Just got back from a great trip to SHIFT S3CTOR in CA with the VTT gang. We had a hectic couple of weeks prior to the event with an engine failure on our hands, so last minute swapping in a new motor, troubleshooting, and finishing tuning with the current config kept us very busy!
The day before the event we got the motor in, running, and put her on the dyno for some tuning before we left for the event on Saturday. This is our closed deck 9.5:1 compression motor, with fully built head, larger intake valves, Manley springs, TI retainers, etc. originally from ABR (the Punisher motor for those who were around back then). We had some issues with the motor when we received it, had those issues addressed via a local engine builder, and it made some serious power. Throw in a few sneaky but effective mods -like our velocity stacks- and we had a motor that ran like a top and just begged for more.
With a little help by none other than VTT's favorite N54 tuning guru Justin (V8Bait) the car laid down a more than impressive 847WHP/726WTQ with an astounding 601WTQ by 3000 RPM held to redline, and 700WTQ held flat from 3500-6500RPM. This power, and tq was made with ONLY 25.4 psi at peak power RPM. We also made 776WHP at 21.62 psi boost at peak power! This is a perfect example of why we continually tell people boost is simply measurement of restriction; NOTHING else. Remove restriction, and power stays the same or goes up at the SAME boost pressure.
We took the car out to Shift Sector on 2/25/17 with 6 tunes; low, medium, and high boost maps, each with a low and high timing version. Our first pass was with the low boost, low timing map and we ran 162.3x MPH. Our second pass was medium boost, low timing, and we ran 166.29 MPH with traction issues and missing 5th gear. We re-ran, nailed it and set a new N54 1/2 mile record of 170.49 MPH using the medium boost/low timing map (776WHP map with 3 degrees less timing). We're very pleased with this; 170 in the 1/2 -especially at a Shift Sector event (more strict)- is screaming.
170.49 MPH On-Car Video Pass:
After the 170.49 MPH pass we were ready to have some real fun. We tried to turn up the boost to the high boost/high timing map (850 WHP map), however something happened to the diff or alignment and the car was dangerously uncontrollable. After a few attempts we trailered the car and looked under -one of the alignment bolts for the rear suspension appeared to had moved significantly. Most likely that was our culprit, but it's also possible we cooked the M3 rear differential -we'll have to open it all up and look when we get some time. Even with the car near uncontrollable we managed a 168 MPH run. We belive the car would have been close to 175MPH with the 850WHP map in it, but "cudda" and "did" are two different things. We'll take the 170.49 MPH.
Engine Specs:
-Closed deck 9.5:1 compression N54 short block,
-Forged Rods
-Forged Pistons
-Fully Ported head with oversized intake valves, Manley springs, Ti Retainer
-Stock cams (wait until we get the big cams running!)
-VTT GC turbochargers
-Custom VTT inlets with 6" velocity stacks
-Custom PCV system
-Custom 4" exhaust
-VTT Double Barrel HPFP system
-EOS V2 intake manifold with top PI (we DID use the PI at very low duty cycle on this setup)
-AD-E 1200WHP FMIC
-Custom triple Walbro LPFP set up with Radium Surge tank
-MHD tuner tuned by V8BAIT
-100% E85
Dynos/Graphs:
847WHP graph
AEM Log Grab (backpressure is off/not recording)
776WHP graph
AEM Log Grab (backpressure is off/not recording)
Logs:
AEM 847 Log
http://www.datazap.me/u/vargasturbotech/vtt-gc-847whp?log=0&data=4-5&zoom=96-420
MHD 847 Log
http://www.datazap.me/u/vargasturbotech/vtt-gc-847whp?log=1&data=3-23&zoom=39-90
AEM 776 Log
http://www.datazap.me/u/vargasturbotech/vtt-gc-847whp?log=2&data=4-5&zoom=118-484
We had an awesome time, and I met several of you again -always fun to put faces to names. Terry Burger of BMS tuning was there, along with the BMS crew -always a good time (and they made hamburgers... which were delicious). After the drive home we went out to celebrate and enjoyed some adult beverages.
So what's next? Well, right now the plan is to put the stage 3's on the closed deck motor and make big power. We do have to figure out what's wrong with the suspension/differential, but hopefully that's not a complicated problem to solve.
Q&A:
Q: Can I get 847 whp from GC's?
A: Not recommended. We optimized everything we could to make this much power, and the shaft speeds are very high. When I say "everything" I mean we even welded on a v-band clamp to the throttle to stop any chance of boost leaks at the charge pipe sort of attention to detail. Right now if you want 850 WHP and some longevity you're either looking at our Stage 3 setup or one of the many big single offerings out there (and everything else... including a built motor). Simply put the turbos were absolutely maxed out; 100% WGDC. Why? Oh come on... because racecar.
Q: Why not run the GC+'s?
A: We're canning the GC+ concept; our testing shows that particular turbine is maxed with the compressor wheels we have, and a larger turbine would require a different casting which likely would not fit stock location. Our larger compressor testing showed the same power but worse spool; not a good trade!
Q: Are ball bearings still something you're looking at?
A: Yes, but we had some setbacks that showed us we need to do quite a bit more testing before they're ready to be released (if ever). I'll post more about this as time and testing permits -we know there is an interest!
Q: I thought you guys said the double barrel direct injection system was sufficient for 800 whp?
A: It is, and even after 800 whp the system pressure is sufficient, however we're running out of injector and time to inject at these power levels. We turned on Port Injection for the 850 whp runs for safety and we needed more fuel than we could do purely with DI. It was close, but you don't take chances at these power levels. It is possible one of the MHD wizards could unlock some tables that help us but that's for the wizards to determine and not so much for me to guess about.
Q: Do the velocity stacks help that much?
A: They do help, but everything has to be in place for the advantage to show. At these power levels everything matters.
Q: We thought you guys said the ported head didn't really make much of a difference?
A: This ported head has larger intake valves, and it made a big difference. With a bigger cam we expect even better results. This is good news for the platform as a whole -especially big power chasers.
Q: What's your favorite color?
A: Blue