Rocman8

The SLR does have a split IC system. And I do agree with everything else you say about this subject.

Welwynnick

That sounds like the right approach.

The job of the IC is to keep the IAT close to the water temp.
The job of the HE is to keep the water temp close to ambient.

In reality both will fail to some extent, but its difficult to know which if you don't have a coolant thermometer. I do have a coolant thermometer on my car. I think I'm unusual, but its very illuminating.

You probably have a well-designed system if those two temperature differences are about the same.

In general, broad-brush terms, heat exchangers usually work with a temp delta of around 10 degC / 20 degF, which is a fair target. If you have a particularly large IC or HE, you might be able to get it lower than that in steady state conditions, but that would be a challenge.

Nick

Hulk

Put ice in your reservoir if you have one and run the car check the water temp and iats there will be a 15-20* difference (in most cases) when running normally, when doing wot there will be much more of a difference between water temp and iat. The ic is not sufficient

Welwynnick

I think that's pretty good evidence that the IC isn't good enough, but realistically,what can you do about it? Circulate the coolant faster?
Nick

whipplem104

You are never going to see full load temps really below around 30-40 degrees above your water temp. But on a hot day, to make some people happy, 100 degree ambient to be running 80-90 degree iat is pretty good. Much better than 140-150 if you just kept your water at ambient and really 10-15 above that because you are at best going to have 110-115 water temps without ice and a proper heat exchanger.

Hulk

The iats will never be below ambient without meth or killer chiller.

The ic is in a crappy place , right in the valley super hot and no air circulation not to mention the ic is small as said over and over

whipplem104

It is an air/water heat exchanger it does not need air circulation. Both of the very large front heat exchangers listed in this thread have resulted in about as good as it gets results.
And a killer chiller simply makes the water cold, so if it works then ice will to. And that means the i/c is doing the job. Cold water is cold water.
The point is if you have an adequate heat exchanger the system will not heat soak. If the intercooler is not sufficient to get the heat out of the air and into the water then nothing short of Meth or Nitrous is going to cool the air.
So what are iat temps with a 5 gallon tank of water with ice in the back on a drag run at the end of the run, Still at full throttle?

Welwynnick

How small is the stock intercooler?

Hulk

Whipple it depends on the ambient temp for the iats at the end of a run. For example some with ice and 50* weather might see 120-125* at the end of the 1/4 with mods like 180 pulley etx.

SterlingE55

This hasn't been a circular conversation at all...

99lightning

does anyone know why my fabtech tank would increase act temp by 50deg over my little cobra tank. last outing I only drained less then a half gallon so I would not have any air pocket issues.

Hulk

lol

Hulk

Something is definately wrong. Check your pump and lines

Hulk

Iirc the actual core is probably 4x5 maybe smaller or bigger but not by much. It is very small

Welwynnick

Thanks. How deep is it? 2 or 3" maybe?


Cheers, Nick

Hulk

About 3" iirc

Like I said nothing that can handle heat that a bigger pulley would make. SLR made 14psi approx stock so they took that into account and made TWO big top mounted IC for a reason

Welwynnick

Thanks. 3 x 4 x 5 = 60 cu in = 1.0 litre. I didn't realise it was as small as that.

The stock HE measures OEM 27" x 5" x 1.625" = 219 cu in, or 195 cu in = 3.2 litres excluding the tanks.
http://www.**************.com/forum/...does-it-matter

I think a balanced cooling system should have similar size IC and HE, and this is way out. The Forge HE in this thread is about 5.6 litres - even bigger.

What are the alternatives (apart from the $$$$ SLR coolers)? I presume the Weistec supercharger has a much better cooler?

Nick

Hulk

Get a killer chiller with a tank or a water injection system but again these are not solutions just work arounds.

JoeNobody

Some have made their own top mount SLR style intercoolers, but figuring out the air intake is usually a problem.

whipplem104

Ok,
So that being said that people are running 125 at the end of the run. Then in a near pefect world you are seeing 45 degrees above what they should be in ambient conditions and say another 15 degrees above a 35 degree water.
The question still lies in what is the water temp at the beginning of the run and the end of the run and how does that correlate to the iat rise. If you do not know the water temp or at least it is still completely full of ice or mostly ice. You do not know.
Just for example we were running a TT hemi charger last year with about twice the size of the intercooler the E55 has. No heat exchanger and a 5 gallon tank with ice. This car made 1100whp and trapped at around 150mph. It would flat melt the ice in the intercooler every run. Temps would have a slight rise as the run went on but no more than 10-15 degrees.
Another thing that Welwynnick has done a lot of studying on is pump flow. If you are not running enough flow then the system will not work to it maximum.
But I think that if you guys want you should just Pony up for slr intercoolers and be done with it if that is the solution. Or have something custom made. Whatever. But I think there is a lot of optimization in keeping water temps under control. And do not kid yourself to believe that you will not have to keep the water cold with any other intercooler. SLR included.

