Turbo question
04 March 2009, 09:15 PM
#1
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Turbo question
Does anybody know what the differance is between the standard 01 wrx turbo unit and the turbo unit off an 01 sti?? Also would it fit straight on??
05 March 2009, 12:17 AM
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Standard MY01 WRX turbo is a TD04, whilst an 01 STi would be a VF35 if it's UK or a VF30 if it's JDM. It should be a straight swap, but ideally you should fit STi injectors, uprated fuel pump and remap at the same time.
05 March 2009, 09:30 AM
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For the VF35 the standard injectors will be fine.
If STi injectors are fitted, they can normally match the airflow of a VF35 running at around 86% injector duty (which on 500cc injectors is 430cc, some 50cc more than the 380cc originals are capable of). If a VF35 turbo creeps on a car with these fitted then a) the AFR will remain safe even if the boost is higher than desired and b) it is possible to implement a "keep you going" strategy by fuel dumping in the creep region; deliberately running richer than necessary will rob exhaust gas energy and drive to the turbo, counteracting the creep. This is not a proper solution, the wastegate will still need porting, but the car can still be driven without worrying about the engine in the meantime.
The safest option, then, is to fit the injectors and turbo at the same time, then have it mapped. If it creeps then at least the car can be driven until the turbo can be sorted, and once it is sorted, you get to enjoy the full benefit of the VF35, rather than having to tail the boost off early to stop the injectors maxing out and the engine running lean.
09 March 2009, 12:08 AM
#6
Cracking reply from Pat 
Aside from the inlet side (possibly better filter needed) what have you done on the exhaust side of things ?? Bugeye WRX is pretty crippled with 3 cats in the system
Shaun
Aside from the inlet side (possibly better filter needed) what have you done on the exhaust side of things ?? Bugeye WRX is pretty crippled with 3 cats in the system
Shaun
09 March 2009, 12:08 AM
#7
Sometimes they are and sometimes they are not. It all depends on the car. What is always true is that the standard injectors cannot flow sufficient fuel to match the full flow of a VF35 turbo, the mixture will lean out. It is, however, sometimes possible to run the VF35 at less than its full potential, but this depends on the car and on the turbo. Often a VF35 will boost creep when fitted to a WRX, and when this happens the ECU no longer has any control over the boost generated (short of going into boost cut and shutting down the engine); under these conditions there simply isn't enough fuel to keep the AFR safe, it leans out and normally knocks, which causes the ECU to pull timing, further increasing the drive to the turbo and pushing the boost up even further, a vicious cycle. The proper solution to that problem is to port the wastegate on the turbo so the creep is eliminated, and it is unsafe to drive the car hard until it is sorted.
If STi injectors are fitted, they can normally match the airflow of a VF35 running at around 86% injector duty (which on 500cc injectors is 430cc, some 50cc more than the 380cc originals are capable of). If a VF35 turbo creeps on a car with these fitted then a) the AFR will remain safe even if the boost is higher than desired and b) it is possible to implement a "keep you going" strategy by fuel dumping in the creep region; deliberately running richer than necessary will rob exhaust gas energy and drive to the turbo, counteracting the creep. This is not a proper solution, the wastegate will still need porting, but the car can still be driven without worrying about the engine in the meantime.
The safest option, then, is to fit the injectors and turbo at the same time, then have it mapped. If it creeps then at least the car can be driven until the turbo can be sorted, and once it is sorted, you get to enjoy the full benefit of the VF35, rather than having to tail the boost off early to stop the injectors maxing out and the engine running lean.
If STi injectors are fitted, they can normally match the airflow of a VF35 running at around 86% injector duty (which on 500cc injectors is 430cc, some 50cc more than the 380cc originals are capable of). If a VF35 turbo creeps on a car with these fitted then a) the AFR will remain safe even if the boost is higher than desired and b) it is possible to implement a "keep you going" strategy by fuel dumping in the creep region; deliberately running richer than necessary will rob exhaust gas energy and drive to the turbo, counteracting the creep. This is not a proper solution, the wastegate will still need porting, but the car can still be driven without worrying about the engine in the meantime.
The safest option, then, is to fit the injectors and turbo at the same time, then have it mapped. If it creeps then at least the car can be driven until the turbo can be sorted, and once it is sorted, you get to enjoy the full benefit of the VF35, rather than having to tail the boost off early to stop the injectors maxing out and the engine running lean.
. Fascinating.Only yesterday I was having a compelling converstion with Paul B about mapping and how each differnet engine has its own distinctive knock charactersitics e.g. the Mitsi's 4G6E and the EJ20 are totally different in what comes through the det cans. He then went on to mention the MR2 Turbo engine's strange foilbles!
... that's an eye-opener for any first-time mapper that one! 
Last edited by joz8968; 09 March 2009 at 12:17 AM.
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09 March 2009, 02:15 PM
#8
ok on my00 my 440's are no good for the VF34, only want around 300bhp.
set up so far is uprated fuel pump, green filter and full de-cat.
mods to be fitted, front mount, GTheaders, uppipe, 3 port, pos HKS induction fitted in the wing, (depends on more research) And the VF34.
set up so far is uprated fuel pump, green filter and full de-cat.
mods to be fitted, front mount, GTheaders, uppipe, 3 port, pos HKS induction fitted in the wing, (depends on more research) And the VF34.
Last edited by scooby1doo1; 09 March 2009 at 03:04 PM. Reason: forgot some mods
09 March 2009, 11:19 PM
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The exhaust side is covered, Its got a full de-cat. As for the intake, i've jus got an uprated pannell filter... My motor didnt run very well with an induction kit.. I read in a technical article by Cobb Tuning that 2001 + can have a lot of problems with induction kits because of the maf sensor...(as i did with mine) They also went on2 say that the factory air box is good up to 350 bhp???? Dont no how true it is, I would like another induction kit, Im sure when i have it mapped next week @ Clive Atthowe tuning they'll let me know??...
10 March 2009, 12:27 AM
#10
o1uk300wrx
The newage induction side is good for 350 plus BHP with a good filter fitted.......it's one of the things that Subaru sorted with the new age
Induction kits for the newage are also not much of a problem as the MAF is pretty robust, problems arise if the diameter of the intake increases and you need to need to tell the ECU that the airflow has changed ! LOL
What you need to be doing is pressing the little red cross at the top right of your screen and closing down scoobynet and sorting this out with your mapper LOL
Shaun
The newage induction side is good for 350 plus BHP with a good filter fitted.......it's one of the things that Subaru sorted with the new age
Induction kits for the newage are also not much of a problem as the MAF is pretty robust, problems arise if the diameter of the intake increases and you need to need to tell the ECU that the airflow has changed ! LOL
What you need to be doing is pressing the little red cross at the top right of your screen and closing down scoobynet and sorting this out with your mapper LOL
Shaun
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