osso Posted June 22, 2004 Share Posted June 22, 2004 I am beginning to notice that there is a loss of power at around 5,000 rpm.. I remember when i went to Thor back in March 2004, there was a dip in the boost curve at 5,000rpm as well but due to the problems i was having back then i never really noticed it as much. Does anyone have a clue what the problem could be? I have since upgraded the Fuel pump to a Walbro pump and now have an FSE regulator and i've also upgraded the spark plugs. I've attached the plot of the power curve here... Link to comment Share on other sites More sharing options...
osso Posted June 22, 2004 Author Share Posted June 22, 2004 and here's the attached boost curve.. Link to comment Share on other sites More sharing options...
Spardz Posted June 22, 2004 Share Posted June 22, 2004 are you running stock turbos?, looks like an issue with no 2, maybe the butterfly valve isnt opening properly allowing it to spool up properly. I had the opposite issue where it was bent open and no 2 overboosted and blew itself up lol. Then again this might be complete nonsense....acknowlege at your own risk Link to comment Share on other sites More sharing options...
richy2jz-gte Posted June 22, 2004 Share Posted June 22, 2004 i have a bit of a dead spot at 5k but (stock uk) boost is stable. think it just cus my intercoolers rotten as it only does it when its hot. Link to comment Share on other sites More sharing options...
Jake Posted June 22, 2004 Share Posted June 22, 2004 Originally posted by osso I am beginning to notice that there is a loss of power at around 5,000 rpm.. I've attached the plot of the power curve here... 253 HP Din ! Mate there's something very wrong there. My Std TT (apart from decat) makes 350.5 on the Thor Dyno. I believe Millhouse's completely standard TT made 303 Link to comment Share on other sites More sharing options...
osso Posted June 22, 2004 Author Share Posted June 22, 2004 Its probably best to ignore the power output and look at why the dip in the curve is occuring at 5000 rpm. Dude has done some work on the car since, and it does seem to be pulling better than it was when it was dyno'd. Link to comment Share on other sites More sharing options...
dude Posted June 22, 2004 Share Posted June 22, 2004 Originally posted by osso Its probably best to ignore the power output and look at why the dip in the curve is occuring at 5000 rpm. Dude has done some work on the car since, and it does seem to be pulling better than it was when it was dyno'd. This is easily solved with a single kit , James you need another go in the car with its big Turbo , now it pulls harder than ever Dude:flame Dev Link to comment Share on other sites More sharing options...
osso Posted June 22, 2004 Author Share Posted June 22, 2004 Originally posted by dude This is easily solved with a single kit , James you need another go in the car with its big Turbo , now it pulls harder than ever Dude:flame Dev I'll take you up on the offer tho! There's too much work needed before my car can go single at the moment obviously, as the car is completely standard a part from some minor things.. I'll need a FMIC, uprated clutch, upgrade jspec brakes, and upgrade fuel rail + injectors, before i can consider even going single.. have i missed anything? Link to comment Share on other sites More sharing options...
Mad Ad Posted June 22, 2004 Share Posted June 22, 2004 A turbo?! I believe the Greddy T88 is quite big? Link to comment Share on other sites More sharing options...
osso Posted June 22, 2004 Author Share Posted June 22, 2004 Link to comment Share on other sites More sharing options...
Matt Harwood Posted June 23, 2004 Share Posted June 23, 2004 Originally posted by osso I'll need a FMIC, uprated clutch, upgrade jspec brakes, and upgrade fuel rail + injectors, before i can consider even going single.. have i missed anything? If you go for a small single, you'll only need to upgrade your injectors to UK 550's, and fit an AFC, or E-manage to adjust the fuelling.... It will still give you a substantial power increase, better reliability, more fun, and you can upgrade other bits as a when you get the time/money The brakes would be a good start, but a decent set of pads would be a good/cheap starting point. Not that I'm trying to tempt you or anything! Link to comment Share on other sites More sharing options...
osso Posted June 23, 2004 Author Share Posted June 23, 2004 Not that I'm trying to tempt you or anything! If i was to go single, i'd get something like Dude's setup, but i dont want to spend a another penny on mods until i get my current problems ironed out.. So moving back to the original topic What could be causing the lost of power at 5,000 RPM? I am running on stock turbo's, and stock exhaust system with 2 catalyst still in there.. Link to comment Share on other sites More sharing options...
osso Posted June 23, 2004 Author Share Posted June 23, 2004 Could it be possible that the pressure line which drives the IACV Actuator and the EGCV Actuator isnt holding enough pressure to keep both actuators open throughout the revs? due to a faulty VSV valve or dodgy pressure tank, or a crack in one of the small vacume pipes in the main pressure line? if the EGCV and IACV actuators were fluctuating could this cause dips in the boost curve? Or could this problem be an issue with the second turbo? Link to comment Share on other sites More sharing options...
