Underdrive Pulley for 1uz-fe!!

[xirforever]

SCV8, if you remind me in two years ill let you know! lol i can barely remember what i even did last weekend

Good analysis lambo, at least your exercising possibilities with me, i like it. But my car still has original engine and has been in my family sense brand new! i love that part. It is possible i suppose my stock pulley had woble in it, i guess that would be the only real explination.

I was curious to see how the tensioner looked if i kept the engine at a slow and stedy RMP rise (new pulley). Sense i was doing this from hand in the engine bay i dont know what RPM levels i was at at any particular time, however it seemed as though the faster it went, the smoother it got (ie the less the tensioner moved to vertually no movement). Seemed like a linear increase in "smoothness" also.

I shipped the second pulley i had (i only bought two, didnt want to buy a few and find out a dimension was wrong or something! lol) today to Lextreme, he will look it over and add his 2 cents. He probebly has a better digital camera than i do too, lol.

 

[toad007]

Ok...I dont understand why the heck you didn't just machine this thing to accept an aftermarket damper! Go look at a summit mag, a good fluid damper is $200-400 and your pulley could be easily adapted to accept one...........

 

[xirforever]

What are you talking about..... fluid damper??? Please explain

Incase that was a typo i just checked out summits product line on harmonic balancers, they dont make any type of damper insert, just the pulleys as wholes... i guess im missing something here...?

$200-$400 plus the pulley itself.. your looking at a hefty price, that is if there is such an insert that i happened to miss on their web site.

 

[toad007]

fluid dampers just use a silicon fluid to dampen the crank instead of elastomer strips. As far as I know the dampers slide onto the crank and bolt to the back of the main crank pulley? Why couldnt your pulley be machined to accept the bolt pattern for a SBC or SBF or whatever damper? Unless i'm missing something here?

 

[xirforever]

You got me there, sounds like a great idea! I can have the pulley machined to whatever i want becuase i can design it however i want, so thats not a problem, i just never knew about these things. Do you have any kind of links or anything to these silicon fluid dampers so i can find out more info on it and get this thing on the ball? Sounds like a great idea, i dont have summit mag, just the internet.

Thanks,
Nick

Thanks,
Nick

 

[toad007]

ok...silicone streerdampr part # for a 6 7/8" chevy crank pulley is... LU-670100
thats a good silicone one for $160, summit has generic 6 3/4" elastomer one for $60 under # SUM-161350. I would think any aftermarket damper that is designed for a internally balanced crank would work? There are a bunch of them and I'm sure you could find one in your price range and the right diameter that would work on a 1uzfe. Anything is gonna be better than nothing. BTW that first damper is made outta aluminum

 

[xirforever]

Oooooo i finnally get what you were trying to tell me

"As far as I know the dampers slide onto the crank and bolt to the back of the main crank pulley?"--toad007

Thats not really how they work. The damper is actually PART of the pulley, it does not bolt to the pulley. I'm only speaking for the 1uz right now, i have not seen every motor in the world, but thats how the majority work as far as i know.

 

[toad007]

The chevy dampers are NOT part of the pulley. Most stock ones are, however the stock chevy and these aftermarket ones are NOT part of the pulleys, they could be retrofited to your project.

 

[Zuffen]

I question if you can use a Chev balancer on our engine.

Every engine has different harmonics and as such has different balancers built in different ways and with differerent grades of elastomer.

Whilst I agree you can bolt stuff together and machine (say) a Chev pulley to fit the 1UZ who said it will do the job. You could be doing more harm then good.

I know there are aftermarket pulleys out there that are built to replace OEM but they are still standard size and construction.

You need to ask what are you trying to achieve.

By underdriving you save a little power in the steering as the pump isn't turning so fast. If you want max power turn off your air conditioning.

Tha alternator is interesting. The slower you turn it the less power it draws? Right? Wrong! The alternator will adjust it's power output automatically to suit what the car/battery are demanding. So turning it slower just means it is working harder at slower revs. You won't save power turning the alternator slower nor faster. Try reading the Toyota training manuals (on the Web) and you'll see this is correct.

The only gain we would see would be a slight rise in percieved power, and the speed at which the engine will pick up revs, due to the lowered rotational weights.

The usual reason to underdrive is to slow down the water pump, as it draws plenty of power. We can't do that so the whole excersize is flawed and a way to spend money for little return.

If you want to reduce reciprocating weight try machining the ring gear so it is narrower across the teeth and the "meat" of the ring gear is thinner. Moving weight from the outer is the most effective way to get the engine to pick up revs faster.

 

[Damien]

A good friend of mine works for Go Fast Bits and I asked him about harmonic balancers and the underdrive pulley kits they make for WRX's. He said for the WRX they don't need harmonic balancers because it has a very short crank and is an inherently well balanced engine but he said it's very important on engines with a long crankshaft. He knows of 1 GTR which had an underdrive crank pully fitted without a harmonic balancer and the engine went bang in a big way...

I don't like to post negative comments but it sounds pretty risky...