prjkt EVO VIII MAYHEM’s New Upgrades

Well, I’m back in Kuwait, and the 2-weeks stay back home in the USA was a whirlwind of getting stuff done. Now that I’ve had some time to think about everything that went on with the cars we did, what was started and what was achieved, I can honestly say that more action occurred in 5 days of turning wrenches than in a whole year that most people would hope to achieve.

First up was prjkt EVO VIII MAYHEM…

Honestly, I had a sour taste in my mouth from the disappointment of February 2014 when I put the car on the dyno at All-Aspects in Chesapeake, VA. I was expecting to crack 440 WHP, but the truth of it was barely able to hold 23 lbs of boost and eaking out a mere 376 WHP in a car that has parts in it that would tell you that it is meant to belt out more.

What’s in prjkt EVO VIII MAYHEM? Well, in 2014, I couldn’t tell you anything other than an FP Green 73HTA stock frame turbo, Forge MBC, HKS cam pulleys, HKS Kevlar timing belt, ZAK LEE clear cam cover, RC Injectors, EGR delete, an unknown intercooler and piping make, a faulty supposedly real HKS SSQV BOV (piece of crap actually created an open in my system and fouled out my plugs twice leaving me stranded outside Tallahassee, FL and Ridgeland, South Carolina on the trip to Virginia Beach in December 2011), HKS catback, Invidia downpipe, and remnants of what was a host of AEM gauges (how could I tell? I could tell by the wiring that was left intact. Who does that?). Basically, the previous owner of the car had raped it of whatever he could before selling it. I bought it in August 2011, drove it for 5 months and parked it in the garage for the next 2 years. Why did I buy this car? Because I was intimately familiar with the layout and how to work on it, having previously owned an EVO 7 GSR, and I really didn’t want to buy a 240SX (I had my fill of Nissan 180SX and 200SX previously) knowing that I would have to put in work (I needed reliable transportation and I wanted to look and feel good at the same time) and I definitely did not want to turn to Ford Mustang or Chevrolet Camaro (I did however buy a 2013 RS/SS2 2 years later).

Back to February 2014 and after the letdown of knowing I was not making the power I thought I could, Chris Carbee, owner of Slowpoke Racing and my tuner for the EVO, told me that the reason could be that the intercooler is too small, the MBC may be faulty and the wastegate actuator may be faulty, as well. Before we strapped the EVO on the dyno, we converted to Speed Density (SD) and got rid of the stock MAF. The EVO would have to be tuned for the SD, so to kill two birds with one stone, we tuned and tried to see what kind of power we were capable of. Again, a letdown.

Fast forward to October 17 2015…

I got home the day before, and went over the stuff I had ordered based on Chris’ recommendations. I received from STM a GM Air Intake Temperature (AIT) sensor, Extreme Turbo Systems (ETS) front mount intercooler with complete piping and new couplers and clamps, Hallman MBC with in-cabin controller and an Autometer mechanical boost gauge with a steering column mount (Autometer product) made for the EVO VII-IX.

Starting with the tedious section first… the intercooler system.


It wasn’t until after I looked at the intercooler design that I suspected that it is an early version produced by ETS.


After placing the old intercooler next to the new intercooler, it is indeed an ETS version and was confirmed later by Freddie Riner that it is indeed an earlier design produced by ETS.

Installing the new ETS intercooler system…

The new ETS intercooler is a little wider and a little shorter. The L and R side tab configuration is the same while the center connect point is different in that it is adjustable front and rear. Little did I know that it is actually a handy configuration when installing the “zero tolerance” piping (no slop; the pipes are metal to metal with no slack inside the couplers).

Before mounting the upper intercooler pipe, I installed the TiAL 50mm Q BOV and the GM AIT sensor.

Just a little note here, I installed the AIT sensor because in “traditional” SD systems, there is an AIT sensor in addition to the MAP sensor. I noticed previously that cold start just using the MAP and the fuel temperature input resulted in “wild” idle searching and having to go through the whole process each time I shut down. The addition of the AIT sensor significantly diminished this. When I saw and the felt the result, my confidence in SD tuning was restored.

Putting the piping in and the result…

Just look at that beautiful sight…

The Hallman Manual Boost Controller (MBC)…

I have been told that the Forge MBCs are faulty and that the ball bearing that resides inside the chamber can get stuck resulting in an overboost situation. Everybody has said hands down that the best MBCs on the market are Hallman MBCs.

Hallman MBC

Additionally, I want the feature of being able to increase or decrease boost pressure on the fly, so this was also bought

Hallman Pro In-Cockpit MBC Controller

Setting up the Hallman MBC In-Cabin Boost Controller Cable…

The cap that is normally located on the MBC itself was removed and relocated the section you see and requires loc-tite once it is installed. A hole was drilled near the steering shaft in order to route the in-cabin controller cable. I decided to mount the controller piece on the lower left side of the center console for ease of reach and to not kink the controller cable.

The last things I did was install a weighted aluminum shift knob from Torque Solutions in a Neo-Chrome finish, an OE steering/air bag delete using a steering shaft hub adapter from Works Bell coupled with a Sparco 368 suede steering wheel and mounted the Autometer boost gauge on the steering column using the Autometer steering column gauge holder made for EVO VII-IX.

My assessment… prjkt EVO VIII MAYHEM’s new upgrades have made a significant positive impact. Firstly, the new ETS intercooler system and its “zero tolerance” (meaning that it goes together and into the car only one way; no slop in the piping fitment; constant pressure whenever pressurized) resulted in immediate response. I am fairly certain that I had vacuum leaks judging from the condition of the previous couplers and the sloppy vacuum lines for the wastegate actuator and the vacuum source for the MBC. The Hallman MBC system allows me to now keep low boost setting at 16 PSI and high boost setting at 38 PSI. I am fairly certain that I can hit 450 WHP on E85. We’ll see this coming year. The AIT sensor reduced the amount of RPM searching on cold start. I may be the one guy out of 10 that AIT actually works in the EVO with SD. In the cabin of the car, the weighted shift knob and the Buschur billet shifter bushings allows for controlled precise shifting. The weight of the knob makes shifting a breeze and the billet bushings eliminate “searching” for each gear. For control, having gotten rid of the factory steering wheel/SRS bag combo and replacing it with  the WORKS BELL steering wheel hub with SRS canceler and the Sparco 368 deep dish steering wheel is a world of difference in steering control and feel. Lastly, the Autometer boost gauge/gauge mount combo is aesthetically pleasing. It sits within normal eye view and requires just a glance when scanning the speedo, tacho and the boost level. I am very pleased with everything, and I must thank Ethan Walker of STM for supplying me with the parts I needed and to Chris Carbee for the outstanding tune and the parts recommendation.


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