| From | Message |
Ian
Dodge Dakota
JOIN HERE
1/29/2003
23:27:22
|
 Subject: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
"Okay the saga of the muffler is over and I'm VERY happy guy. I've been through three mufflers now and I think I have found the perfect solution for my needs and desires.
I wanted a nice sounding muffler that really performs and wasn't just a cosmetic upgrade like many are. I didn’t want to be drowned out of the D while driving either. I talked to Gibson and Borla and they won't even quote performance numbers but Gibson told me it was "about 5 HP". After looking around I found that Magnaflow makes a catback/muffler system that will add 20.9 rwhp and 19.7 ft/lbs of torque. That is huge! I installed it and all I can say is Wow. I've attached an actual dyno chart for the 4.7L D and in the rpm range that the dyno chart says it should you can really feel it. It should add about 1.5-2mpg also. I think that you would get 80 to 90 percent of that improvement just cutting the muffler into the existing pipes and it is a very inexpensive way to go. I recently read an article where they did that and the difference from a 3” and a 2.5” pipe was no more than 15 percent it was quieter. I went the 3” all the way but at the time I didn’t know any better, now I do.
The best part is it is only slightly louder than the stock muffler. No droning at speed, heck if I have the radio on I can't even hear it. Don’t get me wrong, when I stomp on it I can hear it and that is the fun part. Around down and normal driving it is a nice mellow tone that I really like.
Sorry I couldn't post the pic of the dyno he included but just follow this link:
http://www.durangoclub.com/ceilidh-cgi/ceilidh.cgi/ceilidh/?C33fe2d4a019T-4775-820+0d.htm&framed=&xroot=3fe2d4a019T-4775-820+0d.htm
|
ShortSport
GenIII
 
1/29/2003
23:41:54
|  RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
ian i have the same setup ....mine is a duel system stainless. and i have said it before on this site its the best performance cat back you can by. and by the way i to felt the gains.
2002 Reg cab 4x2 4.7 5-spd 3.55.1 LSD
fiberglass tonneau cover; stainless steel cat-back dual exhaust; magnaflow muffler
Go hard or go home!!
|
lacent
Dodge Dakota
JOIN HERE
1/30/2003
00:47:56
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
well if we wanted all the pipes and all how much would it cost?
|
Ian
Dodge Dakota
JOIN HERE
1/30/2003
00:51:11
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
Shortsport...by dual system did you mean just a single inlet and duel outlet muffler or a full on dual catback system?
|
Texas Todd
Dodge Dakota
JOIN HERE
1/30/2003
09:45:01
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
Ian, Or Scott?
That link took me to a page with an author by the name of Scott.
A stock 4.7, only putting down 177HP at the wheels? Sorry, no jive allowed here.
With the catback, it put down what stock 4.7's dyno at!
I'm not saying there are no gains,
but I smell BS from that dyno post!
In fact, stock 4.7's usually put down around 200rwhp, where did this 177 come from, going 3/4 throttle, to try and sell these catbacks?
Anyone with me on this one, just the facts, I'm not saying there are no gains, but if this dyno sheet was from a 4.7(which is NOT indicated), then WTF?
|
notchlx
Dodge Dakota
JOIN HERE
1/30/2003
09:59:44
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
I have a hard time believing 19RWHP out of a muffler myself.
The dyno did not say what tranny the Dakota had. Most 5-spds are dynoing in the 200RWHP range, and autos 180-190RWHP.
The torque on the chart tells me it's an auto. As this number is too low compared to many 4.7 5-spd dyno's I've seen.
My 2000 5-spd dyno'd 201RWHP and 273RWTQ stock.
I also performed a little test of my own. Flowmaster 40 series. Absolutely no change what-so-ever. Same HP and Torque. It was a single in single out muffler with a turn-down.
Any gains from a cat-back on a 4.7 is great, with no other mods, but 19RWHP That's over 20HP at the flywheel, from a muffler? Is the dyno sheet from MAGNAFLOW? If so, there's your answer.
|
Spuds
Dodge Dakota
JOIN HERE
1/30/2003
10:55:51
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
I have a 2001, 4.7 Litre V8 with 21000 kil. I am considering adding a 3 inch magnaflow system including a free flow cat. I am wondering if that may void my warranty. Anyone have any experience in this regard? My exhuast shop guy says there is no advantaage to putting on duals.
|
R/Truck
Dodge Dakota
JOIN HERE
1/30/2003
11:19:38
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
I took my truck in for clogged pre-cats and they wouldn't remove the exhuast since I had a cat back on there. I had to take it to a muffler shop have it cut, then take it back to the dealer. Once they were done I had to take it back to the muffler shop and have the cat back re-installed.
