So you admit that MFs results are meaningless? j/k

 

He's running a lot of boost, and presumably a lot more HP than stock. Maybe the MF makes HP on a stock engine, but suffers on higher HP engines. I doubt they tested with an L with a KB on it.

 

**** Again I will ask, What were your results ? You keep offering a opinion without listing information to make it anything more than that.

 

My results have been posted many times. Do a search, newb ...

 

3300 Posts is alot of searching, I thought it might be easier if you just said, I make X amount more HP X amount more TQ.

 

First, you guys have to realize the limits of the accurancy of the dyno. These things aren't perfect, and do have a % error associated with them.

Second, did anyone bother to check barometric pressure or humidity during your 2 dyno runs? That makes a big difference. Remember, we're talking a measly -7 HP here. A little more moisture in the air and a little less air pressure will easily lose you 7HP.

I am with **** on this. I do not believe a well engineered muffler will lose HP over stock. I do, however, realize that these gains may be small given the efficiency of the stock muffler.

 

If the stock exh isnt a restriction, there wont be any gains found w/ANY other exh-plain and simple. You could take the muffler completely off and not see any gains,probably a loss at certain rpms. The factory exh flows excellent-and is quiet. Aftermarket exh will only provide performance in the sound quality.
And headers are not promising as delivered either. Not that the factory manifolds flow that great, but as the engine was designed to run, they arent a restriction,either. The limiting factor for our 5.4sc exh is at the very beginning,,,the CAMSHAFT exh valve duration/timing and the actual EXH PORTS and valve sizes in the HEADS.

 

a little off topic, but are there any companies making aftermarket modular engine heads? I dont see why they wouldnt make them, I am sure there is power to be found in a set of good flowing heads and cams to take advantage. These engines are the future, I dont see Ford going back to pushrod engines.

Chris

 

The #'s lost were thru out the torque and HP range. I dynoed the truckand the conditions were identical humidity and Barometric and temp. The truth of the matter is: The Magnaflow Exhaust lost power. We monitored the ECT,ACT,TFT, to make sure the truck was runnin at same temps. On the top end there was a 14hp loss at 5200 rpm. The ECT was 184 the ACT1 was 94 and ACT2 was122 the TFT was 130. We used the NGS for the monitoring of sensors. Hope this clears things up. Have a nice day.

 

Your Dyno Methodology is flawed. If you arent going to compare the stock system to the aftermarket system same day, with same cool down and same operating temps, youre disclosing nothing.

 

Not if he's talking corrected numbers. That's what corrected numbers are produced for.

The dyno is a tool - it is not the end all, be all of performance, but rather a means of measuring performance and performance change with a given modification under a given set of circumstances. If he made back to back runs in identical atmospheric conditions, which should be shown on Dynojet's pep program along with corrected and actual numbers, then he's got an accurate of a test as it would be if he had tested on the same day. It sounds like the poster went to great lengths to ensure the same operating temp as well as conditions. His numbers are as meaningful as they are going to get.

my 160hp ZX11 has been dyno'd in excess of 100 times, the Cobra I traded for the lighning, half a dozen times. I had the very same argument about the K&N cone I put on my Cobra years ago on the Corral. I went to a local dyno day, and in front of the operator, and 10 witnesses, picked up 10 hp with ONLY the K&N cone. Backed up in 3 passes - stock, then k&N, then stock, then back to k&N ( ok, it was only 9.9 rwhp but who's counting ) Sure enough, someone from the NE SVT or Cobra email list called me on it, saying "those numbers are worthless because you didn't disconnect the battery between runs & reset the EEC". Ok, a couple months later, when I confirmed 13 degrees btdc with the Steeda timing adjuster was 5 hp over, I yanked the k&N, put the stock filter back & ... disconnected the battery... Sure enough, lost 9.9 hp... Back went K&N, I hot - footed it home & posted my results. That in no way is to say everyone should expect similar, simply that my cobra showed a consistent 10 hp ... and the dyno testing correction numbers do have meaning.

Incidentally, I did have magnaflows on the Cobra, which had a really, really nice sound with the Bassani X pipe - worth 13 hp on my Cobra, btw, when the cats weren't falling apart. I had them cut into my stock cat back in place of the stock mufflers. They cost me zero hp, they gained me zero hp. This guy lost hp across the rev range, and that cannot be attributed to atmospheric conditions if they're the same values on both dyno runs. It could be attributed to another mechanical part, but if the exhaust was the only change, it's also the leading suspect.

 

Maybe Magnaflow has some same day same L dyno data. I'm sure they compared their stuff to what the stock setup offers. They certainly would not sell something that did not make power right? In fact most of the companies out there that sell after market products that claim to increase HP make sure that their products do in fact give the increases promised RIGHT? .

 

EVERYTHING was monitered and was the same. Don,t get upset with me. I didn't make the thing. All that I did was buy it and put it on my truck. It lost horsepower under a same condition test. It still looks about 1000 times better than stock and the sound is great. No one said that it was a bad product, I just said that on MY truck it lost horsepower. Skip

 

Elasped time between tests has nothing to do with their validity. Actually, back to back tests are very seldom equal. Usually the temp is up/down the truck is cooler/warmer, the humidity is different, etc. If they measured all the data points on the truck and they were the same, then it's a valid measurement, within the margin of error for the equipment they have.

In over three years of watching this and other L forums (other than vendor forums!), I've yet to see a consensus that ANY catback exhaust makes consistant hp over stock....period--end of story.

 

All this from a Catback only