Are Underdrive lightweight pulleys safe to use for a racing application. Ive just bought a B18c5 and im thinking of what I can do to it initially.

Currently Pondering:
-Lightweight Flywheel (any recommendations to which brand is good?)
-Underdrive pullyey (again which is good and sould I use one?)
-Intake Manifold (which is good?)
-TB
- any other recommendations?

 

??

 

i'm using the unorthodox race pulley on my 89 civic. Seems to work good so far and haven't had any problems.

 

I'm using a fidanza flywheel i got as an ebay clutch/ pressureplate / flywheel package. i like it.

 

I would recommend not using a pulley for track use. Also check and see if they're legal in your class? They do feel great with a light flywheel but you really increase the torsional vibration of the crankshaft... this is will reduce the life of your lower end bearings and oil pump... also will create higher loads in the timing drive.

I did have one but change back to stock. Best thing would be to go to a fluidamper.

I use an ATI flywheel because it was super light and super cheap (all steel - does no have a friction surface insert)

 

There's sooooo much information and disinformation out there on this topic... so, I'll add to it.

There are a bunch of people (me included) that have run the D16A6 with an undamped/underdriven main pulley... very few failures traced back to this.

There are a bunch of people that have run later D-series engines with undamped/underdriven pulleys and lunched bearings in short order.

There are plenty of folks who've run the B-series VTEC engines with the undamped, CTR N1 pulley and not had any issues... flipside is that some folks have had problems with the same (or similar) pulley. I've not seen anything that seems to indicate why some engines fail and others don't... if *I* were running an undamped pulley, getting the whole rotating assembly (including PP, clutch, flywheel) seems like a super smart move.

Everyone raves about the ATI Fluidamper... no first hand experience on my side but I don't know that they're worth the coin vs. a lightweight pulley and balancing everything. Also, at nearly 8#, the ATI is not what I'd call lightweight either...

YMMV, my $0.02, etc.

 

Xian said it all. i run an ati dampener because i want all the protection i could get (especially after last years fiasco).
i have an unorthodox underdrive crank pulley in the garage. if you really want to run one, you can have it. free. just pay for shipping.

 

I will ignore the fact that people are responding to a 9 year old thread and help Xian and his misinformation.

You are blending two companies with GREATLY different dampeners. You have ATI that makes a elastomer dampener. Then the company Fluidampr uses a viscous dampener. Different ends of the spectrum when it comes to harmonic balancers.

http://www.atiracing.com/products/da...amper_tech.htm

http://www.fluidampr.com/what/how-do...amper-work-55/

The ATI wins hands down either way. Sure there has been a lot of debate on this topic but there have been countless stories about issues with Fluidampr flying down the track. Go hang out in the Drag Racing section to find out...

 

That's why I have an ati.

 

I use cheap aluminum lightweight pulley on 2 different motors. First one sunk a sleeve at 30k, bearings looked good. other has 3k on it, no problems, driven hard as **** hitting 8,000 rpm on the reg.

 

I use Unorthodox pulleys on my ITA built D16A6. Been using them problem free for 4 seasons. The only issue i have run into is the alrernator pulley is machined only to fit Denso alternators, not Mitsubishi.

 

Since I'm whoring this morning.... To comment on Xian's post the damper can help with imbalance of the rotating components... My entire bottom end is balanced and silky smooth... but the dampers are for the torsional vibrations (speed fluctuations that happen every time a valve is opened and when a cylinder fires, etc.).. not really the radial loads...
and lol @ the old thread. But still I feel it's worth noting. I would love to be able to do some measurements and comparisons but unfortunately the $100,000+measurement systems at work aren't exactly available for weekend funsies... But If anyone wants to measure flywheel and crank speeds at about 300increments/revolution through a speed sweep I can analyze it and do a comparison!

 

Since it's been 8 years, I wonder what OP ended up doing?

Just chiming in to say that there is no such thing.

ATI makes the Super Damper

Horschel (formerly Vibratech) makes the Fluidampr


<- works for ATI

The purpose of the damper is not to save weight. In some cases the aftermarket piece is lighter than OEM, but weight is necessary to help dampen the harmonic vibrations. Typically aftermarket dampers are designed for a higher than stock HP application, but they also work on stock or near stock engines.

 

Agreed. When the OEM's make any change to their prototype level engines and even production engines... it's a guarantee that the damper is changed to exactly fit the crankshaft/drive system irregularites... and thus affects the whole front end drive. With our cars we're less worried about what the alternator is seeing and more worried about keeping the amplitudes down at the crank. Not sure exactly how much these affect each other since the OEM parts are rubber element dampers and they typically run an entire FEAD....
Tim - do you have any data from damper testing that is able to be shared? Would be really interesting to see.

 

Didn't I already clear that up and show links to help people? I don’t get it.

 

Yeah the links showed how they work but was hoping for some details

 

No issues with the following:
Lightweight flywheel, dk brand. On a B16, every spinning ounce matters and this is a good thing to use.

Underdrive pulleys, yes, by all means use them. AEM Underdrive power steering and alternator pulleys have been used on all of my engines. They live above 6,000 rpms. An oem motor lives at 1500-4000, stop and go and idle, it needs the power to maintain charge and pressure. Our race engines do not have that issue. Underdrive these things, no problem.

TB and Skunk2 have great choices in TB and intake mani.