Does anyone have any experience with this product (http://www.dieselpowerproducts.com/tag)?

Yes! They do work. Will quiet down turbo whine and does improve air flow... net result of which is less boost required to maintain speed! This tells me the turbo, and therefore the engine is working more efficiently. Difference is subtle... but it's there.

Less throttle needed to maintain a set speed may translate into better mileage... especially if towing heavy.

RJ

I had the TAG I on my 96' with the Scotty II. Didn't notice any performance benefit with the Scotty II. The Tag did remove the high pitch whine from the Scotty II which made the wife happy.

Save your money.

Do a search. There have been many threads on TAG's.

I wouldn't be without my TAG.
It's not for the folks who like to remove their silencer rings though, it will make your turbo whine disappear.
You won't see a lot of performance gains though unless you tow, the higher your boost the better your engine performs. I've told four of my towing snowbird friends about the TAG, all of them have reported better mpgs on hills than on flatland when using the TAG.

If you don't drive for hours on end with boost over 20psi or want to hear the turbo whine don't bother with a TAG.

BTW, the new common rail engines all come with Cummins' version of the TAG.

As was stated, the TAG really shows its stuff for those of us who tow heavy. I bought my TAG for 2 reasons:

1. The turbo whine with the BHAF was driving my wife nuts after hours on the road with the 5th wheel in tow.

2. Pulling hills at 2300 RPM or so in 6th gear (4.10 axle) under heavy throttle, I could get some turbo compressor instability at times. This was not the typical drop-throttle surge or bark, but it was definitely audible.

The TAG took care of both problems.

Again, if you're looking for a quick 100 horsepower, look elsewhere. Whether the TAG is worth it or not depends on what you're trying to accomplish.

Rusty

I wouldn't be without my TAG.
It's not for the folks who like to remove their silencer rings though, it will make your turbo whine disappear.
I use it to soften the noise a little. But I'm not one of those that thinks "the more turbo whine... the better"... so I agree with you.

I left my Scotty II hole to help feed cooler air to the AFE Pro Guard 7 that came with my twins. My 'scientific' reasoning for doing so is... couldn't hurt. :) With the hole it can get loud.

I did 2 hrs of testing on my first TAG - gross wt., 3 miles of 4% grade, 60, 70 & 80 mph... each with and w/o the TAG.
At 60 & 70 mph, with the TAG, I averaged 2 psi less boost required (3 psi less at 80 mph) to maintain speed, with a corresponding 25 - 50* lower EGT.

This was with a B-1 turbo. As Bill said above, heavy towing, with a stock turbo, should produce a bigger difference.

RJ

Thanks guys...... From what I had read I suspected no great power improvement, but assumed more lamanar flow had to be better. The pulling/towing comments hit the nail on the head[duhhh] Good mod for a "working" truck that will be spending it's life pulling loads.

One of the best things about the TAG is that there is a 30 day no questions asked return policy.
If it doesn't do what you want send it back.

Isn't this similar to the device you guys are pullin' outta your '05 and up air ducts?

Isn't this similar to the device you guys are pullin' outta your '05 and up air ducts?Yes it is. Some people mistakenly think it restricts airflow when in fact straightening out the airflow provides less resistance.

The problem comes down to the restricted space under our hoods. Most stationary engines, where space isn't as much concern, have straight section of pipe in front of the turbo to reduce turbulence. There is even a formula used to determine how long the straight away needs to be according to engine horse power.
Notice on a Dodge the intake tube from the airbox to the turbo is basically one big curve, no straight away at all. This is where the TAG and the '05 vanes come in.
I wouldn't doubt that the curved intake tube is the reason for the silencer ring also.

You are correct, sir - if the turbo is screamin', the compressor blades are cuttin' into turbulent air.

Similar straighteners are used thru-out various industries to improve flow efficiency, and are spec'ed at X diameters of straight pipe upstream, and in some cases, X diameters straight pipe downstream.

Upstream = inlet, downstream = outlet

I work for a manufacturer of industrial engines, turbochargers, reciprocating and centrifugal compressors. Our company's engineering standards for installation of our equipment require a minimum of 5 diameters of straight pipe ahead of a turbocharger inlet. Any less and a flow straightener (such as the TAG, turning vanes, etc.) must be used.

Rusty

..... and in some cases, X diameters straight pipe dowstream.
Interesting..... to reduce backpressure? Any more specifics?

RJ

I'm running a TAG right now and I've noticed no difference in performance or EGT's, only noise. But with the KSB-1 and a scotty 2 it's worth the money for the noise reduction.

You probably won't notice any difference when you're blowin' the doors off a Yugo or Geo Metro, as there are many dynamics in that type operation.

A dyno run where the engine\drivetrain is under constant loading, or towing over long distances, stationary engine service, marine service and such is where the difference would be most obvious, as stated above.

Anywhere the engine is under constant loading and producing power in a relatively constant band.

And, you do have straightening tubes, of a sort, on the output of the turbo compressor - take a look at that large aluminum piece between the turbo and the engine.

And remember - the pressure drop across that heat exchanger is not because it is restrictive to flow, but is directly resulted when the temperature of the compressed charge-air is reduced.

Reduce the temps, the gas contracts, the pressure drops.

I thought someone over on the TDR did a dyno test on the TAG, a couple of years ago, and showed a small loss in hp.

Normally when a device like this comes along I classify it as a "magnets on the fuel fuel line" sort of thing. But when guys like rjohnson, infidel, and Rusty come along and sing its praises, I stand up and pay attention. Plus, I know Cummins put an increadable amount of engineering into thier version of it, on the 3rd gens (which, ironically, is usually one of the the first things most folks modifying 3rd gens throw out). So there must be something to it.

My only question is, irrespective of the quality and precision of its construction, why is it so darn expensive?

My only question is, irrespective of the quality and precision of its construction, why is it so darn expensive?Dave of Diesel Power Products (http://www.dieselpowerproducts.com/tag) who makes the TAG told me the honey comb that it's made from is a highly specialized material mostly used in wind tunnels to straighten the air flow. He didn't tell me how much he had into materials alone but I assume it is quite a bit. Then you add in all the time in R&D plus some profit and you have an expensive product.
Still worth it in my situation but as said- it's not for everyone.