Supraguy Posted June 23, 2004 Share Posted June 23, 2004 Back on track from everyone and their brother trying to sell you something... Do you have your graph for your AFR readings? Curious to see if you have a weak spot in your fuel map thats causing over / under fuelling and making you lose the power. Link to comment Share on other sites More sharing options...
osso Posted June 23, 2004 Author Share Posted June 23, 2004 you noticed that too? I do have the graph for the AFR readings some where, and at the time it was running very rich at a ARF of around 10.5 or 11.. over 4,000 rpm. But this dyno was taken around 3 months ago, I have since got a Walbro pump, FSE and Denso Iridium IK22's installed.. so i have no idea if the car is still running rich, if it is still running rich, what else can i do? are coil packs servicable items? do they need placing after so many miles or years? my car is 7 years old now and i bet its got the original coil packs in there.. But for now i am assuming that i dont have an issue with the ignition system.. Link to comment Share on other sites More sharing options...
Ian C Posted June 23, 2004 Share Posted June 23, 2004 Originally posted by osso you noticed that too? I do have the graph for the AFR readings some where, and at the time it was running very lean at a ARF of around 10.5 or 11.. over 4,000 rpm. That's not lean, that's rich. Anything under 11.7:1 AFR i.e. 10.5:1, is running over-rich and you will start to lose power. Anything over 12.5AFR and it's starting to run lean and you'll gain power until your engine goes pop. That's why some cars give a huge power hike at 1.3bar of boost. Briefly. But this dyno was taken around 3 months ago, I have since got a Walbro pump, FSE and Denso Iridium IK22's installed.. so i have no idea if the car is still running lean, if it is still running lean, what else can i do? are coil packs servicable items? do they need placing after so many miles or years? my car is 7 years old now and i bet its got the original coil packs in there.. But for now i am assuming that i dont have an issue with the ignition system.. Sparks are nothing to do with running rich or lean. If you are blowing the spark out or they are running too hot to spark, you'll notice as the engine misfires, trust me you can't miss that symptom. You need another AFR check on a rolling road to see if it's running rich or lean. If it's too rich you need an airflow adjustment box like the Apexi AFC or the Greddy E-Manage to trim the fuelling down. If it's running lean you'll need bigger injectors and said airflow adjustment box. -Ian Link to comment Share on other sites More sharing options...
osso Posted June 23, 2004 Author Share Posted June 23, 2004 sorry i actually meant it was running rich... The thing is, you shouldnt have to buy a Apexi AFC or the Greddy E-Manage system to rectify the problem on a virtually stock soop. These problems should be ironned out before adding mods like that. but you're right about getting my car back on the dyno tho, i need to see whats going on. Link to comment Share on other sites More sharing options...
Supraguy Posted June 23, 2004 Share Posted June 23, 2004 Ok, if you say it was running rich and then since the fitted a Walbro and FSE I can only imagine it getting worse. Not to fret though! Running rich wont really hurt anything cept your plugs, but it most certainly will cause you to drop power. (your symptoms) If you have no plans on running a Big Single setup or anything wild, it can be fixed with a couple hundred quid on an S-AFCII and a little Dyno time back at Thor. Link to comment Share on other sites More sharing options...
Supraguy Posted June 23, 2004 Share Posted June 23, 2004 Originally posted by osso The thing is, you shouldnt have to buy a Apexi AFC or the Greddy E-Manage system to rectify the problem on a virtually stock soop. These problems should be ironned out before adding mods like Thats not entirely accurate though. The whole point of the AFC is to fine tune your existing stock fuel map. If youre trying to squeeze every once of power out, than you need a new map via the AFC or Standalone. You said yourself that you have added a Pump and FSE, so youve already changed your stock fueling. The AFC will just fine tune it for you as its most definitely needed now as well as when you decide to turn up the boost. Link to comment Share on other sites More sharing options...
osso Posted June 23, 2004 Author Share Posted June 23, 2004 The original AFR chart using stock fueling system and stock spark plugs can be found on the link below.. Here's the link to the orginal dyno plots taken when i was at thor in march 2004 Link to comment Share on other sites More sharing options...
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