Scion XB 1NZ-FE Turbo build

[Parmas]

Originally Posted by xbgod

Cali this is for you.......


Thanks Parma, will look at the same issue you had. I hope thats it and problem solved.

And yes will be in around 380 hp when done. That motor of mine is a beast and sounds awsome. It spools up quick with that new GTX style turbo. I have alot more power available just gotta change that spring and fix that tranny cable.

XBG

I fixed it by replacing the cable, don't waste time repairing it. Also had to wait for weeks for the cable tru Toyota service.

380bhp with Nos and Turbo is easily achievable.

Can you give detail information about the head you are running now instead of gude? I am interested because I am running a stock head and I wish to know how much power it's components withstand, especially the valve springs.

[PETERPOOP]

sweet

[cali yaris]

I have the wrong spring in my Tial MV-S wastegate

What is the wrong spring?

[cali yaris]

^ I know that. You didn't answer my question.

I'm using a 10 psi spring and I can run up to 30 psi. So what spring are you using now, and what's wrong with it?

[cali yaris]

^ I still don't understand why it's the "wrong" spring.

[xbgod]

The gold spring was only allowing me to get to 5.8 psi before it would shut me down. So in order to make more PSI we took the waste gate out of the equation for now and set up the boost controller through the Greddy boost controller only and by-passed the wastegate all together. The problem with that is boost creep so I'm not pushing the envelpoe untill I change the spring sometime next week. Also had to reroute a couple of vacuum lines to do so.

Hope this explains it a little better.

XBG

[Nexus1155]

Even if you have a lower wastegate spring, isn't the purpose of a boost controller to only allow the wastegate to crack open once it has reached the desired boost level? So even if you had the spring in with the boost controller attached, you would crack once the boost controller allows the air to flow into the wastegate regardless of whatever spring is in it?

I dunno if I am reading it wrong or am missing something, let me know

[cali yaris]

This is not making sense, sorry.

The spring determines the minimum boost you can run, not the maximum.
The purpose of a boost controller is to run more than that (and get to it faster).
How did you control boost without a wastegate?

The gold spring was only allowing me to get to 5.8 psi before it would shut me down. So in order to make more PSI we took the waste gate out

[xbgod]

Yes I understand that too. Which is why I think Tial preinstalled that smaller spring. But my tuner has something else in mind. So off to what ever he deems necessary.

I don't care what he uses as long as I get to 380hp. Which at this point I know I can.

Turning off the VVTI with my system has worked out great. no issues what so ever.

XBG

[xbgod]

Hope this clears up the spring issue:

The gold spring I had in the waste gate was a 4.8 and is only good for twice that amount of boost before it cant hold. (about 10psi)

The new combination is a Grey/gold which will hold upto 29psi. but the car must be able to make at a minimum 14.5lb of boost or you will never hold pressure.

Hope this helps peolpe understand a little better.

XBG

[cali yaris]

It doesn't clear it up. Above the spring's rating, the boost controller keeps the wastegate shut until desired boost is reached.

I'll say no more on this, looking forward to your results which I'm sure will be good.

[xbgod]

Thats the best I can do for ya Cali. I even talked to the Jake at Tial he said that gold spring would never work either for 28psi. Has to be the grey/ gold to make it happen.

On the other hand.......and this is for Parma..........

Shifter cable was burned right through. 200.00 for a new one. Wrapping the new one in DEI shield and having a aluminum shroud with a heat resistant material from DEI put on the other side of it to also block the heat.

You were right on with your S.W.A.G

XBG

[Parmas]

Originally Posted by xbgod

Shifter cable was burned right through. 200.00 for a new one. Wrapping the new one in DEI shield and having a aluminum shroud with a heat resistant material from DEI put on the other side of it to also block the heat.

You were right on with your S.W.A.G

XBG

The trans cables are the only reason I kept the exhaust downpipe at 2.5". If I increased it to 3" I would surely burn a cable every month probably

The yaris engine bay is too compact to go extreme without issues like these...

[Bluevitz-rs]

Originally Posted by cali yaris

It doesn't clear it up. Above the spring's rating, the boost controller keeps the wastegate shut until desired boost is reached.

I'll say no more on this, looking forward to your results which I'm sure will be good.

The physical pressure inside the exhaust turbine is becoming greater than pressure of the spring before the desired boost level is being reached. So the pressure of the exhaust alone is enough to open the waste gate. No need to add vacuum pressure on the other side of the spring to open it, so no boost controller will ever be able to hold it closed if the there's more pressure inside the exhaust than spring pressure holding the gate shut.

So, desired boost pressure is a combination of exhaust pressure, spring pressure and vacuum pressure. The only one we have control over is vacuum.

[Tamago]

i went through a set of cables after my turbo build too. it was a struggle. toyota put the cables dangerously close to the stock exhaust, and when you upgrade "go bigger" you immediately heat up your stock cables.

good luck Aras (asshole).

[Blown_xa]

looks like promising results so far. Hey remember i mentioned the wastegate spring a couple weeks ago.... hehe. I remember looking at your build pictures, one thing that is probably causing the creep is the fact your recirculating dump is kinda short and dumps at a perpindicular angle into the downpipe. The exhaust flow from the downpipe may be causing pressure in the dump therefore causing a reverse wastegating effect... boost creep. Worst case run an open dump. Having the wastegate opposite from turbo entry won't help either, but with a top mount log manifold i guess there is no place else for it. Your gonna run a lot of boost anyhow so creep wont really effect u at 30psi. With a proper wastegate spring, you should be able to hold 30psi all the way to redline with that turbo I would imagine.

[xbgod]

Your so kind Tamago.....Thanks brother.

And I think your right about that.BlownXA

XBG

[cali yaris]

ooh 30 psi... nom nom nom