[QUOTE=MugenRioS2k,Apr 14 2009, 09:40 AM] In the end believe what you want.....turbos run on heat or they don

 

Heat into the turbine is a bigger deal than most people realize. Ever seen those rear mounted turbo setups made by STS turbo? You can roll one of their cars onto a dyno cold, make a pull, and have a boost curve that looks like it's got a centrifugal blower on it. Then you can give it several seconds of WOT with the dyno loading it down to get the exhaust pipes and turbos nice and hot before making another pull, and you get quick spool like what you get on the street with the car fully up to operating temp.

It's important to have some real heat energy going into the turbo, but that statement that turbos run on heat is an oversimplification of cosmic proportions.

 

There is heat going into the turbo but it is not really being used for anything significant. Its just passing through


In the case of the STS system it takes a while for there to be sufficient pressure differential accost the turbine to get it to spool because the entire exhaust piping must be filled up before the pressure differential reaches the threshold necessary to turn the turbine. Hence most of there setups do not reach full boost untill around 4k even on a +6.0L motor.

Also the return piping must be filled to get positive pressure in to the manifold.



you mentioned heat on the street in the STS systems that because the oil temp and thus the viscosity of the oil at start up is causing a lot of drag in the turbo bearings.

These do not look like a centrifugal boost/power curve to me.







Have you seen a dyno that has a Tq/boost graph that shows a similar profile to that of a centrifugal... Wonder if they received the wrong turbo.


Not sure if you guys know this but Garret actually builds the turbos STS uses with very specific AR and trim parameters to try and compensate for the lower exhaust velocity speeds and the higher mass density at the muffler instead of the higher velocity exhaust directly coming out of the head.

I have my sources.

You can't ignore the fact that STS took an excellent and innovative approach to solve the problem of turbo based FI on cars that do not have sufficient area under the hood or where under hood temps are a problem.


When there is sufficient room to put a turbo under the hood and temperatures are not an issue then a traditional Turbo is the better option the the STS turbo.

 

I am aware of all that. My info about the sts kit that looked like a centrifugal boost curve was a post on another site where an owner asked one of the sts reps how they got such nice looking dyno charts when his wouldn't spool properly on the dyno. The sts rep told him how they ran it with the dyno loading it down to heat the system up prior to making a power pull, and then there were images posted of the dyno sheets.

 

sounds like the dyno operator/ or the owner of the kit in your case did not know what they were doing with this kit.


I always set the dyno to load at 3 to 3.5k rpms and get the turbo starting to spool and then let the load hold go so the rpms can ramp up. (Dyno dynamics).

I only hold the stage load for about 1/2 to 1 sec.

 

this is turning out to be really informative.... ive learned a lot just in reading this thread a few times lol.... and it comical besides lol.... thanx guys.

 

Yeah don't get the nerds started on theoretical discussions. You might get more than you bargained for

 

[QUOTE=urBan_dK,Apr 15 2009, 10:40 AM] Yeah don't get the nerds started on theoretical discussions. You might get more than you bargained for

 

I used to have a miata for years. It was turbo for 5 of those years. Corky knows a lot, i would trust him before you....sorry.