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2011 cts v coupe
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Discussion Starter · #1 ·
So I recently picked up a 2011 V coupe automatic. I could tell that the tune seemed very very docile to say the least. I contacted Jeremy from black market racing who I have trusted with builds in the past and he was a huge help in getting the car up to par and dialed in. His tuner Rhett knocked it out of the park. We had to fix a previous shops piss poor wiring as it wasn’t turning the emp pump on so IAT went high. Then had to fix a faulty flex fuel sensor and we were off and running. Below is the DYNO sheet and mods I have. Let me know what you guys think! I’m super happy and the car really came to life.
Fuel used: 91 octane and then e85

air raid intake w/ green filter
102mm TB
ZL1 lid
Weapon x heat exchanger
EMP pump w/ 8 gallon tank in trunk
2.45 upper pulley
ID 1050x
DSX aux pump kit
DSX flex fuel kit
2in headers to 3 in catless x pipes to stock muffler
Rectangle Slope Font Parallel Technology
 

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Discussion Starter · #5 ·
What percent “E” and no lower? That’s in STD, have one in SAE?
it was reading 80%. We ran all 91 out of it and then put in 10 gallons of e85.

no lower pulley yet. I did forget that the previous owner claimed the blower was ported. However I haven’t had it off to confirm this.

I’ll get BMR to send me a chart in SAE as well.
 

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2011 thunder grey coupe a6 recaros.
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If your running a 102 you at the very least have a ported snout, if you have a ported blower only it could also explain high iat’s
 
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Much smoother
 

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Steve, I know you know this, just thought I would post this for others.

The speed / a given velocity (FPS) through an orifice, is
determined by the size / area of that orifice, versus the
amount of air flow (CFM)that is flowing through that orifice.

While the information below is relative to flow / velocity
on a flow bench using a water drop of 28", the information
is relative, as flowing at a depression of 28" of water is
just about 50% of the velocity seen through a live engine.

So. . .If the velocity value at 28" of water depression is 200 fps,
then the velocity through a live engine would be 400 fps.

This engine is an NA 442 CID SB Chevrolet, which made 901 fwHP.

This amounts to 2.04 HP per CID,
and 1.41 Lbs Feet of Torque per CID.
Font Rectangle Screenshot Parallel Number


----------------------------------------------------------

In past posts I have referenced the use of the 90%
rule regarding MCSA for the intake side.

As you can see below, this puts one right in
the 'Ball Park' regarding the intake valve. . . .

The correct area for the exhaust is highly dependent
on several variables, and is difficult to predict the
appropriate area for best Torque & HP, as related
to the appropriate velocity for a given exhaust port.

--- Cross-Sectional Areas at various Intake Port Velocities (@ 28 in.) ---
127 FPS at Intake Valve Curtain Area= 6.455 sq.in. at .934 Lift
216 FPS at Intake Valve OD Area and at Convergence Lift = .550
267 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 3.079 sq.in.
--- 8300 RPM
Intake Cross-sectional areas in Square Inches ---
350 FPS CSA= 2.343 Port has Sonic-Choke with HP Loss ( too fast FPS )
330 FPS CSA= 2.487 Port may have Sonic-Choke with HP Loss ( too fast FPS )
311 FPS CSA= 2.639 Highest useable Port velocity ( possible HP loss )
300 FPS CSA= 2.736 Smallest Port CSA ( Hi Velocity FPS • good TQ and HP )
285 FPS CSA= 2.879 Smallest Port CSA ( very good TQ and HP combination )
260 FPS CSA= 3.156 Recommended average Intake Port CSA (very good TQ and HP)
250 FPS CSA= 3.283 Largest recommended average Intake Port CSA ( good HP )
240 FPS CSA= 3.419 Largest recommended average Intake Port CSA (less Peak TQ)
235 FPS CSA= 3.492 Largest recommended Intake Port Gasket Entry area CSA
225 FPS CSA= 3.647 Largest Intake Port Gasket Entry CSA ( Slow FPS )
215 FPS CSA= 3.817 Possible Torque Loss with Reversion ( Slow FPS )
210 FPS CSA= 3.908 Torque Loss + Reversion possibility ( too slow FPS )
200 FPS CSA= 4.103 Torque Loss + Reversion possibility ( too slow FPS )
Note : these are calculated average Port cross-sectional areas and FPS

