Announcement

Collapse
No announcement yet.

LQ1 turbo, 91-95 or 96-97 head

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • LQ1 turbo, 91-95 or 96-97 head

    How much of a benefit would the 96-97 head over a 91-95 head be in a turbocharged application? Assume that either would also have custom headers.

  • #2
    That's a good question that I don't think anyone has answered. I know the 95 heads are much easier to build headers and turbo manifolds for. I do have a 97 engine I'll be rebuilding soon, so hopefully I'll find out. I would tend to think the intake manifold makes a lot more difference than the exhaust ports. I think there are combustion chamber differences too.

    Tim
    1995 Z34 - T04E "60" trim, 42.5 lb/hr injectors, AEM WBO2, FFP UD&DB, 3" exhaust, 2800 stall, shift kit, tranny cooler, Powerslot, Hawk HPS, rear disc conversion, KYB, Eibach, HMS F&R STB, Fittipaldi Force 18" wheels, big stereo, lots more coming eventually...
    325 whp 350 lb-ft

    Comment


    • #3
      Been a long time Tim.


      "For better boost response, minimize the exhaust volume between the exhaust ports and the turbine inlet "


      Would seem to suggest not to over size the primaries. If the primaries would be sized on HP (indirect measure of exhaust gas flow), would it matter if the exhaust port is restricted down to a certain primary size inside of the head (91-95) or outside the head in the header itself (96-97)?

      Comment


      • #4
        The 96-97 heads are a clover leaf combustion chamber that is 51.5cc. The 91-95 is pent roof and open, with 54cc chamber. I have not flowed the heads to compare, nor have I measured the export volume between them either.

        I wouldn't be concerned with which is better, just build one with a turbo and enjoy it because its gonna make a lot of power.
        Ben
        60DegreeV6.com
        WOT-Tech.com

        Comment


        • #5
          True that. Designing from scratch so just trying to figure out the best and if it is worth the hassle. Part availability on the 91-95 heads are also a lot better.

          Comment


          • #6
            The newer style heads like to drop exhaust valves, so keep that in mind and have yours checked if you go that route. Having the guides machined with a groove and a clip installed to prevent them from falling would rock as well. I've yet to see the older style have this problem, where as every newer set I've seen has had it happen (some more than others).
            -60v6's 2nd Jon M.
            91 Black Lumina Z34-5 speed
            92 Black Lumina Z34 5 speed (getting there, slowly... follow the progress here)
            94 Red Ford Ranger 2WD-5 speed
            Originally posted by Jay Leno
            Tires are cheap clutches...

            Comment


            • #7
              valve guides, and they all do it. The heads on my 92 were done with all new guides with the clips on them so they will never fall into the ports.
              Ben
              60DegreeV6.com
              WOT-Tech.com

              Comment


              • #8
                I wouldnt worry about swapping heads on a Turbo car as well.. I did swap from the '95 intake to the '96-7 intake and it feels much smoother. between the intake and leaning it out a tiny bit i picked up IIRC 30whp. if you look in my photos you will see the difference in the intake design, im glad i did the intake swap.

                S
                Shane "RedZMonte"
                2004 Corvette Z06 Commemorative Edition -VIRGIN
                1995 Monte Carlo Z34 14.38@101mph, 331hp/355tq
                -Turbonetics T04E Super 60 Turbo, 2.5" Borla Catback, OBDII, 42.5# Injectors
                2004 Subaru WRX STI -Lightly Modded (SOLD)
                1994 Lumina Z34 -VIRGIN (SOLD)
                1992 Lumina Z34-VIRGIN (RIP)
                1992 L67 Lumina Z34 (SOLD)
                1990 Turbo Grand Prix (SOLD)

                Comment


                • #9
                  Originally posted by SappySE107 View Post
                  valve guides
                  Thank you. That's what I meant, guides.
                  -60v6's 2nd Jon M.
                  91 Black Lumina Z34-5 speed
                  92 Black Lumina Z34 5 speed (getting there, slowly... follow the progress here)
                  94 Red Ford Ranger 2WD-5 speed
                  Originally posted by Jay Leno
                  Tires are cheap clutches...

                  Comment

                  Working...
                  X