I have the magnaflow exhuast and really like it. No advantage to a dual out muffler, however a true dual exhuast with an X pipe can sometimes give you better performance with a better sound.
|
dakotaman4dr
Dodge Dakota
JOIN HERE
1/30/2003
11:19:59
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
I've got a magnaflow 3"in and 2-1/2" dual out dumped after the muffler. I've been told if you go 3" all the way down you'll loose tq unless you got a few mods done to the engine to push that extra exhaust making the bigger diameter pipe nessisary. Mines a 3" in but it's just a flared fitting coming off the stock pipe into the muffler. As far as adding 19rwhp, the old butt-o-meter dosen't feel that much differant than before the magnaflow was added. Sounds great though, and I think I'll have a little more of oomph when I add the air intake and pipe the cat. If your gonna do the exaust you might as well do the air intake also (deep breath in, deep breath out)
|
Texas Todd
Dodge Dakota
JOIN HERE
1/30/2003
12:51:01
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
Ian,
by the ? in your subject line, I'm assuming you were questioning this also, right?
|
Ian
Dodge Dakota
JOIN HERE
1/30/2003
13:21:23
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
Yes Texas Todd I was questioning this assertion. I share in the skepticism of this. As far as the dyno is concerened I agree we need to know more. 177Rwhp is not impossible with an auto and the engine just unfortunately being one of those who puts out a little less from the factory, but 20rwhp from a cat back (his is the full catback system not just the muffler)does sound like a lot. What really caught my interest was the fact the dyno showed such a gain in torque when all other 4.7 owners switching to a cat-back report a loss. Basically, to date I have not seen any concrete evidence that either a catback or a muffler swap has any performance benefit whatsoever for the 4.7 (naturally aspirated). If this guy is tellng the truth and the dyno is not a fake than this is quite a discovery, we really need to verify this.
|
Texas Todd
Dodge Dakota
JOIN HERE
1/30/2003
13:33:08
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
I'm with ya Ian,
He did state in his link post that he is a dealer of magnaflows. Hhhmmmmmmm.
I think you could get a dyno like that, by doing your first run at NON-WOT, and then WOT for the second run! LOL
Todd Bouton
01, QC, 4.7, 5spdmanny, HO cams, ported 68mm TB,homebrew air intake & K&N filter, no belt fan, and STOCK EXHAUST. Lsd, t&h package,etc.
|
j
GenIII
1/30/2003
16:20:16
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
I think people who put a 3" catback on the 4.7 notice a loss in low end torque. That chart starts at 3400 rpm.
2000 4.7 CC auto, clear corners, Magnaflow catback, Kenne Bell s/c.
|
ShortSport
GenIII
1/30/2003
17:57:39
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
Ian what i meant by duel is 3" inlet and two 21/2" outlets...my canadian truck i think has differant cat system.. you guys are always talking about the third cat...well my truck has one cat least that i've noticed....further more i put 350lbs of weight in the back(canada winter) and that slowed the truck down some..i then had the system instaled and upon driving the truck i emediatly noticed the truck was faster than before the weight....not because it had better traction i drove the truck for two weeks with the weight before the system was installed. so i know thats not dyno proof but,thier was no loss anywhere in the power band
2002 Reg cab 4x2 4.7 5-spd 3.55.1 LSD
fiberglass tonneau cover; stainless steel cat-back dual exhaust; magnaflow muffler
Go hard or go home!!
|
Strat79
Dodge Dakota
JOIN HERE
1/30/2003
20:17:49
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
I've been following a lot of the posts on the site about exhausts, and I kept wondering about the exhaust diameter and why some guys seem to see a loss in performance at the low end with larger diameter low restriction systems. This link gives a pretty good explanation about why bigger is not always better for exhaust diameter. I thought the exhaust velocity might have something to do with it, and this article explains why.
