Plus his diff cooler fan, trans cooler fan, electric water pump, etc, etc.

Just concede man,

 

Even worse!

I'll get the alternator charts for our alternator then hop on the dyno.

$50 says there's an increase in the calc load at cruise once all the accessories are turned on.

 

So far I see no evidence that I have current problems..the Bat+ is 13.8-14.3 driving and the batterys last fine. That's even with 4GA battery relocation to trunk and the potential voltage drop from that

Suppose I will have to put a current clamp on the main line and see what kind of amperage I am drawing.....

 

In calculated load?

 

We are talking about 2 different things..I am talking about Current Draw and Shady is worried about calc load increases......

Load will just burn a bit more gas...I already have a big problem with that

 

Yes, if the calc load goes up then we know something is causing the engine to work harder.

If we remove all variable from that equation ( bumps in the road, elevation, pressure, etc) then we can only assume that the alternator is causing the engine to work harder.

If the load stays the same then we know the alternator is not working harder and is supplying the same amps as it was prior to the increase in load from the system (turning on lighting, radio, blower)...

Its a fairly simple test.

 

And about as accurate as eye surgery with a machete

 

His entire theory is that the added amp draws are detrimental to the performance of the car and that there is a potential to overtax the system and cause issues. My point is that it would take a lot of **** to cause performance issues and that the stock alternator can handle aftermarket fans, pumps, etc. just fine.

It's really not an argument since it has been proven by you and many others though. The only person I know of to overload the factory charging system and need a more robust alternator was running air compressors for an air ride suspension and a crap ton of screens, actuators, speakers, amps, etc. etc.

 

I am not doubting that our system is capable of handling the hz/amp/volts of all the electronics.

I am saying that it adds load which = less HP more fuel consumption.

When you have a track built REW with a fatty turbo none of that matters. LOL

 

Now you are changing your stance, your whole point was that the added amp draw would overload our system and that is why you would'nt run the larger coolant fans, etc. You should really read the last link I posted, you just are not comprehending fully how the alternator works. I get what you are saying about fuel mileage but if you think the same car with diff coolers, etc. running will make less horsepower than without them running at the same RPM then you are wrong homie.

Not to mention the increases in power and efficiency that theoretically should be provided to the engine and drivetrain by running cooler, etc. Remember, we have a pretty serious alternator compared to other small engine cars.

 

This was my main point and one of my first posts.

Never said anything about overloading, just making the point that less amp draw the better.

The more amps you add the harder the alternator works, harder it works more is required from the engine.

 

Your still not getting it man. So you are saying my idle coolant temps would be less if I had the stock radiator fans in?

The alternator makes more than enough to supply the needed voltage for anything that you could want to add realistically, even at low RPM. And your argument initially (before this thread even) was that the RX-8's charging system was taxed as is, which is why you did not support adding additional fans, etc. My point is that is just not true, and adding fans, etc. has no negative effects. The idea that adding fans, etc. reduces horsepower is just kind of ludicrous man.

 

They wouldn't be less but the fans would run less.

If your amp draw is higher than the factory fans the alternator will work slightly harder. If the alternator is working harder the engine will work harder to keep the idle up.

With everything energy related there is always a trade off, the idea is to find out where you want to be most efficient. Remember Energy cannot be created or destroyed only transferred.

Now in your case, if the fans are pulling more heat off the rad than the extra load is causing you wont see any increase. It is effectively balancing the extra load. If they aren't pulling enough heat off you will see a slight increase in coolant temps which would cause the fans to run more often.

Theres always a break even point... Example, if you had one 80 amp 3000 cfm fan the engine would eventually overheat due to the increased load not being compensated for.

So if you had fans that flowed more air than stock while pulling less amps, they would run less. Reducing fuel consumption/load on the system.

Its not like 30 gallons of gas, its very minimal amounts.

 

I still think the factory system is taxed as is...

We have so many things pulling amperage from the system as is. adding all the gauges, sound systems etc... It all pulls amps.

Amps are the devils!

