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    1. #1
      Join Date
      Feb 2011
      Location
      Silver Spring, MD
      Posts
      92
      Country Flag: United States

      TVS 1900 / LS3 makes NO POWER!!

      Hi everyone, have one of those "Perpetual Projects" that always seems a week away but never gets completed. While the history of this build is fraught with delays, missing items, dis-interested customer service reps, incompetent dealership "Master Techs" and weather, it all boils down to this.. I have an L92 with the VVT removed and replaced with a Comp blower cam. I don't have the specs with me, can get them if it makes a big difference. Patriot dual-springs, long tube headers and a TVS 1900 are the rest of the engine combo. Trans is a 4L80E, rear is 3:73 with 265/75/16 rubber. It is a 4WD vehicle, running on the dyno (2wd) it only made 316 HP / 342 LB FT. Boost comes right up to 6, occasionally to 7. But it feels slower than with the last engine. There's no urgency, no snap, just a mild pull in the upper register. Magnacharger says its the tune, tuner thinks its a mech problem. Compression is good, varies from 175 to 210, with 210 being the anomaly. All the other cyls are 175, 179, 185, 180, etc. Pretty close to each other. How can ANY V8 with 6 pounds on it be such a slug? A bone stock Tahoe with the L92 makes 322 to 377 at the wheels. Anyone had this issue? Suggestions?? Thanks, would be nice to finish this thing. Has been since APRIL! That's 6 (SIX) months of being jerked around.

    2. #2
      Join Date
      Jun 2006
      Location
      Phoenix
      Posts
      89
      Country Flag: United States
      Post the dyno sheet if you are able. Also are you getting any engine knock ?
      1995 Caprice 6.0 LQ4,L92,L76 Leading Edge Performance Tuned
      http://www.cardomain.com/ride/456803...caprice/page-1

    3. #3
      Join Date
      Jul 2011
      Posts
      239
      Weird problem

    4. #4
      Join Date
      Feb 2011
      Location
      Silver Spring, MD
      Posts
      92
      Country Flag: United States
      Quote Originally Posted by tooblue View Post
      Post the dyno sheet if you are able. Also are you getting any engine knock ?
      Waiting to receive it in an e-mail. Curve was pretty flat, just super low. Hopefully will have it to post today.

    5. #5
      Join Date
      Jun 2001
      Location
      Newbury Park, CA
      Posts
      5,821
      Country Flag: United States
      What does the timing look like?
      VaporWorx. We Give You Gas http://www.vaporworx.com

    6. #6
      Join Date
      Feb 2011
      Location
      Silver Spring, MD
      Posts
      92
      Country Flag: United States
      AF is 12-1, Timing is 15deg. from talking to the tuner, still waiting on the sheets / logs though.

    7. #7
      Join Date
      Jan 2008
      Location
      Long Beach, Ca
      Posts
      1,564
      Country Flag: United States
      First off, I know very little about boosted tuning; but 15* sounds very low, IIRC ~20-25 is where you usaully tune a FI engine?
      Jon Rasmussen
      Ex Team OLJ.
      '72 Nova

    8. #8
      Join Date
      Jun 2006
      Location
      Phoenix
      Posts
      89
      Country Flag: United States
      What Cam is installed (Specs). Was this done with convertor locked? Hopefully Trans is not slipping? What gears and how tall are the tires? Has the Tuner performed tuning on supercharged vehicles in the past?
      1995 Caprice 6.0 LQ4,L92,L76 Leading Edge Performance Tuned
      http://www.cardomain.com/ride/456803...caprice/page-1

    9. #9
      Join Date
      Aug 2008
      Location
      ocala fl
      Posts
      279
      Country Flag: Wales
      are you still running a catalytic converter if so you should remove one of the o2 sensors the one before the cat and check exhaust back pressure with a pressure gauge. you should not have more than 1 to 1.5 psi at 2000 rpm if you have more it can kill your power. good luck
      ''Courage is being scared to death
      - But saddling up anyway''.......John Wayne...

      Anthony

    10. #10
      Join Date
      Aug 2008
      Location
      ocala fl
      Posts
      279
      Country Flag: Wales
      Timing and boost can be tricky I’m putting together a supercharged sbc. I’m going to run a crank trigger set at 30 degrees. Low compression motor around 8.2-1 so starting wont be a problem and my msd box will take out 1deg of timing for every lb of boost. So 10 lbs of boost 20 deg max timing. So your timing might be a little on the safe side but better safe than sorry. Good luck

      ''Courage is being scared to death
      - But saddling up anyway''.......John Wayne...

      Anthony


    11. #11
      Join Date
      Feb 2011
      Location
      Silver Spring, MD
      Posts
      92
      Country Flag: United States
      Well I finally have the HPT file, but not the dyno sheet. Of course, I have nothing at the moment that can READ the HPT file, but I can send it if anyone wants to have a look. I am waiting to see the dyno sheet with RPM / AFR info.... waiting..... dammit.

    12. #12
      Join Date
      Feb 2011
      Location
      Silver Spring, MD
      Posts
      92
      Country Flag: United States
      Quote Originally Posted by anthonys 69 View Post
      are you still running a catalytic converter if so you should remove one of the o2 sensors the one before the cat and check exhaust back pressure with a pressure gauge. you should not have more than 1 to 1.5 psi at 2000 rpm if you have more it can kill your power. good luck
      I put 2 new Magnaflow bullet style cats on it (3").

