ATI Harmonic Dampner

[nikitopo]

It is not a good idea to under-drive the crank pulley. The water pump is a very important component for the health of your motor and is rotated by the crank pulley. Engineers that designed such solutions shows that their knowledge of this engine was superficial. If you want to under-drive the system, the best option is to focus only on the alternator. You can achieve this by installing a larger pulley on the alternator and keep everything else equal.

Additionally, if you want a smoother operation focus on the root cause of the problem and buy an OFT unit. The reason the engine is not as smooth is because two of the cylinders have different timing compensation. This means that the whole system is not so well balanced. This is solved with OFT by making the timing compensation same for all the cylinders. It keeps a difference only above 6800 rpm for safety – a rev range you'll not use that often. Trying to solve the problem with a damper pulley is not the smartest move.

[churchx]

Engineers may have also designed in extra safety margin, within which those 10% differences may fit into, or also ill-effects may propagate well after engine's life ends due different reasons, especially if subjected to race-ish abuse. As there are no statistic data pro or contra i wouldn't claim blindly either way, but underdrive/lightened FW & crankpulleys also get used in racing world, so i wouldn't write them off as complete gimmick.
Underdriven pulleys are imho used more to lessen power losses on turning all those accessories, pump, generator, AC .. from where smooth operation gets into this? Those losses are specific number per each engine rpm and won't change per rpm however one tune engine, will they? And one may try to compensate cooling efficiency loss from lesser pumping with tuning fan switching on at tune/lower temp thermostat.
Though then again, if power spent on turning all those extras is eg. 10% (completely wild guessed number), and 10% underdriving CP saves 1% of total power .. is 1%/2hp worth the price of it? Imho not, and that money may well be better spent in area with better return per buck. But if it's some thorough tune-improve-squeeze-out-everything build? Why not. I'd add to that AC delete kit too though then.

[Scrappydoo]

Snake and oil.

[nikitopo]

Personally I am using a crank pulley kit. I was just questioning the decision to underdrive the whole system.

The remark on smoothness is related to fluidampr's claims. I believe that the engine will run much smoother by solving the tune "issues", than using a fluidampr pulley.

[Kodename47]

Originally Posted by nikitopo

The reason the engine is not as smooth is because two of the cylinders have different timing compensation. This means that the whole system is not so well balanced.

So that's a fact is it? It may be that the car runs better with different timing compensations..... after all each cylinder is under different conditions.

[Yoniyama]

Two more points to add for reference:

(1) Fluidampr is an 1-piece design, whereas ATI Super Damper is a 2-piece; and

(2) Installing the ATI Super Damper may lead to cancellation of warranty, since it is 10% under-drive. (I can already imagine what excuse the friendly dealer would produce.)

I have seen a few positive use feedback for the Fluidampr. I have not seen any feedback for the ATI Super Damper on FT86 application, although there were a few positive feedback for other application (on other forums).

I would be really appreciative if any ATI Super Damper user for FT86 could comment on his experience.