well. For funsies I ordered the MRZ underdrive pulley for my SS/TC. After some simple research, I found the LNF uses the same crank pulley as the 2.2 2.4 ecotecs. Install is exactly as JN2 stated in his how-to. many thanks go to him..
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my mods b4 this install include:
-- snorkel delete, K&N drop in and AEM elbow
--CIA charge pipes
--HAHN FMIC
--HAHN offroad DP
--HAHN 3" catback

OTTP rotated tranny mounts and SCA bushings for the drivetrain.

tune by trifecta with the selectable tune, stock and comp mode @24psi
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just starting the car and lettin the idle settle, everything is still nice a smooth, pulley does not wobble a bit. This pulley is very nice, the black coating is flawless. With headlights, fog lights, rear and front defrosters on the voltage still stays around 14 at idle according to my interceptor.

i drove around the block in stock tune a few times, just being as civil as I could. I noticed 1st, 2nd and 3rd do rev alil quicker. ive had my car for a year and half, drive it 75miles a day, i notice any changes pretty well.

imma go out later and give it hell on the highway in stock and competitive mode and update this. im goin to watch my mileage for the next few weeks and see if that is affected at all. Im not expecting to gain much power overall, but everylil bit helps.

until my next update, happy modding

 

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alrighty then, spent a half hour or so just dicking around. Around town, in both stock and comp mode, i noticed i can shift earlier to the next gear without feeling the engine lug, the engine is much smoother at lower rpms. ill keep track of rpms vs speed vs gear tommorow, I was having to much fun today.

and now, what im sure every one wants to hear about. performance changes.the highway runs were done in Comp Mode. i can safely say that yes, at wot throttle in 3rd 4th and yes 5th gear, it revs quicker and the speedo climbs faster especially at higher rpms, ambient temp was 63degrees F, IAT 2 temps were 73degrees F. (LOVE THE HAHN FMIC btw). a few days ago with similiar weather versus today, I can say there is a marked difference in acceleration. ofcourse, ill keep driving hard the next few days to account for weather changes
but, this is just today, so ill give it a few more days with updates to account for weather changes.

Now, i feel like ive made this sound like the most amazing thing ever. it does work but remember, its not making more power, its allowing more of the available power to make it to the wheels.

i had a March power pulley set on my 00 s10 blazer and those made no difference at all.

the engine/ tranny/ wheel combo in the balt seems to like the the weight loss at the crank in every aspect. And yes, finally, only will time will tell of negative effects.

 

wow this sounds kool. how much was it. was it hard to install??

 

My past experience with u/d pullies is that they are more trouble than theyre worth. You will mose likely end up wearing out the alternator as I did. Its gonna be working double time while at idle to supply power, especially at night with the a/c on. It may take a year or so to start to show signs

 

im aware of the risks, I had everything goin just to see if the alt would be ok. I personally rarely use the a/c or rear heater. or have the stereo bumpin'. those with larger stereos, or use there a/c alot in the summer or the defroster and rear defroster alot in the winter will have issues much sooner. and id recommend staying away from UDP if that be the case, the stock size lightweight could be an option. I may be deleting my ac aswell once i get a decent car for DD. we'll see how that goes.

install took about 45, tryin to work that tensioner, even with the tool was a bitch. other than that, its very straight forward, the pulley was 166usd i think. add on the new belt if you go underdrive. there is a howto in that section

 

the belt i used was a 050390. recommended by mrz. it was a bitch to put on though. a 39.5 in belt woulda been better though getting the belt on and still maintain good tension.
water pump is internal driven, so no pulleys to change there and the alt i didnt bother with all that hassle to take the alt out. MRZ makes an alt pulley for the 2.2/2.4 cars, im not sure if we share the same pulley with those cars.

 

Sorry, got tired of editing my same post. Yeh I know the ss/tc WP is internal. I posted it up then caught it, brain fart. The alt is the only thing driven by the drive belt, so I am curious what accessory are we really underdriving?

I know MRZ gained 3-4 available WHP on a nearly stock 2.2, so basically a 2.5% increase in avaialble WHP, but is the 2.2 drive pulley set up like the LNF? With the just the Alt?

