Is there an oversized water pump pulley? I want to keep the same size main in the hopes of adding a supercharger one day...

Thanks,

Tim (Roxy's pit crew)

 

crap! I forgot I started this thread. I just so happened to run across it just now..... see what happends when you forget to subscribe to your own thread.

I will try to update the first post today with the new info you guys provided.

 

I think this is a bit off topic?
The Greddy pully kit does not replace the main/crank pully. It consists of the water pump and alternator pullies only.
Check Link; http://www.vividracing.com/catalog/p...ducts_id/23066

 

so how much does the koyo rad cool down? is it worth it?

 

These larger than stock radiators are more efficient at cooling down the engine. The engine still runs at the normal tempratures as this is governed by the thermostat and not the radiator. But if you run your engine at greater stress and high ambient tempratures that is when the more efficient radiator helps to keep things cool without any fear of overheating.
There is another/different mod available which reduces engine temps. That mod changes the radiator cooling fans cut in tempratures, http://www.mazsport.net/store/page9.html

 

thanks for the info! hows your PWR radiator? can you tell the difference?

 

Cant tell any difference. I did this mod with FI in mind for the future.

 

Forgot to say that the PWR requires a small mod to fit to the stock radiator mounting positions. Cant think of why this should be. It appears that the Koyo radiator fits OK without any modifications.

 

in ga with the track ambient temp at 100F my coolant temp never went above 210 and my oil temp not over 230. I have the stock radiator.
My set up is this
1- coolant mixture for the warm months is 65% water and 35% coolant.
2- agency underdrive pulleys
3- synthetic oil I use royal purple(and yes dino oil does run hotter) 5/30
4- track temps can vary a lot according to how you are geared for that particular track, shifting at 8.5(unless you have a better pcm set up) and keeping the car between 7-8 instead of 8-9K makes a lot of differance.
5- on the street--always use the a/c on the 3nd or 4 th fan setting so the fans are activated.
6- get real gauges no substitute.
7- coasting (with clutch in and engine idling)on a 95 degree day for approx 1/4 mile will lower coolant and oil temps 10 degrees F.
8 --take off those protective screens--they do block air flow(if you are worried about the heat)
olddragger

 

That is obviously alot of really good information from someone who has alot of experience with the 8 and maintaining its temperatures. What would your opinion be on a street car with a SC or turbo? Would it be a waste to get an aftermarket radiator?

 

that was a general theoretical statement, it was not RX-8 specific

 

if you are running fi(totally differant ball game) on the street i would recommend this in referance to cooling.
1- better radiator
2- better waterpump(check with mazmart--they have one)
3- sleeve type 180F thermostat
4- some mechanism for fan control(various options available)
5- the stock airbox is already out of the way(with fi) of the fans so move the battery box also out of the way and get a vented hood.(not absoulutely req)
6-run 65/35 coolant(unless you are ina cold climate)
7- synthetic oil 5/30wt
8- get gauges(probably will already have
9- no screens
hope that can give you some ideas.
olddragger

 

you don't need a different radiator until the t-stat is open 100% and the coolant/water/NPG temp is out of control ... until then you won't see any noticeable difference because the t-stat is going to maintain a specific temp range regardless ...

 

just dug up this thread while searching...
anyways, i'm curious about the use of an underdriven water pump pulley kit. i noticed pettit racing offers one but they don't have any info on it. does anyone care to shed some light on these for me....

 

ok sorry it took so long, updated the first post... Man its been a while.

 

Are there any significant weight differences between the options listed? Obviously you wouldn't want to trade weight for effectiveness (beyond a certain point), but that radiator is definitely hangin way out there up front so it's going to have quite an effect on polar moment of inertia.

On the tails of that, I have seen adds for several products, and one convincing 3rd party review, of alternative chemicals or addtitives for the coolant. IE, liquids that allow lower temps without any hardware change due to their higher boiling point and ability to maintain liquid contact with the engine metal instead of vaporizing.

 

all of what you said is true. when looking for a nice radiator of course you want effectiveness, and weight loss.

yes there are a few products out there that help keep engines cooler. water wetter is one of them. we use to use this in my fathers race car. works pretty good on engines that are running high RPMs for long periods of time. we also used 40 below. it also seemed to work just fine.

now bear in mind that if you have an overheating issue, running this stuff is not the fix. a stock or slightly modified RX-8 will run plenty cool on the stock system. also running these product will help none since the thermostat regulates the temp.

In my opinion this stuff is more for race cars with restrictors rather then thermostats. but if you want to run it in a street car, I dont see the harm in that.

and as for the radiators.... only reason to upgrade (to me) is the weight loss. but unless you are trying to race the car...... what’s 8 pounds????? take the crap out of your car and there you have the 8 pounds you were looking for. (in an RX-8 you dont even get the bling factor since you dont even get to see it)

and yes to those of you that are going to chime in about better radiators having better thermal efficiency. yes I know. bigger sizes, bigger tanks, more cores, more rows alum vs steel or composite.... blah blah blah... gotcha I already know. but again, unless you are running high RPMs for long periods of time, and you replace the thermostat with a restrictor... I just don’t see the point in a stock car that keeps its self cool just fine.

does that help?

(sorry I dont meen to shoot anyone down that is thinking about getting one, its just my .02 it's not like its a bad thing to get a better radiator.)

 

+1

I ran the RX-8 last summer in 100+ ambient temps all day and the car was fine. Only powertrain mods I have are a high flow cat and cat back exhaust. Another guy with a NSX could only drive his car for ~10 minutes at a time before having to pull in because the car was beginning to overheat.

 

....wow. thats suprising.

 

i am guessing that is because of other reasons... at least i hope... i love those cars

 

Not always the cooling on the stock car is so perfect. Today I did a mountain road climb with about 100F temp here in "race" mode with some friends from sportcarclub.com and after some time trashing it the temp started to go up and it went up to 3/4 of the gauge. I disconnected the climate control and then it went to normal values again, but it happened. So I'm getting a Koyo and a Mazsport mod; at least it can't hurt.

 

so what range is the thermostat?
I see mine crack open at 89 deg C. highest temp I've seen is 115 deg C and climbing (totaly stock car 1 oil cooler .au)

 

Greddy has a new radiator out for the rx8

 

You might want to read up on what many find with the koyo...

 

$900+ and I wonder what kind of warranty comes with it. Probably same as the Koyo.