Ok here is the deal, I need all of your help. This situation is becoming really draining for me and I'm about to hit the deck. Ok of course most of you know that my engine blew, i had another one installed and all of that good stuff. well now i have new troubles. I got my car back and everything seemed fine. I had 370 injectors installed, Addae and I installed my greddy emanage and my AVC-R boost controller. Everything seemed fine, untill it was time to turn up the boost. I originally had a deltagate II boost controller in my car. 6 pound spring, I only got 6 pounds sometimes 8 with my controler so since i wanted to go up to 15 lbs of boost, I needed to get a 9 to 13lbs spring. I installed the spring and I get 9lbs of boost. Perfect right? Well yes.....NO!!! My boost controller is set to 11 lbs but all i see is 9 and an occaisional spike to 10. I take the car to dyno and figure we can turn up the boost. After 5 runs we notice hey no matter what , the boost is not raising. So we figured maybe its the fact that the AVC-R is really hard to set up, So I leave the dyno, set up an appointemnet for another day and get a manual controller. To no avail, no extra boost on that dyno day. while we are there, the shop owner says well lets take one of their controllers and put it on my car and raise the boost. then i can figure out my controller woes later. Well to make a long story short, after he worked on my car for 1.5 hours he figured it was probably the wastegate, boost was not raising. So we switch to a tial Wastegate 38mm. which had a 3psi spring in it I got up to 6psi with the boost controller, and 3psi without it. but to could not raise any higher. I then ordered next day air mail a 10.15 psi spring for the tial and figured this would be my ticket. But nope i only could get 8.5 psi with the controller and 6psi without it. And I know that the spring is the correct spring. We have tried all different kinds of changing around the vacuum hoses on this car, and to no avail are not able to raise the boost. Can anbody help does anybody have any ideas? I called the chop which installed my kit and they are telling me that they can't look at my car this saturday , that i would have to wait for a day during next week. I live in MD and they are in Jersey. I can't take off a day during the week to get my car fixed!

 

first lets scratch off anything that occured while the AVCR was on the car...hate to say it Corey, but that thing is worthless on a street car IMO, way too much trouble and unecessary features for the average car.

the real things we need to focus on is when you hooked the turbo DIRECTLY to the wastegate, it would not boost up to its limit(or at least the limit you assumed was the spring you bought)...right there could be two probs, wrong spring(despite what you think they sold you) OR somehting is VERY wrong within the turbo.

again you might wanna CAREFULLY try the "overboosting" method by running the hose from the top of the wastegate(as opposed to the side) to the compressor nipple...and I mean carefully see if boost goes up to 10 or 11, on the Deltagate but as usual be very careful.

other possiblity...maybe the specs on your T04B is waaaaaay off...its quite possible...the S-trim T04B I think only has comparable specs to a TD0516G(which is designed for most 1.6-2.0 4cyls)...if you indeed are using a turbo with comparable specs to that of one used on a 2.0l 4cyl...its quite possible you could be pushing it to its limit on your 3.0L...again I'm only guessing, but the facts show, the fans of the T04b S-trim are only slightly larger than the 16G. I'm no turbo expert, but a T04B H trim or T04E might be something to think about. again I'm only guessing, but since it seems that no matter what you can't pass 9-10lbs, its something to consider

I dunno man, after all this work this weekend, I'm clueless as to what your issue is, 2 wastgates, 3 springs and 4+ boost controllers later I have no idea at all. I'll call you later tonight...maybe this weekend we can take the turbo off and actually measure the wheel/fan and see what trim that thing really is.

 

Open the turbo and measure the fans and see if you can figure out what it is.

 

That IS KEY.

You said with the 6 lb spring you got 6. you said you installed the 9 lb spring and you got 9.

So right there, to me, everything works as advertised.

Now a silly question. Where is your wastegate getting it's boost flow from? The manifold or the turbo before the manifold?

