[Stan Weiss]

Someone please help me out with this slow velocity thing.

I keep hearing about slow velocity and numbers around 250 fps.

280 cc intake port with a 5.3" port length has an average CSA of 3.2239 sq. in.

an average CSA of 3.2239 sq. in. that flows 380 cfm has an average velocity of 282.89 fps

Taken from a simulation done using Larry Meaux PipeMax Program
--- 7500 RPM Intake Cross-sectional areas in Square Inches ---
350 FPS CSA= 2.554 Port has Sonic-Choke with HP Loss ( too fast FPS )
330 FPS CSA= 2.711 Port may have Sonic-Choke with HP Loss ( too fast FPS )
311 FPS CSA= 2.877 Highest useable Port velocity ( possible HP loss )
300 FPS CSA= 2.982 Smallest Port CSA ( Hi Velocity FPS • good TQ and HP )
285 FPS CSA= 3.139 Smallest Port CSA ( very good TQ and HP combination )
260 FPS CSA= 3.441 Recommended average Intake Port CSA (very good TQ and HP)
250 FPS CSA= 3.579 Largest recommended average Intake Port CSA ( good HP )
240 FPS CSA= 3.728 Largest recommended average Intake Port CSA (less Peak TQ)
235 FPS CSA= 3.807 Largest recommended Intake Port Gasket Entry area CSA
225 FPS CSA= 3.976 Largest Intake Port Gasket Entry CSA ( Slow FPS )
215 FPS CSA= 4.161 Possible Torque Loss with Reversion ( Slow FPS )
210 FPS CSA= 4.260 Torque Loss + Reversion possibility ( too slow FPS )
200 FPS CSA= 4.473 Torque Loss + Reversion possibility ( too slow FPS )
Note : these are calculated average Port cross-sectional areas and FPS

Stan

[slowbird]

Originally Posted by Stan Weiss

Someone please help me out with this slow velocity thing.

I keep hearing about slow velocity and numbers around 250 fps.

280 cc intake port with a 5.3" port length has an average CSA of 3.2239 sq. in.

an average CSA of 3.2239 sq. in. that flows 380 cfm has an average velocity of 282.89 fps

Taken from a simulation done using Larry Meaux PipeMax Program
--- 7500 RPM Intake Cross-sectional areas in Square Inches ---
350 FPS CSA= 2.554 Port has Sonic-Choke with HP Loss ( too fast FPS )
330 FPS CSA= 2.711 Port may have Sonic-Choke with HP Loss ( too fast FPS )
311 FPS CSA= 2.877 Highest useable Port velocity ( possible HP loss )
300 FPS CSA= 2.982 Smallest Port CSA ( Hi Velocity FPS • good TQ and HP )
285 FPS CSA= 3.139 Smallest Port CSA ( very good TQ and HP combination )
260 FPS CSA= 3.441 Recommended average Intake Port CSA (very good TQ and HP)
250 FPS CSA= 3.579 Largest recommended average Intake Port CSA ( good HP )
240 FPS CSA= 3.728 Largest recommended average Intake Port CSA (less Peak TQ)
235 FPS CSA= 3.807 Largest recommended Intake Port Gasket Entry area CSA
225 FPS CSA= 3.976 Largest Intake Port Gasket Entry CSA ( Slow FPS )
215 FPS CSA= 4.161 Possible Torque Loss with Reversion ( Slow FPS )
210 FPS CSA= 4.260 Torque Loss + Reversion possibility ( too slow FPS )
200 FPS CSA= 4.473 Torque Loss + Reversion possibility ( too slow FPS )
Note : these are calculated average Port cross-sectional areas and FPS

Stan

Not sure where the velocity talk came from (lil jack post?) but Pipemax uses a target velocity of 250-260ft/sec for average port velocity. So if a head is in that range it isn't bad. Local velocities will be higher and/or low.
Pipemax is a pretty darn good engine software tool!

[455GRIN]

Now you guys are taking velocity flow numbers from a plumber?

[Stan Weiss]

Originally Posted by 455GRIN

Now you guys are taking velocity flow numbers from a plumber?

