0TheRadioFlyer97

2 weeks....worth the wait.
for those of you interested in the math, the stock 75mm LS1 TB ported to 78mm gives an additional 3.605cm^3 cross sectional area to the throttle body's interior.

The installation was simple....however my anxiety and stupidity of not letting the car cool resulted in a large coolant spill when i disconnected the TB from the coolant lines.

The installation would have taken probably a half hour or less if i didn't have to walk to the local auto shop (thankfully only 3 stores over) to get the tamper proof torx screws on the TBP sensor and motor switched to the new unit.

Initial response was a little sluggish, but the following morning i definatly felt results. The car just feels stronger and gunning it gives me a much firmer pickup.

An excellent mod definatly worth my time. Kudos to Mr. Shaner for his excellent work.

madmatt9471

Nice! I too had mine ported and polished from LAPD last week!

Do you have any before and after pics or just a new pic of the one you have now?

Did he use epoxy or aluminum on the fillin? Just curious.

Here is a shot of mine:


Thanks,Matt

rws.1

From his web page http://www.s2performance.net/

pictures
http://www.s2performance.net/vettepage.html

94legaleagle

Glad to hear it's worth it - I've got one sitting on the bench ready to install -

madmatt9471

Thanks! Very nice work too!

Thanks,Matt

David426

Did you get the satin or polished.. Is there any performance difference between them besides the extra $30.00?? I'm considering having this done, however I have seen mixed reviews on this forum

0TheRadioFlyer97

i didn't have my camera with me during the install. The before/after pics don't look too different when it's all back together. I believe he used aluminum on the fillin.

The only reason to go with the polished is if the rest of your engine compartment is shiny. There are no performance differences between them.

4BTINGU

Did you have to retune after the install?? Do you need too??

0TheRadioFlyer97

the change in airflow isn't significant enough for a full-on dyno tune, however i am planning on a laptop tune within the month. I'm going to wait on the dyo tune until after the cam.

YO-EL

Mark is the man for sure!

Pwrtrip75

Unless you actually change the size of the butterfly valve in the middle how is this going to flow more air? A funnel with a 1/2" opening on one and a 1ft opening on the other is not going to flow any different of you make the 1ft end bigger. Also making it smoother for the air transition would only be effective on a forced induction engine, seeing air is being drawn through and not pushed. You could cut the entire front of the throttle body off and you will not gain a thing....except psychological gains. I'll make a technical drawing if no one understands the simple physics of this.

gpracer1

Try sucking air through a 1 foot straw.
Now cut 2/3rds off and try again.

Pwrtrip75

The TB is already funneled. Its not a perfect geometrical cylinder. Try breathing through a funnel. Now cut 1" off the big end. As long as the small end stays the same, any larger diameter opening on the other end will have no effect. You can cut the entire front of the TB off and not flow any more air.

Pwrtrip75

I drew something quik.
http://www.geocities.com/nova442.geo/TB_flow.pdf
And on a side note, ported with boost isnt going to create more airflow, but smooth the transition out some. Actual HP gains are probably not even measureable.

0TheRadioFlyer97

your work is partially accurate. Assuming that the fritional force of the air against the side of the intake walls is negligable, the total energy of the moving air remains constant at any point in it's path.

this is found with the following equation: Pressure energy + Kinetic energy + potential energy = constant.

this basically means that the vaccum on the engine side of the TB will cause the airflow velocity past the butterfly valve to be higher than at any other part of the intake tube. The purpose of porting is to create a smoother transition from a larger cross-sectional area to a smaller cross sectional area. This does two things:

a) reduces turbulant vorticies in this transitional area caused by sudden cross sectional area changes. Turbulance causes air to lose kinetic energy and disrupts uniform airflow. Turbulance causes drag which results in slower moving air.

b) Since air is easily subject to pressure change, a faster airflow creates an area of low pressure. Since this air is moving towards a vaccum anyway, the negative pressure is compounded past the butterfly valve causeing the air to be sucked into the TB even faster. The smooth taper of a ported TB maximizes this effect.

The gains on a naturally asperated engine from a ported TB are small but the biggest gain is torque due to a higher air velocity. xmize the effectiveness of a ported TB, a quality intake and camshaft are highly reccomended. Like any performance mod, it's only as good as the weakest link in that area.

Pwrtrip75

You dont need an equation to figure it out either. Doing his mod and expecting kind of gain with it is the same as adding a bigger gas pedal and expecting more power from that.
Your velocity will not change as long as the hole/valve size in the middle doesnt change.

Sleazy Rider

i sent a throttle body off to shaner this past monday, from what i have seen of his work, it will help out a little.