New Tomohawk build - Supercharged/EFI

Discussion in 'Race 400/430/455' started by offbrand Racing, Jul 16, 2020.

  1. offbrand Racing

    offbrand Racing Platinum Level Contributor

    I thought some of you would be interested in seeing our dyno session from last week at R&R Performance. This video is with the blower turning as slow as we could and with a very conservative tune. There is probably another 400hp or so in it when we speed up the blower and start to lean on it if needed.

    I don't have all of the specifics on the build but I am sure JW will jump in and fill in the blanks.

    555 cubic inch
    Vortech XB110 blower
    9.5 compression
    Oliver rods
    Diamond piston
    Crower crank
    Crane tool steel solid roller
    TA Stg 2 TE heads w/ Jesel rockers
    SPX intake
    Wilson elbow and throttle body
    SRE Pan
    Holley EFI
    Pumpless water meth system in place of an intercooler

    BuickGSrules and sriley531 like this.
  2. Bruce Hunter

    Bruce Hunter Well-Known Member

    Wow, very nice, save a couple bucks for a few sets of tires, your gonna need em'!!
    got_tork likes this.
  3. Tom Haeffner

    Tom Haeffner Well-Known Member

    That is an awesome build. Was just curious how the water meth injection compared to an intercooler?
  4. offbrand Racing

    offbrand Racing Platinum Level Contributor

    It kept the IAT temps under 170 but w my new nozzles we will be able to get IAT under 100. The current system is pump less and runs off co2. In the early cars an intercooler would be PIA to package.
  5. Tom Righter

    Tom Righter Well-Known Member

    Great to hear about A tomahawk build. It’s been a while! Nice work, Keep us posted when you crank that thing up! I am finishing up my 535 EFI N/A build right now,It’s been challenging at times, your build gives me Energy and enthusiasm!
  6. Todd69GS

    Todd69GS Silver Level contributor

    Very nice Jim. What fuel and injector size?
  7. Briz

    Briz Platinum Level Contributor

    Great news and nice numbers. One out the door and the next one on the bench. Hopefully mine! ;)
  8. Bens99gtp

    Bens99gtp Well-Known Member

    Sweet, can't wait to here results when the juice is turned up
  9. Jim Weise

    Jim Weise 1000+HP

    One?... funny guy.. I wish my life was that easy.. finished that one, bring on the next.... ya, more like a tap dance thru a mine field around here.. so much going at once... I am not complaining mind you, busy beats the alternative.. but that comment just struck me as funny.

    Here is my last two weeks..

    I dynoed the 1000HP NA Billet headed motor, and this one 4 days apart, with a stock 70 resto Stage 1 motor in between them... Now finishing the car that Billet head motor goes into.. and those of you who have built a race car, know exactly the hell I am in right now.. We did a complete chassis upgrade to 7.50, complete interior redo with a new dash/firewall, new driver compartment sheetmetal, parachute, rear suspension upgrade and anti-roll bar install.. 4 wheel brake upgrade, 4 new wheels and tires, including the 33x16 rear monsters.. and now are doing final assembly, and complete wiring..

    Motors you say? in the shop we have:

    One 470 and one 482 built and ready for EFI setup and dyno..

    Two more Supercharged motors in process

    A twin turbo efi 350 project I need to finish..

    Two older projects I need to finish..

    12 current NA street/strip builds, all in a line.. several of them promised for yet this month.. about 4 of them going on right now.. with a couple more just starting..

    And Your Tomahawk shortblock..

    Throw in the occasional TH 400, Q-jet carb, and converter sales, just for fun...

    Covid delays slowed everything down, now the train is going again, but my best laid plans are in shambles.. I was going to work on my trailer and race car, and just acquired motorhome this summer.. ya, that's a pipe dream..

    But your right, I am clearing these old big projects out of here pretty fast now. This motor was here a long time, mainly while we gathered experience with the Tomahawk, to insure that it went home after the dyno, with output well past 1300 HP.. or actually more than that... remember on these supercharged things... it's consuming over 100 HP to turn the blower.. so that m0tor actually made well north of 1400 HP on the dyno, in NA terms.. And went home it did.. Not hurt...

    My Tomahawk block count does show the progress tho... there were 7 of them in here at one time last year.. now down to just 2..

    As soon as I can get just a minute, I am going to sit down and show all the pics and videos from this one. And Jim is right, had we leaned on it, it was capable of a lot more power. Ron at the dyno likes to say that centrifugal supercharged motors will put out as much power as you want.. the only limit is how far you want to push the parts. I felt safe on this one to mid 20's on the boost, but Jim was happy at 18 psi and 1337 HP, with over 1000 ft lbs of torque. A few more degrees of timing, a few less pounds of fuel, and a few hundred more rpm, this would have made 1500 easy.. and that is with the big pulley.. we had two smaller ones that never came out of the box.

    But this motor represents a sizeable investment, there was no need to try and push it, to prove something to somebody.. I don't know what he is going to do with 1300HP in a 65 skylark with 10 or 11 inch tires....

    Ok, Enough time on the internet for today... off to work..
    Last edited: Jul 17, 2020
    mltdwn12 and Briz like this.
  10. offbrand Racing

    offbrand Racing Platinum Level Contributor

    Fuel was E85 and we are running Siemens 220lb injectors.
  11. Todd69GS

    Todd69GS Silver Level contributor

    E85 is where it's at. Single set of 220s I assume.
    I'm interested to read the full write up on the build.
  12. offbrand Racing

    offbrand Racing Platinum Level Contributor

    Yes single set if 220s. I am waiting on JW to complete a build up sheet on the motor. Been too long to remember all of the details. I will post specifics when i get them.
    Doug Hoyle likes this.

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