You know you do need good velocity and swirl if you want the chit to flow.

Stan

[PAUL K]

PLUMBERSTTF!

[slowbird]

Swirl is VERY important!

[Slick]

Originally Posted by LiL Jack

BS, velocity sucked so you made it smaller after a few of the good head porters looked it over and then it was changed to a smaller port.

Don’t try to spin it.
If it walks like a duck, quacks like a duck, it’s a duck.

You all need some actual track time and get away from your computers and assumptions.


The BS stops on the ET slip!

Jeff Rana ran 9.7-9.8 in his 3450# 64, N/A with a very early set of CV-1 heads. Not prepped by any guru, not filled in to fix imaginary velocity issues.

Switched to a KRE High Port top end that I never personally saw, but understand it came from a successful team. Jeff can fill us in. Using the HP top end, the car slowed to 10.0.

So Jack, we agree, the B.S. stops on the ET slip.

Does plumber B.S. ever stop?

[LiL Jack]

Originally Posted by Slick

Jeff Rana ran 9.7-9.8 in his 3450# 64, N/A with a very early set of CV-1 heads. Not prepped by any guru, not filled in to fix imaginary velocity issues.

Switched to a KRE High Port top end that I never personally saw, but understand it came from a successful team. Jeff can fill us in. Using the HP top end, the car slowed to 10.0.

So Jack, we agree, the B.S. stops on the ET slip.

Does plumber B.S. ever stop?

A lot of variables in that swap, that you don’t know about.

Bottom line is if they are so great and sold 100 sets over ten years, where are they all at?

[JSPONT]

With all do respect, 9.7 to 10.00 car is not what most are talking about here. That is an average street car now.
Street Outlaw cars can run a high 3 second pass in the 1/8, that is a 6 second 1/4.

With a Pontiac, when you are 7's and below that is a real fast race Pontiac.
This is the race section. I have no dog in this fight but the plumber's car you speak of runs 7's. Few on here should comment unless you are one of the elite. That is just my feeling, so I have no comment on what head is the best. Each head manufacturer has some fast cars.

[Dragncar]

I thinks it funny some crack on "plumber". 95% of you don't have as nice a car or have gone as fast. That's all you can say ? Nothing wrong with plumbers. Its hard work, I have done it.
Jealousy at work here.

[PAUL K]

Originally Posted by Dragncar

I thinks it funny some crack on "plumber". 95% of you don't have as nice a car or have gone as fast. That's all you can say ? Nothing wrong with plumbers. Its hard work, I have done it.
Jealousy at work here.

See post #465

[PAUL K]

Originally Posted by Slick

Jeff Rana ran 9.7-9.8 in his 3450# 64, N/A with a very early set of CV-1 heads. Not prepped by any guru, not filled in to fix imaginary velocity issues.

Switched to a KRE High Port top end that I never personally saw, but understand it came from a successful team. Jeff can fill us in. Using the HP top end, the car slowed to 10.0.

Maybe Mysticmissle will share his experience with us? I know he is running pretty darn good with some E-heads currently.

[Stan Weiss]

Originally Posted by JSPONT

With all do respect, 9.7 to 10.00 car is not what most are talking about here. That is an average street car now.
Street Outlaw cars can run a high 3 second pass in the 1/8, that is a 6 second 1/4.

With a Pontiac, when you are 7's and below that is a real fast race Pontiac.
This is the race section. I have no dog in this fight but the plumber's car you speak of runs 7's. Few on here should comment unless you are one of the elite. That is just my feeling, so I have no comment on what head is the best. Each head manufacturer has some fast cars.

Actually that is the exact range of ET that we should be looking at

Way back a set of head was pulled and a set of CV-1 were installed and the car ran slower. That was the start of the P & G show which continues to this day. With the claim port velocity was the reason the car ran slower.

I am sure others will add or post up different versions of these events.

Stan

[slowbird]

Originally Posted by JSPONT

With all do respect, 9.7 to 10.00 car is not what most are talking about here. That is an average street car now.
Street Outlaw cars can run a high 3 second pass in the 1/8, that is a 6 second 1/4.

