2.75 or 2.85 pulley tune long tubes

Discussion in 'SRT Hellcat Performance' started by Dr Satan, Jun 24, 2016.

  1. Dr Satan

    Dr Satan Senior Hellcat Member

    Joined:
    May 25, 2016
    Messages:
    84
    Likes Received:
    27
    Trophy Points:
    58
    Location:
    albuquerque
    Vehicle:
    Challenger SRT Hellcat
    Hello everyone. Looking for a little help with what pulley I should use. I m in albuquerque so elevation here is around 5000 ft. I would like to know if I should go with the 2.75 pulley or the 2.85 pulley. We only have 91 octane here. Would the 2.75 be ok on 91 and stock injectors or should I just do the 2.85. I also plan on doing kooks long tubes with catted mids.
     
  2. Jettster

    Jettster Gold Member Hellcat Car Club

    Joined:
    May 1, 2016
    Messages:
    284
    Likes Received:
    153
    Trophy Points:
    213
    Vehicle:
    Challenger SRT Hellcat
    Others may disagree, but exhaust has not been found to be a limiting factor on these cars-the pcm swap to unlocked, either pulley and tune is by far your best bang for the buck.
     
    • Agree Agree x 2
  3. Dr Satan

    Dr Satan Senior Hellcat Member

    Joined:
    May 25, 2016
    Messages:
    84
    Likes Received:
    27
    Trophy Points:
    58
    Location:
    albuquerque
    Vehicle:
    Challenger SRT Hellcat
    But is the 2.75 safe on 91 since I'm at 5000ft making less boost here
     
  4. Jettster

    Jettster Gold Member Hellcat Car Club

    Joined:
    May 1, 2016
    Messages:
    284
    Likes Received:
    153
    Trophy Points:
    213
    Vehicle:
    Challenger SRT Hellcat
    I would ask Top Cat, Linda, or HHP
     
    • Agree Agree x 2
  5. NorCaletch19He77Kat

    NorCaletch19He77Kat Silver Member

    Joined:
    Aug 30, 2015
    Messages:
    905
    Likes Received:
    270
    Trophy Points:
    173
    Vehicle:
    Challenger SRT Hellcat
    do a gear swap
     
    • Agree Agree x 1
  6. Mills

    Mills Silver Member

    Joined:
    Jan 28, 2015
    Messages:
    589
    Likes Received:
    133
    Trophy Points:
    153
    Location:
    Airdrie, Alberta
    Vehicle:
    Challenger SRT Hellcat
    You will be ok with the 2.75 at that elevation
     
  7. graycat

    graycat Automobile Aficionado Extraordinaire Staff Member

    Joined:
    Oct 1, 2015
    Messages:
    1,355
    Likes Received:
    522
    Trophy Points:
    193
    Location:
    Knoxville, TN
    Vehicle:
    Challenger SRT Hellcat
    Welcome to the forum!

    Let me first say that you will get lots of good information and advice from other members on this forum. I am and have been a member on several other forums but I've never been very active posting, just reading on the other forums. This one is different. It's a generally much friendlier and more helpful crowd here.

    Next I'd like to make a suggestion. NOT to discount anyone's opinion here but I'd like to suggest that you find, contact and take the advice of a knowledgeable Gen III HEMI tuner. I'm not going to suggest a specific tuner but that is some advice that you can get from folks on this forum. There are several good people here that have personal experience with tuners, good and bad.

    All of the tuners do not do things the same way so one may say an upper pulley in one of the sizes that you've mentioned or may say just a lower 10% overdrive pulley. Or maybe an upper and a lower pulley. Either way a good tuner will be able to point you in the right direction for what you want to do with the car and for the type of tune that the tuner is able to do for you.

    I understand the altitude question and it is very relevant along with the octane of pump gas that you can get where you live.

    Now if I hadn't already made a speech about finding a tuner I'd also say that the general consensus seems to be that the CAI's and the headers available for these cars do not seem to be a worthwhile investment unless you are after every single bit of power possible.

    Very best of luck to you!!!
     
  8. Wack_Cat

    Wack_Cat Senior Hellcat Member

    Joined:
    Feb 5, 2016
    Messages:
    166
    Likes Received:
    20
    Trophy Points:
    48
    Location:
    Northern Colorado
    Vehicle:
    Challenger SRT Hellcat
    At 5000 feet and a 2.75 will net you about 13-14 depending one temp. So will be a little better then stock. So you won't need injectors or a tune. The computer can adjust that little change. Yes headers unless you want all the power you can get are a waste.