    13. #13
      Join Date
      Feb 2011
      Location
      Silver Spring, MD
      Posts
      92
      Country Flag: United States
      Quote Originally Posted by tooblue View Post
      What Cam is installed (Specs). Was this done with convertor locked? Hopefully Trans is not slipping? What gears and how tall are the tires? Has the Tuner performed tuning on supercharged vehicles in the past?
      Cam is from Comp, but purchased through a Frederick shop that kind of screwed me over. I should've gone with a sponsor.....next time I will. Anyhow, Adv Dur is 277/285 @.050 227/235 LSA 114 Lift 613/620 It was my mistake to believe the shop, I thought I was paying for expertise, not advice. Comp tells me its not ideal for what I have, but they still expect to see at least high 400's at the wheels. And I'm making less than a STOCK motor at the wheels. Sooooo next step?

    14. #14
      Join Date
      Jun 2006
      Location
      Phoenix
      Posts
      89
      Country Flag: United States
      Quote Originally Posted by Hambone! View Post
      Well I finally have the HPT file, but not the dyno sheet. Of course, I have nothing at the moment that can READ the HPT file, but I can send it if anyone wants to have a look. I am waiting to see the dyno sheet with RPM / AFR info.... waiting..... dammit.
      Can u attach the file to your thread? I have HPT and should be able to read the file.. If not send it in a PM if that works better..
      1995 Caprice 6.0 LQ4,L92,L76 Leading Edge Performance Tuned
      http://www.cardomain.com/ride/456803...caprice/page-1

    15. #15
      Join Date
      Mar 2005
      Location
      Woodbine, MD
      Posts
      2,770
      Country Flag: United States
      Quote Originally Posted by Hambone! View Post
      Cam is from Comp, but purchased through a Frederick shop that kind of screwed me over. I should've gone with a sponsor.....next time I will. Anyhow, Adv Dur is 277/285 @.050 227/235 LSA 114 Lift 613/620 It was my mistake to believe the shop, I thought I was paying for expertise, not advice. Comp tells me its not ideal for what I have, but they still expect to see at least high 400's at the wheels. And I'm making less than a STOCK motor at the wheels. Sooooo next step?
      wow...so comp said the cam was wrong but our "favorite lil speed shop" said it was ok? That's a smack in the face....but we are both getting quite used to that aren't we?? If you want you can email it to me and we can look at the charts tonight on my iphone. Im pretty sure it can open any kind of file.
      Douglas Lutes
      1988 Monte Carlo SS

      "Never race anything you can't afford to set on fire and push off a cliff."

    16. #16
      Join Date
      Feb 2011
      Location
      Silver Spring, MD
      Posts
      92
      Country Flag: United States
      Quote Originally Posted by SicMonte View Post
      wow...so comp said the cam was wrong but our "favorite lil speed shop" said it was ok? That's a smack in the face....but we are both getting quite used to that aren't we?? If you want you can email it to me and we can look at the charts tonight on my iphone. Im pretty sure it can open any kind of file.
      More like a punch in the d i c k. I found out the cam they sold me was actually from another customer's build. Was for a Trailblazer SS project and it must've been left on the shelf. Yay. How do you attach files to here anyhow? I'll just mail it to anyone that wants to see.

    17. #17
      Join Date
      Feb 2011
      Location
      Silver Spring, MD
      Posts
      92
      Country Flag: United States
      Quote Originally Posted by tooblue View Post
      Can u attach the file to your thread? I have HPT and should be able to read the file.. If not send it in a PM if that works better..
      Well another wrinkle....I can see the file the tuner sent is 472KB, I can see it ends in .hpt, but it won't download. Keeps saying server is not responding. File coming soon......stay "tuned". Ha, that's not funny, I'm sorry. I hate this project now.

    18. #18
      Join Date
      Jul 2006
      Location
      Indianapolis, IN
      Posts
      350
      If you want e-mail the file to me at [email protected] and I will see what it has. It would also be nice to see a data log during the dyno run which would end with .hpl if at all possible.

      As far as the cam, it may not be perfect for what you have, but it takes a big screwup on specs for an LS engine to be missing that much power. I generally use a 224/236 114 in any SC'd LS3 and in M6 cars get 575-625 RWHP at 9-10 PSI.

      I am still thinking cam timing may be off.

      Let me know on the tune and hopefully the log.

      Mike Norris
      Mike Norris

    19. #19
      Join Date
      Feb 2011
      Location
      Silver Spring, MD
      Posts
      92
      Country Flag: United States
      Quote Originally Posted by Mike Norris View Post
      If you want e-mail the file to me at [email protected] and I will see what it has. It would also be nice to see a data log during the dyno run which would end with .hpl if at all possible.

      As far as the cam, it may not be perfect for what you have, but it takes a big screwup on specs for an LS engine to be missing that much power. I generally use a 224/236 114 in any SC'd LS3 and in M6 cars get 575-625 RWHP at 9-10 PSI.

      I am still thinking cam timing may be off.

      Let me know on the tune and hopefully the log.

      Mike Norris
      Tune sent. Thx.

    20. #20
      Join Date
      Jul 2006
      Location
      Indianapolis, IN
      Posts
      350
      I got the tune and have a few concerns for sure. I am going to reply in the e-mail and I would really like to see an HP Tuner log of the best dyno run as well as a look at the dyno sheet with air/fuel reading.

      One other thing I forgot to mention is about the 4L80E in that it will show about 35-40 HP less at the tires then a 4L65E. Not saying that this thing should not do 450+ at the tires even with a 4L80E, just saying. And on top of that if you have a less efficient converter that will not hold with the lockup commanded on, there could be another 25 or so HP loss at the tires.

      What brand converter do you have and what stall??

      Mike Norris
      Last edited by Mike Norris; 10-19-2011 at 04:11 PM.
      Mike Norris

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