HP Junky Posted June 7, 2020 Share Posted June 7, 2020 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. Link to comment https://www.sau.com.au/forums/topic/480560-underpowered/ Share on other sites More sharing options...
GTSBoy Posted June 7, 2020 Share Posted June 7, 2020 (edited) No boost. (look at the chart). Edited June 7, 2020 by GTSBoy Link to comment https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7932541 Share on other sites More sharing options...
Duncan Posted June 7, 2020 Share Posted June 7, 2020 yeahbut. and rb25 with no boost will make about 100rwkw not 205. 1 Link to comment https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7932543 Share on other sites More sharing options...
BK Posted June 8, 2020 Share Posted June 8, 2020 Blocked cat, check it first. 1 Link to comment https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7932564 Share on other sites More sharing options...
HP Junky Posted June 8, 2020 Author Share Posted June 8, 2020 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. Link to comment https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7932567 Share on other sites More sharing options...
GTSBoy Posted June 8, 2020 Share Posted June 8, 2020 1 hour ago, HP Junky said: OIt makes 15psi of boost on the graph that's the lower 2 lines. 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. Link to comment https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7932585 Share on other sites More sharing options...
GTofuS-T Posted June 8, 2020 Share Posted June 8, 2020 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 More sharing options...
kowalatea Posted June 8, 2020 Share Posted June 8, 2020 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 More sharing options...
KiwiRS4T Posted June 8, 2020 Share Posted June 8, 2020 I see only one boost line which barely gets off the ground. What is the boost gauge in the car saying? the original 300+kw sounds right for the turbo. Have you checked for boost leaks? Link to comment https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7932593 Share on other sites More sharing options...
BK Posted June 8, 2020 Share Posted June 8, 2020 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 More sharing options...
HP Junky Posted June 8, 2020 Author Share Posted June 8, 2020 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 More sharing options...
BK Posted June 8, 2020 Share Posted June 8, 2020 That's what I thought. Check it out and let us know the result dude. Link to comment https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7932613 Share on other sites More sharing options...
tridentt150v Posted June 10, 2020 Share Posted June 10, 2020 Could it also be a wastegate issue? Stuck wide open? Link to comment https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7932739 Share on other sites More sharing options...
HP Junky Posted June 18, 2020 Author Share Posted June 18, 2020 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 More sharing options...
BK Posted June 18, 2020 Share Posted June 18, 2020 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 More sharing options...
HP Junky Posted June 19, 2020 Author Share Posted June 19, 2020 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 More sharing options...
HP Junky Posted June 23, 2020 Author Share Posted June 23, 2020 Well after pulling plenum, turbo and exhaust manifold I finally found the problem. See if you notice it. 1 1 Link to comment https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7934410 Share on other sites More sharing options...
admS15 Posted June 23, 2020 Share Posted June 23, 2020 That looks like it's eaten something. Must've been hungry. Link to comment https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7934411 Share on other sites More sharing options...
PranK Posted June 23, 2020 Share Posted June 23, 2020 2 hours ago, admS15 said: That looks like it's eaten something. Must've been hungry. Or something ate it! Link to comment https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7934415 Share on other sites More sharing options...
GTSBoy Posted June 23, 2020 Share Posted June 23, 2020 Well, there was definitely something wrong with it! Link to comment https://www.sau.com.au/forums/topic/480560-underpowered/#findComment-7934416 Share on other sites More sharing options...
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