Online Turbo Calculator

[DSM90AWD]

http://not2fast.wryday.com/turbo/glossary/turbo_calc.shtml

This may / may not be accurate and although it does ask users to estimate VE, BSFC, AFR, it is still pretty helpful in graphically illustrating how changes in turbo/boost pressure, IC efficiency, RPM, VE, Air Temp..etc all come into play to determine Airflow and HP

Another nice feature is the max airflow overlay on several different Compressor Maps (yes these are the lb/min maps ). Note that in selecting a properly sized turbo you should run the calculations for several RPM/Boost/VE scenarios based on what you'll be expecting to run.

FYI.. Inputing my vehicle-specific variables did yield a reasonable Airflow estimate (42Lb/min @7K RPM).

Just compiling some of the users inputs:

Convert F to C

4G63 2.0L
Bore = 85mm
Stroke = 88mm

4G63 2.3L
Bore = 85.5mm
Stroke = 100mm

4G64/4GCS 2.4L
Bore = 87mm
Stroke = 100mm

VE = 100% @ 6K, 94% @ 7K, 87% @8K (Base VE Table on DSM Link v2.5 manual for RPMs > 6K)
** note that all cars have different VEs and this is just on case on a lightly modified DSM that DSMLink uses for their base VE map.

BSFC = .60 (RC Engineering)

Would be cool if a few of you could hash thru it to see if it has some degree of accuracy and give feedback as to reliability (if any)

 

[napkinthief]

This is very much like desktop dyno. Later tonight when I get some time I will put some numbers into both of them and see if the results are the same.

 

[90AWDTalon]

Something is wrong with there calculations. If you lean the motor out you loose horsepower. Richer gains horsepower. And I'm talking large amounts.

With the settings I inputed;
10:1 = 441hp
11:1 = 401hp
12:1 = 367hp

Defineatly not right.

 

[DSM90AWD]

Something is wrong with there calculations. If you lean the motor out you loose horsepower. Richer gains horsepower. And I'm talking large amounts

I haven't delved into the HP Calculation side yet, though your findings could be explained by the fact that running overly rich would also increase the Specific Fuel Consumption.

Running the calculator for 11:1 @ .60 BSFC and 10:1 @ .65 BSFC, I get similar HP estimates.

How did your airflow numbers come out?

 

[deletrius]

Something is wrong with there calculations. If you lean the motor out you loose horsepower. Richer gains horsepower. And I'm talking large amounts.

With the settings I inputed;
10:1 = 441hp
11:1 = 401hp
12:1 = 367hp

Defineatly not right.

Nope, when you lean a motor out you gain horsepower at the expense of the engine's life. More air = bigger explosion, but can lead to detonation. You only gain ponys by making it richer when you have a large turbo to offset the amount of fuel you are adding.

 

[DSM90AWD]

Nope, when you lean a motor out you gain horsepower at the expense of the engine's life

He was referring to the calculator itself (the topic of the thread) which is purely a "benchracing" tool. If I enter 2:1 AFR with all other inputs the same I get > 1,000 HP which is obviously not realistic (or possible). But, as I mention above, AFR and BSFC are related (as is VE). So if one does changes, the others will also.

You only gain ponys by making it richer when you have a large turbo to offset the amount of fuel you are adding

That makes no sense but unless it directly relates to the subject of this thread please don't elaborate here.

A smaller less-efficient turbo will generate more heat which running a rich A:F ratio can help offset knock (again at the cost of an elevated BSFC). A larger more-efficient turbo at the same airflow levels would be able to run leaner A:F ratios without knock

 

[90AWDTalon]

How did your airflow numbers come out?

At first before I found the error with the afr calculations, I put in 10.9:1, which is what I am currently running, and the airflow came out to 47.xxxlb/min at 6500rpms, the last time I datalogged a run at this same boost as I inputed into the calculator I logged 47.xxx lb/min. I think that the airflow changed when I changed the afr however, I'll have to check when I get home.

 

[Turbocharged]

I stand to make some 500 extra hp if I go from my 150cc water injection to 5000cc's.

Programs like this always interest me but they are far from accurate. I do like the compressor map graphing though.

 

[90AWDTalon]

I think that the airflow changed when I changed the afr however, I'll have to check when I get home.

I remembered wrong, the airflow didn't change with afr.