I keep looking for a muffler/exhaust that will actually show some real gains and not just imagined HP based on "it sounds baaaad" or "it feels faster" butt dyno claims... still searching.......
http://modernmusclecars.net/articles/exhaustdynamics.html
|
ShortSport
GenIII
1/30/2003
21:08:49
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
you won't have to wait much longer i'maaooking for a dyno shop as we speak.....here in canada the performance shops are far and few between.
2002 Reg cab 4x2 4.7 5-spd 3.55.1 LSD
fiberglass tonneau cover; stainless steel cat-back dual exhaust; magnaflow muffler
Go hard or go home!!
|
Ian
Dodge Dakota
JOIN HERE
2/23/2003
17:14:08
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
get to that dyno shop yet?
|
ShortSport
GenIII
2/24/2003
01:42:33
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
ya i called forrest & forrest they want $110 for three pulls thats close to were i live, however $110 is not available at this time.....waiting for the fipk to come out for my 2002.its $440cdn thats steap but the wife says yes....but $110 is not yet available but soon as it is i,m there.
2002 Reg cab 4x2 4.7 5-spd 3.55.1 LSD
fiberglass tonneau cover; stainless steel cat-back dual exhaust; magnaflow muffler
Go hard or go home!!
|
CThomp
Gen III
2/24/2003
08:31:59
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
Why spend so much money on a FIPK when there are other intakes that probably make more power and cost less? Have you looked into 360airintakez.com? I bet the 360 intake probably makes at least as good if not better numbers than the FIPK. The FIPK didn't even make that good of numbers.
|
Texas Todd
Dodge Dakota
JOIN HERE
2/24/2003
09:39:28
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
We COULD always believe the dyno sheet, which STARTS at 3400, and IS DONE by a MAGNAFLOW DEALER!
I still say he wasn't WOT for the non magnaflow pulls either.
I have heard that it is a good system however. It hasn't been overruled yet, BS flag still up!
|
02Durango
Dodge Dakota
JOIN HERE
4/17/2003
15:50:51
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
If you think about it though, on a Auto 4.7 4x4, you might be able to assume up to 25% drive train loss. So 235HP *.75 = 177 HP. That would be about what that chart shows. HOWEVER, if the drive train loss were only 20% (non 4x4 or whatever factors) then the BS flag should go up.
|
20.9 RWHP NOT
Dodge Dakota
JOIN HERE
4/18/2003
17:45:32
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
There is no way in hell you would get an increase like that with that combination!
|
Pittdawg
Dodge Dakota
JOIN HERE
4/18/2003
17:52:01
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
I belive Notchx replaced the stock muffler with a flow master and saw no real gain nor loss (obviously I'm speaking of before his s/c). After examining the stock muffler it appears that no gain was had because the stock muffler is quite adequate (it's a pretty damn large muffler for a stock "compact" truck) My question is if I simply replaced my muffler with a single inlet and dual outlet (probably 2.5 in and dual 2.5 out) as opposed to just another aftermarket 2.5 single in single out would this flow much more? The reason I ask is that it appears that unless you have some serious mods a full 3-inch catback only produces top-end horsepower at the expense of low end torque. This I do not want, I never hit the track but I do like to gun it from stoplight to stoplight every now and again. The only catback I have heard of that produces gains w/out a loss in low end is the MBRP dual exhaust system, however I do not see the point in paying for an entire system when a simple muffler swap should achieve the same result (I say this b/c the MBRP piping from the muffler to the cat is 2.5 just like stock). The MBRP then utilizes 2.25 piping after the dual exit, I believe this is why it has no loss of low end. Now, I'm just trying to decide if I will get even better gains with simply swapping the muffler and utiliziing 2.5 dual pipes, would I really be overkilling it by not sticking with 2.25 dual pipes like the MBRP or do you guys think 2.5 dual tail pipes and keeping all the other pipes stock would be the best match?
|
jtha03
Dodge Dakota
JOIN HERE
4/18/2003
18:01:17
| RE: Magnaflow makes significant 4.7 power?
IP: Logged
Message:
If MBRP uses 2.25 it more than likely because it proved to be better in testing. You are right in thinking that you can get your exhaust to big.
|
| | P 1 |
|
Post a reply to this message:
Username Registration: Optional
All visitors are allowed to post messages
|
