Chucky_waR Posted October 9, 2011 Share Posted October 9, 2011 Hi folks, I need some advice pls. I have a MKIV single T78 33d Turbo running at 650 bhp (gearbox) with 650cc PE Racing Fuel Injectors. I have been told that I'm running full capacity on my injectors and have reached the maximum I will get out of them. I have it turned down and mostly running 450 horses but do switch to 650 horses on occasions. Am I at risk of my injectors failing and do I need to consider upgrading to 850cc or 1000cc injectors? Thanks for looking.. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted October 9, 2011 Share Posted October 9, 2011 Definately better to upgrade to larger injectors, for a bit of safety. Whats your fuel system like? General rule of thumb for JZs is roughly 1hp per cc injector size. If you go to 800cc or more you'll have a bit of duty cycle in reserve. Quote Link to comment Share on other sites More sharing options...
Chucky_waR Posted October 9, 2011 Author Share Posted October 9, 2011 It has a Sard fuel pressure regulator and Twin racing high flow fuel pumps (mounted in tank). I'm not planing to uprate BHP in near future and not always on 650 BHP. I will def upgrade the injectors next year but will I be ok for now or am I at serious risk of failure? 650 BHP on 650cc injectors = 100%.. guess that answers my question working on rule of thumb 1hp = 1cc.. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted October 9, 2011 Share Posted October 9, 2011 Fuel pressure plays a part as well, if you crank that up you can squeeze more fuel out. Id certainly avoid runnig them at max duty for too long mate Quote Link to comment Share on other sites More sharing options...
Scott Posted October 9, 2011 Share Posted October 9, 2011 When I was looking I had the idea in my head of 100cc more than the HP I wanted to run. For 650 I would be looking for 750cc plus. Is 650 your end goal? If it is then I would just get some bigger injectors to be safe rather than sorry. If you are planning to run more power in the future then I would accommodate for that. Quote Link to comment Share on other sites More sharing options...
dude Posted October 9, 2011 Share Posted October 9, 2011 When I was looking I had the idea in my head of 100cc more than the HP I wanted to run. For 650 I would be looking for 750cc plus. Is 650 your end goal? If it is then I would just get some bigger injectors to be safe rather than sorry. If you are planning to run more power in the future then I would accommodate for that. Pretty much spot on Scott, I always say 1cc per hp less 10% for safety. What ecu are you running, the logs should tell you what duty cycle the inj are running at. Quote Link to comment Share on other sites More sharing options...
Chucky_waR Posted October 9, 2011 Author Share Posted October 9, 2011 I'm not sure about the ecu but will ask the previous owner. I've only had her for two weeks. Will def avoid running 650hp until I have upgraded the injectors. Quote Link to comment Share on other sites More sharing options...
letmeshowyou Posted October 9, 2011 Share Posted October 9, 2011 I'd definitely try and steer clear of 100% duty cycle on the injectors. It's not great for injector reliability. Quote Link to comment Share on other sites More sharing options...
dude Posted October 9, 2011 Share Posted October 9, 2011 I'm not sure about the ecu but will ask the previous owner. I've only had her for two weeks. Will def avoid running 650hp until I have upgraded the injectors. You bought a 650 hp car without knowing what ecu it has !!!! brave man Quote Link to comment Share on other sites More sharing options...
Scott Posted October 9, 2011 Share Posted October 9, 2011 So is it possibly a "650HP" car then? Quote Link to comment Share on other sites More sharing options...
Chucky_waR Posted October 9, 2011 Author Share Posted October 9, 2011 Lol.. He most probably did say but the supra has scared me to memory loss.. I have a full dyno pack from Thor race engineering and dynamics SPC Horsham. Mapping> AEM FIC done earlier this year. I'm going through the specs now.. Quote Link to comment Share on other sites More sharing options...
JamieP Posted October 9, 2011 Share Posted October 9, 2011 If its on an AEM FIC you will need to upgrade the ECU if you plan on fitting bigger injectors. Quote Link to comment Share on other sites More sharing options...
Chucky_waR Posted October 9, 2011 Author Share Posted October 9, 2011 Seems I need to look into this in more detail as it's my first supra. I will def look into upgrading the ecu and injectors asap. Thanks for the advise folks.. Quote Link to comment Share on other sites More sharing options...
Chucky_waR Posted October 9, 2011 Author Share Posted October 9, 2011 Would i need to buy a whole new ECU or remap the current? any suggestions on a good ecu if I need to replace the existing? I had a look under the passenger dash but it looks like a standard black box. Quote Link to comment Share on other sites More sharing options...
dude Posted October 9, 2011 Share Posted October 9, 2011 Would i need to buy a whole new ECU or remap the current? any suggestions on a good ecu if I need to replace the existing? I had a look under the passenger dash but it looks like a standard black box. It depends on your budget, I would say the ECU is the most important part of the conversion, if you go standalone the only one to go for at the moment is the Syvecs. PM me your reg or name of guy who owned the car and I'll look up your Dyno runs. Quote Link to comment Share on other sites More sharing options...
JamieP Posted October 9, 2011 Share Posted October 9, 2011 Would i need to buy a whole new ECU or remap the current? any suggestions on a good ecu if I need to replace the existing? I had a look under the passenger dash but it looks like a standard black box. Yeah, the ecu you have at present wont control the larger injectors you want, id advise a syvecs ecu. Quote Link to comment Share on other sites More sharing options...
Chucky_waR Posted October 9, 2011 Author Share Posted October 9, 2011 Coolio Dude.. Just sent you the info.. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted October 9, 2011 Share Posted October 9, 2011 As above, the FI/C will only control up to 650cc Quote Link to comment Share on other sites More sharing options...
Scott Posted October 9, 2011 Share Posted October 9, 2011 Get it on a rolling road and pull the boost back till the injectors are putting out about 85-90%... job done. You will still be seing ITRO 600hp. That way it will be minimal cost and you will still have an animal of a car Quote Link to comment Share on other sites More sharing options...
Chucky_waR Posted October 9, 2011 Author Share Posted October 9, 2011 Thanks Scott, this sounds like a definite must do till I can get the ecu and injectors replacement.. I will do it this coming week as I'm off work for two weeks.. compulsory 10 days.. Quote Link to comment Share on other sites More sharing options...
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