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overboost?

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Old Jul 30, 2007 | 02:32 PM
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overboost?

what do you think could happen if you load 18PSI on a stock engine with only exhaust, downpipe, twin turbo, FMIC??
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Old Jul 30, 2007 | 02:35 PM
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If you have no ecu to add more fuel you can say goodbye to your motor. I would highly recommend reading the FAQ and doing a lot of searching. Also the stock twins can't flow 18psi.
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Old Jul 30, 2007 | 02:37 PM
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hmm with a RE Redom ECU?
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Old Jul 30, 2007 | 02:37 PM
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what do you think could happen...
Anti-Gravity!

yeah, that...or a blown motor.



This is simple. Air and fuel have to be balanced correctly or your motor will not survive. You want to almost double the stock air flow (even though, as mentioned, you wouldn't be able to on stock twins), so you have to increase the fuel too. Stock ECU can't handle it. A tuned ECU might, but you have to make sure your injectors and fuel pump are also up to the task.

Personal recommendation: get an Apex'i Power FC standalone ECU, some larger injectors, a higher flowing fuel pump if you want to make that much boost...you'll need a different set of turbos (or one big one) to do it, too.
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Old Jul 30, 2007 | 02:37 PM
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If you try that with the stock ECU, you'll hit fuel cut. In the event you could spike that high before fuel cut happened, you'd be in a very lean condition. The chances of detonation are substantially increased.
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Old Jul 30, 2007 | 02:42 PM
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ok thx guys
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Old Jul 30, 2007 | 02:43 PM
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but isnt it wierd that the redom ECU increase the boost that much?
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Old Jul 30, 2007 | 02:52 PM
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Originally Posted by robzter
but isnt it wierd that the redom ECU increase the boost that much?
It all depends on what it's mapped for... It could very well be mapped to work with larger injectors and handle higher levels of boost.
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Old Jul 30, 2007 | 02:53 PM
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What year is your FD. I wasnt aware that even the 99 spec twins could reach 18psi.
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Old Jul 30, 2007 | 03:03 PM
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Basically if you have to ask, then you're going to break something.

I don't think the twins would last more than a few runs at that much boost if they could even make 18 lbs. I think they hit their max efficiency at something like 15 psi, so you'd probably lose power over 18psi.
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Old Jul 30, 2007 | 03:04 PM
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well i have a 92 or 93 :P. that is why i was so worried. i called the seller and he assured me that everything was in order. now i prolly stand with an broken apex and a rotorhouse and a rotor that is just trash. the rebuilder i think is RE Worx in england. 18psi is 1,2bar right?
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Old Jul 30, 2007 | 03:28 PM
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1.24, yes.

So did you try this and blow something up? I'm confused now.
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Old Jul 30, 2007 | 03:40 PM
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i didnt "try" i experienced it a week ago...

when i went to get the car from the boat. i called them and asked them if it realy should boost that much. they assured me that it was suposed to do that becouse of that ECU. and now i blew something up after one week!

now i am trying to discuss this with the seller and trying to get them to rebuild the engine.
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Old Jul 30, 2007 | 03:48 PM
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well after the engine gets rebuild again. ill get PTS for the rotors, step 0.5 port, powerFC, boost controller, injectors and a fuel pump.

do i also need new fuel rails and a fuel regulator?
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Old Jul 30, 2007 | 03:52 PM
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With larger injectors and a larger fuel pump, you should run an aftermarket FPR. As far as the fuel rails, that will be dictated by the injectors you choose to use.
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Old Jul 30, 2007 | 04:02 PM
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hmm ok do you have any sugestions on the injectors? if i can use the stock rails that would be nice to my wallet :P
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Old Jul 30, 2007 | 04:11 PM
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Originally Posted by robzter
hmm ok do you have any sugestions on the injectors? if i can use the stock rails that would be nice to my wallet :P
First you need to define your goals for the car. Then, you can start putting together the parts which will get you there.
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Old Jul 30, 2007 | 04:26 PM
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well my goal is around 400hp with twins
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