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A DC Power alternator is the answer, their ratings are actually real and come with test sheets unlike a majority of the others with their "250 amp" and higher ratings. For example I have their 180 amp alternator on my Z06 with a relatively large pulley for high RPM use (8000+ rpm) with dual brushless fans, huge intercooler pump, and triple 525s and voltage stays around 13.5 at idle and does not sag at all at high RPM.
Got some info. First off,,the two speeds works like I wanted it to. For some reason Testing with my scanner didn’t work the same as the programmed signals. Cool. I got it at 85% on low and 100% on high. high comes on at 198 and cuts off at 195.
I chased my tail for a while with an idle issue. Like said, my idle table is sensitive to changes because of a lack of resolution in my tables. Found out the fans pull alot less amps and require less idle air compensation. Heck, it idles at 13.2v with the ac on and headlights and stereo playing. Bout 13.4-13.6 at cruise. Used to be half a volt lower both ways. On high they sap up another .1v
today at lunch it was 96f (hot asf!) and I took a 40 minute nap in the car with the ac on, just idling. I woke up and temp was 206. Went get some food, while waiting, flashing and revealing it a few times, I saw 212. Easily would have been 221 before the fans in the same conditions. Add to it, I popped the hood and temp starting dropping. So now I need to plan on some hood vents or a vented hood if I want lower temps. But all in all, fans are doing good so far.
yea i am having the same exact issues. if i open the hood, temp drops quick. I was recommended to install a couple hood vents. though my hood now has a 2" cowl i may need to open the holes at the rear of cowl to get better flow. But your review gives me hope . Thats a great start, if i can keep under 215 i win.
Just looked at their 250a fbody style. That's pretty decently prices tbh.
The 320amp is overkill for what I'm doing but I wanted more power than I could use, plus I intend on adding more amp loads.
The 250amp would be ample for what most street cars need.
Would love to see you do the same video on a 16" Delta PAG fan. Basically all three available brushless fan on the market. Also, you should really translate those numbers to CFM to compare apples to apples. The diameter of the hub is a huge factor.
You want to send me one to test? I would calculate CFM but my meter doesn't allow me to input the specs to convert it.
Turbo LS Miata, rear mount radiator, power master 165a alt, 2 14" proform brushless fans.
Holy **** I just scrolled for an hour to get down here lol.
GOT MY UPDATED PROFORM FANS LAST SATURDAY AND SO FAR WORKING GREAT!!!
I drove about an hour away on one of the hottest August days here in South Carolina. Cruising on the highway (which is what I my biggest problem was, temps were up to 220 before) 6th gear about 75mph, temps stayed below 200. 199 to be exact. Down shift and give a little throttle and dropped to mid 190s. (Mechanical pump needs rpm to flow well to the rear mount radiator.) took the car out today temp was 190 cruising 195 after making pulls. Fans have stayed on the whole time so far. Wired wide open all the time. Only draw back is they didn't like my 3.2" alt pulley at 850rpm idle. Sat at 12.5 volts. 900-950rpm gave me 13ish volts. Swapped a 2.5" pulley today and idle is 14.1. now I have a high rpm voltage drop again above 7k. Whole different problem to address all over again.. calling power master tomorrow to see if they can sell me a different alt that's actually worth AF for high rpm. All in all I'm happy with the fans so far. There's a lot of heat in my tiny engine bay and this has been the answer to my cooling problems. I'm making a YouTube video on my experience so far. I'll post it in here when it's uploaded in a few weeks. Dennis said fans should be in stock to the public by the end of the month.
Old spal fans. Haven't got a picture of the proforms yet. Just for reference that there is no cut out in trunk, just about a 6 inch gap between. And all the turbulence under the radiator.
I can’t believe you’re having charging issues with the power master alt. I have the 165 small from them and it keeps up with my dual spals, walbro 450, full sound system etc. I know the cheap replacement large case 145amp are really like 170+ amp alternators. But if I remember your pulley is wayyyy too big. Mine are closer to 2” if I remember correctly. Either you have it slowed down too much or you got a crazy load somewhere.
im looking around. I don’t really want to buy a whole hood but here my dilemma: I have no room to store the hood that’s on my car, I don’t want to sell it and I’d really rather not cut it up. However, I’m more willing to cut it than spend $1500+ on the hood I want. If I don’t spend that, I’ll be settling. So either which way, I’m damned. I’m kinda ok with the stingray type vent but I may just do the side vents like some mustangs have.
My 3rd gen formula hood has a scoop and i removed the backing plate so it’s open. At speed I’m sure it pulls the heat out as it’s like a mini cowl hood and at idle I can see heat pouring out of it like a chimney stack. I don’t love it being open as water goes in and pools on the intake/head and valve cover.
Only draw back is they didn't like my 3.2" alt pulley at 850rpm idle. Sat at 12.5 volts. 900-950rpm gave me 13ish volts. Swapped a 2.5" pulley today and idle is 14.1. now I have a high rpm voltage drop again above 7k.
I went thru a few different size pulleys with my ad244 alternator and found that a 2.85" pulley gave me 14.4v at 800 rpm idle. And it stays 14.4v all the way up to 7000 rpm.
