Tricky-Ricky Posted October 11, 2015 Share Posted October 11, 2015 Enough airflow to run lean on 440cc injectors at the upper end of the RPM scale has to be 450hp+ though. It would all need to add up surely? Whats so odd about a pair of hybrid turbos being capable flowing enough air to make 450 +BHP, add the 264 cams, which will also allow more airflow. A decent BPU setup with std turbos can make 400BHP. Mine was making over 480BHP not even fully mapped when I was offered a single turbo setup at a price I couldn't refuse. Quote Link to comment Share on other sites More sharing options...
Scott Posted October 12, 2015 Share Posted October 12, 2015 Whats so odd about a pair of hybrid turbos being capable flowing enough air to make 450 +BHP, add the 264 cams, which will also allow more airflow. A decent BPU setup with std turbos can make 400BHP. Mine was making over 480BHP not even fully mapped when I was offered a single turbo setup at a price I couldn't refuse. On what dyno and at what boost? Remember we're talking 1.0bar here. I've seen 500hp on stock twins, I don't believe it for a second though. Quote Link to comment Share on other sites More sharing options...
David P Posted October 12, 2015 Share Posted October 12, 2015 Has the charcoal filter been removed and the tank vent left open? If so, the fuel system will be running at 2psi less. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted October 12, 2015 Share Posted October 12, 2015 (edited) On what dyno and at what boost? Remember we're talking 1.0bar here. I've seen 500hp on stock twins, I don't believe it for a second though. That question doesn't make sense! as we ARE talking 1.0bar! Unless your referring to the 400BHP on other peoples BPU supras, in which case I have seen a couple of graphs knocking around here in the past, backed up by the tuner, (until then I also would not believe that 400BHP was possible on stock twins, but I'm sure it was at 1.3-4bar though. You also seem to be hung up on boost pressure rather than air flow?? you can flow very different amounts of air at 1.0 bar depending on turbos and engine spec etc, and what has the 500bhp on stock twins comment got to do with anything? sorry cant remember that far back, don't even have the dyno plots, gave them to the new owner years ago. Edited October 12, 2015 by Tricky-Ricky (see edit history) Quote Link to comment Share on other sites More sharing options...
Scott Posted October 12, 2015 Share Posted October 12, 2015 You seem pretty hung up in thinking that I'm the one that's confused here, have you actually read what I'm writing? Just to make sure I'm not getting confused here. Are you telling me that you saw 480hp at 1.0bar with hybrid twins? If so then I straight up don't believe you, or anything else following on from that statement. I'll spell out the rest of my reasoning as my point is being lost here. The op had their car on the dyno at 1.0bar. A stock BPU car at 1.0bar will see around 360-380hp at the absolute most. Hybrid turbos, as my understanding goes, are good for 1.5bar (or thereabouts) hence why members with them see a bit more power than BPU cars. Lets say for argument that hybrid turbos are more efficient at 1.0bar and with the 264 cams there is more airflow being generated. The lean condition would only come about when there wasn't enough fuel to richen the mix below 12:1. With the stock fuel system, this is around 450hp. Ergo, the car would need to be making more than 450hp at 1.0bar on hybrid twins, which is completely totally and utterly unheard of. 1.3bar possibly, but not 1.0bar. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted October 12, 2015 Share Posted October 12, 2015 Your quite at liberty to believe what you like.. but my set up was not average. However your laboring under the wrong assumption that all hybrid turbos are the same! mine where certainly not your average hybrids with just a change of usually inducer size /shape, and sometimes exducer, so not all are the same spec, therefore can produce different airflow for any given boost pressure. Your also laboring under the assumption that the std 15 year old 440cc injectors are actually still flowing 440cc, a lot of people don't have them cleaned or replaced, I have seen quite a few injectors that never flowed anywhere near what they where supposed to. And your still ignoring air flow vs boost pressure issue, perhaps do a little research on the subject, and then perhaps you wont be so closed to the concept. While I am not averse to the fact that fuel flow is not as it should be IE pump/filter or injectors, and may be causing the lean condition, it doesn't alter the fact that its not flowing enough fuel for the airflow which was my point regardless of the cause. Quote Link to comment Share on other sites More sharing options...
mellonman Posted October 12, 2015 Share Posted October 12, 2015 You took the words out my mouth , this could be down to a bad injector as afr is as a combined value of all cylinders which could also be the reason for the knock Quote Link to comment Share on other sites More sharing options...
