philsmith1a Posted July 11, 2010 Share Posted July 11, 2010 My supra will be bpu in a couple of weeks and I was wondering if it will backfire? It is a j-spec tt auto with a 3“ with RR. All the cars I have had before with no cats have popped and banged on the overrun, I know the auto box won’t overrun on D but in theory it should in manual mode. Please enlighten me. Quote Link to comment Share on other sites More sharing options...
Axle Posted July 11, 2010 Share Posted July 11, 2010 Please enlighten me. http://www.biocrawler.com/w/images/thumb/4/43/300px-Chav.jpg Quote Link to comment Share on other sites More sharing options...
Guest Supra-T Posted July 11, 2010 Share Posted July 11, 2010 You need NOS and wolf race 26" rims init! Quote Link to comment Share on other sites More sharing options...
ellis Posted July 11, 2010 Share Posted July 11, 2010 Oh dear. Oh deary, deary me. You've brought this upon yourself now! Quote Link to comment Share on other sites More sharing options...
The Raven Posted July 11, 2010 Share Posted July 11, 2010 If you a buy a total dog of a car and loosen your heat shield it might help. Quote Link to comment Share on other sites More sharing options...
Shane Posted July 11, 2010 Share Posted July 11, 2010 Hang on guys, I don't think he is saying he wants it to pop and bang, he just wants to know will it. However if he does want it to, then please carry on;) Quote Link to comment Share on other sites More sharing options...
Geo Posted July 11, 2010 Share Posted July 11, 2010 Hi mate, try and Explain your explanation a little better please. Are you wanting your car to pop and bang?? or are you curoius to know if it will pop and bang? Guys please try and not rub up the Noobs. Im starting to see alot of this, we all have to start somewhere? A little guidance is always good. Quote Link to comment Share on other sites More sharing options...
Shane Posted July 11, 2010 Share Posted July 11, 2010 Hi mate, try and Explain your explanation a little better please. Are you wanting your car to pop and bang?? or are you curoius to know if it will pop and bang? Guys please try and not rub up the Noobs. Im starting to see alot of this, we all have to start somewhere? A little guidance is always good. I agree. What I can tell you Phil, is that I have only just BPUed mine and so far from the "pop and bang" point of view it doesnt. Mines an auto too. I would have thought most cars with electronically controlled fuelling cut fuel on the overun so this is something you wouldnt get. Quote Link to comment Share on other sites More sharing options...
Branners Posted July 11, 2010 Share Posted July 11, 2010 If he wants it to pop and bang then thats his call. There are people with aftermarket ECUs that specifically have this mapped in so its a personal taste thing. Quote Link to comment Share on other sites More sharing options...
hadyn Posted July 11, 2010 Share Posted July 11, 2010 It wont pop and bang or flame regularly due to the map sensor on Supras. The ECU doesnt massively overfuel on gearchanges like cars with maf sensors even with a vent to atmosphere BOV. I asked this question many many years ago when I first bought a Supra and nobody slated me then. Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 11, 2010 Share Posted July 11, 2010 The popping and banging happens on overrun (or 'coast down' as you might know it) due to unburnt fuel igniting in the hot exhaust manifolds. This is avoided by the ECU by cutting the fuel injectors when the throttle is closed and the revs are above about 2500rpm. This is done for economy and emissions reasons, and also to protect the CATs as they do dislike this (temperatures or something, can't recall exactly). You can really go to town by deliberately overfuelling and retarding the ignition timing a lot if you want, that'll give you spectacular explosions and even flame out the exhaust, I personally consider that going a bit too far, but the "burble with occasional blat" symphony you get with a normal overrun actually sounds quite nice to my ears You can trigger this by keeping the throttle open everso slightly as you coast down, as this keeps the throttle position sensor off the "closed" switch, thus stopping the ECU from cutting the injectors. Takes a bit of practice but sounds great If the guy had come on here asking about flamer kits then yeah, descend away, but come on people - the question was ambiguous for a start, he might have been checking as he didn't want it to happen. And the overrun burble is a nice noise in my overinflated opinion as well, so it's still a valid question Save your ire for those who deserve it... Quote Link to comment Share on other sites More sharing options...
hadyn Posted July 11, 2010 Share Posted July 11, 2010 Save your ire for those who deserve it... Indeed Quote Link to comment Share on other sites More sharing options...
Ewen Posted July 11, 2010 Share Posted July 11, 2010 .....but the "burble with occasional blat" symphony you get with a normal overrun actually sounds quite nice to my ears You can trigger this by keeping the throttle open everso slightly as you coast down, as this keeps the throttle position sensor off the "closed" switch, thus stopping the ECU from cutting the injectors. Takes a bit of practice but sounds great Its quite easy to get this gorgeous 'burble with occasional blat' with the Tiptronic in manual mode. Guilty as charged...many a Dorset village with a slight hill has suffered since my Bpu. Not so obvious in auto mode. Quote Link to comment Share on other sites More sharing options...
Ian W Posted July 11, 2010 Share Posted July 11, 2010 Guys please try and not rub up the boobs Easier said than done. Quote Link to comment Share on other sites More sharing options...
Geo Posted July 11, 2010 Share Posted July 11, 2010 Easier said than done. :eyebrows: Quote Link to comment Share on other sites More sharing options...
Lude Posted July 11, 2010 Share Posted July 11, 2010 if you want it to do that, get a Bee*R rev limiter Quote Link to comment Share on other sites More sharing options...
Darragh Posted July 11, 2010 Share Posted July 11, 2010 Ian c hit the nail on the head don't do what I done and fit a bee r rev limiter it murdered my engine turbos and everything else around it lol Quote Link to comment Share on other sites More sharing options...
little num Posted July 11, 2010 Share Posted July 11, 2010 yeh ive always heard that it kills the turbo, not a good thing to add to your car. Quote Link to comment Share on other sites More sharing options...
philsmith1a Posted July 11, 2010 Author Share Posted July 11, 2010 ooo did I hit a nerve there?! Get your talons out! Cheers for the legitimate responses. Yeah, I simply wanted to know if it would hence the ‘?’ Quote Link to comment Share on other sites More sharing options...
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