raverX

Near the end of 2006 I managed to blow one of the stock turbo's. We're still not certain whether this was a result of the solenoid in the boost controller failing or running 18 psi of boost on a set of turbo's that had done 160,000 KM.

Either way this brought upon the need to start doing some work under the bonnet.

Brad from Boosted Xtremes was consulted and we decided upon a Garret T04Z turbo, Tial wastegate, Ebay T4 manifold and GFB StealthFX BOV. The stock 440cc injectors were kept and a set of US spec 550cc injectors were purchased from a member of the American Supra Forums.

Our goal was to see how much power we could get out of a predominantly stock engine. For this reason we kept the existing HKS F-Con V fuel controller. Unfortunately however we found out that the F-Con V used ROM based fuel maps and for whatever reason no ROMs had been released in the USA for the 550cc injectors so we were unable to use them.

We also intended on keeping the original clutch fan, however this was soon replaced by twin 12" thermo fans when he ran into issues trying to run the plumb back for the BOV.

The initial run in was completed using only wastegate pressure (8 psi). The car ran like this for 2 weeks before we connected the boost controller and started winding more boost into the turbo.

As the boost controller had previously been wired to manage the twin setup we had to re-write the system to suit a single turbo with external wastegate. The car was given a rushed street tune an hour prior to the Qld Supra Club dyno dayn (April 2007) at 1.3 bar (~19 psi) and scored a respectable 455.5 HP.

Following this we took the boost back to 1 bar to try and iron out a few boost spiking issues. We originally thought the boost spiking was a result of the way we had the solenoid wired in, however checking various options discovered that the solenoid was not holding boost. We were getting a boost bouncing effect, which may have been what killed the stock twins in the first place.

The HKS boost controller was replaced with an Apexi AVC-R unit and re-tuned for 1.3 bar and scored a 450.0 HP figure at the following Hyper Zone car show on the Gold Coast.

From here the next stage will be the fuel system and ecu.