Scott Posted October 12, 2015 Share Posted October 12, 2015 While I am not averse to the fact that fuel flow is not as it should be IE pump/filter or injectors, and may be causing the lean condition, it doesn't alter the fact that its not flowing enough fuel for the airflow which was my point regardless of the cause. I totally agree with that, hence why I said I believe it was a fault rather than the setup being ridiculously efficient. Not enough fuel for the amount of airflow is the issue, I'd be looking at the low fuel rather than the high air flow though as I do not see how that setup at 1.0bar can produce more air than a working system can provide fuel for. Assuming the fueling was OK and running as it should, 440cc injectors with a walbro pump at 100% duty is good enough to provide enough fuel to mix with air for 450hp. Even more if you ran lean as hell (as in this case), it would be a bright star before burning out though. If the dyno showed the car to be producing 480hp at 1.0bar then the simple fact is that the turbo and cam combination is just too much for the system..... that's just not going to happen though. Quote Link to comment Share on other sites More sharing options...
supra_24 Posted October 14, 2015 Author Share Posted October 14, 2015 So a quick update on this guys. My garage contacted me today and they tested the fuel pump, filter, injectors and all checked out ok. They did however find that it was my Fuel cut defender causing the lean issue and knock. I purchased the unit back in July and had it fitted whilst at Whifbitz. It was a Chris Wilson FCD. Car ran on dyno fine after removal of FCD and made decent power too on low boost Obviously it did hit fuel cut as well, but cured the intial problem. Not sure if its just gone faulty or whether it just needs re-adjusting. If it has gone, can you guys suggest a replacement fuel cut defender? Quote Link to comment Share on other sites More sharing options...
mellonman Posted October 14, 2015 Share Posted October 14, 2015 Contact chris , If it is bad it must be clamping the voltage to low and injectors might not go 100% duty, On my fic a clamp of 4v and a clamp of 4.2v sees different injector duty Quote Link to comment Share on other sites More sharing options...
Scott Posted October 14, 2015 Share Posted October 14, 2015 That explains things perfectly May need a more bespoke unit given that you have hybrids though. Hopefully not. Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted October 14, 2015 Share Posted October 14, 2015 So a quick update on this guys. My garage contacted me today and they tested the fuel pump, filter, injectors and all checked out ok. They did however find that it was my Fuel cut defender causing the lean issue and knock. I purchased the unit back in July and had it fitted whilst at Whifbitz. It was a Chris Wilson FCD. Car ran on dyno fine after removal of FCD and made decent power too on low boost Obviously it did hit fuel cut as well, but cured the intial problem. Not sure if its just gone faulty or whether it just needs re-adjusting. If it has gone, can you guys suggest a replacement fuel cut defender? Thats what I told them to check first, we normally supply and fit the HKS FCD, we've never had any problems with these. Quote Link to comment Share on other sites More sharing options...
adnanshah247 Posted October 14, 2015 Share Posted October 14, 2015 time for change of ecu buddy and honestly get some bigger injectors in, better to be safe than sorry. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted October 14, 2015 Share Posted October 14, 2015 Personally I would be looking at fitting a stand alone ECU or at least a decent piggyback with your particular spec rather than fitting another FCD and hoping for the best, some bigger injectors too. Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted October 14, 2015 Share Posted October 14, 2015 I just read all this and i am impressed with the knowledge that Scott and Tricky have, IMHO they are a great asset to this club. They have helped me a great deal, and i appreciate it, they must be approaching the "Chris Wilson" status, who i know personally and he is a supra god. herbiemercman. Quote Link to comment Share on other sites More sharing options...
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