Stock twin question

+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 25 of 38

Thread: Stock twin question

  1. #1
    SupraForums Member supralover93's Avatar
    Join Date
    Mar 2002
    Location
    Sacramento, ca
    Age
    34
    Posts
    4,560

    Stock twin question

    Hi, so I've been chasing this problem for about as long as I've had the car. I've discussed it with Stu and a few other and have made changes but nothing has worked. I'm on stock twins and can not seem to boost past 12psi. It might spike higher in first but then fall back off
    I've replace the pressure tank, tested the old one on the bench and it was leaking.
    Running a profec b and have checked the plumbing a dozen times. Also tested the solenoid by applying pressure and it also works.
    We had a half mine event yesterday so I was able to monitor boost up to 132mph and it would hold VERY steady at 11-12 psi, no more than that not matter what changes we made to the bcc.

    Any more ideas guys? Trying to sort this out and have some fun with it before I go with the upgraded twins.
    Thanks
    §§
    93 turbo targa
    auto
    BPU

  2. Remove Advertisements
    SupraForums.com
    Advertisements
     

  3. #2
    SupraForums Member
    Join Date
    Apr 2018
    Location
    Tampa
    Posts
    123
    Have you ever tried removing the EBC and just try using a simple MBC? Have you tried the wastegate spring mod???
    1997 DJG Supra TT 6 speed - BPU-
    2004 Black RX8 13bREW BWS362SXE @ 24 psi
    1995 White Mustang GT 347 PT7675 @ 9 psi
    2013 White GLK-350 4Matic (DD)

  4. #3
    SupraForums Member
    Join Date
    Feb 2001
    Location
    SE PA
    Age
    69
    Posts
    13,569
    Have you ever tried just bypassing the wastegate actuator and see if boost goes higher? Of course keep an eye on it and don't let it go too high depending on octane.
    Nick 95 6sp
    Twin Garrett GT2860's w/TiAL SS exhaust housings, WG's and BOV's, V-band moded HKS twin manifolds, AEM v2, AEM WB, ID1000's,
    AEM meth/water spray, GSC S1's, ported head, Ferrea valvetrain, CP pistons w/crown & skirt coatings, Carrillo H-beams,
    OS Giken triple clutch & Super Lock LSD, Racelogic TC, TRD gen2 catback
    street wheels: Veilside EvoV 9-1/2"F X 10-1/2"R with 265/35F & 285/35R NT05's
    track wheels: CCW LM5 10"F X 11-1/2"R with 285/30F & 315/30R R888's

  5. Remove Advertisements
    SupraForums.com
    Advertisements
     

  6. #4
    SupraForums Member supralover93's Avatar
    Join Date
    Mar 2002
    Location
    Sacramento, ca
    Age
    34
    Posts
    4,560
    Running a MBC was going to be my next option. I have the spring mod done.
    Have not tried bypassing the actuator yet but I'm running 100oct ATM so I can give that a shot too.
    Thank you for the help

  7. #5
    SupraForums Member HotSoup's Avatar
    Join Date
    Feb 2002
    Location
    North Carolina
    Age
    40
    Posts
    9,489
    For the profec B, just pull the hoses on the solenoid....just get out of it at 17-18psi
    1994 Red/Black TT
    86K miles
    Roller...6 speed swap coming soon

  8. #6
    SupraForums Member okinawa-supra's Avatar
    Join Date
    Dec 2008
    Location
    Vista California
    Posts
    756
    What all these wise people say^^^^^^
    1994 6spd Targa Ren Red named "Paris" she has a history.
    1994 6spd Hardtop Baltic Blue.
    1993 Auto TT Ren Red (sold)
    1993 Auto TT white JDM (wrecking yard)
    1993 5spd NA yellow (sold)

  9. #7
    Stock Twins King Stu Hagen's Avatar
    Join Date
    Jan 2002
    Location
    Kirkland, Wa.
    Posts
    4,337
    As stated, a good test is just removing anyone of the 2 hoses on the front Actuator. This (as mentioned) gives you unlimited boost so do be careful. If you cannot get above 12psi (assuming you have a BCC) then there is something you have overlooked. Question tho...have you ever been above since owning the car get above 12psi on a regular basis?

