TMIC basics on a Subaru WRX/STi

TMIC basics on a Subaru WRX/STi:

Which TMIC construction method is best? TMICs have two main construction methods:
1. tube and fin
2. bar and plate
There is much debate as to which construction method is best. There are many pros and cons with each design type, but no real hard data. Bar and plate designs are consistently reported as more damage resistant which gives them the edge with regard to appearance longevity. In the end, you are best advised to chose a TMIC based on other qualities rather than concentrate on construction design.

What about the STI or JDM STI intercoolers? The JDM ver 7 & ver 8 intercooler are 15% larger than the USDM STI intercooler. The Spec C/S202 intercoolers are the same size as their ver 7/8 cousins, but have different end tank designs. All are tube and fin design. This is comparative information of the STI intercooler types only and not meant to sway or dissuade anyone from purchasing these units.

TMIC basics on a Subaru WRX/STi: A STi JDM v7 TMIC
TMIC basics on a Subaru WRX/STi: A STi JDM v7 TMIC

Which TMIC has the best gains? There is no irrefutable evidence that any TMIC has better gains than another. The consensus, if there is one, is they are all within 5HP or less, gain wise, of each other.

What is the best size TMIC to buy for my turbo? This topic is highly debated. The two general trains of thought are:
a. Bigger is better
b. A TMIC should be purchased based on need

Are there any downsides to TMICs?

There have not been significant amounts of problems with TMICs. Care should be taken by the end users to ensure through the Vendor that any special fitment requirements are discussed and understood prior to purchasing. Even “bolt on” intercoolers maybe have slight issues that you need to be aware of prior to purchasing. STi owners need to specifically ask about fitment as the majority of TMICs on the market were designed for the WRX. Some TMICs also have fitment issues with aftermarket BOVs or the hood scoop splitter on the STi. There is also the general consensus that TMICs are prone to heat soak when used in situations of stop and go traffic.

How can I combat heat soak? Heat protections options for TMICs fall under two categories:
1. Heat shielding. The primary purpose of heat shielding is to decrease heat soaking of the TMIC and other engine components. Examples of heat shielding:




Perrin 04-11 Subaru STi / 05-08 Legacy GT / 02-11 WRX / 04-09 Forester XT Turbo Heat Sield

2. Turbo insulation. The primary purpose of turbo insulation is to keep the heat trapped inside the turbo for better turbo efficiency. The side effect of this is to decrease heat soaking of the TMIC and other engine components. Examples of turbo insulation are ceramic coating, Thermo Tec’s wrap, or DEI’s wrap.
These may be used in conjunction to provide the ultimate level of thermal protection.

PTP 000516 Subaru Lava Turbo Blanket / Turbo Shield / Heat Shield – Subaru WRX, Subaru WRX STi, Subaru Legacy GT, Subaru Forester XT, Subaru Outback XT