wtf is this?
http://www.unorthodoxracing.com/nissan_maxima.html

I'm looking at the stock size lightened crank pulley. it doesn't underdrive, its the same size as stock, just lighter.

anyone ever see this?

 

no, ?

 

I'm not sure but I THINK i remember saying something about a lightned drive pulley for sc applications so that could be it

 

Chris is right... stock size to retain proper boost for the S/C application... just lightened to help engine rev faster. Stillen sells them too (UR).

 

I would think that it would give some gains. Another thing to consider would be getting the underdrive pulley and then just getting a smaller SC pulley (keep it the same or smaller ratio). This might even show better gains. It is also used for people with high powered audio and electronic stuff who need to get more out of the alternator at idle than a UDP can provide but still want some gains.

 

The smaller S/C pullies already have reduced surface area for belt contact so it would be a bad idea to use this strategy (underdrive crank pulley).

 

Yeah I didn't think about that. The lightened OEM size one would still be good.

 

i think x-mas money is going to buy one. I might even get b4 and after dynos.

 

if you do you are the man ...before and after dynos would be great!

 

i just have to con those b@stards @ ams (a dsm & evo shop) to give me a good price. last time i went there, they charged me $125 for three dyno pulls, wbo2, and

oh yeah a 4lb boost leak and a loose belt.

I have to find a better shop.
Steve

 

wow that is steep, around my area its $50-60 for 3 pulls with wideband. I guess having 4-5 shops around with dynos help keep the prices down.

 

hey guy's don't install a underdrive crank pulley. Way back i had one custom made, when i did not have turbo. Then i found this out and removed it.

1. can I pull the harmonic balancer off, replace it with an underdrive pulley and pick up 10-15 horsepower?
first, it's not a "harmonic balancer". it's a torsional damper. second, it is NOT a good idea to replace it with a solid underdrive pulley.

torsional analysis of a reciprocating engine is an extremely complex, computerised study and design of a system to smoothly and safely transfer 20,000 explosions per minute into useable torque without destroying the engine or drivetrain. oh, and do it for the life of the car. without exception, every reciprocating engine, pump, or compressor can benefit from torsional damping, but getting it right is an extremely complex process, and the consequences of getting it wrong are broken crankshafts and/or ruined drivetrain components. so in summary, this is NOT a good area to try to pick up cheap horsepower on the supra unless you are prepping a full race engine and plan to rebuild the engine and drivetrain on a semi-regular basis.



found this on mkiv.com hope this helps.

 

I have one of these on my car and the car hits the rev limiter much quicker, keeping me in boost for more of the time. I love it.
This all based on but dyno only. Sorry
All in all it wat a noticable difference.

 

the reason i would agree with this on a supra is that it is a straight 6. the crank is longer and motor is only firing up and down, so there is no longitudal forces acting on the crank to balance it other than the counterbalances on the crank itself. in addittion to that, they (supras) are producing power that could actually cause deflection of the stock crank, whereas i don't believe we have reached that power level yet.
I could be completely wrong, so take that with a grain of salt...

 

I would love to buy one, but it's too expensive.

 

It has been a while. But I got mine from courtseyparts.com and it was cheaiper than anywhere else I looked. And no I don't remember what I paid...sorry.

 

this isnt an underdriver though.

its a lightened stock size.

i like that quake is helping, good info man.

 

trust me guys, i'm all about anything for extra power. But if you take a look at your "crank pulley" you will see a rubber insert between the metal. That is what this is for on any car. Don't hurt your engines. If you really want extra power and you have a standard tranny. Get a lightweight fly wheel a least it's balanced. But you can get any other pulley made lighter.

 

The 5th gen don't have the Harmonic balacer on the pulley, but the 4th gens do. Some corret me if I am wrong.

 

not sure about that if they dont' then go ahead and use one.

 

Ummm, the 4th and 5th gens have solid crank pullies. I've yet to come across one VG, VE, or VQ that has snapped a crankshaft or screwed up a drivetrain because they ran a UDP. My car runs a UDP, with no problems at all. Had it on for over 20k miles....and my car is at 210k. If you can show me an actual case of this happening on our cars....or for that matter any other car...I'd like to see it. Otherwise, I'm very skeptical of the statement UDP's will destroy your engine. Now I can see them hurting S/C guys because they underdrive the S/C........but other than that....I don't see any legitimate harm.

S

 

The 4th gen crank pulley does have a thin elastomer between inner and outer parts which acts as a torsional damper. Going to a solid pulley does have an effect on the fatigue life of the crank, but it is probably less important on a V6 than inline 6 due to the decreased crank length. I have heard of BMW inline 6's that have had broken cranks after installation of a UDP without a torsional damper. So far we haven't heard of any cranks breaking in a VQ due to a UDP. At least not here in the org.

 

http://www.greghome.com/Greg's%20Gar...e%20Pulley.htm

 

Greg is mistaken. And you can clearly see the elastomer ring.

I'll have to do some searching to find it, but Bmr4life has posted pictures of the stock crank pulley separated into its two parts.

 

Found it:

http://forums.maxima.org/showthread....t=crank+pulley

 

The pics don't work for me (Another cardomain host ) but I still wouldn't think that a lightened solid crank pulley would do any damage. I understand that there is a chance of it happening but it is very unlikely.