Teck Talk – Intercooler Upgrades

Hi guys, and welcome to another turbo talk. This issue I am going to enlighten you on intercooler upgrades.I am sure that you have all seen pictures of mr2’s with upgraded intercoolers by now, and some of the odd places they get put. As I discussed last issue the purpose of upgrading the intercooler is so that more boost can be run with out the air becoming so hot that detonation occurs which will lead to piston failure.There are various suppliers of upgraded intercoolers from manufacturers like HKS and Greddy. These intercoolers will drop into the factory location and will work reasonably well, but due to the inherent design of the mid engine layout, the air flow that can enter the duct to feed the intercooler is not great and the fact that a hot engine sits on the other side is not much help either, which leads to heat soak when moving at low speeds.There have been numerous solutions to this problem, but most come at the expense of the boot which most of us, with only one car, cant afford to lose as it is the only storage place. Some cars have mounted the I/C (intercooler) in the boot and have it flush with the lid, others have a duct to catch air and force it into the boot. I’ve even seen some that hang the I/C under the car through the boot, and ones that mount flush with the floor of the boot.

These are your more typical solutions, some other odd locations are in the engine bay were the air filter typically sits and was actually quite a large size surprisingly, another one is above the engine, but this destroyed the rear visability. Then there is a water to air I/C which works well and is compact but due to the complexity of mounting a radiator in the engine bay or the front of the car and the associated plumbing, is not one of my favorite ideas. There was also one last one that seemed to work well but looked terrible (Ed: Like you Pete?). It had the intercooler mounted at roof height above the engine, had an aluminium scope to catch the air and sat just above the roof. This was where I primarily got my idea from.

By mounting the I/C at roof level, you retain the rearward visibility but to make it look better you have a rear Perspex lid that would entirely close in the engine area of the car, similar to the Ferrari F40. By creating a scoop above the I/C, you ensure that air is forced through it. To make sure that this happens, the I/C is sized correctly to the scoop in the lid so that it seals around the edge of the I/C. It also has an exit vent sealed to the underside of the I/C and the Perspex lid, so that air the enters through the scoop and exits out the other side without the air entering the engine bay. This is important as air flowing through an MR2 engine bay enters through the side ducts and underneath and exits via the engine lid. The Perspex lid will also has vents to let the hot air out from the engine bay (refer pictures).

I believe this is the best solution. A stylish looking Perspex lid that allows rearward visibility and excellent air flow for the intercooler, while also keeping the intake piping as short as possible. And the best news is that it is (Ed: Should be) quite affordable. Hopefully I will have a Fiberglass lid mold finished by the end of January and the lid made within a week or two of that, so look forward to some pics.

The second project I will also be doing when installing the lid and new I/C (which incidentally will measure 700mm X 200mm X 75mm), is to replace the intake piping with carbon fiber tubing. The simple reasoning for this is heat transfer – if you have ever felt the I/C piping after a drive you will know how hot the piping gets. But, if you have ever had the chance to feel a motorbike exhaust that has a carbon can, you will notice that the can never gets very hot and quickly cools. Therefore, hopefully the piping will not get as hot and shouldn’t transfer heat to the air within, so this again will reduce intake air temperature and lower the chances of detonation.

I am also toying with the idea of making the tubing in composite style. In other words, there will be a layer of carbon followed by a layer of thin high density foam or exhaust bandage tape followed by another layer of carbon. Not only does this create a very light and stiff tubing it also acts as a median to stop heat transfer. To top it all off, if a piece of carbon tubing happens to fracture (unlikely) and gets sucked into the engine there should be no damage incurred as the carbon is softer that metal. (I know this from a friend that runs a two stroke boat engine that runs carbon reed valves. Being a tuned engine with a welded crank and no rev limiter, a reed failure would be disastrous, but a carbon reed valve will not damage the engine if it happens to enter it.)

The last thing that I would like to talk about is brakes. Having done a few track days, I found that I wasn’t driving as hard as I could because there would always be fade at some stage. I thought of bigger brakes and so forth but I did speak to a few people who said that pads and fluid would stop the fade, so I went forth chasing the best pads I could find. I’m sure there are plenty out there but I eventually settled on some PROJECT U pads, HC-TITAN model which are a 0-800oC pad which work fine on the street and the track. At the recent 10th Anniversary weekend, from dead cold to 10laps at a somewhat furious pace they didn’t fade. The first time I pushed hard on them at the track I came forward out of the seat as I just wasn’t prepared for how hard they were going to stop. I also changed to motul race line fluid, which seems to be quite good. As always the disappointing side was the cost. I had to get these pads from America as no one in Australia imports them from Japan. The original cost was US$171 which seemed fine to me. Then there was US$90US for shipping, so A$500 for a set of front pads. Then FedEx ring with more good news, A$140 worth of GST and customs charges, total bill $640 for front pads, but man do they stop!!! Until next issue keep on mr2’in

Pete