5th coil with a 525

[money17]

i have a ppm chASSIS WITH A 525 CRATE IN IT. I HAVE A 5-3 BILSTEIN SHOCK AND A 300 LB SPRING. I CANT CHANGE SHOCK. GOING TO TRY AN RUN THE 525 CRATE SERIES. I HAVE 2 1/4" OF TRAVEL ON SHOCK. SHOULD I NOT HAVE MORE TRAVEL LIKE 3 1/2" OR 4"?

[AmickRacing]

How much preload do you have in the 5th coil?
How far out from the centerline of the axle do you have it mounted?
How big is the track? Normally slick or tacky?

It really seems like there is no by the book rule of thumb with the 5th coil spring/shock, it's really driver preference. Doesn't sound like you're far off, just a few tweaks away...

[money17]

3/8" preload
35" out
a little tacky but bone dry after qualifying
1/4 to 3/8 mile

[MasterSbilt_Racer]

If you want more travel, drop the preload to 1/4" or so. You will have to see how much travel works best for you. It depends on engine, track, driver, etc. There is no magic bullet there.

[stevo]

Shoulden shock be stiffer rebound?

[7uptruckracer]

On Bilstein Rebound is the first number so its what most any other brand calls a 3-5 which isn't bad depends on chassis I run from 3-3 to 3-7 (7-3) on a Bilstein

[sj valley dave]

We run a 3-7 with an AFCO on the 5th shock..stiffer rebound than compression...

[money17]

is 2 1/4" enough travel or should i go to a 275 lb spring

[7uptruckracer]

Make sure nothing is limiting it hiking Id say 3-4" go softer till you get the travel, It hooks up and traction doesn't run out before the end of the straight. No book will tell you whats right for your tire and engine combo or track condition not even us but to answer your question yes.

[huckleberry_hound]

Can someone explain what you mean by travel on the 5th coil? And how changing it affects traction,,,,thanks

[sj valley dave]

Measure the actual amount of travel in the 5th shock. Use a plastic tie, or the rubber O Ring that came on the shock (if it still there). You want a desired amount ot travel. We shoot for 3 1/2" or so..If you have too stiff a spring, on a slick track, it acts more like a solid link, you shock the rear tires and whamo, wheelspin..It acts as a cushion for the rear tires, along with "lifting" the chassis as the car gets on the bars...

[huckleberry_hound]

So u move the o ring up to the bottom of the shock body and measure it when u after running some laps? Correct? What would tell u if the 5th coil spring rate is too low?

[7uptruckracer]

Thats correct, and too soft will travel to much and you can lose traction at the end of the straightaway