    I would also remove the inner side EBV hose....again...be careful as this could get you near 18psi pre-transition. If you only see 12psi up to 4000rpms then there is a possible issue with the 1st turbo. I have seen issues with a faulty Inner WG flapper have chips and not sealing properly.

    Lastly have you inspected both the corrugated couplers to see if they are not collapsed.

    Have you read my Seq System troubleshooter? It is on my website. http://97supraturbo.com/Seq%20FAQ/Seq%20FAQ%202016.doc
    Last edited by Stu Hagen; 04-29-2019 at 08:17 PM.

  10. #8
    SupraForums Member supralover93's Avatar
    Join Date
    Mar 2002
    Location
    Sacramento, ca
    Age
    34
    Posts
    4,560
    thank you for chiming in Stu.
    i will remove the hoses and see what happens. i'm running 100 oct. at the moment so that should keep me somewhat safe correct?
    could you explain the EBV hose a little more? not sure what hose that is exactly.
    the last item, corrugated hoses. i was also suspecting this so i replaced them with silicone hoses. the old ones were extremely hard and had some cracks on the inside but nothing major. replacing these made no difference.
    i will also take a look at your trouble shooter.

    i would like to get it working but in the end, when you release your manifold i'm most likely going to pull and build the motor and go with upgraded twins. so far i have the THUK pipe haha.

  11. #9
    Stock Twins King Stu Hagen's Avatar
    Join Date
    Jan 2002
    Location
    Kirkland, Wa.
    Posts
    4,337
    Quote Originally Posted by supralover93 View Post
    thank you for chiming in Stu.
    i will remove the hoses and see what happens. i'm running 100 oct. at the moment so that should keep me somewhat safe correct?
    could you explain the EBV hose a little more? not sure what hose that is exactly.
    the last item, corrugated hoses. i was also suspecting this so i replaced them with silicone hoses. the old ones were extremely hard and had some cracks on the inside but nothing major. replacing these made no difference.
    i will also take a look at your trouble shooter.

    i would like to get it working but in the end, when you release your manifold i'm most likely going to pull and build the motor and go with upgraded twins. so far i have the THUK pipe haha.
    Pull the hose on the right. This then doesn't allow the #2 to prespool so all boost pressures go 100% to the #1 until transition

    Have you ever pressurized the EGCV (about 7psi) and watch the actuator arm rotate. Paying even closer attention to actually seeing the shaft rotate. It is common even tho the actuator does work, where the arm is attached to the internal flapper, is busted and isn't rotating the internal flapper at all. This would never get you past 12psi if so
    Attached Images

  12. #10
    Stock Twins King Stu Hagen's Avatar
    Join Date
    Jan 2002
    Location
    Kirkland, Wa.
    Posts
    4,337
    Flapper. It is hard to really see. Otherwise you have to remove the DP to see it move or not
    Attached Images

  13. #11
    SupraForums Member supralover93's Avatar
    Join Date
    Mar 2002
    Location
    Sacramento, ca
    Age
    34
    Posts
    4,560
    Wow that's a lot of things that can fail. No wonder everyone goes single haha.
    I'll check all of those out and report back. Waiting on a fuel filter.

  14. #12
    SupraForums Member supralover93's Avatar
    Join Date
    Mar 2002
    Location
    Sacramento, ca
    Age
    34
    Posts
    4,560
    Progress.
    So I pulled the hose for the EBV and that had no affect. After connecting that then removing the hose that goes from the BC solenoid to the wastegate, the boost easily shot up to 20+.

    Stu, not sure exactly what that means as I'm still reading through your write up. I'm also waiting for a pressure tester as I only have a vac tester atm.

  15. #13
    Stock Twins King Stu Hagen's Avatar
    Join Date
    Jan 2002
    Location
    Kirkland, Wa.
    Posts
    4,337
    Quote Originally Posted by supralover93 View Post
    Progress.
    So I pulled the hose for the EBV and that had no affect. After connecting that then removing the hose that goes from the BC solenoid to the wastegate, the boost easily shot up to 20+.

