you look a bit pale... think you need to go home....

 

Tom, I am just patiently waiting for the car to be 100% tuned and 100% running... ( getting the boost issue to hold and fixing a few other things ) but the EBC came and everything should all be going as planned.. ( waiting for Vince to re-schedule me )

I cant really compare the 2 at the moment.. because the car isnt running like it should be... 1-2 gear feels like nothing is there, ya know?... feels like boost isnt there? feels like im running a gt42 that doesnt spool till 5k lol... thats probably the best way to explain it...

HOWEVER... doing like 3-4 gear pulls in the highway... its really hard to believe how good it pulls and its not even done and tuned to 8.5 psi... its like.. wait.. wait... then BOOM! just hits you... and the sound is just orgasmic

again I cant imagine when it will hit full boost and holds it to redline.. its going to be something else! for sure. if one 6262 sounds so damn good at WOT.. I cant imagine 2!! cough rich cough..

 

could that be because you dont have the ECU flashed to give you 100% tb in lower gears?

 

no the ecu is flashed and tuned... im not talking about throttle response.. but the power..

 

65% throttle = 35% less power?

Ok get ya.

 

When you put that T4 gasket (and check the rest of the exhaust) in I think things will pick up..EBC will help as well.

BTW, the T4 6262's .58a/r turbos came in yesterday and I will make a new down pipe and install it tonight. Well, I hope I can get it all done tonight.

I want to see how it works on my car. I have the smaller T3 6162 right now with the .81 a/r.

 

Did PTE say that a T4 .58 is actually smaller than a T3 .81?

Since the a/r is just a ratio and the T4 is a much bigger flange, I dont know how much different they will be....

 

They are fery close. There is a .68 available in the T4 as well (for the 6262), and that ofcourse would be larger.

 

I think I have the .68? I gotta look at it

 

The A/R is the inlet cross-sectional area divided by the radius from the turbo centerline to the center of the inlet (where the cross-sectional area is measured). The smaller A/R should help spool the turbo faster.

Here is a good description and drawing: http://www.turbobygarrett.com/turbob...o_tech102.html

Here is a quote from the Garrett website:

"Turbine A/R - Turbine performance is greatly affected by changing the A/R of the housing, as it is used to adjust the flow capacity of the turbine. Using a smaller A/R will increase the exhaust gas velocity into the turbine wheel. This provides increased turbine power at lower engine speeds, resulting in a quicker boost rise. However, a small A/R also causes the flow to enter the wheel more tangentially, which reduces the ultimate flow capacity of the turbine wheel. This will tend to increase exhaust backpressure and hence reduce the engine's ability to "breathe" effectively at high RPM, adversely affecting peak engine power.

Conversely, using a larger A/R will lower exhaust gas velocity, and delay boost rise. The flow in a larger A/R housing enters the wheel in a more radial fashion, increasing the wheel's effective flow capacity, resulting in lower backpressure and better power at higher engine speeds."


I thought long and hard on which A/R to use for my build. I ended up going with a 0.64 A/R instead of 0.86 in order to get faster spoolup, hoping the back pressure does not get high enough to significantly impact top-end performance. We'll see how it works when I get it tuned.

 

Ya Terry, know that.

I guess the question is which would spool faster, as spool is a function of velocity and volume (which is more important??)

T4
A= 5
R = 8.6
A/R = .58

T3
A=3
R=3.7
A/R = .81

or a
T3
A= 3
R= 5.17
A/R = .58

Obviously the T4 flows more volume of air but at a slower speed?, so I am not sure if you can compare A/R with different Turbine sizes

*numbers are pulled outta my butt just for comparison

 

^^^

I think the T3 with the A/R = .58 will spool fastest.

Based on my own experience with my Greddy's, I'm assuming that the back pressure will not be much of an issue at low rpms. Thus, at a given rpm (in the low rpm range) there will be roughly the same volume of exhaust gases flowing through each of the turbos. With the smaller opening, the exhaust gasses will be flowing faster, which will help the turbines spool faster. At the higher rpms back pressure will become more of an issue, thus inhibiting the exhaust flow volume and velocity to an extent, and thus turbine performance.

Also, the turbine is smaller on the last hypothetical turbo you listed, which means that it should have lower mass. This also should help the smaller turbine to spool faster. In this regard, you are correct that you cannot really compare A/R with turbines of different sizes. A larger turbine will take longer to spool, even if it has the same A/R as a smaller turbine.

 

Yah. I have a haltech bcs. I have been working on tracking down electrical gremlins myself. Injected has my back on everything I just have to be patient. Those guys work non stop it is amazing.

 

Injected Performance is great to deal with. All the guys are very helpful and I get all my turbo coponents from them now. Shipping is fast, things are well packaged and they always answer the phone and questions that I have.

Top notch service/customer support.

 

a buddy of mine took the waste gate off and snapped a pic for me.... can someone confirm this is the right spring color / psi? its liek dark grey



also I look through the vacuum port/nipple .. it was like half way closed?.. i untighten it, held it where it was fully open and then tighten the bolt up top.

 

They are up there in the same echelon with you Sasha!

 

soem places say its grey for .6 bar.... some blue?... looks right to me


he is taking it for a spin with the wastegate venting to atmosphere...

 

Can you remove the spring entirely. sometimes you'll see the color at the end of the spring. You'll see a paint color and it's not usually the entire spring that is colored.

 

http://www.tialmedia.com/documents/MVS%20Pressure.pdf

Grey would be correct for .6bar.

The fitting orientation does not matter, as it is open inside the bolt dome.

 

....