 

I am going to video my good box on both load readings and then turn everything on so you can watch. At idle the loads will go up slighty and then watch the loads decrease as I rev up from idle to say 2,000RPM. Then you will get it

 

http://performanceunlimited.com/cobr...ain/img383.gif

 

...if the alternator didn't do its job right off the bat all kinds of **** would happen

This is why modern cars dont use Generators anymore. An alternator is at full voltage output just over idle.
If you put a multimeter across the battery when you start your car, you will see when the alternator cuts in and is charging at full voltage, it will go from around 11.5-12v up to 13.8-14.4v and should only vary around 1v or so when under load.
But if you load up the alternator over its current output, then you will start using up the battery's storage capacity and once you start doing that, it won't take long until you are having problems with flat batteries.
I suggest that if you are adding items to your car that have high current loads, eg - car stereo amps, extra fans, electric water pumps etc, then the best thing to do would be, calculate your total current draw on the alternator and see if the total current draw is more then the alternator amperage output.
If your total load is more then your alternator output, then I suggest that you look into a larger output alternator, and higher capacity battery.

 

Exactly, and to overwork the stock 100+amp alternator it will take a lot more than aftermarket radiator fans and some gauges, etc. that only draw 20 amps max at most.

 

did you quote me OD

I think at this point Shady is trolling....the proof is in the pudding...Science....lmao

 

I think you will find that as OD has posted here, the horsepower used to power the alternator is usually directly atributed to the physical size of the alternator, in other words, it takes more power to turn over a 200amp alternator compared to a 100amp one.
Try it yourself by hand, spin a 50amp alternator by hand and see how easy it is to turnover, now try spinning a 100amp one. You will see that not only is the item physically heavier, but it does take more effort to spin.
The alternator just becomes another resistive force that has to be turned by the engine.

In my own car, I run plenty of extra electrical items, eg - big amp and amplified subtube, 2 extra 6in fans on the oil coolers, 2 extra 10in fans on the aircondensor, ( air condensor lies flat on the undertray ) plus other items that don't use much power, like Hks camp 2, extra guages, gear change indicator, DVD player, etc.
I still use the factory alternator, but I have changed all my battery wiring and I use a large Odyssey battery for plenty of storage capacity.
My alternator doesn't have any problems keeping up with it all.

Rotaman

 

But the alt load is consistent and doesn't change with draw. It always takes 2.3hp to run it :D

Shady will get it

 

Power = volts x amps.

The voltage regulator regulates voltage, not current or power. Except perhaps near idle and under extreme load, the voltage measured from the alternator is essentially constant. Zero amps @ 14v is zero power. Electrical loads from fans, lights, ignition, etc. increase the current (amps) flow, hence increase the power, hence the drag from the alternator on the engine. Draw 746 watts, and it takes 1 hp from the engine (ignoring losses). That's about 50 amps at 14v. There are of course significant losses (the drive belt, battery, wires, motors, etc all get warm.) Figure at least a 50% loss.

A couple hp from a ~200 hp engine doesn't sound like much, but the engine is seldom at full output. A modest steady cruise requires only ~30 hp, and then a couple of hp represents a ~7% power loss and a ~7% reduction in fuel economy. It's one reason new car makers are trying to cut electrical consumption to get better EPA ratings. (EPA tests are done with daytime driving lights off - even if the model is only sold with them - since DRLs are not required by law.) LED lighting and Class D stereo amps are coming on strong for this reason.

Alternators are rated by maximum output. If the car is drawing 50 amps, there is little difference in the power required from the engine between a 100 amp alternator and a 150 amp alternator; both are producing 50 amps. There is some difference though. Weight, power to run the field coils, and cost argue against having overcapacity in the charging system. Plus, when accelerating, one has to deal with the increased rotational inertia of a too-big alternator.

Ideally, as done with some hybrids, one would do most of the charging when the engine is slowing, using the alternator as a form of engine braking when coming to a stop. Then, when accelerating, the alternator is taken out of the system to allow more power.

Considering the gas-slurping nature of the Renny though, an additional fan or two isn't going to make much practical difference.

YMMV.

 

Well I had found a mizu radiator on amazon and bought it. Couple of hours later the company called me and said I needed to cancel the order because mizu discontinued it for the rx8. Which would explain why I can not find it in stock anywhere...

They guy on the phone recommended Mishimoto, and said they are the same radiator.... This is true? I could have sworn I read on here to stay away from that brand....

He also recommended Koyo....


Ideas? I'm going to just go ahead and replace both fans and rad at the same time to be done with it. But would prefer to get away from the plastic radiator...

 

I would go with Koyo over Mishimoto. Koyo makes OEM stuff and the Knightsports radiator. But there is a brand new OEM radiator for sale locally her for $150.00 if you are interested.

 

This one right?
Thanks for the offer on the oem, but I hate plastic radiators!