SC3BOY

I am still pursueing my quest of making my SC300 just a little faster, and therefore I have been considering the purchase of a set of underdrive pulleys. I have seen the posts that say you need a properly balanced crank pulley or you will wear out the bearings in your engine very fast. So in turn I have been scared out of getting one of those. I have also read that that pulley is the only one that really does anything. Getting the other three pulleys, AC, water pump and power steering I believe, would run me about $300. But If they arent going to do anything, then I have better places to waste my money. So does anyone have experince with the performance upgrades? All the pulleys, just one, whatever?

Perry Griffin

I have a SC400, but have formerly owned a stable of Mustangs, on which I always installed 25 percent underdrive crank pullies with no problems ever. I had wondered if I could free up a little parasitic frictional losses by doing the same on my new (to me) 95 SC, but have not researched it yet, was hoping this place would be the "come to" spot for all my lexus questions, as I am completely new to driving these cars. If anyone can answer the question of the underdrive crank pully, please do so for us. Thanks

SupraCoup3

as far as the SC300 goes, you have your choice from several different companies to choose from. But before you do underdrive pullies, I would suggest Apexi S-AFC -- The 300 guys say that they get an additional 25 RWHP and 30 RW Torque. It runs about $300 and seems to be a really good investment.


As Far as underdrive pullies go, I'm a bit shy about reducing the speed of the alternator on such a heavily electronic car. If you wanna try it, go for it. And the power steering pullie, we all know that the power steering is already a problem child, I wouldn't mess with that either.

So basically, for the same price as your pullies, get the SAFC and have some ill looks in your interior (SAFC console looks chill) and real, documented, and safe HP gains.

933005spd

I noticed the biggest bang for my buck from two mods:

- SAFC
- Replaced clutch fan with dual electrics.

The electrical system can easily be thrown out of balance, I would not screw with anything that could interfere with the alternator charging.

Bean

iTrader: (1)

Underdrive pulleys on the SC3 are a no no...

the SC3's stock crank has a harmonic dampener in it; without this, it will wear the engine out much faster... none of the aftermarket underive companies have this in their main crank pullies...

Its not just me saying; all the big boys in the SC3 modding scene say NO Other pullies are ok; but no aftermarket main crank pullies will have this balancer in them.

Oh and to just make another statement... there's no problem with these pullies other than that... the Lexus with all of its electronics would be absolutely fine with the pullies otherwise... the pullies are more of a weight reduction than a size reduction...
the main crank pulley stock weighs around 12lbs... while the aftermarket ones usually weigh under a pound

SC3BOY

Thanks for all the info. Wow, 12lbs, down to 1lb? That is an impressive lightening for the crank pulley. So if the crank pulley is lacking a dampener, and the alternator pulley is not advised and the power steering pulley is a "problem child", why the hell do they sell these things? That only leaves one pulley, which is the water pump, right? It's probably not worth just replacing that either.
Soupcoup, I already own the Apex-i SAFC. I have it mounted in the dash below my aftermarket deck. Indeed it does look cool. I haven't hooked it up yet though. I am getting every performance mod I am going to buy and do it all at once. So I am taking my time and seeing where my money is best spent. There is also the little thing about not knowing how to tune it. My local performance shop says they dont have any experince with it on my car either. The only idea I have now is to contact APEX-i, list all my mods to them and see if they have any suggestion on how to get max power out of it. I had no idea it was worth all that power though. You have me salivating!
If anybody thinks they can help here is my list of mods, as it stands now. Cone filter intake, aftermarket mufflers, cam gears, and the APEX-i SAFC. Any suggestions people? Thanks.

SC3BOY

933005SP, that happens to be the same car I have. You say you got good gains out of the dual fan setup? I saw one being sold on ebay for $100. I would have gotten it had I known it was worth it. I asked my mechanic about it and he said he didnt think it would make much difference so I didnt bother. Where did you get yours and how much was it? And have you been on a dyno or anything?

933005spd

I ordered a used one from suprastore.com but they took FOREVER and NEVER REPLIED TO EMAILS so I ordered a new one from MVPmotorsports. I got the one right away and few weeks later the one from suprastore showed up so I sold it on ebay.

I don't know why your mechanic would say that, the stock clutch fan is huge and heavy ~ 10lbs. Removing that rotational mass would make a hp increase on most any car.

Anyway, I noticed more of a gain with the dual electrics than with any other mod I have made - including the SAFC. Most noticable was performance gain in the low end, where we need it with the SC3.

