N54 6266 dyno at 809whp (796 SAE)

With a new fuel system, maintenance, other odds and ends taken care of I went back to the dyno and sent it again. Boost only on pump E85, no other power adders were used.

I believe this is a new horsepower record for the fairly common N54 6266 top mount setup.

.. ..

809 WHP / 755 WTQ (uncorrected)
796 WHP / 743 WTQ (SAE)

Tuned by me (@veer90). MHD flash / AIC standalone map / JB4 map 6

Mod list:

  • Doc Race turbo kit, Gen2 6266 DBB 1.00AR
  • NTK pre-turbo O2s, Innovate Motorsports venturi heat sinks
  • DIY stage 4 fuel system on pump E85 (tested at ~83%)
    • Walbro 450 + 525
    • BMP 750cc port injectors
    • Precision Raceworks FPR / return
    • 12psi hobbs, 6AN feed, etc etc.
  • R8 coils / NGK 97506 @ 0.025". Plugs indexed (gap facing intake) with shims
  • VRSF 7.5" IC and charge pipe
  • Motiv closed deck N54 short block (stock heads and cams)
  • Spec 3+ / smfw

Logs here, now with 100% less sketch AFRs than before :)

Tuning notes and observations:

  • Boost limit – for 8.7 psi wastegate springs seems to be about 33psi at redline with a 3 port MAC. Car couldn’t hold 34.5 psi target above 5500 rpm. This depends on ambient temperature.
  • False knock fix – trim pots at 85k ohms + desensitize knock tables MHD check box combination is still sensitive to the condition of the plugs. Brand new plugs, no timing pulls. Old trashed plugs = timing pulls of 3-5* or more depending on boost.
  • MBT timing – was 15.5* timing at redline for my setup. Pulls at 15* and 16* put down less power.
  • Fuel system – could not be happier with it. Fuel pressure for dayssss
  • Bank 1 pre turbo O2 got a bit too hot, was reading false lean during the very end of one pull but was not damaged. Cleared codes and it worked normally on the drive home.
  • The spec 3+ slipped at 712 wtq last time and I’m making way more torque now. No clue how it’s still holding together LOL

Much thanks to:

  • @V8bait Justin Hubenak @all4bspinnin David Shoup – really appreciate the tuning advice, patience, and knowledge sharing.
  • Top Secret USA – dyno time and perpetual encouragement to send it.
  • @PC Racing – LPFP and fuel system help.
  • @PRECISION RACEWORKS @BlackMarketParts – good products and very DIY friendly too, answered a lot of my questions on fuel system design.
  • VRSF – no hassle quality go fast parts
  • Motiv – built engine still alive and kicking
  • Friends, too many to list – huge thanks for all the DIY help, prep time, etc etc.
Better late than never, promoted to the front page.
I'd be happy to work through the remaining knock tables (frequency, amplitude, windows, etc), logging params, and document how it all works. End result would be standalone levels of configuration of the knock detection system. However, as it is a very small end user market, it is not something MHD would likely fund. However, if enough built motor guys wanted to all pitch in, let me know.
Put a funding goal and we can start a board sanctioned fund. Always down to progress this kind of stuff.
  • V
  • March 28, 2019
Would you consider putting a cam in? If the head work and cam only net you 6% more peak power there is your 50 whp ;) Granted that is a bad bang for your buck.

Are you going to go with a larger turbo or are you happy at 800whp?
Gonna send it till the 6266 blows then maybe EFR 9180, EFR black series, or bigger PTE. Depends on timeline really.

Any head work is going to be after I complete research, so I know exactly what I want and do it right the first time.
  • V
  • March 29, 2019
This is great motivation and insight for my 6266 bottom mount set up. It gives me a clear idea of where I'll stand. How do you think you would have done with a less aggressive fueling set up given you had tons of pressure to work with?

This is my previous dyno with a twin 450 stage 3 lpfp setup (both pumps bottlenecked by venturi pickup). MMP chinesium injectors hanging on for dear life at 100% duty cycle up top lol

That setup with some margin of safety is probably good for around 750 SAE. I made 786 SAE by maxing it out.
2k? That's more than 1/2 off labor rate for the forum haha.
Excellent. I'll send you a PM.
I have setup the donation campaign, you can find it in the navigation under "Donate" or you can click this link:
  • V
  • April 18, 2019
How is the street manor of the set up? Any pros/cons
You're in luck, I happened to make a trip to Mexico last night.

If you floor it at a reasonable rpm while racing there's really minimal lag and it hits hard. Top end is crazy and that video was only 28 psi.

Low rpm driving around town there's a more pronounced "rubber band" feel to the torque delivery when you try to get on it. I learned to drive around it within a few days of the single install it's not terrible.
  • V
  • April 18, 2019
Legit question, non intending to flame by why do you (and many other people) say only 28 psi? You are probably outside of the compressor efficiency range but you are talking about it like you have a diesel capable of 100+ psi of boost? There is nothing only about 28 psi, you are probably just heating air unnecessarily past that point.

Similar pet peeve: when people go to the dyno make great numbers, and then try to downplay them by saying it was a conservative tune or there is a lot left. If there is a lot left you probably didn't do a good job of tuning, am I right?

The biggest offenders of this are the people I have met at TX2K. Everyone there is on a max effort/credit card maxed out setup but they try to talk about it like it's FBO and it aint shit.
lmao in this context I meant "only" as in not full boost (34.5) and therefore not full power. probably could have picked a better word ha

Ok I'll add my "hey I've been under a rock" question: turn signals blink as a shift light ... never seen that ... ?

jb4 uses hazards flash as shift lights