Installed the raby under-drive pulley
 

I was avoiding this mod because i did not feel like messing with the trimming of the case.
Then I saw a commerical for the dremel multi-max. It is a flush cutting tool.

I got the pulley and belt from Jake, The nut from dealer, Incedently you can not get a new thrust washer. Has to be ordered from germany and for some reason hard to get.

Anyway. the dremel thing sliced throught the caseing like butter, took less than 1 min.

Total install- @45 mins.

Drove it and I am very impressed, there is a very noticeable increase in power. More than I have got from any other bolt on.

Alt voltage holding at 14.3volts.

I vote this the best mod ever!!

Time and time again this install gives us the largest net power increase of any other bolt on.. I've installed a 3,000 dollar muffler and set of headers in the past and haven't gained as much power as this pulley provides.

Glad install went smoothly. The Dremel is the tool for this job when doing the work in-car.

Great, could you provide any tips on what you used to hold the stock pulley in place in order to break the bolt free?

a 5/16" (or 8mm) steel dowel inserted through the crank pulley and into the crankcase locking boss does the trick just fine.
I am putting together a kit that includes this improvised tool for the job.

any idea if this is less detrimental to the crank harmonics than a ltw flywheel? There have been speculations that there are increased IMS and RMS failures in BSR's with ltw flywheels. This might also help avoid power steering fluid overheating

Jake, a quick question: Are you cutting away the boss used to hold the OEM pulley; and if so, how do you hold the new one or lock the engine position for service once the original boss is cut away?

Seems like a good mod to me.

This mod can't be compared to the LWFW. The LWFW won't add steady state tested HP because it only reduces mass. The UD pulley increases HP by slowing down the accessories of the engine.

JFP, the boss extends into the case, so after removing the 12mm necessary for clearance enough of the boss remains to be useful during cam timing and engine maintenance.

Thanks Jake, I've been wondering about that and some customers have been asking about your pulley................

There really is no tips for this. I used a large Allen wrech with the car
in gear to stop the pulley. There are holes in both pulleys. I would think
there is a special tool like the one for the screw on oil filter adapter that
could be used. But not needed. You need a 15/16 large socket and a breaker
bar. Same size used to lever the belt tentioner. Don't loose the washer.
New bolt is 9$. Tighten to 192 ftlbs.
I did worry about turning the crank too far in either direction as not
to turn motor backwards. I don't know if it matters or not.
This is too simple not to do.

I think the multi tool cutter made this go so fast. Otherwise
cutting the boss looks like a pain in the rear.

torgue increase?
 

[QUOTE=Jake Raby]Time and time again this install gives us the largest net power increase of any other bolt on.. I've installed a 3,000 dollar muffler and set of headers in the past and haven't gained as much power as this pulley provides.

Jake, what was the torque increase after installing the pulley? Thanks for your work on these engines.

AKL :cheers:

What kinda hp gain are we talking about here? 5 or 10hp? I ask because if only 5 or less, then it would not be worth the hassle to me, but if something like 10hp gain, then I'd consider it.

Despite any actual values, this mod is one of the few that can be felt in the driver's seat.
I see 5-7 HP at the wheels and a torque increase of generally 5 lb/ft after the installation on my dyno. What should be more considered is this mod creates more power across the ENTIRE RPM range, so the average HP is increased and thats a much bigger gain on a stop watch or in the driver's seat than just a peak HP gain.

Great. Thx for the reply Jake.

This really is the key here. An increase of 5rwhp from 3000-6500 rpm is a lot more valuable than a gain of 5hp only from 6500-7000 rpm in terms of lap times. How much time do we really spend above 6500 rpm? Far more useful than the average software reflash at 1/5 the cost. I did it as a reliability mod to preserve my power steering pump on track days but the bit-o-power increase is icing on the cake. :D

It should be decreasing the pumping losses exponentially as RPMs increase. At lower RPM, the gains are much less than at higher RPM.

Jake, I went by your website, but could not find anything about the pulley; do you have info on it up anywhere yet?

I was wondering the same thing. I have my debit card in hand, but cannot find a place on the web site to order the pulley.

Send a E-mail before they are gone.

When purcashing the UP, do you have to buy another belt? Why not reuse the oem one? and again how can I purchase this.

thanks