A Couple Stock Specs ?s

[Weatheralls Auto]

I am not an Engine builder by any means, very FAR from it lol.
But am learning.

I am trying to get the most accurate info on a Stock LX9 for a Base for a project.
I have a few questions, (some I should know the answer to but school was to many years ago!! )

Volumetric Efficiency (VE) WHat would the 3500 VE be? I have been guesstimating 83%?

By using 83% VE from ^ I calculated (CID x RPM / 3456 x VE % = CFM ) that a 3500 WOULD NEED almost 350 CFM (@83% VE 432 @ 100% VE ) at a max RPM of 7000 Rpm.

So thats what the 3500 would need, how do I find out the CURRENT Avg CFM of a STOCK 3500 LX9 ?

[robertisaar]

you have desktop dyno, it calculates it for you...

[Weatheralls Auto]

I see the Air flow calc, trying to find a quick tutorial on it as I am not sure what to punch in lol,
With that said, how would DD know what the TB is and how it flows?

Thanx for helpin out this Ol Newb!

[Weatheralls Auto]

Alsso, I did find this, however it seems pretty old and was relating to Old Small/Big Block V8s

Notes: Most Street engines are capable of achieving only about 80% VE (Volumetric Efficiency). A modified street engine with ported heads, headers, intake and carburetor can achieve about 85% VE. With extensive head and valve work and a new cam an engine may reach 95% or even more. It's normally not possible to achieve VE's over 100% without some form of forced induction.

What would you figure the Stock 3500 is? (no porting etc)

[robertisaar]

the TB would be the induction flow number. start with what is correct, then scale down if necessary to correct HP/TQ numbers due to other restrictions, such as a horrible downpipe or anything else that could effect it.

[robertisaar]

as for what i think the stock 3500 is capable of:

that answer your question?

[Weatheralls Auto]

Ok, I see where you are coming from now, ^^^

Thanks for the help, much appreciated!!!!

[Superdave]

Here is what a built 3500 will do...

[Weatheralls Auto]

I am attempting to get the most accurate numbers for a base,
Then add my turbo, so I can figure out my injectors and fuel pressure etc to run.

The numbers I got for the stock 3500 TB was 327CFM,

So, does this look correct for a complete stock 3500 LX9 ?

[robertisaar]

your lifter acceleration rate is crazy, which is why the low end torque is WAY too high...

[Weatheralls Auto]

Ahhh I missed that,

2.23, that would be accurate? anyother screw ups?

[robertisaar]

i'm assuming you are going off of my stuff? i have a 3500 setup in there already done...

but i think you have it right now.

EDIT: may need to tweak induction flow a bit more to get the stock numbers...

[Weatheralls Auto]

Yes I am, but trying to learn as I go,lol, main thing I changed from your file was the CFM, you had 200 in there, and my research gave me 327cfm for stock TB and 440 for the WOT 65mm TB.

If this is correct? my next step is to get the info on the Turbo I am looking at ( or other Turbos if this one is not appropriate)

[robertisaar]

true that the TB flows at least that well, but the downpipe interferes with the flow capability, lowering the power quite a bit. those numbers would be correct for a well-thought out and proper exhaust system.

[SappySE107]

Stock 3400 TB is 327 @ 1.5hg (56mm). Stock 3500 is 65mm, so identical to the TCE Billet TB. Stock 3500 is drive by wire so you can't use it.