No dyno or gtech, and unfortunatly I did not baseline the car prior to mods. The improvement was immediate and noticable by others who are familar with my coupe.

from mvpmotorsports.com:

Powerhouse Racing Electric Fan Conversion for 1993-98 Supra
Visit http://www.powerhouseracing.com for more info ITEM # PHR Elec Fan
These fans can/should be wired up to operate at all times your engine is running. They work on both autos & standards. Stay away from the thermostat-controlled electric fans, these stay on all the time providing the ultimate cooling possible. PHR is the original electric fan source for the Supra. Since 1996, they have used dual Flex Lite fans to cool the radiator while increasing much needed engine bay space and reducing rotating weight by 10 pounds. A must for hot environments, tested in Texas heat for 5 years without problems. Works without problem for those of you with a front mount intercooler. Used and recommended by the owner of MVP Motorsports (yes, he has a front mount intercooler).
MSRP $295.00 Your Price $249.00

SC3BOY

Small world. Dammit, I shoulda bought it. Oh, well. Thanks for the info.

sc300vb

dont sweat the aftermarket crank pulley, i have one, and i love it! i did alot of research so as not to buy something i shouldnt. the balancer everyone keeps telling you about isnt a balancer. the sc300 have INTERNALLY balanced rotating assemblies. this part they are refering to is a dampner that stops vibration from the accessories. is you have any questions about this or any other concerns call up UNORTHODOX RACING. i bought mine from them and it was and is on special for $130. oh yeah, there underdrive crank pulley has no adverse effects on the charging system. it can support up to a 1000 watt stereo system or hid lights....but dont go crazy above that!

NAZTY97

I can agree with sc300vb, i installed underdrive pullies on my 300zx and the same fear and argument existed over there. No harmonic balancer, blah blah blah,.. the guy at the shop, who didn''t sell them, and specialized in that car ( Z clinic ) said he had installed hundreds of the unorthodox, and not one ever created a problem. The other thing is, that engine was sluggish when I got it,... if you SC300 drivers are fortunate enough to have a 5 speed, the biggest thing I noticed next to the SAFC was the lightened aluminum flywheel. The stock was 27lbs and the new one was only 9lbs ( fidanza ). That alone made my car feel like i had a new engine, the rpms rev'ed a lot faster, and when I got the pulley ( main crank only ), it rev'ed that much quicker,... I d@mn near couldn't drive my own car after those two mods,... took a while gettin' used to, but I was smokin' every lightly modded and comparably modded non-turbo Z i ran up on. ( I know this isn't the Z forum, but cross-referenceable info ).

get the pullies, SAFC, intake, exhaust, and you'll be good to go. a lil nawwwwsss won't hurt either.

pcmw

NAZTY,

Question? If someone put in the electric fans that pull 30amps and then the underdrive pulley, would that begin to heavily tax the altenator in the summer with the A/C on?

I would hate to do both of these mods just to defeat the purpose.

Thanks

MW

NAZTY97

dont underdrive the whole system,... the main crank is the only one that really makes significant gain. I had a high powered sound system in my car, plus it's hot as hell in TX, so you know the AC blows all day/nite long,...and it was never a problem. I don't think it'd be problem if you don't have a lot of other hi-current capacity draws on your system,... ie. the 1000 watt system, some higher wattage lights,... and you could always upgrade the alternator to a higher amperage capacity.

sc300vb

true, the tech at ur said hid lights and 1000 watts plus sounds systems are the biggest cullprits. after i installed my pullies, i turned the car on, and turned on every single electric item on the car (i.e. high beams, seat heaters turn signals hazards, a/c, heat, defrosters, radio, etc.) and the system still charged at a perfect 14.7! dont sweat the pullies and dont listen to the nay sayers! like nasty97 said though, only get the crank pulley......l8r guyz!

Onelove

Lightweight Flywheel + Lightweight Pulley on a SC300 = Big no no. I can't quote about mustangs, or 300 ZX's, but I can tell you in a NA supra I have personally seen a 97 tranny with 35k miles start going only because of a UR pulley installed. On a Twin Turbo Supra I have seen numerous flywheel / clutch problems as a result of the lightweight flywheel and pulley. For this reason we created a dampened and SFI approved crank pulley and we use a Lightweight flywheel in conjuction as the gains from the flywheel usually outweight that of the crank pulley.