Sorry guys. It's not what it Claims. It only raised horsepower levels about 4 ponies and torque numbers around 7.http://dieselplace.com/forum/smileys/Cry.gif This was installed in the same place as they show on there website and after the factory Cat. The 32 horse increase there getting I didn't see. EGT's also stayed the same. The testing they did had to be on a non Cat truck. Great for those that don't have one but what about those that do and all the new ones being built. The pictures imply different in my mind. We ran 2 tests with it closed and 2 with it open to show the consistency. If anyone has any questions just let me know. I plan on having it at the next So. Cal. Dyno Day If anyone wants to see it. Hopefully we can install it again after the 4-bolt flange (By-by kittie) and see it run against one of the aftermarket exhaust.


The drone by the way is horrible when dumped underneath the truck. It was drove to the Dyno closed and open on the way home. Now if you wanted it to run a second pipe to the other side for when you're being polite to your passenger and need to blow smoke out the other side of the truck.http://dieselplace.com/forum/smileys/HiHi.gif


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http://www.dieselplace.com/forum/uploads/Run_4.jpgEdited by: Terrain Twister

Does it seem sluggish on the bottom end or stay about same. Seat of the pants feel
Scott

On a turbo motor, you should install a cutout as close to the turbo as is feasible. The turbo supplies backpressure whether or not there is an exhaust system. Installing after the cat just proves how restrictive the muffler is.

Texas, Feels about the same.


McRat, I agree, it needs to be as close to the turbo as possible. I installed it after because so many are not going to have a choice if they drive their trucks on the street and have the emissions testing to comply with. The other reason was that Speed Pro has a picture of a black Dmax that they have it installed on that has the Cat. IMHO, if their showing pictures of the very trucks the claims are being made for, those claims should match the installation.


Guys, I'm not out to disprove the Speed Pro product as a bad item. I was honestly hoping to see it work to the claims. The problem is they only tested it against one truck and yet they show it installed on many in different applications bypassing the muffler only.


I Plan on bringing it with me to the next So Cal Dyno Day at J&D Performance. If anyone wants to run it on their own truck I have no problem. I'll even have it set up to bolt up to the 4-bolt flange. Let me know if any wants it set up for 4" or 3.5". Or someone can bring a adapter. I have a spare 4" clamp I'll bring.

Terrain Twister ---- Thanks for your testing report on the 4” Street Pro Cutout --- There may be some misunderstandings about what we try to do at Street Pro, but one thing we have never tried to do is mislead anyone about our product and the results we have seen in a particular application. “Technical” guys like you do us all a service by being willing to put a product to an honest test. In that spirit, we would like to make a few brief comments.

First, please note that we provided a Power Master unit FREE of charge knowing that it would be used for testing. I don’t think I’ve seen another “cutout” producer step up to the plate like that. I’m sure you have seen other cutouts and I hope you will agree that the Street Pro product is far superior in terms of construction, design and function.

Second, as you know, a cutout, no matter how well designed, can only “make available” that power which can be gained by reducing exhaust backpressure and EGT at the point it is introduced into the system. We would have been shocked to see anything like 32 horsepower produced on a stock truck simply by adding the cutout to the system. Street Pro has NEVER claimed a 32 HP gain on a stock truck. Our Dyno results on a “stock” chip setting with stock (no cat) exhaust did show an improvement better than the numbers you report, however, nothing like 30 + RWHP. Please note that our brief description on the web site says “Dyno tested 32 RWHP gain on chipped Duramax with stock exhaust. Results will vary.” So where did the 32 hp gain come from? Perhaps it was the result of EGT reduction at higher “chip settings” thus allowing the engine to continue building power. Or perhaps also from a reduction in exhaust back pressure at higher horsepower settings. Maybe we had more “potential” HP to work with due to not having a cat in the system. You and others are better equipped to address the question than we are. We only reported what our dyno shop reported.

Third there is the question of “sound”. Truly what is music to one man is noise to another (I love AC/DC very loud – My Mother In-Law thinks I’m crazy). We have well over 100 electric cutouts in service today. We have received comments from “it doesn’t make the noise I wanted” to “how can I reduce the noise?” We have seen (and heard) a few diesel trucks with “under belly dumps”. While this is “cool” on a 600HP F-Body, we personally don’t like it on a Dmax or Power Stroke. We prefer a pipe routing the “free” exhaust to the area in front of the right rear tire, however, that’s personal preference. This is the reason we show various installation photos on our site. If it feels good, do it!

Again, we truly do thank you for your input.

Street Pro,


1st: I applaud you for understanding that I'm not out to attack you or anyone/thing else. I do feel that more testing to back up any claims should have been done. But that's personal preference.


