underground

I've had the GT4088R, The Borg Warner S374, the S372R, and now the Billet 6765....soon to try the Billet 6262. Being a Precision Distributor, I wanted to find out whether the hype surrounding the billet wheels was fact or fiction. Going from a Borg Warner 72mm to a Precision 6765 netted me full boost 1700 RPM's sooner. (7000 vs 5300). I lost about 40whp at peak, but picked up power throughout the powerband, which was worth the switch. Here is my latest dyno graph, showing the T4 .68 A/R. Notice that torque/boost falls off, indicating the exhaust housing is too small. I have a .81 A/R backhousing on order, and should have some new dyno numbers to post this week. They also make a .96 A/R, though I feel the .81 A/R is probably the housing to use on a street setup RB26. 25 PSI 33 PSI (Full Boost at 5300 RPM) 33 PSI with -4 Degrees Timing on the Intake Cam Gear (Full Boost at 5600 RPM)

Update: Wanted to welcome Deatsch Werks to the list of corporate sponsors on the project car. We went back to the dyno this past weekend with a set of 1600cc DW Injectors, and they performed flawlessly. The car now has plenty of injector for the current setup. With that being said, the day didn’t end up as we hoped. We maxed out the dual Walbro 255 lph fuel pumps @20 PSI on E85. The car made just over 650whp before we had to call it a day. I made a call to my friends over at MagnaFuel this afternoon, and they suggested their street friendly, Inline Protuner Series Fuel Pumps. The particular model they suggested is MP-4303 rated at 2000HP in N/A Applications using gasoline. (good for around 1300 HP on E85). What’s unique about their race pumps is they are E85 compatible, rebuildable, and they don’t require a fuel controller like the Weldon’s. (And various other brands of “race” pumps.) This is a significant cost savings, and makes this pump is fairly “bolt-on” affair in a car with an aftermarket fuel system already installed. The new fuel pump will be installed in the next two weeks, and I will write a review for those that may be interested in our findings. We knew three weeks ago the 1000cc injectors and dual walbros were not going to get us to our goal, but I wanted to see how far they could be pushed on the E85….as I know many on here are debating switching over in their own vehicles. Here’s the latest dyno video, notice the fuel pressure gauge video at the end: Underground Motorsports Demo Car1998 RB26DET 240SXMaxing out the dual Walbro 255lph Fuel Pumps at 650whp@20 PSI.Borg Warner S374 Turbo, 1600cc Injectors, E85 Pump Fuel, AEM ECU, etc.

Sorry about the delay on posting up dyno numbers, but I have crazy busy and the car has sat for the past few weeks. I have not added C16 yet, but I did tune the car for E85 Pump Gas. Right now, E85 (106 Octane) is $2.18/gallon at the pump here in Texas, so it's a no-brainer. As you can see at 25 PSI, the car made 629/490. I'm decently happy, but will be upgrading probably to a GT42R, as I really want to break 700whp on pump gas. Also, took the car to be weighed, and I was pleasantly suprised. With full interior minus a passenger seat, and 3/4 tank of gas, the car came out to 2890 lbs. Look for a larger turbo, and big power numbers over the next few weeks!

I'm shooting for 9 sec 1/4 time slips.

Interior, as the interior is bone stock right now.

While I still have the interior to finish off, here are the completed exterior shots. This 240SX has been four years in the making, with 30 corporate sponsors on the stage II build. I want to give a special thanks to Andy Vaughn @ Southern Imports, and Chris Hamilton (tuner) for their work on the vehicle.

We now have everything finished with the motor minus the installation of the new 24x12x4 intercooler that arrived today. I want to thanks Matchless Performance (Addison, TX) for the fabrication of the downpipe, which came out better than I would have ever imagined. The welds are amazing, and extremely clean. Here are the latest images:

Yes, I'm about 3 hours from Austin. I'd love to meet you.

Monday Night, Andy and I worked til 2 a.m. @ Southern Imports to get the motor running. When we attached the AEM EMS ECU, it started first crank with the AEM supplied base map. I was very impressed with how simple the box is to use, and I want to thank Sean Morris for taking my phone call late at night to confirm we had the configurations setup accurately. We still have lots of work left to be done, and these are, by no means, final images. As you can see, there are aftermarket gauge sensors that need to be hooked up. The boost controller is not installed, the intake for the turbo still needs to be ordered, downpipe has not been fabricated, and the upper intercooler piping has not been polished. But the motor runs, and that's a success in itself. Yesterday, I transported the car to Texas, and will be finishing up the car here. Once again, thanks to Andy Vaughn @ Southern Imports in Murfreesboro, TN. He, by himself, built 95% of the car that you are fixing to see. He is a amazing fabricator, engine builder, and friend. Thanks again Andy! Here are the images and the start-up video:

Hey Guys, Just wanted to make those of you who are using the AEM EMS for the RB's aware that AEM has released a new aftermarket trigger wheel. Many of you who have experienced issues with this box now have a solution. The CAS fix is a new trigger wheel that goes in the existing CAS housing and they are currently available. This will require some modification to the OEM CAS, so you may want to leave this job up to your mechanic.

A shot of the finished oil cooler assembly: McKinney Motorsports Race Motor Mount Kit, Tranny Mount, and Driveshaft Everything on the bottom fitted up nice and snug: Step-by-step Photo Guide: Greddy RB26DETT manifold, adapted to run twin-scroll and the Tial Sport 60mm wastegate. The wastegate had to be moved to fit into the 240SX engine bay.

Yesterday, Andy (Southern Imports in Murfreesboro, TN) began finishing out the fuel system, which should be done today. Up Next was the Exedy Triple Disc Clutch, special thanks to the team at Exedy for their support over the years. Ran the -10 AN Lines from Desynz Motorsports Oil Return Mod from the back of the head to the oilpan, as seen in the following two photos. Finished the lines to the cooler, so that mission is completed.

Speed by Design (Setrab Model #925) Oil Cooler Kit for the 240SX

We are both now using the GT4088R, so it would be an interesting matchup.

Getting Closer: