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How much power out of twin turbo upgrade?

Discussion in 'N54' started by AzNdevil, Nov 22, 2016.

  1. On my quest to research for future upgrades....

    How much power will I be able to get out of a pair of upgraded twin turbos running on pump 93 gas without PI or meth?

    I couldn't really find any numbers for people with upgraded twins + upgraded LPFP.... I understand I will need to add fueling to extract the real potential of upgraded turbos.
  2. Dave@Fuel-It!

    [email protected]! Corporal Vendor


    What are your support mods? I don't want to assume, but I imagine FBO, what about inlets/outlets?
  3. Waiting for my VRSF 7" HD intercooler and catless downpipe to be shipped.

    Will get in and outlets if and when they are available from whoever makes them (I am guessing RB as they are the only ones with somewhat successful RHD installs) the same time I replace my turbos.

    I just haven't decided whether I should stay with a new set of stock turbos or go bigger. ST is not an option for me either...

  4. We did 560+ on our GC's on pump 93. We turned PI on after low 500's for safety, most likely could do that on just a stock hpfp but we don't know that for a fact -always good to leave plenty of room in your fuel system capacity. I believe AD-E has done more than 600 on a single turbo pump gas no meth/PI but I don't want to misspeak.

    Attached is dyno showing 16 psi and 30 psi on 93 octane.

    16 psi and 30 psi.jpg
  5. ATL-IS-N54

    ATL-IS-N54 Sergeant

    Noob question what's Pi? Port injection?
  6. Dave@Fuel-It!

    [email protected]! Corporal Vendor

    Correct, PI = Port Injection :)
  7. Twisted Tuning

    Twisted Tuning Lieutenant Vendor

    How much power can be made on upgraded twins is a very broad question. As there are like 10 different sets of upgraded twins for these cars. Which offering are you looking at getting. power can range from 500whp mid 700's at the wheel with current available twin options.
  8. V8bait

    V8bait Sergeant

    If you're staying on pump gas please avoid PI at all cost, the vtt shotgun is a better option, or meth, you need every octane you can salvage. After 500 on pump it gets more inconsistent with heat and all but with the right setup you can make a good amount of power still.
  9. TurboMike

    TurboMike Corporal

    To start Here's a short performance mod list
    07 335i 71k miles
    Pure stage 2 turbos
    BMS meth kit
    HKS Legamax full exhaust
    VRSF 7.5" big race FMIC
    Vrsf inlets
    Mmp outlets
    Hks legamax exhaust
    Vrsf downpipes
    Synapse dv/BOV
    Vrsf chargepipe
    Bms oil cooler valve
    Bms oil catch can
    Rob beck PCv valve
    Bms short shifter kit
    KW V3 coil overs
    Bms modified clutch valve
    Act 6puck clutch
    Wavetrac lsd
    M factory single mass flywheel
    Big brake kit

    I was able to put down 586whp on 93oct and meth. I used a custom MHD map similar to the race fuel OTS maps and jb4 to control meth and boost. I was in map 3 running 25 psi max with the meth additive at WOT. At the time I was using a VRSF 7" not the 7.5". I only upgraded as I will be changing my fuel to c16 and raising the boost to around 30psi.
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  10. Thanks everyone for your input.

    To be honest, everything is still in the planning stage that's why I am trying to figure out how far I can get on pump gas before deciding on a set of turbos. From my point of view, theres no point getting a set of Pure S2 Hi-Flows (for comparison) which says it can support up to 700whp if I can't even provide the fueling required right? I may as well get the DD's which will fit the requirements easily with room to spare.

    Fueling options at where I live are very limited. Ethanol is not an option for me. Methanol @ 97% purity costs ~2-3$USD/L and I have to drive 30 minutes to get it from a Lab Supply Store. 93 Pump gas costs ~2-3$USD/L as well so if I run meth full time it will cost an arm and a leg....

    Regarding the VTT shotgun, the purpose of this is to get the most out of the HPFP right?
  11. rac

    rac Lurker

    135i ST
    What's your reasoning for staying away from PI on pump, losing a small amount of DI cylinder cooling?
  12. Abacus38

    Abacus38 Sergeant

    Tampa/Orlando, FL
    2007 Ti Ag 335i
    From what i been told the effective octane rating is alot higher when the fuel is DI instead of PI. Plus Its easier to tune DI only
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  13. ATL-IS-N54

    ATL-IS-N54 Sergeant

    That is probly from port heating fuel charge? As stated above in the form of "afraid of losing the extra cooling from DI" or something
  14. V8bait

    V8bait Sergeant

    Exactly this, it's a high compression motor with forced induction and pump gas is not very forgiving when it comes to heat. DI helps with that a whole lot, thus why we even have a high compression turbo motor to begin with. Also, on pump gas you shouldn't run out of hpfp for quite a while so it shouldn't be much of a concern.
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  15. Twisted Tuning

    Twisted Tuning Lieutenant Vendor


    Both very valid posts
  16. ATL-IS-N54

    ATL-IS-N54 Sergeant

    So question is, what is the max on pump 93? Without ANY other fueling mods, aside from a larger pump? No meth, no e85... pump 93 run thru DI? What is safe I guess is the question? And do you really need twins upgraded to obtain this level on straight no chaser DI pump? I know the stockers are good for 450, 500+ on e85... But again pump 93 only DI Max? Stock or upgraded
  17. TurboMike

    TurboMike Corporal

    I'm going to say it's going to vary between 500-600whp. Depends on the dyno, and how aggressive you want the tune to be.
  18. time to bring this back from the dead... stupid question

    will i be octane limited or hpfp limited if i stay on pump around 500-600?
    if i am octane limited then going TB/PI meth injection makes sense but if its hpfp limited then then vtt double barrel solution would solve the fueling issue
  19. TurboMike

    TurboMike Corporal

    Essentially your both.

    Even with adding meth and 93 pump to be safely pushing it I would say 600 is the max and even then is pushing it towards the limits.

    If you decide to change to e85 mixture like e40 or whatever you choose then your putting the strain on both the lpfp and hpfp as you'll need a larger volume of fuel.

    What is your goal, if we have an understanding of that we can help more.
  20. well i have no access to ethanol so its out of the equation unfortunately...
    meth is available but its a one hour drive roundtrip for me to get it and since i live in an apartment there is no place to store it..

    truth is... i am just trying to piece together all the info i can find as i am trying to justify whether a set of upgraded twins would be useful if all i can run is 93 pump... thats all

    from a financial perspective... it doesn't make sense to fork out 3000+ usd for let say... a set of Pure S2 DDs if all i can get is 400-450whp due to limitations on my side...i may as well replace with a pair of stock turbos or S1 and put the extra $$ elsewhere