If thats right then a 300 WHP LNF would gain around 7-8 avaialble WHP, for less than 200 dollars. Wow.

 

wtf is an underdrive pulley

 

A smaller and/or lighter crank shaft pulley. When you can lighten or shrink the rotational mass of a the crasnkshaft pulley, you can make more of your BHP actually hit the wheels. You dont really gain anything HP, you just make more available. Samething with a lightened flywheel. Which I am also curious to see if anybody has done this to the LNF tranny yet.

 

its underdriving the alt and the a/c compressor, granted, if your not using the ac, its not producing much drag, if any. I know its not underdriving much. i went underdrive to get off as much weight as i could. next summer when its clutch time, ill be trying out the lightweight flywheel with it.

 

I had a ton of cooling issues on my Subaru when I had a Underdrive pulley set on it. Just keep an eye on things if you sit in traffic!

 

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Yeh its probably not underdriving much, but still, if you can connect even 2-3 more Hp to the wheels, its still a better bang for the buck than a 500 catback exhaust, lol.

Regarding the flywheel, I guarantee most would say dont do it, since our cars are boosted. More load on the engine, the faster the spool. BUTTTTTT, since most limit boost in first gear, most NLS 1-5, and the K04 is tiny and twin scrolled, I think it would be beneficial, and the lag would be very minimal. Plus our cars arent that heavy, so we can go fairly light on the flywheel. I would really like to see how this works out.

 

our waterpumps are internally driven, so this underdrive pulley wont affect cooling

 

If it causes enough drain on the alt then the fans will turn slower at stop lights which could result in higher temps.

As for the lightweight flywheel. Ive seen some turbo cars develope a surge at idle cause there isnt enough rotational weight to keep the idle steady

 

i feel the alt will be more than enough, on a STOCK car, i.e, no additional electrical drag, systems, hids, etc. this pulley is underdriven approx 10%.
09blue, just curious, what pct was the underdrive pulley for your subaru? im thinkin of putting a lightweight, not underdriven pulley on my girls STI.

 

Well what if you put on the alt. underdrive pulley? It says on the site that it will compensate for drain that may occur.

 

Reduction of rotational weight hurts spool time. That's why a lot of turbo people will stick with stock flywheel when upgrading clutch.

 

I have also heard of turboed folks just upping the idle slightly, to accomodate for the shitty idle some encounter. I am curious to see the difference on a small turbo like the k04 in comparison to a larger turbo like a gt30.

 

well, fishing around this site, some other guys have a lightweight flywheel on the lnf and arent experiencing any issues, spool time is still next to nothing and idle is still smooth

 

A tsb recently came out for the lnf stating lightweight flywheels/pulleys could cause misfires at idle.

 

can you try to find me the tsb, Id be interested in what is has to say

EDIT, found a portion of it

Condition/Concern:
A technician may comment of MIL lamp on with DTC's of P0300, P0301, P0302 or P0304. They typically report they cannot determine a root cause. This concern (misfires) usually occurs with extended idling and may be reduced/eliminated by raising the RPM slightly or inducing an engine load (such as A/C).

Recommendation/Instructions:
Engineering has determined that aftermarket parts (such as a light weight aluminum flywheel or accessory belt drive pulleys) can contribute to this issue. Anytime any portion of the rotating assembly is changed to an aftermarket component, there is a potential for this concern. When diagnosing a misfire DTC and no concern can be found following eSI, the technician should inspect for aftermarket components installed. This concern (misfires) usually occurs with extended idling and may be reduced/eliminated by raising the RPM slightly or inducing an engine load (such as A/C).

found a new test, imma let her idle for while a few times a week, see if i pop this code, ill keep track of misfires on my aeroforce as well. the tsb doesnt state that lightweight pulleys or flywheel cause the issue, but seems that they can aggravate it if the issue exists

 

I dont know how it will affect the lnf. On my previous vehicle even with the alt pulley it took about 18 months to begin messing with the alternator. At idle it would make like 11 volts and at cruising rpms it would make 13 volts. Normal is like 14-14.4

 

sounds like more trouble than it's worth