KRAS55Bi 1150HP 985 ya @ 41psi

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doublespaces

Administrator
Free Vendor
Oct 18, 2016
7,046
AZ

List Of Modifications:

  • Built Engine Stock Bore/Compression (CP Pistons/Carrillo Rods)
  • Headgames Motorworks Cylinder Head (Please Contact Headgames For Details)
  • ASR Engineering Intercooler
  • ASR Engineering Heat Exchanger
  • Intakes
  • Catless Downpipes
  • Dodson Sportsman Plus DCT Clutch Kit
  • Fuel-It PI
  • Stock Intake Manifold
  • BMS 4 Bar MAP Sensor Kit
  • Maximum PSI Crank Hub Kit
  • BootMod3
  • HCP 4 Bar Custom Tune
  • KRAS55Bi Turbo System (Standard Billet Wheel Option)
  • Ignite E85 (83% Via Fuel-It Sensor)
  • Motul Sport Esther Oil
24596
 

doublespaces

Administrator
Free Vendor
Oct 18, 2016
7,046
AZ
Can someone explain why power dies after 6300? Are they out of turbo or what? Also, check it out Dodson DCT clutches holding 1000 foot pounds of torque.
 

langsbr

Lieutenant
Apr 5, 2017
814
Can someone explain why power dies after 6300? Are they out of turbo or what? Also, check it out Dodson DCT clutches holding 1000 foot pounds of torque.
Looks to me like the boost curve is probably coming down, similar to overspeeding N54 stock turbos in the lowend and midrange. Without a datalog to show the boost curve though, that's just a guess. If the boost isn't dropping after 6300, then I'd say it has to be the cams, but the way it peaks and dives makes me think boost taper, otherwise I'd expect it to just flatline at 1150 hp and carry that to redline.
 

Torgus

Lieutenant
Nov 6, 2016
889
Boston
I think it has to do with the intake cams. Which are not possible to upgrade or something to that affect.
 

Nugs

Private
Nov 5, 2016
27
Perth
Can someone explain why power dies after 6300? Are they out of turbo or what? Also, check it out Dodson DCT clutches holding 1000 foot pounds of torque.
I think I saw them post somewhere that the turbos are running out of flow.
They only rate them for 850 and they are making 1150.
 

Torgus

Lieutenant
Nov 6, 2016
889
Boston
From kratos:

The first thing that has to be considered is that the engine was designed in such a way that it's meant to be most efficient within a specific rpm range. This basically means that the valve timing and camshaft profiles are part of an equation that allows the engine to perform and breath it's best within that rpm range. Another thing to consider is that as the RPM increases, it gets harder to get the optimal amount of air and fuel into the cylinder and burn it at an optimal rate. The faster the engine revs, the less time there is to induce, compress, burn, and exduce. This in turn affects your ignition timing, which means you start the burn process earlier than what's ideal so the flame dies just before the exhaust valve opens. Unfortunately, there is no way to install an aftermarket camshaft on the intake side due to the valvetronic and currently there are no exhaust cam options. Another thing to consider is the flow capabilities of the turbo system. At our peak output of 1150whp our max boost duty cycle is 94% which produces 41psi. The turbos are able to maintain 41psi all the way to the rev limiter. We also measure the shaft speed of our beta systems with custom shaft speed sensors installed on the compressor covers. This tells us the shaft speed the turbos were designed to operate within. If we go above that shaft speed, the turbos will create more heat per pound of boost and be less efficient which is what we do not want. According to our data, we are close to the upper limit of shaft speed we would like to stay within which means the drop is not related to compressor. That leaves us with the turbine wheels which were designed to support just above 1200whp as a pair. Taking all this information into account we feel it's a combination of limitations between the two. Flow capabilities being reached sooner as a result of camshaft lift and duration limitations.
 
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Nugs

Private
Nov 5, 2016
27
Perth
I think I saw them post somewhere that the turbos are running out of flow.
They only rate them for 850 and they are making 1150.
Looks like I was wrong.

Continuing on from above.

Many people may not be familiar with the valvetronic system's limitations as it relates to valve spring pressure. We spent approximately 6 months working with Headgames so they could develop a valve spring with enough spring pressure to negate valve float as much as possible while still being able to maintain the functionality of the valvetronic system. If the valve spring pressure is too high the valvetronic system will not function properly and the throttle simply won't open. That being said, could we use more spring pressure? Of course, but it would be at the expense of potentially running into valvetronic and throttle issues. In short, Headgames was able to develop a valve spring that was a great compromise that helped overcome these obstacles. However, we may be at a mechanical limit that there currently is no solution for. Only time will tell with more R&D testing.
 

Rob09msport

Lieutenant
Oct 28, 2017
990
Monroe CT
Mother of God. I hope they will release s58 and s63 turbos soon for all new awd version M cars will be on GTR level with same power
Considering that the trans will be able to hold them without clutch upgrades like gtr they will actually be way better in my eyes
 
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