SU Carb damper fluid

[Tom Donnelly]

What damper fluid are you using in your SU's? I remember Katman was tuning piston travel with damper fluid and springs and using a dowel pin shaped needle. What fluid and how much? David? Mike? Keith? Steve? Joe? Ron?

[Streetwise guy]

If yer tunin yer SU with oil, yer doin it wrong. ATF is the juice, and the only juice.

[JeffYoung]

Marvel Mystery ain't bad....it's a Mystery!

Man I am so glad I don't have to worry about this anymore.

[dspillrat]

Hey Tom.....
Glad to see you twisting on your Z!!!!
I've heard so many things about this...... Stormin Norm, uses 3 washers and no oil, no spring in the dampers, Seriously. Runs 12.8 quarter miles with a su, carbed 2.8 litre 240z..... My present car came with no oil at all in dampers, but with springs...ran great for 1 and half weekends til I ground off a cam lobe, and pulled the engine. But ran rich occaisionally, but otherwise made decent power... My present engine, a sunbelt build from 2005 has a fairly thick oil that really restricts piston movement....I'd guess 10w or so. Motorcycle fork oil, castorl oil, mineral oil, engine oil, tranny fluid, brake fluid. I've heard all of these, being the thing to use...... Likely temperature related to optimum vicosity needed..... Check out the videos on ZHOME.com showing the piston doesn't ever open fully.... So don't want'em flopping up and down wide open......

david

[pballance]

20 wt Redline synthetic.

I am sure Katman will check in......

[Ron Earp]

I think David has pretty much said it - people use oil weights all over the grid.

I was using Marvel Mystery quite a bit (still do from time to time) but my preferred oil is the 20W motorcycle Fork oil that I keep in the trailer. I meter it into the bore accurately with an eyedropper, have to check my notes but on the 260 flat tops seems 2.5mL is about right.

[Parrish57]

I've been using ATF just like the recomendation on the ZTherapy videos. When I got my new motor back from Sam Neave he had taken the fluid out. He swears by the no fluid concept, and it works great on the dyno, but I found that corners needing partial throttle caused it to run rough. WOT- no problem. Putting the ATF back in smoothed out the midrange response.

[x-ring]

Tom didn't ask me but I'll throw my two cents in anyway

DOT5 brake fluid.

I rarely, almost never, run the black car below 5000 feet elevation. I wonder if that makes a difference?