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Hey just wanted to ask you guys. I have a apex-i AVCR installed in my car and for one of the lines that go to the wastegate i have a straight adapter in the line. Now my question is if this would cause any kind of restriction ? Also i am not sure why but i cant seem to hold the boost higher then 15psi. I mean in 2nd when i go WOT it will go to like 17 and bleed to 15 around redline and when i shift into 3rd it will stay at 15. I cant figure out why. I have a 2.5" turboback with a highflow cat. I dont know why it wont stay higher. I cant seem to get higher then 98mph in the 1/4 becuase of this. If someone can give me some ideas that would be great because i am on my way to the dyno tomorrow. I mean could it be that my cat is clogged ? thanks in advance.
 

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but remember, when you go over 16psi the turbo will just start blowing hot air, which wont really be helping you at all, just stick with what you got or upgrade to a better turbo that can produce more power, and upgrade the head gasket which has a tendency to blow at around 18-20psi, even try hard ic pipes, 3 inch exhuast, cam, headwork, limited slip, weight reduction, larger injectors, fuel pump, flywheel.

tom
 

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sleepermx6 said:
but remember, when you go over 16psi the turbo will just start blowing hot air, which wont really be helping you at all...

tom
Umm, yeah it will help more. More boost is more power, if you can get the higher boost to hold on the IHI. Some can, others can't. I know the turbo is not efficient but the truth is in the timeslips. I just had this debate not long ago with someone else.

As far as the head gasket comment, where do you get this info? Stock head gaskets are stronger than you may think. What are you talking about upgrading to anyways? Last time I checked copper doesn't work on aluminum, and aftermarket head gaskets are crappier than stock. i blew a topline running 15 psi of boost myself but now I'm back to an OEM and no problems.

Moridin I would suggest to remove the cat. That will free your exhaust up and may give you a few more PSI. I know you may not want to do this, but try disconnecting the wastegate line completely. See if the boost goes any higher. I doubt it will, the stock turbo has a hard time keeping up with the CFM the F2t needs at higher RPMS. Looks like you may be limited to that boost until you get a bigger turbo. I am running a T3 with a welded wastegate myself, and I'm still only getting 15 psi.
 

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FlySwat said:
Rebel, Your high altitude is probably the biggest factor to why your turbo can only pump 15 psi.
yeah, good point. I think I will be able to get a higher boost level if I switch to a bigger T3 unit though, don't you think?

A few of my friends have pushed 18-20 psi on talons around here, so there should be enough air. I just don't think my turbo can compensate because it's undersized.
 

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I have had lots of evidence in the headgaskets blowing at or around 20psi. You may get lucky but once all the negative factors start building up it will go. If you want to hold more pressure(boost), I would suggest o-ringing your block and running a oem gasket. That should make it strong enough. The restriction would be in flow somewhere(duh) you can start with the exhaust to see if that helps. I was able to spool up faster but I didn't gain any increase in boost. One thing that does workin making your trapspeeds higher is making a shortrunner intake manifold and having a high volume collection area. That should boost your high rpm power decently so you can pull harder. I thought it was the other way around, the head has trouble keeping up with the flow of the turbo and therefore slows it down.
 
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One thing that does workin making your trapspeeds higher is making a shortrunner intake manifold and having a high volume collection area.


Dyno, TimeSlips, Picture?

Oh thats right...You havent made one, nor could the average person.

Lets stick to pheasable advice.
 

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Flyswat, I have been too busy with the mustang to worry with the 6 for right now. The turbo isn't liking the nitrous due to the fact that the exhaust is hotter than normal so I have to do a little work in tuning and maybe a new manifold with a better turbo so I won't strain this one due to rpms being to high for the turbo. Patience Flyswat, Its only been 4 months or so since I thought of the idea. If you haven't noticed I have relocated once again so I have a mess with work and am in the process of designing the new network infrastructure. All in due time. Ok don't worry about the manifold yet just the exhaust and headgasket info. Sorry.
 

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Moridin said:
I have a 2.5" turboback with a highflow cat. I dont know why it wont stay higher. I cant seem to get higher then 98mph in the 1/4 becuase of this. If someone can give me some ideas that would be great because i am on my way to the dyno tomorrow. I mean could it be that my cat is clogged ? thanks in advance.
on my 91pgt when i had it..

i was trapping @ 97mph with the stock cat and dp.. i punched the cat out for fun..

and traps went to 98.9.. put a 2.5 inch dp on and they went to consitent 99-102 mph
 
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