TurboCharger Upgrade Recommendation

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  • #1

    TurboCharger Upgrade Recommendation

    Hello,
    I am looking for a TurboCharger upgrade recommendation for street use.
    My aim is for something to produce about 10 - 12 lbs. (max) of boost with good drivability. A simple bolt-on replacement would be ideal.

    The car is a 1985 Turbo GL 5-Speed with the following engine modifications:
    1) Gutted intake plenum with overpressure valve plug
    2) Euro-Cams
    3) Ported heads
    4) Jim Wolf ECU and electronics with larger MAF sensor
    5) 1mm oversized intake and exhaust valves
    6) Fidanza lightweight flywheel
    7) 460 cc Bosch injectors and high pressure fuel pump
    8) Recirculating blow-by valve
    9) z32 fuel filter (for higher flow)
    10) Upgraded ignition transistor
    11) Higher voltage ignition (not too crazy)
    12) Elimination of OEM intake snorkel with more direct plumbing
    13) Poly engine mounts (allowing modification 12)
    14) Electric fan and water pump
    15) 10 psi Waste Gate Regulator

    As is with the OEM Turbo (at 10 lbs) I had the car on the dyno showing 220 RWHP at around 6000 RPM. I am thinking that an upgrade would allow for better air flow as the stock unit is likely staining at my boost level and producing too much heat. I saw this upgrade from PureTurbos and was wondering what some here might think.

    http://www.pureturbos.com/store/oem-…ade-375hp.html

    Stage 1 is all I'm after. I'll be more than happy to answer any questions and concerns you might have.
    As always, thank you for any information/suggestions you might have.
    Last edited by NewJerseyZ; 11-26-2016, 02:40 PM.
  • #2
    That looks really pricey to me. Do you have an intercooler? What are your goals for the car?
  • #3
    The car will be used as an occasional driver on the street --- no track use.
    It does not have an intercooler, which is why I'm looking for only about 10 psi of boost, but with a better turbo to safely get me there. The stock turbo (as you likely know) takes forever to get up to 10 psi and is at its limit. I may install an intercooler down the road, but I haven't found one that won't require a good deal of chopping up some metal. I have removed the A/C compressor and condenser, so there's room up front should I need it. (I like a stealthy look.) My goal to get at least 250 - 275 RWHP --- not 400. I have looked at various turbos with their maps and sweet spots, but I'm still not confident which ones are best for my goals. To me the Pure Turbo seems good (SEEMS), but I will be asking many questions before buying.
    Thank you.
    Last edited by NewJerseyZ; 11-26-2016, 11:23 PM.
  • #4
    Originally posted by NewJerseyZ View Post
    The car will be used as an occasional driver on the street --- no track use.
    It does not have an intercooler, which is why I'm looking for only about 10 psi of boost, but with a better turbo to safely get me there. The stock turbo (as you likely know) takes forever to get up to 10 psi and is at its limit. I may install an intercooler down the road, but I haven't found one that won't require a good deal of chopping up some metal. I have removed the A/C compressor and condenser, so there's room up front should I need it. (I like a stealthy look.) My goal to get at least 250 - 275 RWHP --- not 400. I have looked at various turbos with their maps and sweet spots, but I'm still not confident which ones are best for my goals. To me the Pure Turbo seems good (SEEMS), but I will be asking many questions before buying.
    Thank you.
    Have you looked at something like a HY35 or HX35? If you want an easy bolt on upgrade you should get your stock T3 rebuilt as a T3/T4 from a place like AZ tractor and turbo

    Comment

    • NewJerseyZ
      #4.1
      NewJerseyZ commented
      11-28-2016, 11:06 PM
      No, I haven't. I have tried to study some maps on T3/T4 turbos but can't seem to make out how to choose what's best for my goals.
      I will give AZ a look though … thank you.
  • #5
    that sounds low for your modifications.

    If you think the stock turbo takes forever to hit 10psi you may have other problems.

    I'd highly suggesting getting a management system, not a drop in like JWT, and find a tuner with a dyno to get the most power out of your setup

    Comment

    • NewJerseyZ
      #5.1
      NewJerseyZ commented
      11-28-2016, 11:14 PM
      Perhaps my wording wasn't the best for how I should have described it.
      From looking at my boost gauge (stock OEM) I did not see the needle go above the factory maximum level until about 4500 rpm or so. It did go to the maximum factory level (just to the red) as quickly as it did prior to my modifications --- which I believe to be 6 lbs. of boost. Now that I have a 10 lbs. actuator I would have thought it should rise into the red sooner.
      I tried a Nistune ECU originally, but here in NJ I could not find anyone to tune it. It's a wasteland out here for performance modified cars. (At least 3 shops closed up in the past 5 years.) Once I installed the JW-Tech. unit the car ran great. I can't even find a shop that will rebuild my other car's engine. (1991 LS Integra) They advertise like crazy, until you actually try and get them to take on the project.
      Last edited by NewJerseyZ; 11-29-2016, 07:00 AM.
  • #6
    Originally posted by 88sinZ View Post
    that sounds low for your modifications.

    If you think the stock turbo takes forever to hit 10psi you may have other problems.

    I'd highly suggesting getting a management system, not a drop in like JWT, and find a tuner with a dyno to get the most power out of your setup
    You have a good point there. I wonder if it could be his pop off valve? Before I plugged mine if I raised my boost it would flutter and kill my performance.

