QR25DE Spec-V development

[mike kojima]

The balance shafts are good for 7-8 wheel hp on a
QR25DE.  Surprisingly the affect on NVH is minimal. I
drove a QR25 with no balance shafts and it was quite
hard to tell, except posibly at idle.  Without the
shafts the vibration was still better than a KA24DE.

Since the balance shafts spin at twice engine speed,
the bearing life on these could become an issue when
the car is raced.  So for racing use with a higher
than stock redline, There removal might be considered.

Mike

--- "geo3@earthlink.net" <geo3@earthlink.net> wrote:

> Hey Mike, can you go into that at bit.  I know it's
> a really popular mod with
> the 944 folks (also a 2.5 liter 4 with balance
> shafts).  Rumor has it that
> it's good for 5 hp on the NA 944 and about 10-15 hp
> on the 951 (944 turbo).