Project Civic SI: CT Engineering Intake and Exhaust (Video Inside)


Before adding parts we needed a baseline of our SI K20Z3 engine.  We went to the best damn shop in town at Technosquare for our dyno test.  They use the Superflow AutoDyn 30 chassis Dyno that uses both inertial and static loading weighted wheel rolers and an eddy current power absorber.  The AutoDyn loads the engine more than a Dynojet making the results more accurate and closer to the actual results of the car being driven.  As expected our baseline results were more conservative than Dynojet or Dynapack dynos with 164hp and 114.1 torque.

Civic SI CT Engineering Intake

You can see how the CT-Engineering intake incorporates both the upper and lower stock intake tubes.  Since half the engine is buried underneath the hugely long Civic dash you get nice wooshing noises from the intake in the cabin on heavy throttle.

It took less than thirty minutes to install the intake with the mounting bracket that bolts to the chassis, the heat-shield that mounts to the bracket, the MAF adapter that mounts to the heat-shield and a couple of hose clamps that hold the filter and stock piping in place.  To make installation easier we removed the battery which could have lead to some problems on the dyno for our subsequent runs.

After warming the car up again we made a few pulls and had about the same or less power than stock.  We were a little baffled as plenty of customers have been happy with the results of the intake and proof of results with an independent dyno making 8 wheel hp.  We resorted to taking the big shop fan and blew air directly on the intake which produced gains between 4-5 whp.  So, there are a few lessons we learned and some points worth mentioning.


Supercharged Civic SI Dyno

While this isn’t a dyno of our car, clearly it shows the CT-Engineering intake makes power.  You'd be right in suspecting the car used for this dyno is not normally aspirated.  Read on for more rationale…

  1. We might as well blow the lid off the goal to supercharge the car with CT-Engineering’s CARB legal kit
  2. The CT-Engineering intake is essential on a supercharged car because the stock intake tube literally collapses at high RPM
  3. We now understand why so many SI owners have gone to bumper vent kits
  4. Modern OBDII cars fight to return the car to factory specifications
  5. The CT-Engineering intake is one few aftermarket intakes on the market with CARB exemption and its designed to work well with the supercharger so that's a big bonus for us

As a measure to force the ECU into submission mode we uploaded a MAF (probably mistake #2) tune for an SI with a short runner intake with our Hondata Flashpro which we will cover in our next article.  Resonance from hi-performance intakes can sometimes play havoc with Mass Air Flow sensors which mistake resonance for detonation.  Hondata also offers many Speed Density tunes which are more consistant than MAF tunes but we were getting real detonation on the Speed Density tune for a stock SI with crappy California 91 octane pump pee.  Peak power with the Hondata MAF tune was the same with the power smoothed out and increased across the powerband as expected.  Our last Ace up the sleeve for power was the CT-Engineering exhaust. This better work or we’ll be going home with our tail between our legs.

Tuning the SI with Hondata Flashpro

If there’s a way to turn an easy task into calamity I’ll find a way.  Here I uploaded Hondata’s MAF tune for the AEM short runner intake.  It was the closest map to our CT-Engineering intake.  As another spoiler in the next article we switched to a speed density map and made tons of power with the experts at Church Automotive Testing.

Many exhausts for the SI were made for the 2-door coupe (FG2), having the 4-door sedan (FG5) I expected to do some custom fabricating.  Turns out there’s a Greddy universal exhaust adapter to adapt the coupe exhaust to the sedan.  In retrospect buying this adapter could have been a smart play.  Instead, I decided to do things the hard way as I usually do because aesthetically I didn’t want an adapter coupled to my beautiful stainless exhaust.  I scoured the internet and I do mean scoured to determine the extra length I’d need for the exhaust.  It turns out all this extra effort is for about 2” of pipe.

Civic SI Exhaust CT Engineering

With all this nice stainless you can understand why I didn’t want an adapter in the mix


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