addi Posted July 19, 2004 Share Posted July 19, 2004 ok .. quick scenario, i have a 94 l reg supra tt j spec with full decat running 380 bhp @ 1.1 bar with an greddy electronic boost controller the engine has blown so the car was trailered to grass hopper pro sport for sorting out, it it needs a rebuild and has two cracked pistons. i am told the reason this has happened is due to spiking because of the full decat and i MUST replace the first cat. i am lothe to do this as the decat was done to aid performance, is this correct and can anything else be done to solve the problem i am having? any help appreciated addi Quote Link to comment Share on other sites More sharing options...
ChrisB Posted July 19, 2004 Share Posted July 19, 2004 you need a restrictor ring from somone called chris wilson on here do a search for restrictor ring and youll find loads of info Quote Link to comment Share on other sites More sharing options...
Suprash Posted July 20, 2004 Share Posted July 20, 2004 Originally posted by addi ok .. quick scenario, i have a 94 l reg supra tt j spec with full decat running 380 bhp @ 1.1 bar with an greddy electronic boost controller the engine has blown so the car was trailered to grass hopper pro sport for sorting out, it it needs a rebuild and has two cracked pistons. i am told the reason this has happened is due to spiking because of the full decat and i MUST replace the first cat. i am lothe to do this as the decat was done to aid performance, is this correct and can anything else be done to solve the problem i am having? any help appreciated addi Mate, Im really gutted to hear of this news, but the fact is a £20 restrictor ring would have stopped this as soon as you went decat......... Quote Link to comment Share on other sites More sharing options...
addi Posted July 22, 2004 Author Share Posted July 22, 2004 any 1 got a first cat pipe kickin about they wana sell for a 94 j spec?? Quote Link to comment Share on other sites More sharing options...
Kitt Posted July 23, 2004 Share Posted July 23, 2004 I am going for a full de-CAT on a NA - I assume I won't need a restrictor ring or anything along these lines to prevent any damage to my baby ??? Quote Link to comment Share on other sites More sharing options...
Nic Posted July 23, 2004 Share Posted July 23, 2004 Kitt, no you don't need a restrictor ring for you NA. Fitting a free-flowing performance exhaust to a TT can cause high boost pressure, so a restrictor ring is fitted to reduce the boost to a safe limit. Quote Link to comment Share on other sites More sharing options...
Justin Posted July 23, 2004 Share Posted July 23, 2004 Originally posted by addi any 1 got a first cat pipe kickin about they wana sell for a 94 j spec?? I've got one in the shed but I don't think this is the answer. I've been full decat for 2/3 years running at 1.2 and above If the engine blew at 1.1 it's not just the boost pressure that did it. Like SimonB says if you want to reduce boost fit a restrictor plate for under £20. Quote Link to comment Share on other sites More sharing options...
Suprash Posted July 25, 2004 Share Posted July 25, 2004 Originally posted by Justin Like SimonB says Im confused..... He hasnt replied in this thread EDITED: Penny dropped, you meant ChrisB..... Quote Link to comment Share on other sites More sharing options...
richy2jz-gte Posted July 25, 2004 Share Posted July 25, 2004 are you sure it was runnin 1.1bar and your guage is not faulty cus what ive read on this site a decated j-spec always seem to run about 1.3 bar wich i guess is to much for the j-spec fuel system and would cause detonation and would end up in engine failure. sorry to hear about it though...... Quote Link to comment Share on other sites More sharing options...
Nic Posted July 25, 2004 Share Posted July 25, 2004 Not all j-spec's will run 1.3bar when decatted, it depends on the exhaust fitted and how free flowing it is. Mine only boosts to 1.05bar with decatted ARC titanium exhaust with the boost controller turned off. Quote Link to comment Share on other sites More sharing options...
addi Posted July 25, 2004 Author Share Posted July 25, 2004 the boost controller was holding the boost at 1.1, i doubt it is a faulty gauge because the boostcontroler readout was the same, so is a restrictor ring a try it and see type of thing or are there just off teh shelf sizes to hold certain boost? Quote Link to comment Share on other sites More sharing options...
Alex Posted July 25, 2004 Share Posted July 25, 2004 You tell Chris what boost you want to run and he'll send you a restrictor plate with the correct sized whole in it. FWIW it's not the boost as such that blew your engine it's that there isn't enough fuel going in to cope with uprated boost. Your engine has suffered from detonation. I would check the condition of your fuel pump and replace it with a higher spec model. Also, boost controllers can only raise boost pressure they can't hold it down/lower it. (Boost Controller is really the wrong term). Even if your unit was set to 1.1bar the boost could have gone higher. Quote Link to comment Share on other sites More sharing options...
green_dragon Posted July 27, 2004 Share Posted July 27, 2004 I know it's not the same subject, but after a full de-cat does it fail an MOT ? Cos I got fed up of replacing the cat every year on my last car and don't want to go through it all again. Quote Link to comment Share on other sites More sharing options...
SimonB Posted July 27, 2004 Share Posted July 27, 2004 Originally posted by Ashley Willis Im confused..... He hasnt replied in this thread EDITED: Penny dropped, you meant ChrisB..... LOL! Have I achieved grand mastery of the BBS by being able to post without actually posting? Do not try to post a reply, for that is impossible. Instead realise the truth - there is no post... Quote Link to comment Share on other sites More sharing options...
Suprash Posted July 28, 2004 Share Posted July 28, 2004 Originally posted by SimonB LOL! Have I achieved grand mastery of the BBS by being able to post without actually posting? Do not try to post a reply, for that is impossible. Instead realise the truth - there is no post... Shut up Neo, go loose yourself in the Matrix Quote Link to comment Share on other sites More sharing options...
toyotasuprauk Posted July 28, 2004 Share Posted July 28, 2004 Originally posted by green_dragon I know it's not the same subject, but after a full de-cat does it fail an MOT ? Cos I got fed up of replacing the cat every year on my last car and don't want to go through it all again. Yes it fails the MOT and its illegal to remove both your cats. Not that anyone cares;) , except some big exhaust companies that wont remove them due to legal reasons. Quote Link to comment Share on other sites More sharing options...
Darren Posted July 28, 2004 Share Posted July 28, 2004 Where you seeing spiking on your boost gauge or controller?? Quote Link to comment Share on other sites More sharing options...
green_dragon Posted July 28, 2004 Share Posted July 28, 2004 Originally posted by toyotasuprauk Yes it fails the MOT and its illegal to remove both your cats. Not that anyone cares;) , except some big exhaust companies that wont remove them due to legal reasons. Thanks for that, I wont bother then! Quote Link to comment Share on other sites More sharing options...
toyotasuprauk Posted July 29, 2004 Share Posted July 29, 2004 You could remove one cat and it would still pass the MOT. Quote Link to comment Share on other sites More sharing options...
green_dragon Posted July 29, 2004 Share Posted July 29, 2004 Nice one! Cheers mate. Quote Link to comment Share on other sites More sharing options...
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