Gernby

iTrader: (1)

I expect that the gains from underdrive pulleys on our cars would be considerably less than other cars for the simple fact that we don't have a power steering pump, and our A/C compressor shuts off at WOT. It seems like a high hanging fruit, especially considering the fact that a solid pulley would shorten the life of the engine. I don't consider 50K, 70K, or even 100K with a solid pulley much of a success story. I'm sure that any of those engines would show above average wear if disassembled.

fritZman

Man, I'm sorry to see so much negativity for what is really a decent little mod.

Contrary to the reports, there's been extremely few engine failures related to lightened pullies. This fear mongering can be applied to any little situation such as getting bad gas at a mom & pops gas station - with likely worse results to the engine IMO.

I've run lightened pullies for years on Hondas, Mazdas, and recently over 5 years on my 350Z. All cars have seen tones of track time and visits to the redline. Zero engine issues.

Having said that, I wouldn't install one on my is350 for one simple reason. It's has an automatic transmission. The best benefits of a lightened pulley are like a lightened flywheel, it helps the engine rev a little easier. It helps bigger v6 and v8s feel more like a 4 cylinder. This makes the throttle a little more easy to modulate and heel/toe during downshifts.

Besides improved throttle sensitivity, the actual seat-in-the-pants gains are very little.

lobuxracer

iTrader: (2)

Many Hondas come from the factory with solid pulleys. There is no danger in a lightweight underdrive pulley on those engines.

Here's a great story which emphasizes how potentially dangerous anecdotal evidence (I ran one for years and never had an issue) is when making a decision about modifications.

Way back in the 60's BMW brought motorcycles to the US with chain driven overhead cams. The broke repeatedly for US drivers, but never broke in Germany. Extensive investigation determined that typical engine speeds experienced at US driving speeds were at a harmonic which rapidly wore out the cam chains and they broke prematurely. So a design that worked perfectly on the German Autobahns and German backroads did not work at all in 75 mph limited America.

This is the same issue experienced with harmonic dampers. BTW, they are not balancers, they don't balance anything, and calling them balancers is a complete misnomer. Harmonic dampers are there to quell vibrations caused by piston firing, and there are rpm ranges where this vibration is extremely dangerous to the engine's service life. There are a number of ways around this problem. The most effective is to put a damper on it, and anyone with small block Chevrolet experience will tell you a damper is mandatory if you don't want to break your crank. Various engine designs have greater or lesser needs in terms of managing this vibration. Many Honda four cylinders have no damper at all because the crank was designed to deal with the potential for vibration from the factory.

Saying you never had a problem just means you never saw anything. If you haven't pulled the engine apart and examined the rod and main bearings, then your experience is anecdotal at best. You didn't suffer catastrophic failure - it doesn't mean your main bearings aren't 3/4 thrashed and ready to die unless you've examined them. It doesn't mean your crank isn't cracked and on it's way to being a paperweight unless you've magnafluxed it and determined it to be crack free.

So, if the manufacturer saw fit to put a damper on the crank from the factory, removing that damper and replacing it with a solid pulley is, at best, a crap shoot. Maybe the engine will last. Maybe it won't. Any decent diagnostic mechanic/engine builder will be able to tell the difference between an engine run without a damper and one run with a damper if the factory install a damper in the first place.

If I were running in ALMS, I would run a solid pulley. Every pound I can save is worth a lot, and I have a budget set with the expectation the engines are going to be routinely disassembled, inspected, crack checked, and rebuilt. This is not what the typical car owner does and why there is inherent unspecified risk in running a solid pulley on an engine factory equipped with a damper.

al503

I installed the pulley on my MT G35 and noticed a nice little benefit in responsiveness. I put 2 other pulleys, one in a coupe and one in a sedan, which were both AT's and they noticed the difference also. A lightened pulley/flywheel will help regardless of the tranny.

fritZman

My point was more that for me the pulley has the most benefit in throttle sensitivity. While I don't doubt that some throttle response improvements could be felt through an auto, I also don't doubt that the very nature of an auto tranny would mute a lot of that effect.

