I bought a GT3574 turbo kit from a-spec and now my setup is complete, the car is running but i'm waiting for steve kan to tune my car in 30 days. My only concern is about some boost creeping or spiking because i have the 13psi spring in the wastegate. Should i get a 10psi spring or i should be okay with the spring i have. BTW, i want to run 15,5 or 16 psi MAX. I don't have any cats on the car too. I have a old school profec-b boost controller,

Thanks,

Max

 

Bump.....anybody know if it would be more ideal to run a 10lb spring and use the BC to crank it up to 15. Getting creep on the current spring in a Tial 44mm, maybe too strong?

 

old bump, I have the same question.

 

yes you are fine, you should only have problems if you more than double what the spring is for. example 10 psi spring should be good to 20 psi safely

 

I know this thread is old, I just wanted to give some input since I bought WanKeL FD RX-7's FD.

The 13 lb spring (big blue) is too much for this set-up running 15-16 lbs. I was running the car off just the wastegate and getting boost creep up to 19 psi at around 7000 rpm's in third gear.

I just switched to a 10 lb spring (big red) and there are no more boost creep issues. Running off the wategate, the car hits 13-14 psi at redline.

 

Not to break your ***** or anything but a 10lb spring going to 13~14psi would be 3~4lbs of boost creep no?

 

That's my point - with the 13 lb spring, I was getting creep up to 19 psi at 7000rpms and it kept going. With the 10lb spring I get creep up to 13 lbs (by around 6000 rpms) and it held at all the way to redline. This is much more manageable.

All i'm saying is that with the A-spec long runner manifold, GT3574 turbo and Tial 44mm WG, a 13 lb spring is overkill for a 16 psi street car.

 

I know.. I was breaking your ***** because you said no don't have creep

Now you have a manageable creep where as before was too much and unmanageable.

 

All i'm saying is that with the A-spec long runner manifold, GT3574 turbo and Tial 44mm WG, a 13 lb spring is overkill for a 16 psi street car.[/QUOTE]

BUY a Boost controller problem solved you can get a manuel one off ebay, your going to need it come winter because it will creep up on you in the cold

Im running the tial 44 with 2 springs RED and Yellow for a rating of around 1bar (14psi) and i can set my boost to 12psi solid with the manuel boost controller

 

What are you talking about?? I have a boost controller. It was doing me no good because they do NOTHING for over-boosting.

That being said, there is no way in hell that you are running at 12 psi with a 14 lb spring...A tial red and yellow equals about 13 lbs. That's the lowest you're going to run regardless of the boost controller. If that's what your running and you have no creep, that's great, but don't tell me to buy a boost controller to stop over boosting.

That's why I brought this thread back to life - to correct the bad information.

 

Uh dude, if you are creeping to 13psi with a 10psi spring (with no boost controller) your wastegate is undersized for your given combination of turbine housing, manifold, and engine porting.

 

Uncontrolled boost rise is creep. But not all boost rise is creep.


My Tial 46mm with a 10lb spring and the EBC turned off, will hit about 11.5psi boost around 3500rpm and then stay there to 8000 rpm. With EBC controlled 16psi boost, hits it about 4000 rpm and also stays flat to redline.

So my 10 to 11.5 is not creep.

 

Some people have luck fixing issues like this by using a different source for the boost control and wastegate lines. A larger exhaust housing will also help, though your boost response will change. Could always go aux injection and run more boost too.

 

I have the same gate. When i went road racing, I ran a 10lb spring. It held a constant 10psi all day.

 

where is the boost source coming from? for a no boost controller setup, the wastegate will crack earlier if you use a source on the compressor outlet. i remember running a 10psi on my old HKS gate with no boost controller. with a pressure source at the compressor outlet I could hear the gate crack at 6psi.

 

I have the same problems. Im trying to run a low boost setting of 10psi with a tial v44 on my 35r .82 t4 housing and i get lots of creep. Right now I have a 7psi spring and it goes to 14psi. Im trying to decide if i should go with dual gates or have a better manifold built. Im using a profec spec S and getting pressure right after the comp housing.

 

have you tried running without the EBC to see if you get creep? Cant you just go with a bigger gate instead of running 2? I suppose this may not help if the manifold is the culprit. Maybe you should run 14 psi as low boost haha

 

I had a HKS EVC EZ and it held 10lbs like a rock.

 

I found that my EBC controlled boost better when I took my main boost source for the WG and WG solenoid after the IC instead of from the turbo outlet.

I have the A-Spec GT35R 1.06 with 3" DP, MP, and RB cat back. The WG dump pipe goes back into the DP which does cause more back pressure on the WG.

How the dump pipe is connected makes a diference.

 

I've had the best results sourcing boost from the compressor housing and using only the side port of the wastegate. Leave the port on the end vented. That seems to get me the most stable boost. The only time I find I need to hook up both wastegate ports is if a customer wants to run significantly more boost than his spring, but I don't recommend it. You shouldn't be creeping with that wastegate if it is set up properly. Also, anyone using the old school profec b setting the wastegate up like this needs to set it to "actuator type"

 

I also have a 10 lb spring in a TiAL 44mm and it usually creeps to about ~12 psi. My issue is the manifold, the wastegate placement is all wrong.

 

Wastegate placement makes a HUGE difference

 

Id bet your running you boost controller off one of the manifold nipples which if you are then thats why you cant lower your boost by the time the pressure gets to the boost controller its already in the engine!
Now I used to have your problem
BUT Ray wilson put a nipple right off the compressor for the boost controller and now I can turn the boost down to 12psi constant with the red and yellow springs in the wastegate
The only bad info in this thread is the crap your saying

 

moehler if your so confident I cant do what im saying take a trip to Baltimore and Ill show you my setup so you can learn something

 

The farther from the turbo the wastegate boost source is, the more pressure drop there will be. So the turbo could be making 14 psi, but by the time it goes through the intercooler/piping the UIM only has 12 psi. In this case a 14 psi spring would make the engine receive less boost, although the turbo is still making 14psi. If you source the wastegate at the UIM then the turbo would have to make 16 psi (or more) in this case because of the 2 psi pressure drop.