The crank damper pulley sits on the front of the RB26's crankshaft and controls its torsional vibration. HKS makes a damper pulley designed for the RB26, one for the R32 GT-R and one for the R33 and R34 GT-R. Its pulley sizes differ from stock, so it comes with its own water pump pulley and belt. We supply parts; your engine builder fits them.
What the HKS damper does
HKS calls it a harmonic vibration damper specially designed for the RB26. HKS says it absorbs and counteracts the torsion of the crankshaft, and that it was designed from torsion data measured on engine test benches.
HKS damper pulley by chassis
| Part | Fits | Notes |
|---|---|---|
| 24998-AN002 | R32 GT-R (BNR32) | HKS makes it to order |
| 24998-AN003 | R33 GT-R (BCNR33) and R34 GT-R (BNR34) | One part for both cars |
| 24998-AN001 | R35 GT-R | Only for the HKS 4.3L capacity upgrade kit 21004-AN019, not a standard VR38DETT; HKS makes it to order |
HKS damper pulley, R32 GT-R | HKS damper pulley, R33 and R34 GT-R | HKS damper pulley, R35 4.3L | HKS 4.3L capacity upgrade kit
Pulley sizes and ratios
| Pulley | HKS | Stock |
|---|---|---|
| Crank pulley | 139 mm | 146 mm |
| Water pump pulley | 154 mm | 137 mm |
HKS gives reduction ratios of 0.85 for the water pump, 0.95 for the alternator, 0.95 for the air con compressor and 0.84 for the power steering, so each turns a little slower than stock. HKS says its water pump pulley is purpose-built to prevent cavitation of the coolant, and the kit includes an HKS Fine Tune V-belt, 4PK875.
Belts to order with it
HKS recommends these HKS belts for the power steering and air con, which aren't in the kit:
- R32 GT-R: power steering 4PK925 (24996-AK009), air con 4PK910 (24996-AK008)
- R33 and R34 GT-R: power steering 4PK950 (24996-AK010), air con 4PK895 (24996-AK007)
Ask us for the belts with the damper, and we'll confirm them for your chassis before you pay.
When to fit it
The damper sits at the front of the engine, so plan it with other front-of-engine work, such as a timing belt service. Your engine builder fits it and torques the crank bolt to the correct figure.
RB26 timing belt guide | RB26 oil pump and crank collar guide
Large-snout cranks
The ATI front kit we list is for cranks with a longer, large-diameter snout. It includes an ATI balancer outer with a water pump pulley to suit, an ARP balancer bolt, a timing belt gear and a front cover seal. Ask your engine builder whether your crank needs it.
ATI front kit for large-post cranks
Ordering
All the parts above are price on application. The HKS dampers are shipped from Japan, and imported parts usually take 1 to 2 weeks at the minimum. UK delivery is quoted before you pay. Email us or use the contact form with your chassis number.
Delivery and returns | Skyline GT-R engine parts | HKS
Related guides
RB26 rebuild parts list | RB26 timing belt | RB26 oil pump and crank collar
FAQ
What does an RB26 crank damper do?
It controls torsional vibration at the front of the crankshaft. HKS says its RB26 damper pulley absorbs and counteracts the torsion of the crankshaft, and that it was designed from torsion data measured on engine test benches. Your engine builder can check your factory damper when the front of the engine is apart.
Is an aftermarket RB26 crank damper worth it?
Ask your engine builder, because it depends on your build. HKS designed its damper pulley specifically for the RB26, and it comes with a matched water pump pulley and belt. If the front of the engine is coming apart anyway, for example for a timing belt service, that is a sensible time to fit one.
Which HKS crank damper fits my GT-R?
24998-AN002 fits the R32 GT-R and 24998-AN003 fits the R33 and R34 GT-R. The R35 damper, 24998-AN001, is only for the HKS 4.3L capacity upgrade kit, not a standard VR38DETT. Send us your chassis number and we'll confirm the part before you pay.
Is the HKS RB26 damper an underdrive pulley?
In effect, yes. HKS gives a 139 mm crank pulley against 146 mm stock, and a 154 mm water pump pulley against 137 mm. Its reduction ratios are 0.85 for the water pump, 0.95 for the alternator and air con and 0.84 for the power steering, so each turns a little slower than stock.
Which belts do I need with the HKS RB26 damper?
The kit includes an HKS Fine Tune V-belt, but not the power steering or air con belts. For the R32, HKS recommends 4PK925 and 4PK910. For the R33 and R34, it recommends 4PK950 and 4PK895. Ask us for them with the damper.