Rummy Posted August 14, 2014 Share Posted August 14, 2014 (edited) Hi all Full decat, single, jspec I've just changed my TRD cat-back for a HKS Silent Hi power exhaust and now suffering from overboost up to 1.67bar. When I stripped out the TRD there was no sign of a RR from cat-back and have now stripped the whole system and still no RR so I want to put one in. IIRC it needs to go close to the turbo as in 1st decat, but my problem is I have a custom 3" downpipe with a section of Flexi-hose at the end. My question is : Will placing the RR here be detrimental to the integrity of the Flexi-hose with the added resistance/back pressure or should/can I place the RR further down to 2nd decat and still be efficient? Just to add, there' s no leaks, wastegate or otherwise. TIA Mike Edited August 16, 2014 by Rummy (see edit history) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 14, 2014 Share Posted August 14, 2014 A single turbo installation should not need a restrictor ring if the wastegate is adequately sized, and the wastegate port on the manifold sensibly orientated and sized. Quote Link to comment Share on other sites More sharing options...
Rummy Posted August 14, 2014 Author Share Posted August 14, 2014 Hmmm that's not what I wanted to hear. It was all working fine prior to the exhaust change. Suggestions where to go from here apart from put old exhaust back on? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 14, 2014 Share Posted August 14, 2014 I think you just have to accept removing restriction and possibly resonance damping chambers (cats)from an exhaust inevitably changes the exhaust note. As has been said, wrapping the flexi pipe section with something akin to ma home made turbo blanket may help. I sold dozens of similar N/A first de cat pipes and no one ever mentioned this, although, for sure, they did change the tone of the exhaust. Quote Link to comment Share on other sites More sharing options...
Rummy Posted August 14, 2014 Author Share Posted August 14, 2014 I think you just have to accept removing restriction and possibly resonance damping chambers (cats)from an exhaust inevitably changes the exhaust note. As has been said, wrapping the flexi pipe section with something akin to ma home made turbo blanket may help. I sold dozens of similar N/A first de cat pipes and no one ever mentioned this, although, for sure, they did change the tone of the exhaust. Sorry Chris, you've lost me completely here Was this meant for this thread I had no boost problems with the TRD exhaust, just since fitting the HKS cat-back. I guess the HKS is more free flowing than the TRD but didn't think it would cause massive overboost. Sadly I'm running an XS power mani and WG and can't afford to shell out on a new twin WG and mani yet, So will it do any harm to fit a RR on a single or is it a no-no? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 14, 2014 Share Posted August 14, 2014 Oops, that last reply of mine was meant to go into a different thread, not sure how I managed that, sorry, ignore it Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 14, 2014 Share Posted August 14, 2014 You can use a RR, for sure, but it would be much better and less stressful, EGT wise, to see why the wastegate isn't flowing enough. You certainly shouldn't need two wastegates. I have seen several Chinese manifolds where there was a lot of weld excess blocking ports for wastegates, is that the case with yours? If so get somewhat with an air die grider and a decent burr to clean it up. It could be that the WG isn't opening enough, is plain poor design, or the manifold to WG port is not in a good position, only hands on would tell me. Do others with this set up have this problem? Quote Link to comment Share on other sites More sharing options...
makri Posted August 16, 2014 Share Posted August 16, 2014 What kind of wastegate are you running? Screamer pipe? Sounds to me like a WG related problem Quote Link to comment Share on other sites More sharing options...
Rummy Posted August 16, 2014 Author Share Posted August 16, 2014 You can use a RR, for sure, but it would be much better and less stressful, EGT wise, to see why the wastegate isn't flowing enough. You certainly shouldn't need two wastegates. I have seen several Chinese manifolds where there was a lot of weld excess blocking ports for wastegates, is that the case with yours? If so get somewhat with an air die grider and a decent burr to clean it up. It could be that the WG isn't opening enough, is plain poor design, or the manifold to WG port is not in a good position, only hands on would tell me. Do others with this set up have this problem? What kind of wastegate are you running? Screamer pipe? Sounds to me like a WG related problem XS Power 50mm WG with 45mm screamer. UPDATE I stripped and cleaned the WG, (PITA without taking mani off!) diaphragm and valve are fine with free movement. Replaced all the turbo vac hoses and decided not to use the RR. Test drove and now boosting to the programmed 1.2bar Cheers for the help Quote Link to comment Share on other sites More sharing options...
makri Posted August 16, 2014 Share Posted August 16, 2014 XS Power 50mm WG with 45mm screamer. UPDATE I stripped and cleaned the WG, (PITA without taking mani off!) diaphragm and valve are fine with free movement. Replaced all the turbo vac hoses and decided not to use the RR. Test drove and now boosting to the programmed 1.2bar Cheers for the help Grate, good you figured it out Quote Link to comment Share on other sites More sharing options...
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