Hulk

Guys have checked water temps as well and as I said water is still colder than the iats. For example someone ran and iats went to approx 110* but water was still at approx 80* As evidenced above taking the ic core with measurements it's tiny and in the hot valley without air flow.

Welwynnick

Being in a hot valley without airflow isn't as important as it might seem. Pragmatically, what other architecture are you going to use on a supercharged V8 engine? There are lots of them around (in the US at least) and they all seem to have the IC sitting underneath the supercharger (or above, in the Corvette's case).

But what parts of the engine are hotter than others? My V12TT has lots of engine heat issues, and I've adopted lots of thermal control measures to try and deal with it. Its a crammed engine compartment with two turbos in it, and everything that's rubber or plastic is baked. After a few years, everything fails if it isn't made of metal.

Therefore I've added aluminized fibre-glass thermal insulation to the ABC suspension pipes, the charge cooler feed and return pipes, and the charge coolers themselves. I made some new aluminium sheet heat shields for the vulnerable coil packs, and I plan to do the same for the compressor outlet pipes (which are in direct line-of-sight of the exhaust turbines). Once the engine is thoroughly warm, everything runs at around 85 - 90 deg C.

Now, some of these measures were worthwhile, but some of them, I wouldn't recommend to anyone else. That's what happens with development, some things work and some things don't.

My car has a programmable IC pump controller that displays IC coolant temperature on the dash, so I can see what affects that. Very interesting. However, the point of all this is that I also stuck a load of temperature sensitive tape all over the engine compartment to see what made things tick. In bald terms, EVERYTHING except the turbos and the exhaust ran at the engine coolant temperature.

So I don't think there is really any hiding from engine heat anywhere. For what its worth, I did manage to reduce the peak coil pack temperatures by 6 degC, but in reality there's no hiding from the ambient operating temperature. The charge coolers are cooled by the IC coolant, and that's the dominant factor for them, as long as you're not heat-soaked.

Nick

whipplem104

If you really want to know the effect of high ambient temps to the i/c and water. Take your supercharger belt off and drive around. Let it sit at idle at full operating temp drive around some more. You will see very little effect. The reason is going back to btus of air and the conductivity and surface area to exchange the heat to the water. The very fact that there is not flow is in some ways good because the volume of air is low. Therefore the btus are low. But mostly it is the i/c cores ability to transfer heat from the outside based on surface area. Basically it does not have fins.
This is why you see no to little effect by insulating the i/c core from the engine other than maybe long idle time heat soak or shut down time heat soak but even then it is mostly heat transfer through the aluminum that is in constant contact with the hot supercharger and the engine itself.
And if you want to insulate items in the engine compartment from heat use stainless steel or sandwiched heat shield.

EREBUS

Having a tiny long flow design intercooler 3" from our blower is the main problem. The first half of the core is heat soaked due to the 200+ degree air slamming into it leaving the last half to dissipate the heat. Stack flow designs like the whipple blowers use respond better to ice water due to more air to core contact area.

EREBUS

We have found some interesting data along our journey with our top mount intercooler project. One issue that has plagued many, ironically enough, was fixed with the help of my 15yr old son?


1) Laminar Flow. My son used my Intercooler project as a school project for his AP Physics class. Awesome results followed. He received an "A" and I received intercoolers that work now. lol

2) See that 6 gph nozzle pre intercooler? Bad idea. Water/Meth was actually coating and insulating the intercooler core from the hot air. 2 pgh nozzle is the max flow that could be used. Period. (especially with higher water to meth ratios)

3) There is a 1.2-1.7 psi loss post intercooler. The 1.2-1.3 psi loss was taken with outside temps in the 40's while the 1.5-1.7 psi loss was with 91 degree outside temps. Factory intercooler flows a lot better than I thought, honestly. As I stated before, the first half is becoming heat soaked......