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Oct 4, 2008

Turbolag - 2.8 liter , GT-RS Turbos

Jeffs R32 GT-R went back on the dyno yesterday at RB Motorsports. This is a continuation of my turbolag charts. These are all eyeballed numbers off dynocharts. Not 100% scientific, but not grossly off either. Jeffs car has been a long build. Its one of those ongoing shop projects. Something that gets worked on for a while, and then is pushed to the side for a while. The car has a ton of modifications, but it looks mostly stock. Underneath, the car is almost all R34 GT-R. Front and rear subframes, brakes, ABS , V-Spec rear diff. Lots of cool things that you wouldn't notice. However, this post is all about the dynocharts.
We got the Dynapack controller back earlier in the week and tested it out on Thursday. Everything seemed fine, and we even had new upgraded software. Jeffs car doesn't look too crazy underneath the hood. It still has the twin turbopipe , it still has the stock airbox on it.

Its always the stuff you can't see that is important. The engine is a 2.8 liter that was built several years ago by XS Engineering. The engine actually came with another car that RB purchased . The turbos are HKS GT-RS with strengthened actuators set at 16 psi base. The twin turbo pipe looks polished but its actually got a splitter/divider in it. The airbox looks stock, but it has an extra air feed going to it. Exhaust manifolds are N1's. Exhaust outlets are Nismo cast outlets. Exhaust is all titanium. Camshafts are fairly small. 9.1 mm and 8.9 mm of lift. 272 / 264 duration. +4 on the intake cam , 0 on the exhaust cam. The head has been ported and modified by Jeff of RB Motorsports. Hard piping. Nismo collector. Stock throttle bodies. ARC intercooler. HKS Racing BOV. Engine management is AEM with 24-1 CAS wheel. NGK #9 Racing plugs. Stock "new" coils. Stock "new" coil harness. 1000 cc injectors. Two Bosch 044 pumps in the tank. Twin -8 feeds.
Stock fuel tank with Two Bosch 044 Fuel pumps and -8 feeds in the stock tank
We started on the dyno on pump gas - 91 octane here in California. We were still learning the new software with the dyno. Figuring out how long to setup the ramp time. Mitch Peterson did the tune on the car. Mitch worked at AEM, taught the AEM EMS class, and he knows his way around the AEM EMS. The dyno chart just didn't look right. The car just wasn't running right. We spent a little time troubleshooting it. We thought we had some leaks, or that we had a cam gear slip . We went over and over things, and we found that the timing was off about 10 degrees.
R33 GT-R power steering pump. Rear hydraulic Hicas delete

The first pull on pump and about 16 psi did a little over 400 whp uncorrected. It was about 80 degrees and a decent amount of humidity. We kept pushing and pushing the pump gas setup. We had the boost up to about 23 psi. Best we saw was 567 whp on 91 octane. I would say that the repeatable number is 550 whp and 470 lb-ft. We were pretty happy with that number on pump gas.
The day before Josh had called me and asked if we wanted to run the car on race gas... I thought it might be a good idea, so I went and picked up 10 gallons of C16. $131 - $13 a gallon. Cheaper than an engine. Not cheap by any means. At the end of the 91 octane runs, we drained the fuel and put in 5 gallons of C16. 25 psi of boost, more timing and the car was up over 600 whp and 500 lb-ft. Mitch added some more duty cycle to the wastegates to get the boost up even higher. 27 psi and we exceeded the maximum KW of the dyno. Over 540 lb-ft, and the dyno shutdown. Ramping the boost in slower , got us up to 630 whp and 530 lb-ft. The peak torque would have been higher, but the dyno couldn't handle it. We tried one run, pulling the K & N panel air filter out of the stock airbox, and we only gained about 5 whp. If we would have tightened the turbo actuators up more, we could have made more peak boost, but may have run into the torque limit, but up higher in the rpm range. I think we are pretty close to being done on this setup, at least for this week. Throwing some correction at the numbers, I saw 690 whp. The 1/4 mile dyno doesn't lie.
Oil catch can returns to the sump. R34 GT-R ABS unit and control

We took the car up and down the alley a few times. The first 6000 rpm launch on Jeffs car lit up all four tires for about 30 feet. Hopefully next Thursday we will get it to Irwindale, and perhaps to IDRC in October.

11.0@131 mph video.

Timeslips from Irwindale. Best 60 foot 1.61 with a 7.299@99 mph pass on pump gas
60 foot times sucked. On the 11.0@131 mph pass, it was a 1.899

1 comment:

Mike M Images said...

I <3 disco potato