With a Pontiac, when you are 7's and below that is a real fast race Pontiac.
This is the race section. I have no dog in this fight but the plumber's car you speak of runs 7's. Few on here should comment unless you are one of the elite. That is just my feeling, so I have no comment on what head is the best. Each head manufacturer has some fast cars.

I might be mistaken but i thought Jeff ran 9.8s with the HP heads. I thought the results from the swap was very close. This 5yrs ago? so i very well could be wrong. Hopefully he'll see this and respond.

[[email protected]]

Originally Posted by Stan Weiss

Actually that is the exact range of ET that we should be looking at

Way back a set of head was pulled and a set of CV-1 were installed and the car ran slower. That was the start of the P & G show which continues to this day. With the claim port velocity was the reason the car ran slower.

I am sure others will add or post up different versions of these events.

Stan

Alot of facts in ths post

[LiL Jack]

Originally Posted by JSPONT

With all do respect, 9.7 to 10.00 car is not what most are talking about here. That is an average street car now.
Street Outlaw cars can run a high 3 second pass in the 1/8, that is a 6 second 1/4.

With a Pontiac, when you are 7's and below that is a real fast race Pontiac.
This is the race section. I have no dog in this fight but the plumber's car you speak of runs 7's. Few on here should comment unless you are one of the elite. That is just my feeling, so I have no comment on what head is the best. Each head manufacturer has some fast cars.

I really don’t mind if someone has a slower car.

We all start out somewhere.

I still remember my first pass: 13.53@105 on 255-60-15 Goodyear Eagle St.
I was hooked from that day forward.

It’s all in good fun.

[Scott Stoneburg]

Originally Posted by JSPONT

With all do respect, 9.7 to 10.00 car is not what most are talking about here. That is an average street car now.
Street Outlaw cars can run a high 3 second pass in the 1/8, that is a 6 second 1/4.

With a Pontiac, when you are 7's and below that is a real fast race Pontiac.
This is the race section. I have no dog in this fight but the plumber's car you speak of runs 7's. Few on here should comment unless you are one of the elite. That is just my feeling, so I have no comment on what head is the best. Each head manufacturer has some fast cars.

I'm thinking that 9.7 to 10.0 is not exactly an "average" street car, if its N/A and really a street car. The Street Outlaws cars are nowhere near real street cars. There are only a few NA Pontiacs capable or low 8s high 7s. And maybe a handful more that can do it with a power adder.

[Stan Weiss]

Originally Posted by Scott Stoneburg

I'm thinking that 9.7 to 10.0 is not exactly an "average" street car, if its N/A and really a street car. The Street Outlaws cars are nowhere near real street cars. There are only a few NA Pontiacs capable or low 8s high 7s. And maybe a handful more that can do it with a power adder.

We could make a list. Note all of these people are /were members here

These come to mind for 7 second N/A Passes
Mike L
John Langer
Dwight A
John Snyder

7 second power adder pass
Billy
Jeff K
Jack P

Stan

PS let me added I saw the Pickett's run an 8.05 but understand they did get into the 7's N/A

Power adder Scott Rex

[JSPONT]

Originally Posted by Scott Stoneburg

I'm thinking that 9.7 to 10.0 is not exactly an "average" street car, if its N/A and really a street car. The Street Outlaws cars are nowhere near real street cars. There are only a few NA Pontiacs capable or low 8s high 7s. And maybe a handful more that can do it with a power adder.

Demons Run 9's, Corvettes with mild mods run 9's, Just about every car with a super charger/ turbo charger 10's and lower.

When you run 7"s and 6's, you really have to know your stuff, if the tune is off, you break stuff. Cars like that are a different than a 9-10 second street car.

9's now are like the old 11's!!!

[JSPONT]

Originally Posted by Stan Weiss

Actually that is the exact range of ET that we should be looking at

Way back a set of head was pulled and a set of CV-1 were installed and the car ran slower. That was the start of the P & G show which continues to this day. With the claim port velocity was the reason the car ran slower.

I am sure others will add or post up different versions of these events.

Stan

Stan, I just feel the guys that are jabbing at each other are the sub 8 guys. There are plenty of every head manufacturer running 8's and up.