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Over time on TS I have read a number of post about "porting" a TB. All I have ever really seen is the TB being polished. Porting involves reshaping something having to do with the airflow into and out of an engine and the TBs I have seen on TS are not reshaped; only polished.

 

You usually see "porting" used right next to the words "cylinder head." That is because a cylinder head is an integral component that controls how air flows in and out of an engine. By reshaping and enlarging (usually but not always) the ports, you allow the engine to take in and expel more air. When you do that, you can add more fuel which, in turn, produces more power.

 

Polishing a TB is probably okay and will do no harm because no fuel is introduced within the TB itself (that takes place in the heads).

 

Contrary to popular thought, polishing a head usually speaks to just the exhaust side and specifically not to the intake side. Cylinder intake surfaces are typically deliberately textured to a uniform "roughness" to encourage fuel deposited on the port walls to quickly evaporate. There is enough science behind this to put you to sleep but trust me that there are additional reasons for a textured surface on the intake side. Exhaust ports can be smooth finished because of the dry gas flow and to minimize exhaust by-product build-up.

 

Having said all that, your TB looks super!

 

Jim

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Very true, Jim!

 

That TB does have some reshaping that might reduce flow resistance a bit. Can't hurt, imo.

 

 

 

...see below re the truly superb L&M TB (literally the best TB in the Eaton-compatible bolt pattern).

 

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With a supercharged car -- especially with a fixed-displacement SC for which it's volumentric efficiency is partly dependent on very low negative intake pressure drop -- a meticulously ported and polished TB can add signif HP (with no other changes) and enable even more HP (by raising the flow point at which SC efficiency is impacted) which can be even further uncorked with exhaust mods and pulleying, etc.

 

The L&M TB (soon to be released) is an all-new from-screatch design (like no other availble) that adds +/- 16HP on a bone stock GT500 but also adds +/- 37-44HP on a TVS at 16# with long tubes and optimized intake and exhaust) with no other changes except bolting on the TB ...so much so that one can even back off to a slightly larger pulley on the TVS and still make the same HP -- more efficiently.

 

It will be available shortly (very shortly) for those interested ...check out the L&M TB thread here on TS or, for more, check the L&M TB and Plenum threads on Stang Mafia (engine section, I think?). In testing, the L&M TB blew away every other bolt-compatible TB, including the CJ and the big Monoblade and does it with true factory driveability (unlike some others) because it was designed to respect Ford's calibration engineering (servo curve, etc). It's got loads of tricks engineered into it.

 

Based on extensive independent comparative dyno testing Evo did last weekend they are buying the entire first-production run!

If you're also a Stang Mafia member there'll be an intitial group buy at a special price but you have to get on the list over on Stang Mafia now. Check it out if interested. Good stuff!

 

-Dan

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thanks guys.

the rod was removed from the front side and is only on the back now where a stock TB has the rod on both sides. yes there is quite a bit of material removed from the center of the TB and the whole thing was polished. i figure it cant hurt and i might pick up a few poneys at the same time.

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thanks guys.

the rod was removed from the front side and is only on the back now where a stock TB has the rod on both sides. yes there is quite a bit of material removed from the center of the TB and the whole thing was polished. i figure it cant hurt and i might pick up a few poneys at the same time.

 

Looks good and every little bit helps!!

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thanks racer

i took her out today and there is a noticable difference in the response and mid to top end power. i dont have a dyno close by so no info on how much it added if any as far as HP but i do like the results and in the end thats all that matters right. lol

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thanks guys.

the rod was removed from the front side and is only on the back now where a stock TB has the rod on both sides. yes there is quite a bit of material removed from the center of the TB and the whole thing was polished. i figure it cant hurt and i might pick up a few poneys at the same time.

Thanks for that information. I would love to see it charted where material was removed. I always have wondered if the factory knew it would perform better shaped differently and the bean counters required it to be shaped as it is. Someone who knows what he is doing can always make it at least a little better. Sounds like, in your case, it was more than that. If you can actually "feel" it, it is real.

 

Jim

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I suspect, but dunno, that it's partly cost and partly inertia/history. Ford likely spec'd a flow rate for the TB that would support the target HP with a nice buffer built-in, and the vendor probably delievered a TB with that flow rate (likely there were a lot of other specs for this fly-by-wire TB too ...sensor specs, rotational forces/angles, stops/sets, servo specs, gears, spring forces, and so on...). Now, the vendor could have done a scratch-optimized design which would have permitted a much smaller openings at much greater expense or, they could have done a scratch-optimized design that could support 1,500HP also at much greater expense, or they could take an existing/proven TB design modified to spec for fly-by-wire specs/fenesration and just punch the bores out to the necessary flow spec ...with less effort/cost. :shrug:

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Thread drift special:

 

Let's say your (anyone's) SGT is showing 300 HP at the rear wheels. Let's say you make an improvement to the power train (any component). How many HP, or what percentage increase must there be for a driver familiar with the car to sense the change in road performance? One percent? Five horsepower?

