Greddy Rb26 Pulleys

[Roy]

Does anyone understand with enough detail why the RB26 pulleys cannot be used on an RB20? I understand that the power steering belts are different, meaning i would have to run a GTR power steering pump (not really a big deal)...but anything else different ?

[noone]

Sorry cant really answer your question but curious if you going for the I believe its oversize or stock size

Had considered these a bit further down the track and curious to see others thoughts on which size to get

Not sure of the size of rb20 pulleys though you would have to take this into account as well I guess

Can measure my rb26 ones if that'll help?

Edited January 20, 2008 by noone

[benm]

What sort of a performance improvement are they over standard?

[Roy]

Well i have an RB20 in the car. RB25DE on engine stands and RB26 in the shed...so suppose i can get out the verniers...only the engines are in three different places.

[Duncan]

I've just put these on my rb26, no results as yet but they look like they should do the job - hopefully slow down both power steer and fan which are both running way too hot.

ben I'm not changing them for performance but they are lighter than standard - but if it makes 1kw difference I'd be surprised.

Roy if you are running this kit you won't need to change to a 26 power steer pump if the wheel fits on your pump. but the # of ribs on the power steer pulley needs to match the balancer.

I don't have any experience with them on the rb20 - but surely if you get belts with the right length and # of ribs you can't go wrong?

[benm]

I was thinking performance as in lighter = more responsive?

Are they slightly lighter or a fair whack?

[Duncan]

well I didn't weigh them but I would guess half of factory weight, pretty good considering they are a fair bit larger than factory as well. but its not more than a kg or 2 in total for the pulleys - I can't see them making much difference to power.

but like I said, my problem is high water temps and boiling PS fluid. hopefully driving the water pump and PS pump slower will help with both problems - if not standard ones go back on and I have a set of these for sale lol

[SysLink67]

I was actually going to buy some of these :

(a) If they did infact reduce rpm on componets at high revs, and

(b) Where lighter so engine could rev faster on the basis of reducing rotating mass.

But I'm yet to have this confirm that the factory items ARE NOT TO BE CHANGE AS THIS CAN ALTER BALANCES WITHIN THE ENGINE THAT CAN CAUSE EXCESSIVE WEAR AND MAY CAUSE OTHER PROBLEMS.

I'm not sure but I don't think many of the High HP cars run after market pulley configs? Maybe ask Paul? or SK or Proengines ETC....

[Duncan]

a. they do. they have larger circumference than standard (didn't measure exact difference but they are a fair bit bigger than standard). lets say 20-30% larger than standard so they must turn 20-30% slower than standard.

b. they are lighter but not substantially.

but to answer your shouted bit....they can't affect the balance of the motor because they are only connected by belts, not directly mechanically. They will turn slower so there should be less drag not more, so I'm not sure what raised your concern? plenty of (most) race use underdriven pulleys.

And mine are going on my race car. If you put them on a road car which spends much more time at idle than >4000 you should keep a careful eye on water temp and alternator charging rate at idle.

[rev210]

The pulleys are good for the reasons already mentioned.

I had a set on my old GTR and I'll get around to a new set for this one.

If you add the weight saved by swapping them along with a fan change to electric, a lighter/better balancer and some adjustable alloy cam pulleys then you get a pretty decent improvement in response. Be about 5kg or so, which isn't shabby.

[turboedsloth]

howd you go with trying to stick these on your 20 roy?

[Roy]

Im waiting until i have the fronts off a couple of motors and i can compare pulleys etc.

[rev210]

Roy,

If you have any fabrication places around, they can machine alloy pulleys up for you to suit. Before I got into GTR's I used to this for other cars. Give them your old ones and ask for the diameter changes you want.

Only reason I got a Greddy kit last time was because it was mega cheap 2nd hand.

[Duncan]

hmmm.... rev210 or anyone else who has run them, did you have any trouble with the water pump/fan pulley.

The rear lip on mine is touching the harmonic balancer, and if I space it out a little the studs are too short to bolt the fan on

balancer lines up fine with alternator and power steer pulley so I don't think its in the wrong place - means the water pump or pulley is wierd

[Adriano]

I have the greddy water pump pulley, adn it lines up perfectly with the balancer, however its not a stock balancer, so i dont know about the fouling issues.

[Duncan]

yeah its wierd, these kits from japan normally bolt straight up 100%, makes me wonder if there is something wrong with mine. interesting about the aftermarket balancer, I noticed a lot of them are smaller diameter and/or have a smaller lip on the back.

[STATUS]

i tried it on a 25 and could not make it fit without enough dramas to make me say "fk it" there are two Pwr steer pulley splines and well the 25 (ver 1.5) had a differrent one to the 26 kit i had. I have R34 gtt, 25 and GTR pumps at home so i will compare the splines and depth 2moro for you.

obviously there are two alternator types hitachi and mitsi so that should be no dramas.

if there is enough demand i could get trust to do a run? they made rb25 cams for me (for those who went to TAS 08)

[ssxRicho]

time to dig.

trent did you find a nice way to do this? or is it still a pain in the ass?