not perfect, but it’s getting closer. I have 1000# on each rear corner of my car. I am running 400 over 500 springs with no valving, per say, in the coil carriers. I have a ton of rebound valving in my 3.0 4 tubes, with 1 turn out on the short tube and 1.5 out on the long tube. I am actually backing the compression tubes out for this next race, it seems to be just a little stiff. I’m going with 2 turns in the on the short tube and 2 on the long. We’ll see…

I am running the fox shox, just as you are. With the fox, it only takes about 2-3 turns and it’s the same as being wide open. Has to do with the valve seat angle being low.
 

Fourstroker

Well-Known Member
Joe - Don't know if this helps your decision on shock size. Alot of guys, including myself are running 3.0's on the rear of our 12 cars. I would think a 3.0 at a minimum on a 3000# Class 1 on the rear.
 

sickdayz

Well-Known Member
It is simply a “free Bleed” tube. It allows fluid to travel back and forth (compression and rebound stroke). It is good for the small choppy stuff. Similar to the bleed screws in the piston.
 

joe1369

Well-Known Member
Joe - Don't know if this helps your decision on shock size. Alot of guys, including myself are running 3.0's on the rear of our 12 cars. I would think a 3.0 at a minimum on a 3000# Class 1 on the rear.
Yes that definetly puts some perspective in things. :D
 

desertracer

Well-Known Member
We run 3.0 4 tube Fox on the front with 3.5 5 tube on the rear of our jimco class 1 (~3500lbs) and hardly get much fade. Used to run 2.5 3 tube front/3.0 4 tube rear, worked well but once we went to 35'' tires in front started to fade faster leading to bigger shocks all around.

Think many of the newer 1 cars (~4k lbs+) are running 3.5's front and rear.
 

joe1369

Well-Known Member
We run 3.0 4 tube Fox on the front with 3.5 5 tube on the rear of our jimco class 1 (~3500lbs) and hardly get much fade. Used to run 2.5 3 tube front/3.0 4 tube rear, worked well but once we went to 35'' tires in front started to fade faster leading to bigger shocks all around.

Think many of the newer 1 cars (~4k lbs+) are running 3.5's front and rear.
Yea, those 35" baja ta's are flatproof for the most part, but heavy as hell, thanks for your input!!!!!:cool:
 
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