# hot racing shock bore size

• 11-03-2012, 04:57 PM
yellowufo
hot racing shock bore size
Anyone ever measure the bore size? It would answer alot off questions as to why the shocks r softer after switching
bodies.......
• 11-05-2012, 01:45 AM
50togo
Sounded like 7.62 my red piston are a little bit bigger
• 11-05-2012, 09:13 AM
yellowufo
[QUOTE=50togo;5328618]Sounded like 7.62 my red piston are a little bit bigger[/QUOTE]

Stock red two hole (.500) piston is 7.6mm wide stock bore is 7.80mm = .2mm differance, perfect.

On my hot racing shock the bore size is 7.95mm that = a .15mm differance when using the stk piston
Not perfect or even close
That lets lots of blow by and a piston rod that will wobble back and forth.

Lesson to learn if all the hot racing shock bodies r 7.95mm your shocks will be way softer then your stock
Shocks i have read many a story of this happining with confusion being the end result.

Measure your hot racing and all shock bodies to know what you have. Before you waste your time.
• 11-05-2012, 01:20 PM
aburg2

Stock red two hole (.500) piston is 7.6mm wide stock bore is 7.80mm = .2mm differance, perfect.

On my hot racing shock the bore size is 7.95mm that = a .15mm differance when using the stk piston
Not perfect or even close
That lets lots of blow by and a piston rod that will wobble back and forth.

Lesson to learn if all the hot racing shock bodies r 7.95mm your shocks will be way softer then your stock
Shocks i have read many a story of this happining with confusion being the end result.

Measure your hot racing and all shock bodies to know what you have. Before you waste your time.[/QUOTE]

I just got another set of HR Bodies in the mail, and I have a set of new red pistons. I got pretty much the same numbers, 7.5mm pistons, 7.9mm dia on the HR Bodies. I used a 50/50 mix of 70WT oil & 10K Diff oil to stiffen them WAAAY up for my boy's Grave Digger. I also used this setup on my Mini Slash 4X4, & Boss Mustang with stiffer springs.

AB
• 11-05-2012, 04:19 PM
yellowufo
[QUOTE=aburg2;5328855]I just got another set of HR Bodies in the mail, and I have a set of new red pistons. I got pretty much the same numbers, 7.5mm pistons, 7.9mm dia on the HR Bodies. I used a 50/50 mix of 70WT oil & 10K Diff oil to stiffen them WAAAY up for my boy's Grave Digger. I also used this setup on my Mini Slash 4X4, & Boss Mustang with stiffer springs.

AB[/QUOTE] thanks as you said you can overcome the oversize bore by mixing up some thicker mixture just wish
The cut them better the shaft wobble will cause leaks overtime and may cause binding

Jim
• 11-05-2012, 10:06 PM
aburg2
[QUOTE=yellowufo;5328950]thanks as you said you can overcome the oversize bore by mixing up some thicker mixture just wish
The cut them better the shaft wobble will cause leaks overtime and may cause binding

Jim[/QUOTE]

I haven't had any shaft wobble, although at first I had oil leaking down the shafts. Instead of using the new o-rings from the HR Bodies, I used the original stockers with the HR spacer. No leaks. No wobbles.

AB
• 11-05-2012, 11:02 PM
yellowufo
I used the stock o rings also along with the hr spacers, to be honest after i sealed the stockers
Im happy and wont be buying hr bodies again.

Thanks again for the confirmation on the bore size it took me since september to get someone
To measure the hr bodies. on another forum the idea that a bigger bore would cause a softer
Shock seemed to be beyond a few i.e. the mod in perticulars grasp.
soooo
Again thanks

Jim.
• 11-05-2012, 11:25 PM
aburg2
You're welcome. FYI, when measuring, I found out that the HR Bodies are slightly tapered towards the top, probably to assist in compression. Also, the holes in the pistons are tapered, with the larger side on top. When I rebuilt mine, I reversed them, as I'm trying to prevent dive on braking, and minimize squat on acceleration. Those two features also assist in spring rebound.
Good luck!

AB
• 11-07-2012, 07:49 PM
50togo
I use the stock blue seal -stock spacer -blue seal then a hr seal and that works pretty good no leaks