2nd: Yes, I agree it's a better design than the others I have seen. I also feel the construction is good, but has room for improvement. But again, personal preference.


3rd: I completely agree with you on the noise. That is all personal preference. I was just giving mine and didn't mean for anyone to take it as the final word.


4th: Any company that is willing to hand out a product FREE of charge for unbiased testing deserves recognition. It takes guts and confidence to do this and to many don't. Word of mouth is the strongest advertisement out.


I will be doing some future testing of this unit to see if it helps with any power upgrades and would be happy to forward those results to you. Please feel free to post and/or PM any questions you may have.


Chuck

http://www.dieselplace.com/forum/smileys/Big Smile.gif Gotta love posts like these: good intel; honest discussion; no name calling; no product bashing. I'll deal with a company that is honest about their products and stands behind them. Hats off to all that posted! JJ

Twister,


Thanks for the response and the effort you have put into this. We are anxious to hear any comments you may have as you continue the testing using various configurations. I will PM you regarding areas you feel could use improvement in the construction. We appreciate any suggestions.


Thanks,


Richard http://www.dieselplace.com/forum/smileys/Approve.gif

http://www.dieselplace.com/forum/smileys/Big Smile.gif Hats off to all that posted! JJ


Thanks JJ, http://dieselplace.com/forum/smileys/Clap.gif


Richard

Thanks JJ,


Chuck

I've played with cutouts on GM gas engines a bit. They work only if the existing system is restrictive. To give you an idea to compare to, a 388rwhp Corvette engine only gains 6rwhp with a cutout when using the stock mufflers. Why? The stock muffler is only losing 6hp.


As your HP goes up, so does the benefit of a cutout. I will be putting a cutout on my truck near the turbo downpipe. I will open it only at the track or when I needs mo' powa'.


PS - 4rwhp is still a gain. Not all mods make gains, and some actually lose power. There are many mods that cost over $500 that get 4rwhp and less on cars. But you get 4 here, 6 there, 3 here, 7 there, and you have 20rwhp.

It does make sense to think that the stock muffler is not too restrictive for a stock truck. As the power lever increases, so does the need for air. That's why some intake systems don't look very good from a stock standpoint but are good on a moded truck. If more air goes in; more air most go out and you get closer to the limit of the stock muffler.

I see intakes and exausts as helpers to reach the full potential of your other performance enhancers that DO generate more power (chips, programmers, turbo, injectors, nitro, etc) because intakes and exausts don't realy "generate" any power themselves.

You can't blame a cutout for not generating any power; it has to be there in the first place AND restricted for a muffler, cutout or straitpipe to show some improvment.

I've played with cutouts on GM gas engines a bit. They work only if the existing system is restrictive. To give you an idea to compare to, a 388rwhp Corvette engine only gains 6rwhp with a cutout when using the stock mufflers. Why? The stock muffler is only losing 6hp.


As your HP goes up, so does the benefit of a cutout. I will be putting a cutout on my truck near the turbo downpipe. I will open it only at the track or when I needs mo' powa'.


PS - 4rwhp is still a gain. Not all mods make gains, and some actually lose power. There are many mods that cost over $500 that get 4rwhp and less on cars. But you get 4 here, 6 there, 3 here, 7 there, and you have 20rwhp.





So, then, it will always be open?http://www.dieselplace.com/forum/smileys/Big Smile.gif

Twister you said you installed it post cat for emission purposes. There should be no legal issues with installing it pre-cat. The logic in that being when on the steet (DOT jurisdiction) you would be running the cut-out closedhttp://www.dieselplace.com/forum/smileys/Wink.gif. And on the track the cut-out would be open, and DOT has no jurisdiction there. Just make sure you flip the switch to the closed position when you pull up for testing.

Crawler,


Unfortunately, the way the emissions laws read is something like this: If at any time it can bypass or exceed the set limits of emissions (this also apllies to the tuners), then it is considered unacceptable and not legal. That why the tuners are all tested at their highest settings. The Banks Six-Gun I run for example is not legal because settings 5&6 wouldn't pass even though 1-4 probably would.


I don't know the law however, this is just what I've been told and understand. I would also think that different states might have different interpretations of performance add ons and emission laws. Either way, I'm not qualified to say what is or isn't legal.

We are spliting hairs but it would not be legal installed pre cat. open or closed. The law is very clear in this area of the exhaust system. You cannot modify anything pre cat. but can do whatever you like post cat. Just so you know it's the federal anti-tampering provision this violates so if it's on highway anywhere in the USA the law applies. In CA and a few other states the state law extends the anti - tampering provision to include offroad as well if it is registered as an on road vehicle. http://www.dieselplace.com/forum/smileys/Disapprove.gif