Sunday, October 16, 2011

Slowtra does it Doggy Style - Turbonetics Spearco Intercooler

Collected my intercooler and got taxed big time (40%) by our dear customs. "This is the lowest I can go! Spare part kereta memang mahal" said the customs officer all the while eyeing her prey like a natural born predator. She was not going to let me off this time as I had avoided tax a couple months back with my gear selector rods. She even mentioned "I've seen you here before". I wonder how automotive innovation and engineering is going to grow in our dear country when an enthusiast who is not making a cent out of his or her passion is getting royally screwed?

Anyway my intercooler is an American Turbonetics Spearco unit. When ordering the intercooler I mentioned that I wanted the intercooler from a certain famed Sentra time attack race car. Due to the shape and vents of the Slowtra's front bumper a wider but shorter height intercooler is required versus the more common narrower but taller height intercooler found in Jap performance cars such as the Evo. Picture below of the technical drawing. Spearco can make any specification intercooler to your drawings if necessary.
The Spearco intercooler is a bar and plate type intercooler. This is different from many Japanese aftermarket performance intercoolers which are of the tube and fin type. The most noticeable difference between a bar and plate versus a tube and fin intercooler is the header plate. The header plate is also where the end tanks are welded to. Tube and fin intercoolers utilizes header plates to seal the charge rows from the ambient rows. The header plates seal around the oval tubes during the brazing process and are generally around 0.125" (3.175mm) thick. However, over time and constant vibration the header plate starts to crack away from the tube. Per Turbonetics you will not find this problem with bar and plate intercoolers. The end tanks for a bar and plate intercooler are welded directly to the core. Tube and fin intercooler uses extruded tubes to carry the charge air across. The thickness of the tube ranges but are generally 0.020 (0.5mm) thick compared to 0.125" (3.175mm) solid extruded bar on the bar and plate intercooler. This increased strength comes at the expense of additional weight for the bar and plate intercooler. However the bar and plate intercooler in a given size or space will have more capacity and surface area. Efficiency of both (bar and plate & tube and fin) are about the same. So in summary which type of intercooler is the "best"? There's no such thing unfortunately in engineering. Everything is a compromise.

Picture below of my intercooler. My intercooler is 2-255 assembly part number with custom end tanks based on 2-203 core 3.5" (88.9mm) thick, 6.52" (165.6mm) height and 24" (609.6mm) wide. 640 cubic feet/min flow rate.

The construction is simply superb and I concur with Greg on the lovely quality of the TIG welds. Of course with quality comes higher cost. Paid RM2.5K for the intercooler at USD1 for every MYR3.2 exchange rate including shipping not including tax. Pokai!!! On top of that one inlet/outlet pipe flange is dented from the shipping hence also need to get that repaired :(

Compared to a conventional bar and plate intercooler, Spearco utilizes W.A.V.E. (Wide Area Vane Effectiveness) technology which is also used in the aerospace industry where space is a constrain and performance is critical. A Spearco W.A.V.E. core incorporates a complex network of highly effective vanes to regularly decrease temperatures by as much as 30 degrees Farenheit over conventional tube and fin cores. Spearco W.A.V.E. cores are also capable of withstanding pressure in excess of 200 psi. Spearco cores undergo a strict manufacturing process which require numerous cleansing steps to ensure a 100% braze throughout the entire core. Two close up pixs of the core.

Picture of my upside down intercooler with the Slowtra.

Here's how the intercooler looks like installed on Kojima's Dog III btw. Picture courtesy of MotoIQ.

Install to follow when my engine is ready not so very soon. Also undecided if I should use some trick W900 clamps/connectors from Adel Wiggins although this means I would have to chop off the inlet/outlet pipe flanges.

2 comments:

Chang Chew Soon said...

i know how you feel bro, malaysia customs are all bunch of fucked up fellas.......

but looking on the bright side, damn that intercooler looks so fineeeee

Andrew Saw said...

Money is beautiful Bro! :P