Got my Renntech intecooler and boy, it's huge. I'll try to get it installed during the week and I'll take some pics as before. The old intercooler is from a '99 SLK, not a coupe but it's similar.

 

I know nothing about the internals of the intercoolers, but even I can tell you that the new one seems much better.

Hope it all works out well Buell

 

From what I understand about intercoolers, which isn't much, the two things that help are flow (how little the intercooler restricts flow) and mass (the more mass, the more heat dissipation). This thing has plenty of mass, very heavy compared to the factory intercooler. The picture doesn't do it justice as to how huge this thing is.

 

It appears that the new intercooler introduces additional resistance to the air flow (due to air turbulence) - look how poorly it is ported compared to the stock one. It seems they goofed up here - it could be even more efficient had they done a better plumbing job.

 

I thought so exactly and argued that point but Spearco claims they know what they are doing and because of the pressure the funky end tanks work out, don't ask me how but they do. The outlet seems very different from the inlet, don't know why. If I designed it I would have a smooth transition between the core and the inlet/outlet but what do I know about designing intercoolers. BTW, the pressure drop at 10 PSI is only .25 PSI.

 

Buellwinkle,

That's my intercooler !!!!!

 

vadim, you are correct on the flow(turbulence) that you say would be present, and this would be the case if the air was flowing through on its own. but once you pressurize the air, flow design isnt much of a consideration. this is why on forced induced cars a ported cylinder head isnt as important as it is on a na car. another analogy would be plumbing. if you take 70 psi of water pressure and run it through 25 90 degree bends, the outlet pressure is still 70 psi. when things are under pressure, the flow isnt nearly as important.

 

even if you dont get that much of a gain, that is one nice looking intercooler compared to the stock one!

 

That's correct if there is no flow - static situation isn't affected by the passage configuration. Add flow into equasion - and you are dealing with the effects of resistance. An electrical analogy is fairly appropriate here: If you have a resistor, the tension would be the same before and after it if the circuit is broken, as there is no current. Reconnect the conductors, and you have a voltage drop at the resistor U=I*R.
Equal voltage applied to a circuit - the higher the resistance, the lower the current - as we know from the Ohm law, I=U/R.

Returning to the subject: under equal pressures, the intercooler with better porting (less resistance) will allow more air through, which means better efficiency.

 

Buellwinkle, how much did the new intercooler cost you?

 

Under pressure you will have friction loss. That is dependent on the suface properties more than shape. There is only a .25 lbs pressure drop that is less than the stock intercooler. The tanks are larger than the stock ones, less restrictive. The shape is dictated by the design of the car and getting it to match up with the available space.

Randy

 

Not only friction losses. Turbulence creates resistance to the flow, and it is directly related to the configuration of the plumbing. In addition to reduced air flow (=less boost), any resistance means that there is an energy loss in form of heat. This means that such intercooler will be less efficient as such.

I'm not disputing the gains that this particular intercooler helps to achieve, I'm just trying to speculate as to why it wasn't made even more efficient. By comparing the stock intercooler with the Renntech one, I'm still wondering why smooth porting wasn't used on the latter, as there seems to be enough room for that.

 

I see what you are saying, it is hard to see in the picture the tank size is more than double the stock tank and the tube lenth is shorter the overall volume is easley twice if not three times the more round version on the stock cooler. Given time and money we could make a smoother tanks but the gains would not be enough to off set the extra money you might gain .15 lbs from the pressure drop.

Randy

 

obviously spearco knows more about airflow than we think we do who knows. is all i can say is that this ic does work, and it works good. i felt the inlet side after driving a car with one on it and it was friggen hot, however the outlet side was nice and cool.

 

Just a thought - what if an add-on heat sink is attached to the stock intercooler, much like those used to cool computer CPUs?

Reports that each consecutive run yields less power compared to the previous one leads me to believe that the intercooler's core accumulates heat and is unable to dissipate it quickly enough. If this is the case, then an additional heat sink may help.

 

Yes it is Linh, thank you for your generousity in sharing this intercooler with my family for sooooo long, it has a special place in our house and my family has grown very fond if it. But the time has come where we'll have a spare factory intercooler of our own and we can finaly come to terms with saying goodbye to your intercooler. It will always have a place in our hearts and in our minds.

When are you coming by to pick it up?

 

The Renntech intercooler does just that. It is much more massive than the stock intercooler. It also has three times the surface area, if I remember correctly.

 

[QUOTE]Yes it is Linh, thank you for your generousity in sharing this intercooler with my family for sooooo long, it has a special place in our house and my family has grown very fond if it. But the time has come where we'll have a spare factory intercooler of our own and we can finaly come to terms with saying goodbye to your intercooler. It will always have a place in our hearts and in our minds.
Lol...lol...Buell, i'm too busy try to find my new "crib". I hope to pick it up someday.

 

That's right. What I meant - add on a heat sink to the stock one as a cheaper alternative. The mass itself is of little help (actually, could be quite the opposite, since it takes longer to cool down) if there is no way to dissipate the heat accumulated into the ambient air (or coolant if it is water-cooled). Heat sink provides more surface that lets the heat escape. Hence, my suggestion.

 

Sure is! Too bad you can't see it when installed

 

The alternative that I looked at was a electronically controlled misters in front of the intercooler. You can probably easily add the factory pump for the headlamp washers in the windshield washer reservoir (assuming you don't currently have the headlamp washers) and then run tubing down to in front of the intercooler with two misters. The electronics I've seen are very clever, they measure intercooler core temp, ambient temp and fuel injector pulse width and calculate when it's time to spray. Here's a link for a good practical article on the unit.

http://www.audiworld.com/tech/eng22.shtml

 

and to bad no one will see engraved "RennTech" logo. it looks good.

 

Hey that article look familiar :p so Buellwinkle are u thinking of doing it? As I mentioned originally do you think its possible without headlight washers (extra liquid capacity)? BTW the Renntech intercooler looks nice and I can see the cost/benefit of not going with mendrel bent tubing as it is VERY expensive to mendrel bent something (I learned that when I tried to get a custom exhaust for my A4). Those machines cost like half to one million dollar and big (so I heard). And I guess Renntech didnt want to go with a crush pipe either (which is what I had to get for my exhaust on A4). Anyhow would love to see result (dyno) of the intercooler as well as the mister

 

The spot on the windshield washer tank has to be there so that you can just snap the headlight washer pump on there, no mess, no extra plumbing or custom brackets. Also the harness is probably already there so it should plug in. You just need to splice in the activation wire from the mister control unit. Should be relatively plainless. It's not necessary with the new intercooler, it cools down to ambient temperature under all circumstances so there's no benefit to misting. Misting is just a lower cost alternative with the negative being that you have to fill you water tank more often. Still not as good as the intercooler because the new one flows better.

 

what are the projected HP gains with this intercooler? thanks