 

I'm a great believer in the kind of improvements represented by "porting and polishing", within the bounds of the sleep-inducing science mentioned by Jim. I'm just not convinced that any single such procedure will yield anything but psychological uplift. I've spent a great many tedious but happy hours grinding passages and matching ports, and in all honesty, the cars receiving these ministrations really seemed to come to life, just lope along with less throttle, and growl more ferociously when opened up. But I don't have any controlled data sessions to support those impressions. No before/single-change/after dyno charts or lap time logs. Testimonials only.

 

In my reading I have learned that we humans are able to make and report ridiculously fine discriminations in every sensory modality. Automobile driving calls on all the senses, so there is potential for recognition and expression of tiny differences. I want to know what, and what size, are the differences that tell us our modifications have had a significant effect.

 

If I were editor of a car magazine and drove a dozen different examples every week, I would probably develop a relatively precise language to make notes and tell myself what I was experiencing. No reason I shouldn't be able to do that with my own stable of four, if I paid attention and was motivated. But even - especially - an experienced car mag editor sees the value in laying as much science as he can on his tests.

 

The editor is doing his judgments on a car-to-car basis, mostly. We'll do it in a before-mod to after-mod comparison, and we too should put as much science on it as we can. So, when we say, "It's much more responsive", what do we mean? More acceleration for less throttle? Less time between throttle-push and neck-snap? "My ears pop sooner than before"?

 

Most of us don't have the resources to do much more than that. Pretty gross measures in the context of 300+ HP, 3700-pound machinery. Lucky me: I'm fifteen minutes from an eighth-mile horizontal dyno at Qualcomm Stadium. RaceLegal runs Friday night drag races there two or three times a month. Granted, the track is not usually well-prepared in professional terms, and some of the readouts are a little suspect, but if you get there early, make your changes between samples (passes), you might be able to generate a little scientific-like data.

 

Even luckier, last Friday was the second week in a row, and between them I acquired a set of BamaChip tunes (91 octane)(eh, it's California). So I was able to run tire pressure tests week before last, and Tune tests last Friday, under very similar conditions, in the same car with no other changes. Elevation is in the 50 to 60-foot range. Temperatures and humidity were close to the same. Moon was fuller, second time.

 

Test car is a 2008 GT/CS automatic convertible, 2,100 miles on the clock. "Bullitt" FRPP CAI, GTA mufflers. About five gallons less gasoline in the tank, second day. First week was all top-down runs; after probably sixty passes with the top down in this and the previous V6 convertible, they finally said I needed the top up or a full-face helmet (boggle). Same everything else, as near as I could tell.

 

With the Torque and Race tunes, the car chirps the tires on the 1-2 shift; gear changes are dramatically quicker, on the order of one-fourth the elapsed time between one gear and the next; shifts are much sharper, by which I mean to say quicker in time and with no perceptible "taper" to ease from one to the next. Gear changes with wide-open throttle are at 6,000 RPM, close as I can tell. In the Torque Tune, the exhaust note is "punchier" than stock, to my ear; "taut", "tight" also come to mind. I don't know how to measure that. I haven't driven the other tunes on the street, so I can't report their sound differences, if any. It takes a much lighter touch on the pedal to increase acceleration; neck-snap latency is reduced. In "D" the transmission stays in lower gears to higher RPM on light throttle. I could be in 4th overdrive by 25 MPH on stock tune: it won't come out of third until more than 35 MPH.

 

I think I have eliminated all the transcribing errors. Perfect Reaction Time is 0.500. I converted red-light R/Ts to positive difference to make it easier to get them into the spreadsheet. I believe the left lane is slightly faster than the right. I tried to use the same technique for each launch: just enough "burnout" to dry the water off the tires; brake-hold at 1,500 RPM; slap the throttle when the second light goes off; let the wheels do what they will; accelerate well past the finish (I like braking, too)(amazing to me how many opponents quit while they are behind, and how many sandbaggers are there looking for a cheap trophy). I actually had the impression my best run was that good; otherwise, only a very general "better" or "not so good", not always correct.

 

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by more responsive i mean that there is more acceleration for less tip in than with the old TB and by mid to high end power i mean it pushes me back in the seat and snaps my head back shifting at 85 to 90 when passing cars from 55. with out any way other than illegaly racing on the street i have no other way of testing a mod within a 2 hour drive of me.

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