Ok I now done two set ups on my vq30dek. Iv never got this turbo to spool right. My first set up was a foward Y-pipe made of 2.25 merging two pipes into 2.5 inch and then going to the turbo (HX35 IS MY TURBO) Well I could not get full boost 10psi till 5000 Rpms. Then I went with a shoter det manifold set up in the rear and stock manifold in the front modded to make 1.75 pipes coming out of both manifold then about 4 inches step them up too 2 inch pipes and then merged them into 2.25 collect about 3 inches before the trubo. The pipe are with in 1inch of being equal leanth. They are only about 16iches long on both sides. Well I thought it was spooling fast but when I data loged some runs It will make a half of psi at 2600rpms in second but it takes till 4800rps to make 11.5 psi. Well other guys that run this turbo with the vg30 engine from the z or maxima can make 15-18 by 3800 rpms.
So what could it be with my set up that mine spools all the way up so slow. It comes on fast but just takes so long to make full boost! I have a 10.1 ration and double over head came plus more stock horsepower over the VG30 but they get it quicker. Got to be something wrong!

 

Could the wastegate not be working properly? Might be leaking air same way as when using a manual controller.

 

Yeah at idel it seem just to have tiny tiny tiny leak Like a pin whole what have! Would that small leak do all that. I know some people have small cracks in manifold and dont lose much at all!

 

When streetz had a manual boost controller. His wastegate wasn't full y closing thus cause a slower boost build up. But as soon as he switched to electric boost controller his wastegate stayed shut untill his desired psi. He said it helped spool a lot. I am not sure if he has an internal or external wastegate and if would make any difference.

 

I'm running a TO4E and have never gotten the turbo to spool before 3500 RPM. I think it has to do with the distance between the exhaust manifolds and the inle to the turbo. It takes some time for pressure to build up throught the lenght of the pipe before it spools. 300Z's boos quicker because the turbo is mounted right to the manifold.

 

kind of a dumb question, but since you dont have it listed (or in that holset build up thread), what are the exact specs on this turbo?

All that is known is that its supposed to have very similar characteristics to the GT35's.

 

I have a questions, what type of boost controller do you have, is it the E01? What WG are you using, the hx built in one or external, and at what psi is the WG set up for?

How do you have your controller setup? Try this, at below 3,000rpm put values so that the WG is completely closed, that way the turbo will spool alot faster (since it thinks its going to put out the maximum boost 20+psi), then have is so when it reaches near your desired pressure, you start changing the values so it holds it at w/e pressure you want. You wanna start changing values right before full boost, that way you dont get a sudden spike since the turbo is spooling up so far. do this at low rpms and see where the full boost comes in.

 

Sounds like a plan. Is that something an EBC can do? or something you have to make out of scratch, because I cannot imagine having a manual valve in the car and turning it manually when it hits higher RPMs.

 

That will work with a electronics controller since you can control it. You can do something similar to increase spool up by creating more pressure entering into the turbo exhaust inlet, there is basically a valve that is closed under no boost, then as it spools up, it opens up. i am currently doing a search on this, but cant find it right now, grey99 and nealoc had mentioned it to me, but cant find it.

 

yeah i got the eo1 and I have it set up that way. The external gate is a hks. Its set up to open at 9.7 psi I have the boost controller keeping it closed till 8.5psi and the rpms at 3500 with the valve having 100%. It must be the leaking wastegate leaking stoping it from spooling on up!

 

Either that, or simply a boost leak.

 

Well i built me a boost leak tester and wow I did have two leaks but they were in weird place around coupler not sealing. One was i had the cupler to close to the curve of the pipe. I will test when I get the car back going hoping for a quicker spool

 

How does this boost leak tester device work?

 

http://www.mirage-performance.com/Ec...aks/index.html

 

Yeah that a good way too. i just rigged up one with stuff I had laying around the shop.