Jump to content
SAU Community

Recommended Posts

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

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

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

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

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

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...

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

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

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


  • Latest Posts

    • did you go to the us gtr festival? any progress on getting the car back out and running?
    • I had some time over the last week  and decided to test if block filler will hold the blocks shape similar to a torque plate after the head has been removed. 1, 3 and 5 were measured at 9 points each before and after. MY goal was to see how much impact a torque plate has on the shape of the bore. The first set of measurements were taken with the main girdle and head off with no filler. The block was then filled with grout up to the water pump (half fill) and the girdle and head were torqued to spec. The block sat leveled for 7 days and was disassembled. The second set of measurements were then taken. Results are presented as the delta between the original and new value. All values in the PowerPoint are presented in inches because America. The largest changes were 0.0035 in or 0.0889 mm between cylinders 3 and 5. There may have been even greater changes if the block was filled to the top with grout. I hope this information is useful and I'm curious to hear what you guys think.       Notes: My block had the most wear in cylinders 3 and 4. Due to the amount of change in 3, I measured 2, 4 and 6 separately. 4 was also all over the place. 6 was similar to 1. They were not included to keep the test objective.    
    • I also find it hilarious, everyone thinks chop idle tunes sound cool, and they do... Because they sound like an angry rotary engine idling.
×
×
  • Create New...