    Comment

    • NewJerseyZ
      #6.1
      NewJerseyZ commented
      11-28-2016, 11:22 PM
      I have two springs available for my recirculating pop-off valve. Right now I'm using the lower tension spring … which as I see it, should allow for an easier time achieving boost. (When vacuum is sensed, it releases. While under boost it works with the spring, keeping the valve closed, right?)
  • #7
    you want to go external wastegate and address airflow, the Z31 plenum and heads can't suck air well.

    It should not flutter. If you're fluttering it means the blow off valve has too much preload.

    I'd highly suggest reading Street Turbocharging: Design, Fabrication, Installation, and Tuning of High-Performance Street Turbocharger Systems


    by mark warner if you're relatively unfamiliar with turbocharging systems and functions

    Comment

    • NewJerseyZ
      #7.1
      NewJerseyZ commented
      11-28-2016, 11:25 PM
      I don't think my valve is fluttering, as the boost gauge rises smoothly and remains fairly motionless under boost (as described earlier).
      I will however have a look at your text recommendation. Thanks.
  • #8
    Originally posted by 88sinZ View Post
    you want to go external wastegate and address airflow, the Z31 plenum and heads can't suck air well.

    It should not flutter. If you're fluttering it means the blow off valve has too much preload.

    I'd highly suggest reading Street Turbocharging: Design, Fabrication, Installation, and Tuning of High-Performance Street Turbocharger Systems


    by mark warner if you're relatively unfamiliar with turbocharging systems and functions
    I know a decent amount about turbo charging. I'm not talking about the blow off valve. I'm talking about the pop off valve Nissan put on the z31s as a safety device if the internal wastegate ever failed. It is screwed into the passenger side of the intake plenum. Before I plugged mine with an npt plug the pop off valve would dump air out of my plenum if I raised my boost. The OP calls it an over pressure valve plug. I'm wondering if that is stopping him from hitting 10 psi hence his lower then expected performance.

    Comment

    • NewJerseyZ
      #8.1
      NewJerseyZ commented
      11-28-2016, 11:27 PM
      Yes, that's what I was referring to. The overpressure valve on the front of the upper plenum is plugged with a 1 inch NPT plug.
      Maybe 220 RWHP is all I can get with 10 lbs. of boost.
  • #9
    oh whoops, thought you were the OP
  • #10
    Maybe your factory boost gauge isn't working right or maybe where it gets vacuum is causing the issue. I have a similar setup as you do but without any head work and I have a glow shift boost gauge. I run around 12-14psi and I definetly hit full boost before 4500rpm

    Comment

    • NewJerseyZ
      #10.1
      NewJerseyZ commented
      11-29-2016, 12:20 AM
      Is that with an OEM T3 Turbo?
      My boost gauge pressure source is still where it's always been.
  • #11
    Originally posted by 88sinZ View Post
    you want to go external wastegate and address airflow, the Z31 plenum and heads can't suck air well.

    It should not flutter. If you're fluttering it means the blow off valve has too much preload.

    I'd highly suggest reading Street Turbocharging: Design, Fabrication, Installation, and Tuning of High-Performance Street Turbocharger Systems


    by mark warner if you're relatively unfamiliar with turbocharging systems and functions
    Another good read that others on the z31 forums have mentioned is Maximum boost by Corky Bell
  • #12
    Its a stock T3. I have an 84 turbo GLL

    Comment

    • NewJerseyZ
      #12.1
      NewJerseyZ commented
      11-29-2016, 12:56 PM
      You were able to get just under 1BAR from a stock T3 … I always thought that was beyond the turbo's ability.
  • #13
    Well I was running 14 psi with an intercooler on 93 octane gas but I'm still using the stock 260cc injectors. I already upgraded to a walbro 255 and a z32 fuel filter but just to be safe I'm running 12 psi for now. From what I heard the stock T3 turbo is good up to about 14-15 psi (so about 1 BAR). After that it is far out of its efficiency range and you may make more power until about 17-18 psi but the air temperature is really high. If you do have an intercooler I wouldn't run the turbo above 10 psi on 93 gas. I plan on getting nistune eventually (I already have a spare 87 NA ECU) and 550cc injectors. Then I'll get an HX35 or something like that

    Comment

    • NewJerseyZ
      #13.1
      NewJerseyZ commented
      11-30-2016, 01:28 PM
      The HX35 is something of a monster (IMHO) for my application --- the HX30 looks a bit more tame (up to 5 Litres). Would there be any issues with fitment? … meaning exhaust downpipe configuration and water cooling for the bearing? I do like it having an internal wastegate.
  • #14
    From what I've read the HX35 is good to about 450whp on a z31. You can get a holset turbo with a waste gate but if you do end up going with a holset you will need to make a downpipe that connects to the stock exhaust. There was a guy on here making them so it would basically be a bolt on but I don't know if he is making them anymore. It would probably be easier for you to get the stock Nissan T3 rebuilt and upgraded to a T3/T4. There are many different variations you can get for your HP goals

    Comment

    • NewJerseyZ
      #14.1
      NewJerseyZ commented
      11-30-2016, 08:14 PM
      Thank you.
      Yes, the latter suggestion is really more of what I'm after … a clean swap with my OEM turbo. And I have looked into T3/T4 units and their maps/specs, but I have a hard time zeroing in on specific parameters, like optimum A/R ratios, boost efficiencies and the like. I've calculated maximum mass air flows against HP etc. etc. but never seem to get a definitive … "This is the size for me" confidence in doing it. My greatest fear is getting one too large or too small for my goals.
  • #15
    Talk to a turbo shop and let them know what your goals for the car are and they can point you in the right direction. Or ask some of the more knowledgeable guys on this forum
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