--- Cross-Sectional Areas at various Exhaust Port Velocities (@ 28 in.) ---
127 FPS at Exhaust Valve Curtain Area= 4.252 sq.in. at .846 Lift
268 FPS at Exhaust Valve OD Area and at Convergence Lift = .400
331 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 1.629 sq.in. at 8300 RPM
--- 8300 RPM Exhaust Cross-sectional areas in Square Inches ---
435 FPS CSA= 1.239 Sonic Choke at Throat Area (too fast FPS velocity)
380 FPS CSA= 1.419 Sonic Choke at Throat Area (possibly too fast FPS)
350 FPS CSA= 1.539 Exhaust Port has Sonic-Choke with HP Loss (too fast)
330 FPS CSA= 1.634 Exhaust Port has Sonic-Choke with HP Loss (too fast)
311 FPS CSA= 1.734 smallest Exhaust Port ( very high velocity FPS )
300 FPS CSA= 1.797 smallest recommended Exhaust Port (Hi velocity)
285 FPS CSA= 1.892 smallest recommended Exhaust Port (Hi velocity)
265 FPS CSA= 2.035 Recommended average Exhaust Port CSA
250 FPS CSA= 2.157 Recommended average Exhaust Port gasket area
240 FPS CSA= 2.246 Recommended largest Exhaust Port gasket area
225 FPS CSA= 2.396 Largest Exhaust Port Exit gasket area (Slow FPS)
210 FPS CSA= 2.567 Largest Exhaust Port Exit gasket area (Slow FPS)
190 FPS CSA= 2.838 Torque Loss + Reversion + Scavenging loss (too slow FPS)
180 FPS CSA= 2.995 Torque Loss + Reversion + Scavenging loss (too slow FPS)
Note : these are calculated average Port cross-sectional areas and FPS
 

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@Rubber Duck answered it for me, albeit much beyond what my response would have been. Haha.
My suggestion regarding a good general velocity value through a TB
would be about 100 CFM / Sq." of area, where we desire a 'Mean'
value of about 240 CFM TO 265 CFM when using the appropriate area.

You begin by taking the value of ~100 CFM / Sq." and multiplying
it by the value of 2.4, as is shown within my signature below, which
returns a velocity value of 240 fps. Shrink down the 'Mean' area, and
this will increase the 'Mean' velocity value, as one might desire.

This will then provide for. . .
260 FPS CSA= 3.156 Recommended average Intake Port CSA (very good TQ and HP)
250 FPS CSA= 3.283 Largest recommended average Intake Port CSA ( good HP )
240 FPS CSA= 3.419 Largest recommended average Intake Port CSA (less Peak TQ)
 

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For those interested in what the value of 2.4 is. . .

First we must understand;
360 = ( 12 inches * 60 seconds ) / 2 Revolutions ...for a 4 Cycle

We now can move forward with the following. . .
12^2 = 144
144 / 60 Seconds = 2.4

2.4 = ( 144 Sq.Inches / 60 Seconds )

And for those that work with 'Mass Flow' instead of CFM. . .
1 / 2.4 =0.416666667, or simply 0.4167.
 
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Discussion Starter · #13 ·
Duck is really good at math. My meathead ass went cross eyed reading most of that lol.

will probably leave the car alone for now and enjoy this power level for a bit. Then look into cam and head work if I feel the need for more.
 
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Duck is really good at math. My meathead ass went cross eyed reading most of that lol.

will probably leave the car alone for now and enjoy this power level for a bit. Then look into cam and head work if I feel the need for more.
But the math does lead to a greater understanding, of how much air (CFM) can be drawn through a given induction systems 'Mean Area', and / or it's Minimum Circular Square Area (MCSA), as it will be related to a 'Mean Velocity', which cannot be either too slow, or too fast, or both the HP & Torque will suffer. . . .
 

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Discussion Starter · #15 ·
I definitely am thankful when you post stuff like that as it helps me and others learn
 

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I definitely am thankful when you post stuff like that as it helps me and others learn
I post this type of info, in hopes it will help people learn, and help
save fellow forum members time, angst and of course money..:)
 
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I post this type of info, in hopes it will help people learn, and help
save fellow forum members time, angst and of course money..:)
Actually, it justifies the spending of more money to get the desired results instead of just settling.
 
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