Up Graded - Performance Damper when do you do that?

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my68barracuda

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Question(s),
1) at what point does it make good sense to move from a stock style to a genuine performance damper?
and then,
2) Dampers can be elastomer, fluid or friction. Why chose one over the other?

some background, my car is a 68 Barracuda with a built Slant Six, approx. 265 HP, NA, MPFI, long tube headers, windage tray, crank scraper, baffled oil pan, circle track cam grind, ported, OS valves, 190 psi cranking compression, last year light cast crank, light weight 2.2L OS pistons, light weight K1 long rods. Built 904 transmission, 3:55 rear gear, 8.75 cone sure grip.
The engine is a last year 1987 slant, the last year slants have the cast cranks counterweights very much reduced in size from the early cast crank slants (1977).

I run a max of 6200 RPM. Use the car for drag racing and autocross. I when drag racing I will shift at 6000 to 6200 RPM. I have only ran two Autocross events, but I found myself hanging the car at 3500 to 6000 RPM cycling up and down, for much of the course, maybe 45 to 60 seconds at a time. The car is street driven and I drive it to and from the events. Some events are local and some are cross county.

The current damper is a new PowerBond unit. Looks like a well-built piece, but lately there are times when I worry over that long six-cylinder light weight cast crank shaft and I wonder if I should upgrade the damper.
I know that Romac has two levels of a slant six specific damper (elastomer) , and I have a friend that I may be able to talk out of a Fischer Performance Slant six damper (friction).

Thoughts and recommendations are appreciated.
 
Go to PERA.org and look at their webinars. There are some good ones on crank balancing. In fact, there was one last week but I missed it. I need to watch it.

At least one of them has some incredible CFD images of what a crank goes through. It’s eye opening.

IMO, once you change anything in the system like the crank, the rods, the pistons or RPM, anything like that you need a damper change.

Elastomer dampers have a very narrow effective range. Once you change something that changes the frequency of the crank, the OE damper becomes less effective.

Do guys get away with using OE dampers? Yes. Does that mean that’s it’s the thing to do? Not at all.

For anyone turning under about 8500 RPM I use a Fluidamper or the Innovators West damper.

They both have a much wider tuned range. They also don’t require different tuning when you change something.

Just remember, everything has a resonance frequency. Everything vibrates. When you change the mass you change that frequency.
 
^^ good post.
I would say your at the point where moving from the OE replacement dampner would be definitely be a good move.
Not apples to apples but I run a Romac elastomer on my hemi 6 and it's a pretty good unit - it's about 3x wider and 2x as heavy as the OE replacement unit. These engines have pretty bad harmonics going on around 5800-6200rpm and the heavier dampner shifts this point further up the RPM range. I imagine the slant would have a similar "unhappy spot" that you need to tune out of the rpm range your using.
I would recommend a fluid dampner if they are available within your budget - it's what I would be running on my engine if I didn't have to buy a big $$ adaptor to run one.
 
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I would say when you expect to rev the engine past 5K on a regular basis, or have it there for extended length of time. Mine still has a stock balancer on it and it's fine. I'll probably never need a better one. I just don't drive that aggressively.
 
When do we change a OE damper out, right when I build an engine other than a stock one.

Like what ratbastard said….. 100% dead balls accurate plus a 100 yard dart thrown blind folded to a on center bulls eye.

Getting a /6 race balancer might be hard. Call Fluid damper and TCI for the rattler balancer and ask if they have or can make one.
 
Romac makes nice race balancers for the slant 6.
 
Thanks again for the link to the RERA.org, interesting

I am going to look closely at the Romac Dampers, a few questions on those.

question 1) there are two Romac dampers for a slant six, their online info is a little confusing, depending upon which web site is visited.
I have posted links to both below. I want to order the right one.
It appears that the 0224SA is that correct for a cast crank. But that may not be correct.
Interesting that the web site that mentions the differences does not give part numbers
and the site that give part numbers does not mention the differences.

site 1
http://www.romacusa.com/downloads/Romac ... s%20US.pdf
site 2
https://www.hemiperformance.com.au/shop ... ancer.html

question 2) Anyone with actual experience, will a slant six AC pulley, the one that fits on the back side of the damper, bolt to a Romac damper?

thanks
 
On that second page, John, I see THREE different part numbers. Says they're "available in external or neutral balance", but there was never an external balanced slant 6. In this country, at least.
 
B/RB dampers will fit a 6 but you really running A/C? Any fluid type damper will be 2-3X thicker than the pizza on a stock slant.
 
B/RB dampers will fit a 6 but you really running A/C? Any fluid type damper will be 2-3X thicker than the pizza on a stock slant.
I have heard that a big block damper will fit, but have you ever seen one with a groove for a v belt. Along with AC the motor also has an alternator.
 
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The slant six Romac damper will not accept the normal slant six rear or front bolt on pulleys and maintain the OE belt spacing.
Looking closer at side view photos of the Romac damper there is additional material (thickness of the hub) from the edges of the V to the outer edge of the hub in both directions. So even if one could get an add on pulley to bolt up the spacing would be off.
I have included a couple of photos to show the existing front end accessory drive set up.

36E7B5E4-33D5-4CD8-972A-F582756DE350.jpeg


AD80566B-2B28-4071-B0EF-82FFC15C0C3C.jpeg
 
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yeah, nothing will line up with the old fluiddampers before they started scalloping the front. I just spaced my LA fan pulley out and used the 2nd groove of the alternator. It all lines up enough now but the 6 damper has a longer snout than a B so it will be even closer
 
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