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Rb25det Issues (started With Boost T)

GTST4DR

By GTST4DR,
in Engines & Forced Induction

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GTST4DR Apprentice

GTST4DR

Posted
Posted

Hey guys,

So i've got a pretty stock R33 only real mod so far is turbo back exhaust, after reading about manual boost T I thought id give it a shot so out I went ended up grabbing a turbosmart boost T. Got home chucked it in and set it to the lowest setting hoping to get a better boost curve while still remaining stock boost (9psi, gained 2psi after exhaust) took it for a quick drive first full throttle pull jumped to 14psi and started to misfire backed off limped it home. Deciding that it was diffenently on the lowest setting I thought id take it out and put the stock setup back in place.

Now this is where things got interesting its running back at 9psi but I had to creep to 11psi in 3rd under full throttle and things just don't feel right it feels like its working hard to get no where I feel i've lost power and power delivery is no longer smooth it feels like its missing but not completely.

Any Ideas will be muchly appreciated.

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https://www.sau.com.au/forums/topic/277811-rb25det-issues-started-with-boost-t/
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W0rp3D Grand Master

W0rp3D

Posted
Posted
If you have a stock turbo, you shouldn`t be running that much boost. The standard tubby only takes 0.85 bar.

If you read the post you would see that he was trying for the lowest boost setting, not 14psi.

The breaking down at high boost was most likely your plugs, probably still gapped at 1.1mm, gap them to 0.8 and you wont have a problem.

The loss of power might be an ecu thing, try resetting the ecu and see if that works, what cat are you using, if its still factory then the higher boost may have been the final straw and destroyed it, could be the same if you are using old mufflers.

89CAL Grand Master

89CAL

Posted
Posted

Theres two lines that enter the stock boost solonoid. I think one is from the piping and the other is from the bov return line? something like that. Make sure u block off the one from the bov return line. Me being a newbie at the tie thought id just T the one from the bov return line into my line from the piping and it just kept spiking. Seems silly now yes i know but bak then i thought it must have been there for a reason :P

lol

Im guessing thats part of your problem you dont want it running that much boost? Just check all your lins make sure there not leaking or anything. Its a little odd for me that you picked up an extra 2psi when you put an exhaust on because mine didnt? I dont know if its changed cause of somethin different about your car but Check your actuator maybe just to be safe.

As for the missfire, Id agree its probably a spark problem, or maybe ECU. Mine would just hit stutter and be a real pain at anything above about 8psi on stock ecu. Putting the power FC in was one of the best things i did.

GTST4DR Apprentice

GTST4DR

Posted
  • Author
Posted

Exhaust: Can't remember what brand the front pipe was exactly but its running a high flow metalcat 3" Mandrel bent with a high flow muffler (rather loud)

I had a tinker later on yesterday reset the ECU and took it for a drive everything seemed to be working great stock solenoid was all back to the old setting of 9psi and it actually felt better then before, so I thought it was all sweet and I was cheering until today.....

Check Engine light started to come on driving home from work so I limped it up the street to my place and am know confused again! can't chuck the ECU in diag mode tonight to see if its a sensor or what not :banana:

GTST4DR Apprentice

GTST4DR

Posted
  • Author
Posted

Everything seems good now maybe something played up while it was re-learning think ive got it back to how it was maybe even running a bit smoother, just gotta play with idle now seems a bit high running at 1100-1200rpm but that's easy enough to do.

Think ill just save for a FMIC, P-FC, Splitfires etc

Cheers for the tips lads.

shotter Rising Star

shotter

Posted
Posted

When you get around that much boost the ECU see's it and causes the missfire. It's a inbuilt safety. And the ecu probably went into limp mode. I guess next time you play with boost controllers be very very careful and slowly put your foot down. But as you said it should all be good now.

Krishy Grand Master

Krishy

Posted
Posted
Exhaust: Can't remember what brand the front pipe was exactly but its running a high flow metalcat 3" Mandrel bent with a high flow muffler (rather loud)

I had a tinker later on yesterday reset the ECU and took it for a drive everything seemed to be working great stock solenoid was all back to the old setting of 9psi and it actually felt better then before, so I thought it was all sweet and I was cheering until today.....

Check Engine light started to come on driving home from work so I limped it up the street to my place and am know confused again! can't chuck the ECU in diag mode tonight to see if its a sensor or what not :)

If you have reset the ECU mate then let the car idle and warm up for about 10 mins and i have also found that for the first 500kms dont thrash it or hit heaps of boost....then for the next 500kms give it boost here and there and all up after your 1000kms is done the ECU should have by then relearned itself and should be all sweet....well thats what i had to do in mine anyway

Give your car a good servicing with fully synthetic oil, change oil filter and spark plugs....make sure that you regap the spark plugs from the 1.1 to 0.8mm and then you can happily fun a bit more boost....also make sure that you read the instructions of connecting a boost T as i have experienced that if the boost T is connected the wrong way around i was getting like 5psi of boost and a truckload of missfire....

Check Engine light means that your motor is detonating which it shouldnt do if you still have the Stock ECU still in....

Also just to check what fuel are you running....could be a bad batch of fuel or whatver as well

Goodluck with it champ and let us know how you go

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