There's a few charts out there you can look up that calculates alternator shaft speed vs engine speed with various crank/alt pulleys
You want to send me one to test? I would calculate CFM but my meter doesn't allow me to input the specs to convert it.
You don't need the meter, you can do it yourself. It's easy, you take the velocity of the air in (feet/min x the area in sq ft) the area is the diameter of the fan minus the hub diameter, basically the area of a donut.
The 320amp is overkill for what I'm doing but I wanted more power than I could use, plus I intend on adding more amp loads.
The 250amp would be ample for what most street cars need.
So first off. I wanna say thank you for the recommendation!
How about this ****. I look up js alternators to call them. Turns out they're located in my hometown. 9 miles away from my house. Long story short I drove the Miata up there to buy an alternator. (Which did great the whole drive 88° out) It was a little too big case wise, so we talked about other options. Which ended up being them sponsoring me with a custom built powder coated 250a alt!!! Gonna have a meeting next week to talk more about it, but he was like I'm just gonna go ahead and put you under sponsorship and I'll give you the details later. Soo stoked!!!
I went thru a few different size pulleys with my ad244 alternator and found that a 2.85" pulley gave me 14.4v at 800 rpm idle. And it stays 14.4v all the way up to 7000 rpm.
There's a few charts out there you can look up that calculates alternator shaft speed vs engine speed with various crank/alt pulleys
That is what I was guessing would be ideal for the alt I have now. The one I'm getting built rn will have a 2.55" pulley, but it's rated for 20k rpm
I can’t believe you’re having charging issues with the power master alt. I have the 165 small from them and it keeps up with my dual spals, walbro 450, full sound system etc. I know the cheap replacement large case 145amp are really like 170+ amp alternators. But if I remember your pulley is wayyyy too big. Mine are closer to 2” if I remember correctly. Either you have it slowed down too much or you got a crazy load somewhere.
Yeah I was hoping to not have issues with it.. couldn't rev to 6500+ with anything smaller. It came with a 2" pulley. I currently have a 2.5" on rn. Called power master and they said that with the 2.5 I'm still spinning to 21k at 7500rpm. 3k past their 18k rating. He basically said I couldn't idle that low with a big pulley on. Nice guy I talked to there. He recommend a different power master that was supposed to work better for me, but I'm going with the js now.
So first off. I wanna say thank you for the recommendation!
How about this ****. I look up js alternators to call them. Turns out they're located in my hometown. 9 miles away from my house. Long story short I drove the Miata up there to buy an alternator. (Which did great the whole drive 88° out) It was a little too big case wise, so we talked about other options. Which ended up being them sponsoring me with a custom built powder coated 250a alt!!! Gonna have a meeting next week to talk more about it, but he was like I'm just gonna go ahead and put you under sponsorship and I'll give you the details later. Soo stoked!!!
That's awesome!
I drove mine out to my buddies' house yesterday to store for a few weeks while the wife uses the garage to stage her yard sale.
It was about 82 degrees so not bad, running down the highway at 55mph, turning 2,500rpm, coolant temp got up to 194 degrees and voltage was at 13.7 the whole way with all the fans running.
As soon as I hit the off ramp it went down to 180 by the time I hit the stop light.
Anyway, a great unit you'll be happy with.
You sir are an anomaly, and I'd like to know what black magic you used to pull this off lol.
yea I was wondering the same thing. No way that would cut it in my car with ac running, fans and stereo playing. I’m sitting here at work on my lunch break idling. My voltage is 12.9. I have an underdrive pulley but a very small alternator pulley. If I give it a little throttle, the voltage does not come up.
coolant temp it staying between 199 and 204 with the ac blowing nice and cold. When the temp got to 199 I heard the fans ramp up to 100%. It’s 91f out right now.
yea I was wondering the same thing. No way that would cut it in my car with ac running, fans and stereo playing. I’m sitting here at work on my lunch break idling. My voltage is 12.9. I have an underdrive pulley but a very small alternator pulley. If I give it a little throttle, the voltage does not come up.
coolant temp it staying between 199 and 204 with the ac blowing nice and cold. When the temp got to 199 I heard the fans ramp up to 100%. It’s 91f out right now.
So, it sounds like your temps are now under control with the new fans?
So, it sounds like your temps are now under control with the new fans?
I’d say yea. I’ve not seen over 212 on a 99f day. It averages 208 on a 95+ day. Ac blows colder. Temps used to get over 220 on a 90-92 degree day. Forget letting it idle and take a nap at lunch like I usually do in my truck. But now, I can. I like em. If they last, they are well worth the $$$. Easy to pwm them also. I bought a 13$ pwm box, took it apart, removed tge cheesy wire connector. Soldered my wired directly to it and epoxy coated it. Mounted it on the shroud. I got caught in the rain the other day. No issues. I think I posted a pic further up in the thread.
Just wanted to throw this out there. I found another sick deal on ebay. EV company is selling off its new stock of 18.5" SPAL brushless fans for like 1/4 price. I just picked one up for $282 including shipping and tax. This is the 850w motor, SPAL aftermarket with drop in mount (think Camaro Fan)! At that price its an amazing deal and should flow 4000+cfm.
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