bitchin volvo radiator

Hey, JVL, who makes a bitchin aluminum radiator for a 240 Turbo? I wanna know.

-Dave

Me too, mine just started leaking.
I was looking at summit's radiators cause they're the same price as a new oem one from any of the volvo parts places. Aluminum and .5" thicker too. Though I forget the measurements I took for the rest of the size of the rad.
Like this: http://www.summitracing.com/parts/SUM-380324/?image=large
*Please note I am not recommending this size radiator, I forget the measurements of the volvo radiator except that it was like 18.5" high and 1.75" thick, cant remember the width and I didnt look at the hose sizes.

I just put a new Volvo Radiator in the Merkur, it was like $102.00. I also picked up a spare all metal one at the u-pull it for $18, filled it with CLR and flushed.

John Lane has an aluminum radiator in the Fire Breathing Monster. Maybe he will chime in here.

Reason I'm asking is that it turns out the Volvo intercooler/radiator stack slides right into a Miata and everything lines up just right for intercooler hoses and for the new locations of the radiator hoses and heater hoses that you get when you reconfigure a Miata cooling system to actually function properly.

Just not sure if the radiator can keep up with the cooling needs of a turbo Miata, since the air inlet is so much smaller than a brick's. Having a bolt-in option for a bitchin radiator would help.

-Dave

eyesoreracing Wrote:
-------------------------------------------------------
> Reason I'm asking is that it turns out the Volvo
> intercooler/radiator stack slides right into a
> Miata and everything lines up just right for
> intercooler hoses and for the new locations of the
> radiator hoses and heater hoses that you get when
> you reconfigure a Miata cooling system to actually
> function properly.
>
> Just not sure if the radiator can keep up with the
> cooling needs of a turbo Miata, since the air
> inlet is so much smaller than a brick's. Having a
> bolt-in option for a bitchin radiator would help.
>
> -Dave

Well John used the stock Volvo radiator on his 550+ HP turbo V6 for quite a while if that helps.

I pull a camper with my ford 2.3 turbo powered Volvo, with a stock replacement radiator. It put a big load on the cooling system, and it has never overheated.

My car hass a Griffin radiator (Nascar junk) sized with inlet and outlets changed by bill Scribner to make it a drop in in place of the V-6 radiator which is 6" or so longer then the four cylinder radiator.

I'm betting that the Volvo turbo-4 radiator is what will fit under the hood of a Miata.

Volvo guys upgrade the intercooler with the unit fitted to an NPR diesel thing. If it will fit in the nose of your Miata it will not hurt things as the Volvo intercooler is pretty restrictive.

---

JohnLane

Overkill is consistently more fun

What's an NPR Diesel?

Do you know if anybody has actually measured the pressure drop across the Volvo intercooler? Since we're only looking to push about 200 whp (any more just turns into smoke on a Miata), I'm guessing the restriction won't be significant at our flow rates.

-Dave

eyesoreracing Wrote:
-------------------------------------------------------
> What's an NPR Diesel?
>
> Do you know if anybody has actually measured the
> pressure drop across the Volvo intercooler? Since
> we're only looking to push about 200 whp (any more
> just turns into smoke on a Miata), I'm guessing
> the restriction won't be significant at our flow
> rates.
>
> -Dave

I've seen ridiculous figures which neglect to say what they're measuring which shows a Volvo IC a couple of hundredths of whatever they're measuring "worse' that whatever the supposed perfectly bitch intercooler was.

A couple of hundredths.

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

That would be the laughtermarket for you...
-D

eyesoreracing Wrote:
-------------------------------------------------------
> What's an NPR Diesel?
>
> Do you know if anybody has actually measured the
> pressure drop across the Volvo intercooler? Since
> we're only looking to push about 200 whp (any more
> just turns into smoke on a Miata), I'm guessing
> the restriction won't be significant at our flow
> rates.
>
> -Dave

I believe it is an Isuzu cab-over diesel truck. Commercial thingy.

One of the merkur guys did a great comparison of most the IC's used buy people in the XR, The Volvo IC was very good, 2nd or 3rd. Note, the Cosworth IC was about as good as it gets.

http://www.merkurtech.com/merkurtech/magarticles/icprimer.php

Scroll down the page and you can see the chart. Lots of good info. It confirmed my suspicions that Pressure drop across the IC really does not have a great effect on ability to remove heat. By removing heat, and making the charge denser, it will loose pressure, causing a pressure drop. I remember reading the SAE papers for the Chevrolet Corvair many years ago, and after extensive testing of various fan and shrouds, they found that the greatest heat transfer was produced when a 3 psi differential was acting on the cooling system.

Interesting. I admire the thoroughness of their testing, but I question the results. Pressure drops of 0.03 psi? That't not even close to right. For reference, a Mazdaspeed3 intercooler has a peak pressure drop of 4 psi, while the drop-in replacement ARC intercooler for the same car drops 2 psi under the same conditions. There is nothing radically strange about this intercooler that would make it dramatically different from the intercoolers they tested.

We're talking similar power levels here, so flow rates will be roughly similar (flow rate, obviously, has a huge impact on pressure drop. So huge, that it's not even worth comparing numbers if we aren't confident we're in a similar ballpark).

They also show HUGE variations from one intercooler to another, from 0.03 to 0.53, a factor of more than 10:1. That blows my theory that they recorded in BAR and reported the results as PSI.

Instead I'm guessing they measured with two noisy sensors and the drop got lost and mangled in the noise.


These results aside, although higher backpressure intercoolers sometimes do cool better, that doesn't necessarily make them a better choice. Intercooler pressure drop is a big problem in its own right. consider these reasons:

1: If you want to run 14 psi at your intake manifold and you have a 2 psi drop across your intercooler, the compressor output has to be 16 psi. That increased boost means increased heat, so the intercooler is actually indirectly causing more intake heating.

2: If the compressor has to make 2 psi more boost, the work to drive that compressor harder has to come from somewhere. It comes from the turbine, which derives its power from exhaust backpressure. So a restrictive intercooler causes more exhaust backpressure, which reduces volumetric efficiency, causes charge dilution, and reduces knock resistance. All of these things reduce power.

The first WRX I ever drove (and also the best) was a 1997 WRX STi RA. This particular model had the biggest turbo Subaru had ever used at the time (at the time was probably 1999). It also had one of the smallest intercoolers. The core, in fact, was smaller than the standard WRX. Given the very limited packaging space, they chose to prioritize end tank size and shape to maximize flow (or minimize pressure drop, depending on which variable you keep fixed in your mind). The core actually sat diagonally, letting the end tanks take on a bit of a diamond shape, which improved flow on the cold side of the intercooler where it enters the throttle body.

So what I'm saying, I guess, is that this isn't just my hair brained theory, there's a guy a Subaru who agrees with me.

-Dave

Dave in my Volvo with it's three liter V-6 we got a lower boost threshhold, ambient for intake air temps and better all around drivability with installing a Ford Powerstroke intercooler.

The engine in your Miata is smaller.

The Volvo intercooler may be just fine for you.
As another has suggested; the Cosworth intercooler may be worth looking at.
I'd be curious to see real numbers for pressure drop across the core and intake air temps with different intercoolers.

With 200 horses for a goal you will likely do just fine with the Aluminum core radiator that Volvo fitted to the 740 turbo or maybe the 240.

The Griffin radiator we fitted to the Volvo has lasted well and has not been damaged despite a number of incidents involving terra-firma in the rallycar. It was not real expensive.

Have fun with it.

---

JohnLane

Overkill is consistently more fun