    Stu, not sure exactly what that means as I'm still reading through your write up. I'm also waiting for a pressure tester as I only have a vac tester atm.
    Well that is good news really. How did the car feel with this hose pulled? I assume it stuck around 12psi up to about 4K then took off? If this is the case then it doesn't point to the Seq system rather than something in the EBC. If you had an issue with the Seq system, you would be stuck at 12psi past 4K. Cause this means both the gates are opening as they should, It also says you do not have much of a leak anywhere. Id pay close attention to the EBC, hoses to it and and back and the actual settings. You may have a bad EBC.

  16. #14
    SupraForums Member supralover93's Avatar
    Join Date
    Mar 2002
    Location
    Sacramento, ca
    Age
    34
    Posts
    4,560
    Thanks Stu. I'll start testing everything anyway as I'll need it all in working condition for the upgrade. I'll start looking at theEBV hoses and operation as soon as I can.
    Yes, it made about 12psi then just took off at about 4k.

    Thank you all for the help.

  17. #15
    SF Contributing Member bitshftr's Avatar
    Join Date
    Jan 2009
    Location
    Raleigh, NC
    Age
    51
    Posts
    2,922
    OP, what are your GReddy Profec EBC settings? It can be a tricky beast to set up correctly.
    1995 Supra NA, Baltic Blue, targa, TRD LSD, Recaro Sport seats, Cusco carbon fiber front/rear strut tower bars, 97+ front turns
    Passport hardwired, w/ amped remote speakers in seat harness slots
    Hidden/hardwired garage door opener w/ custom Supra dash button


    1995 Supra TT, BPU+, Baltic Blue, targa, TRD front/Cusco rear strut tower bars, 98 headlights w/ 6k HIDs, 97+ front turns, BNR turbos, Tial BOV, HKS Super Drager exhaust, SSR Professor SP1 wheels, Racelogic TC, VPC/GCC
    Passport hardwired
    Hidden/hardwired garage door opener w/ custom Supra dash button
    Subtle white LED dash backlights

  18. #16
    SupraForums Member supralover93's Avatar
    Join Date
    Mar 2002
    Location
    Sacramento, ca
    Age
    34
    Posts
    4,560
    It's spec 2, not the original profec. My boost is at 1.2 bar and gain was high 20s to low 30s.
    Last edited by supralover93; 04-30-2019 at 08:58 PM.

  19. #17
    SupraForums Member kiro1968@yahoo.com's Avatar
    Join Date
    Jul 2009
    Location
    Behindyou
    Posts
    845
    Quote Originally Posted by supralover93 View Post
    It's spec 2, not the original profec. My boost is at 1.2 bar and gain was high 20s to low 30s.
    Would be helpful if you list all your setting.
    1993 Toyota Supra Black NA 5spd -> TT Engine Swap 5spd

  20. #18
    SupraForums Member HotSoup's Avatar
    Join Date
    Feb 2002
    Location
    North Carolina
    Age
    40
    Posts
    9,489
    Quote Originally Posted by supralover93 View Post
    It's spec 2, not the original profec. My boost is at 1.2 bar and gain was high 20s to low 30s.
    Those things suck imo...

  21. #19
    SupraForums Member
    Join Date
    Sep 2009
    Location
    CT
    Posts
    564
    Weird how they're so finicky, and overall just ... not-good. I have an old Apexi AVC-R, and it's absolutely rock-fricken-solid. I set low boost at 14psi and high at 18psi, and it zips right to the set level and just nails itself there all the way to redline (stock twins).

  22. #20
    SupraForums Member supralover93's Avatar
    Join Date
    Mar 2002
    Location
    Sacramento, ca
    Age
    34
    Posts
    4,560
    I actually had a AVC-R before this but sold it because I was going to go with a stand alone soon but ended up getting this in the time being since it was taking longer than expected.
    It's weird because I thought this was one of the boost controllers everyone loved back in the day.
    It doesn't seem to have many settings, just boost and gain so I don't see why it would have so many issues. An avcr is like a computer compared to this ti83 lol
    Last edited by supralover93; 05-02-2019 at 01:02 PM.