Actual full throttle runs to redline could be felt regardless of tranny, but that performance benefit is minimal to the improvements of throttle sensitivity IMO.

fritZman

I wasn't using my own personal experience as the sole justification (although that does help), but that of an entire forum (my350Z.com). There's got to be hundreds of pullies installed by members and very little, if any, complaints.

I wouldn't always use the logic of putting in the car exactly what the manufactures saw fit. They have multiple objectives to meet besides performance. It's possible a damper was installed on a pulley to reduce vibration at the expense of performance. The same logic can be applied about catalytic converters. They suck a LOT of performance from the motor (ironically using up more gas), but are put in place for emission reasons.

While pulleys may not help, modern engines tend to be so over engineered that an undamped pulley is highly unlikely to be the source of catastrophic failure.

lobuxracer

iTrader: (2)

You should read some of the Scion tC forums. Their mileage has definitely differed.

daLex350

I had installed Unorthodox Racing (UR) Pully set on my 2000 V6 Accord and had no real direct problems. I performed this install because I knew before I hit the 100k mile marker the car would be sold so the "chance" of failure on my watch would be unlikely. Being an Automatic, the gains were HUGE and were the best bang for the buck when it came to performance. During my install i could instantly tell where all the so called "lost" power came from, the crank. The UR crank pulley had a slightly smaller radius but weigh 60% lighter. The gains were found in response time and the ability to reach redline a lot quicker. During the dyno tests, torque at the low end was where we found the most gain and we looked for it being a SOHC engine.

But do stop to think that if it were that easy for a Car company to come up with that many horsepower by putting less mass at the crank which would obviously be cheaper in the production of the car, wouldn't they just do that instead of finding more expensive ways to do so? Sure when installing the pulleys you do lose the ability to maintain a certain rpm for the same amount of time then stock but really WHY else would they put "dead" weight there? I mean they only spend several hundred million dollars a year into developing their Formula 1 cars which eventually trickle down into our cars...They've been in the game longer than most of us have been born ha...

I think lobuxracer makes great valid points...just what are you ready to deal with???

On another note after the whole vibration talk...maybe that's why Honda found cracked and broken engine mounts TWICE on my car...if the pulley set didn't do it directly (which i doubt) it sure helped....

Now I take my car to the Fontana Speed Way and other local tracks in Southern California and After reading here that we do not have a steering pump and the AC pump turns off at WOT (AC pump utilizes about 5%-10% of power)...i really don't think i'm looking for 5% increase in power....They spent a lot more money in development of this car then they did on a 25K Accord...I think the mod might hurt on another integral part of the physics on the Engine itself...

If you want to make any head wind in your quest for more "butt" power...Try finding someone to get us the IS-F tranny software so we get better Shifting times...talk about robbing time...I'd gladly pay up to $1000 for that one!

My 2 Cents.

Gernby

iTrader: (1)

IS-F transmission shift software? The IS-F has a totally different tranmission (8 speed).

daLex350

Just want crisper shifting...like the new IS-F....sorry for the confusion

nabbun

the shifting program could definitely use an upgrade

Lextasy89

when racing from a stop i dont think our cars could really shift much better at all... maybe it would help if you were doing a 20 or 40 or 60 punch.. but in that case all you have to do is switch into manuel.. downshift to the lowest gear you can be in.. hit the gas and put it back into auto..

daLex350

I agree with you, however on the track you notice the shifting lag....On track it's not just a straight line fight, and when coming out of a corner the car doesn't down-shift when i want the higher revs to pull away, I lose a lot of time there...one of those things you have to experience...wish it was more like the M3's SMG

Gernby

iTrader: (1)

I think it's pretty bad form to downshift while exiting a corner. If you need to downshift, do it before you enter the corner. If that requires hitting the downshift lever a second before getting to the corner, then click it a second sooner.

lobuxracer

iTrader: (2)

Downshifting IN a corner? Not me.

The one thing the paddle shifters do well - they do allow you to downshift before the turn so you can get into the powerband on exit without a lot of shenanigans or monkey motion. It's about the only thing I've found with the paddle shifters that works the way I'd like it to.