Hello,

I'm currently rebuilding a Mazda MX5 engine (1.6L) with a different than
stock rod ratio
(http://www.edmunds.com/mazda/mx-5-miata ... 1997-mazda
-mx-5-miata-long-rod-bp-conversion-and-nerdery.html)

I'm wondering how this affects the resonance frequency of the cranksaft and
if the Supermiata Crank Damper (Manufactured by BHJ but sold by 949Racing)
or another damper from your range still applies.
Can you get back to me with a precise answer ?

Thank you

Best regards
Charles Kounakowitch

Hello Charles,

One thing we have learned with our Miata dampers, is that we have many very
happy customers running a very wide range of engine setups, considering
components both inside (rod, crank, piston) and outside (clutch, flywheel)
the crankcase. The tune and inertia we originally settled on for our
single-pulley all-out race damper...
http://www.bhjdynamics.com/index.php?ma ... 19&product
s_id=196

...is used in the damper we manufacture for 949 as well. Considering we are
looking at everything from turbo-street, to supercharged, to STX, to E and F
Production motors, we have seen a wide range of replacement parts added to
these motors and all with success. I would say that the rod ratio should
not create any problem for the crank/damper relationship. You can also ask
Emilio at 949 about his experience with rod ratios, for a more hands-on
viewpoint.

This is about as precise as I can get and I hope this suffices. We can do
an analysis of you specific setup, but I imagine it would be
cost-prohibitive and take around three months to complete.

Thank you for contacing us,

Chris Ouellette
BHJ Products Inc.
+1(510) 797-6780 | +1(510) 797-9364 Fax
BHJDynamics.com | BHJProducts.com | facebook.com/bhjperformance