Jump to content
SAU Community

Underpowered?

HP Junky
 Share

Recommended Posts

HP Junky Rookie

HP Junky

Posted
Posted

I finally got a friends r33 gtst on the dyno today and he was telling me it lacks power in the top end. Rb25det fair. Hks pod. Z32 AFM apexi power FC. Upgraded turbo not sure on size smaller than a gt3582r. For facing plenum 80mm tb e85 1000cc injury 15psi boost 3" Full system including dump pipe. Was tuned by a shop and gave a dyno sheet that showed 313rwkw. No today on the dyno it pulled 205rwkw. Haven't investigated yet but any ideas what might have happened timing not advancing or some stupid little think before I go full surgical on the car. 

IMG20200606112151.jpg

Link to comment
https://www.sau.com.au/forums/topic/480560-underpowered/
Share on other sites
HP Junky Rookie

HP Junky

Posted
  • Author
Posted

OIt makes 15psi of boost on the graph that's the lower 2 lines. I'll check the cat it looks like it has a small one but could be missing as it's a dedicated track car.  Here's some pics. I'll check the cat when I lift it up to run new fuel line. Will let you know. Thanks.IMG20190112151146.thumb.jpg.d90a28f8453664d680799d62c6a7fc8f.jpg

IMG20190112151203.jpg

Link to comment
https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7932567
Share on other sites
GTofuS-T Grand Master

GTofuS-T

Posted
Posted
6 minutes ago, GTSBoy said:

No, the boost axis on the right clearly shows it making about 2 psi before the line disappears behind the legend. If it makes it as high as 5 psi on that chart I'd be very surprised.

confusing af... there's 5 lines on that graph, I gather the 2 that peak lower than the other 2 i.e. around 15psi on the boost axis are the boost lines? there's no torque for some even more confusing reason

Link to comment
https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7932589
Share on other sites
kowalatea Contributor

kowalatea

Posted
Posted

Not sure about 100kw drop but difference in altitude/temp in tuners shops as well as calibration of machines could play into it. Might add that they could of tamed the tune after getting rumbers for reliability in their work. Some food for thought 

Link to comment
https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7932591
Share on other sites
BK Grand Master

BK

Posted
Posted

I think you'll find that little green trace on the bottom is one of the boost traces that is still being recorded after the full throttle backoff at the end of the run. Both green lines drop straight down and it starts reverse tracing.

Drop the exhaust at front pipe and run it again. My 33R went from 330kw to about 200 with a blocked 4inch 200cpi magic cat. Front pipe only run shot straight back up over 340.

Link to comment
https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7932595
Share on other sites
HP Junky Rookie

HP Junky

Posted
  • Author
Posted

The green line at the bottom was from not ending power run before throttle was let off that's why it's there. Boost in the car is 15psi. I'm going to drop the exhaust tomorrow and have a look. Then move on with checking cooler piping, plenum manifold gasket and everything in the whole setup to see what the people before did or didn't do and just make sure everything is working correctly. Thanks for all the replies. 

Link to comment
https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7932608
Share on other sites
  • 2 weeks later...
HP Junky Rookie

HP Junky

Posted
  • Author
Posted

Pulled center section of the turbo to tail pipe 3" exhaust off no cat no restrictions in rear muffler. Pulled inlet plenum off to check gasket as it was very hard to tell if it was or wasn't sealing might have had a very small leak but don't think it's the problem. Going to pull turbo and manifold off next. Checked cooler and piping for leaks by pressure testing. Once exhaust side is off I will be doing a leak down test as it will be easier to hear leaks through each port. Will post out come of all tests and inspection. 

Link to comment
https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7933885
Share on other sites
BK Grand Master

BK

Posted
Posted

Did you actually run it up on the dyno with just the front pipe to verify ? Just because you looked inside and can see through it doesn't really mean anything, a blocked cat is not always visually obvious, or is there actually no cat converter ?

Link to comment
https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7933887
Share on other sites
HP Junky Rookie

HP Junky

Posted
  • Author
Posted

There is no cat at all in the system. Haven't had it back on the dyno yet. Pulled turbo and manifold off very very small exhaust leak on rear 2 cylinders but not enough to cause a problem. Turbo looks good. Removed plenum to replace gasket no leaks found but replacing gasket to be sure. When I get a chance I'll get it back on the dyno. 

Link to comment
https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7934012
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Latest Posts

    • soviet_merlin
      Most women will agree that parking is the most taxing part of driving

      By soviet_merlin · Posted

      I'd be worried about having to parallel park a boat like that. Magnificent car though.
    • 25zenki
      S1 rb25/s14 starting problem

      By 25zenki · Posted

      This car has run before on this z32 ecu can get the part number for you, I have tried with no AFM it didn’t change anything, I compression tested today 140-150 across all 6 cylinders, also set fuel pressure to 43psi. The only weird thing was cylinder 1 plug was black and fouled other 5 cylinders were just wet with fuel. Spun cas by hand and confirmed injectors are clicking 
    • MBS206
      new 1.5 LSD issues/concerns

      By MBS206 · Posted

      Since you came here to ask for help, have you thought about answering our questions, that might help us lead you to why it was skipping, or have you given up on getting advice?
    • GTSBoy
      new 1.5 LSD issues/concerns

      By GTSBoy · Posted

      A 1.5 way is a 2 way. It is just a 2 way with a less aggressive ramp on overrun.
    • GTSBoy
      Boost cut after swap(RB25DET NEO) R34

      By GTSBoy · Posted

      The ABS and/or TCS being missing/broken will not cause the engine to misbehave. It just casues CEL to come on and annoy you. The CEL is useless if it is always on, so you have to do the things you have to do to get rid of it, so it can be useful. Being a Stag ECU, then yes, it will not expect TCS to be present. But it will expect ABS to be present and working. You will need to either make the ABS CU talk to the ECU (don't ask me what that will take on an NA R34), and make sure the hardware is working....or, you just need to blank it out in Nistune. Do not persist with the stock ECU. You will just have problems. Gte it Nistuned. Start from there. DO YOU HAVE A BOOST SENSOR? The ECU's boost sensor that it. It is connected to the loom at the rear of the coil cover. Usually rides on the firewall on an R34, but is usually bolted down to a bracket along with all the other crap at the back of the coil cover when a Neo is dropped into another car. If you do not have it, the ECU will shit the bed. So, do you have one?
×
×
  • Create New...