  23. #21
    NiSmO [email protected] supergoji's Avatar
    Join Date
    Sep 2006
    Location
    westchester NY
    Age
    30
    Posts
    521
    I think mine is in TTC, but I get the dip, so wouldn't that mean there is a sequential operation going on?
    https://photos.app.goo.gl/VZ56Gr9mLQKq5HdLA

    I also have a greddy profec 2.
    Quote Originally Posted by OOBE View Post
    the shop power fucked you at 140 mph too :D
    Quote Originally Posted by x X CLoud X x View Post
    why the Hell is there a FUCKN SAILOR MOON ON A SUPRA!!!
    Quote Originally Posted by SupraLB View Post
    Was it over when the Germans bombed Pearl Harbor?
    Quote Originally Posted by wreckless View Post
    hell, he has a better chance of getting gov't funding to build the playboy mansion into an orbital launch vehicle to set a new record of nonstop consecutive orbital blowjobs from playboy playmates.
    94 Alpine Silver Supra TT 6spd ( for sale) https://www.cargurus.com/Cars/l-Used...ting=234504432
    91 Cherry Red Pearl Z32 TT 6spd

  24. #22
    SupraForums Member supralover93's Avatar
    Join Date
    Mar 2002
    Location
    Sacramento, ca
    Age
    34
    Posts
    4,560
    I don't think your supposed to get the dip in TTC. It should run like a small single where you have lag then all the boost. At least that's how mine was in TTC.

  25. #23
    Stock Twins King Stu Hagen's Avatar
    Join Date
    Jan 2002
    Location
    Kirkland, Wa.
    Posts
    4,337
    Quote Originally Posted by supergoji View Post
    I think mine is in TTC, but I get the dip, so wouldn't that mean there is a sequential operation going on?
    https://photos.app.goo.gl/VZ56Gr9mLQKq5HdLA

    I also have a greddy profec 2.
    In TTC you get like 0-3psi up to about 3000rpms then it will go up linear to full boost around 4200-4500. In Seq, about 2200rpms you peg right at 10psi and it holds there until about 4000 then hits hard to the max boost from there

  26. #24
    NiSmO [email protected] supergoji's Avatar
    Join Date
    Sep 2006
    Location
    westchester NY
    Age
    30
    Posts
    521
    Quote Originally Posted by Stu Hagen View Post
    In TTC you get like 0-3psi up to about 3000rpms then it will go up linear to full boost around 4200-4500. In Seq, about 2200rpms you peg right at 10psi and it holds there until about 4000 then hits hard to the max boost from there
    So that video looks like sequential, but the car feels so laggy...

  27. #25
    Stock Twins King Stu Hagen's Avatar
    Join Date
    Jan 2002
    Location
    Kirkland, Wa.
    Posts
    4,337
    Quote Originally Posted by supergoji View Post
    So that video looks like sequential, but the car feels so laggy...
    The video wasn't clear to me. If that is your boost gauge on the right it looked to move in a TTC fashion. To verify, stomp on it and see where your boost is at 3500. Maybe 3800. If it doesn't go above like 11psi then your in Seq. If it approaches anything above 12psi then you are in TTC. It is very evident as once you get to about 2500 rpms the boost does start but not in TTC

+ Reply to Thread
Page 1 of 2 1 2 LastLast

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

List your Car(s)

Where you live

Please select your insurance company (Optional)

Your Supra's Vehichle Identification Number (Not visible to the public)

Log-in

Similar Threads

  1. Replies: 9
    Last Post: 05-23-2013, 10:46 PM
  2. 97 stock twin VS 93 stock twin
    By Zerosoul in forum MKIV (1993-1998)
    Replies: 7
    Last Post: 09-19-2002, 08:21 PM
  3. Replies: 3
    Last Post: 03-27-2002, 04:41 PM

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •