For all of those what turbo for "X" hp questions...

[rbsileighty]

I can finally put my TI89 away (I made a program for this)... this is the best turbo calc I've seen so far. Not sure if this is a repost or not, but this is where people should be pointed if they have the what turbo should I get question. Even if you're not looking at a Garrett, but have access to the map somewhere else... the chart it outputs should work for you.

http://www.squirrelpf.com/turbocalc/

Happy dreaming...

[bmadd2402]

Bump for an awesome calc!!!

[l0nestar]

I posted it a while ago. Did not think it produced accurate results :-\ Carl H and I were playing with it.

[Darius]

I played with it for a while trying to get it to match the calcs I had done using other software and hand calcs, and this program seemed to plot my points way to the left of where I had previously plotted them. Anyone else see the same thing?

[rbsileighty]

I haven't actually run it against my program on my TI... but I'll let you know what I get # for #. From memory it doesn't seem to far off though... the lines really depend on where you set your min and max boost (make sure you click "refresh maps")... but again I'll check it against my program

What equations are you using?

[Shocker]

yeah mine start way left, then come over as boost stays steady...

then again they dont even have my version 35r on there.

[cdorhout]

Yes, I see the same thing with my 3076r. Scared me thinking I'm about to surge.

[rbsileighty]

Yes, I see the same thing with my 3076r. Scared me thinking I'm about to surge.

What were your inputs? Just curious...

I'm by all means not defending it... I'll grab my TI when I go home for lunch

I wrote the guy for his equations he's using in the background... hopefully he returns the email

:edit: or I could just read more on his site...

"Well I just recently finished the third version of my turbo calculator, so these are no longer updated or supported. Th Version 2 is very different from Version 1. I used the equation set from Garrett's Turbo Tech Articles linked below. This method starts out by inputing a specific horsepower requirement. In addition, this helps to show a boost ramp up effect which is still kind of beta. The method for determining the boost ramp up is described in the spreadsheet. It is depended on many factors as you will soon see. I am always open to new suggestions and other compressor maps you may find. Just e-mail me using the 'Contact Us' below.. In addition, this spreadsheet is free and please distribute it. On another note, the V1 Turbo Calculator contains the equation set/method that is similar to the method seen in SCC's Articles. Compressor Maps - Garrett, Mitsubishi, IHI, KKK, and Holset. I hope to have some more soon."

Modified by rbsileighty at 11:47 AM 4/1/2008

Here's the info to what he used...

http://www.turbobygarrett.com/....html


Modified by rbsileighty at 11:56 AM 4/1/2008

[Darius]

Yep that is what I used. I went through the turbobygarrett.com website's "Turbo Tech 101" thru "Turbo Tech 103". I'm not sure about his turbo ramp up calc but I just assumed a linear ramp up based on the garrett equations.

[rbsileighty]

This is what he has in his Excel file for "flow"

"Engine Disp, A/F, and BSFC determine the HP Airflow required to accomplish the Target Peak Power inputed. Once the airflow is determined, the column containing the Peak Power RPM point uses this to determine the boost pressure required based on temperature, RPM, and VE. The boost pressure is then distributed amoung all the columns from Max Boost to Engine Redline. Those RPM points use the equations in a "backwards" method to determine the airflow used based on the RPM, VE, and temperature. For the points below MAX boost, it is either assumed or split between the upper and lower point. Airflow is then caclculated again in the same manner as the other points. Latest addition includes Max I/C Loss. This number is assumed throughout the max boost range for simplisity."

I'm digging through my program and comparing where it differs to his... I'll feed back as soon as I find something

[rbsileighty]

The batt's died in my calc (been a while since I've used it) so I lost my program and have to reprog it... I'll get to that soon, but I did get a reply from the guy who wrote the site and he is NOT to confident in the calculations and agrees with the surge bias of the graph. I'll update with what I can find when I get time to reprogram my calc