    If you change a pulley the. You should pin the crank. I'm speaking for experience. I live at 5000 feet and with 91. So I know where your coming from. 90% of the people here build and tune at sea level so just adjust to your height.
     
    • Like Like x 1
  9. graycat

    graycat Automobile Aficionado Extraordinaire Staff Member

    Joined:
    Oct 1, 2015
    Messages:
    1,355
    Likes Received:
    522
    Trophy Points:
    193
    Location:
    Knoxville, TN
    Vehicle:
    Challenger SRT Hellcat
    Good point Wack_Cat.

    The lower pulley getting pinned would be the very first thing to do BEFORE VOIDING your warranty. I'm speaking from personal experience. My first Hellcat (2015) spun the pulley on the crank and killed the motor. The car was unmodified and FCA took good care of me. If, no, when, I void my warranty on my current 16 Hellcat, the crank and pulley will be double pinned first.
     
  10. Rick@Metco

    Rick@Metco Gold Member Hellcat Supporting Vendor

    Joined:
    Sep 7, 2014
    Messages:
    308
    Likes Received:
    165
    Trophy Points:
    293
    It is likely that the 2.75" pulley would be appropriate for your application and altitude, but as was mentioned I suggest consulting the tuner you plan to use before you make a purchase.
    With regards to injectors, some tuners prefer that the injectors operate at a lower point in the duty cycle range than other tuners, and will suggest larger injectors rather than run the stockers anywhere near the limit.
     
    Last edited: Jun 27, 2016
  11. Wack_Cat

    Wack_Cat Senior Hellcat Member

    Joined:
    Feb 5, 2016
    Messages:
    166
    Likes Received:
    20
    Trophy Points:
    48
    Location:
    Northern Colorado
    Vehicle:
    Challenger SRT Hellcat
    While Rick is right that every tuner is different. There are several cars out there that have over 750-800 on stock injectors. And you having to fight the thin air.

    As a side note fyi if by some change you do excide the injector duty ( aka 90%) the bypass valve will dump boost to keep you safe but you won't see anything past 14 lbs.

    So I other words your fine, but your money and your car.

    IMO
     
  12. Dr Satan

    Dr Satan Senior Hellcat Member

    Joined:
    May 25, 2016
    Messages:
    84
    Likes Received:
    27
    Trophy Points:
    58
    Location:
    albuquerque
    Vehicle:
    Challenger SRT Hellcat
    Thanks for all the help everyone. The headers I know don't net much power just think they sound awesome! The crank is also being pinned. I saw a car in Colorado running the 2.65 pulley and they are claiming it still had plenty of fuel on stock fuel system. It made 790 with no tune and headers. The shop doing my car has done one other hellcat and they went all out on that car. It has heads,cam,upper lower fuel system you name it. So mine is mild compared to that. I do plan on going to e85 and swapping pulleys when I race.
     
    • Like Like x 1
  13. Wack_Cat

    Wack_Cat Senior Hellcat Member

    Joined:
    Feb 5, 2016
    Messages:
    166
    Likes Received:
    20
    Trophy Points:
    48
    Location:
    Northern Colorado
    Vehicle:
    Challenger SRT Hellcat
    Careful with the e85. Each station is different. We run a race car on that. Kind of a pain for daily driving because of the inconstancy.

    Good luck

    What was the shop in Colorado?
     
  14. Dr Satan

    Dr Satan Senior Hellcat Member

    Joined:
    May 25, 2016
    Messages:
    84
    Likes Received:
    27
    Trophy Points:
    58
    Location:
    albuquerque
    Vehicle:
    Challenger SRT Hellcat
    Plan on running a zeitronix ca to monitor the e85.
     
  15. graycat

    graycat Automobile Aficionado Extraordinaire Staff Member

    Joined:
    Oct 1, 2015
    Messages:
    1,355
    Likes Received:
    522
    Trophy Points:
    193
    Location:
    Knoxville, TN
    Vehicle:
    Challenger SRT Hellcat
    Wow. I'd love for the other car done at the shop that you use to post some information on that car.

    I hate to show my stupidity (again) but could you guys educate me on the "zeitronix ca" E85 is very tough to find in my area. I had looked at it for my 2014 GT500 but decided not to go that route due to the need for buying "barrels" of E85 and getting it shipped to me.

    May need to look at it again for the Hellcat?
     

Share This Page