asianflava

Good to hear! I remember when the rumor was that they caused main bearing failure. I've had one on my car since 2002, but I've only driven it a few thousand miles in that time frame. I really don't want to take it off.

jdm ef8 89

Ok lol sorry about that i think ill go with something that exsists like a 1995 jdm sohc vtec (p08) and you said wtf? to a race radiator. The stock 92-95 eg radiators are fine but why not go with the race version off that just to be safe. And why should i have not buy a fuel rail/line for my si?

mattliston

no need for a race radiator

a radiator form the B series VTEC civics and del sols (94-97 vtec trim del sol, 99-00 si civic) is great. factory dual core

find me an aftermarket DUAL CORE radiator for a civic for less then $250 bucks

I can wait. You wont find one that will OUTPERFORM the stock
hondas dont have much power stock

honda DID do a fantastic job of over engineering critical parts

The same cooling system that works GREAT in teh winter (read>no too cold lol, no cardboard!) works great in the summer

Only thing I recommend for better cooling? get a high performance $100-300 electric slim fan AND shroud to direct more airflow

Honda fans are great, but bulky and ugly!! YUCKY!! BLECC!

mattliston

Brand name underddrive pulleys are okay for regular driving

its racing where you hit regular high rpms that they go to crap right away

I still hate them

its not an automatic motor failure

but you DO make it risky

all it takes is a few stoplight battles, and you have potential bearing damage!

not cool.

underdrive pulleys are for show, not go!!

jdm ef8 89

Ok so out of my two radiators which should I run. Currently an integra radiator (replacement for crx radiator) , or I happened to come up on a fresh out of the box 92-95 half sized race radiator with a good brand new fan and oversized hoses?

mruneek

thread jack.... this thread is underdrive pulleys not radiators

raffaelli

My engine builder put Unothordox pulleys on my D16A6 prepped for ITA. It has both...crank and alternator. I believe that if you don't put on both, the alternator will not spin fast enough to generate the field necessary to maintain the voltage level.

The pulleys are WAY WAY lighter than OE. I don’t think that both of them weight more than the OE alternator pulley. Complete savings in HP and resulting heat to spin up these pulleys versus the OE anchors.

SpyLude92

A well balanced lighter weight pulley is a good thing. You just need a brand that backs their work. You might only get a 1 hp gain "for example" but the lighter rotational weight of the pulley allows this to happen throughout the rpm's and not just a peak gain.

Again a well made pulley will reduce your alternator speed by a certain percentage. With that being said, when your car is idling on a factory alternator and pulley it does charge. I can't remember the exact number, it doesn't really matter, when your car is idling at 750 rpm's and you give it a little throttle the voltage regulator kicks in quickly at around 1000-1200 rpm "again an example". Once it kicks in voltage is regulated to around 13-16 volts "typically" throughout the rest of the rpm range. 1500, 2000, 9000 all regulated.

This basically means, with an underdrive driving an alternator, there is a possibility it won't charge at idle, as soon as you get the revs up, it charges normally. This does effect the engines performance in a good way but one of the big factors is reducing alternator speed, which reduces wear and tear from high rpm's. If your like me...my prelude is rarely below 3k when im driving.

I was talking to a part manufacturer years ago, I wish i could remember who it was but he said they didn't change the ratio on the underdrive pulley at the crank for the AC system. They left it stock, when i asked why, he said if you are going to use it for racing, you delete the AC system from the car. If you are just temporarily racing, street racing, daily track, etc...turn your damn AC off. lol it made perfect since to me.

Manufacturers call it a "Harmonic" balancer for a reason. If you slap an aftermarket balancer on for any reason and feel any abnormal engine vibrations throughout the rpm range. I would reverse your setup immediately.

Hopefully this helps answer some of your questions or at least gives you a little insight.

urinc

Actually the power gains can be pretty substantial even when just running the alternator drive (single belt conversion for B, D, F & H Series engines). Now the HP gain from underdrive alone may be small like the 1 HP figure quoted but the weight reduction is the key unlocking much larger power gains. We have never pushed the underdrive percentage much past 15% and we have always tested each underdrive pulley design to make sure we maintain factory specified accessory output even at idle. If you have an issue at idle the regulator is going bad or the alternator output has degraded and needs to be replaced. As for underdrive on the A/C any redcution in speed even for an accessory that is free wheeling is going to show an improvement in performance. When running the A/C why not underdrive, again we confirm maintenance of factory specified functionality of the accessories in testing.

As a rule of thumb on stock motors we have conservatively seen a 2 WHP increase/improvement for normally aspirated engines. As an example the B-Series single belt underdrive crank pulley we make weighs .44 lbs and the stock 3 belt crank pulley weighs 6.14 lbs. which is a 5.7 lb reduction in static mass and based on the design of our pulley equates to over a 98% improvement in moment of inertia. We would expect roughly an 11.4 WHP increase/improvement, likely around the point where the VTEC kicks in but we would also expect atleast 1/2 to 3/4 of this gain across the entire powerband.

The term harmonic balancer is as actually the combination of two words that don't belong together when applied to engines. It is either a harmonic damper, a balancer or a harminic damper that has a counter weight to balance the engine. As for harmonic dampening it is purely of function of NVH control and has nothing to do with protecting the engine, this is the case for any engine we have made pulleys for over the years. There has been no engine we have made pulleys for that requires a balancer, the pulley iteself must be balanced and our pulleys have been 0 gram balanced since the beginning.

Respectfully,
Shawn