I just try and help with the obvious stuff

 

I was told tonight from the shop in jersey to check to see if the cat is clogged. I will change from the cat to the test pipe in the morning and see what happens

 

yeah of course 6 pound spring = 6 pounds on the Tial, but we even tried this with the Tial and 10lb spring and still only hit ~8lbs. on the Deltagate which is a 9-13lb spring, he only saw ~8psi and this is with the adjuster screw ALL the way in(which means wastgate will open @ 13psi)...but besides that even using a manual boost controller with the screw all the way out on both wastegates, boost never climbed above 8 or 9 lbs. we tried hooking the wastegate source up both ways...once from the nipple on the compressor outlet to the side port and then from a source after the manifold(I think he used the brake booster line(I wasn't around when they tried that))I know what you might be getting at...

WG source from intake mani-->10lb spring-->WG opens when 10lbs enters intake manifold(ie-"true boost")

WG source from compressor-->10lb spring-->WG opens when compressor hits 10psi--> but only 8psi might be getting to the manifold

either way with the MBC installed and adjusted, boost would not raise ANY higher


I think we really need a whole day to try and figure this out...screw the AVCR and just for now run it directly off the WG and see what happens. last Saturday was rush cause he was trying to get the car tuned and then get to the track the next day...after switching everything around 50 times my brain was scrambled so it was really hard to put **** together in my head, byt midnight we were all puzzled. I really think its the turbo's trim.

 

Yeah that's what I was thinking, I did completly forget about the MBC.

what size exhaust, cat back, are you running?

What kind of cat are you running?

Ramius could not get more than 7 PSI from his T4 with the stock exhaust.

Just a thought

 

he's running the custom maxima duals. there shouldnt be a problem with his exhaust, i saw it before he boosted.

it seems to me that its probably the trim

 

right now Corey says that the cat might be clogged possibly due to the excessiive richness before we initially tuned it and afterwards when we added a little xtra fuel(on the street) a few weeks after. its a start and I can see how it might prevent full boost being achived...but if that doesn't solve it I really wanna get a crack at that turbine and measure the fans, ****ing T04Bs have about 5-6 different trims from what I've found and like I stated before the "S-trim" looks crazy pussified for a 3.0L motor

 

Ummm, I see a problem right now.

When I was running my old 2.25" cat-back system with my old PFI kit, I could not go about 8 pounds of boost for the life of myself. The exhaust was so restrictive that my T4 could not "push" the extra exhaust out of the car.

So, I went to Grand Muffler here in GA, had a full 3" exhaust made and installed a 3" cat. WAH-LA, done, works perfect.

I suggest unbolting your cat and leaving the down-pipe exposed to the atmosphere. Take it to out on the street and turn up the boost. I guarantee this is your problem.

 

you running 2.5 exhaust w/cat? then that can be one your problems. Trash that dual crap and just get a single 3 inch exhaust. You cant have a restrictive exhaust and your trying to turn up the boost. Those two dont go together.

 

nope, I have a 3" warpspeed exhaust. I am using mardigras old 3" cat right now wich might e clogged. I am tryin to get to the muffler shop mow so that they can instll my test pipe for me. if i can not get there today, i will try what ramius suggests and see what happens.

 

Corey, I have only had that cat on for a week when I did emissions testing, thats it. No way its clogged.

 

yep matt your right, not clogged. Hey i found the specs on my turbo , they were in an email that the people in jersey sent me last year

Turbo specs:
60-1
Stage 5 Turbine wheel
on center, .58 housing

T04B - compressor side
T3 - exhaust side


Good for 575 hp up to 28 psi

 

so there is definently a leak somewhere...I tried to call you and left a voicemail..I just woke up

 

My compressor housing is lager than Coreys, either I have a T70 or his is not a 60-1. I gave him my dial calipers to measure the blades so he can be 100% sure.

 

Also we found out yesterday that the stock Pre cats were left on the car. when the kit was made. So now I will have to gut the cats today. Addae i think i am going to do this today instead of waiting till tuesday

Matt your housing size might be larger only because you have a t04E housing and not a B housing but if the gutted cat doesn't work, then the dial calipers will have to go into use!!

 

well you might have to do it without me

http://forums.maxima.org/showthread.php?t=294010

just some advice BE VERY CAREFUL, make sure you gut it and fully clean it out...remember any debris from there goes STRAIGHT into your turbo!!!! that would be....how do you say...VERY bad!