| From | Message |
Bullock
Dodge Dakota
JOIN HERE
3/03/2005
00:30:34
|
 Subject: 4.7L exhaust
IP: Logged
Message:
I read a post on here one time about guys leaving the 2 1/2 inch pipe and just putting the magaflow muffler on. Any thoughts? And or part numbers? Thanks
|
01Motorsport
Dodge Dakota
JOIN HERE
3/03/2005
09:23:37
|  RE: 4.7L exhaust
IP: Logged
Message:
Changing the muffler only is the least expensive first mod to the exhaust. If/when you increase the air intake flow with air intake, throttle body and cam mods, you would consider a "cat-back" system with duals. The next level would be y-pipe and converter mods, or true duals.
|
opie
Dodge Dakota
JOIN HERE
3/03/2005
09:59:11
| RE: 4.7L exhaust
IP: Logged
Message:
I'll be that guy who says "do a search."
I went true duals and would never do anything else. The sound, performance, aid to other mods, etc. etc. is beyond compare.
The biggest restrictor in the whole system is the Y-pipe, not the muffler or the extra 3rd Cat. Just picture two highways, 4 lanes each, merging onto a single 4-lane highway. What a mess.
DC does a good job with it's high-flow multiple catilitic convertor system as well as it's massive muffler that does it's job without hurting the flow too badly.
Then aganin, opinions on this site are like A$$-holes: Everyone has one, most of them stink, and no one really wants to hear yours.
|
JES
Dodge Dakota
JOIN HERE
3/03/2005
10:38:46
| RE: 4.7L exhaust
IP: Logged
Message:
I have the Magnaflow 2.5" single in / dual out. Sounds good. Have no idea what the gains were. I think the Part Number is 12158 (aluminized -- but u can get the SS variety). I had a local shop in W. PA put the muffler in, use one of the stock tailpipes, and add a pipe beside the stock one for about $110 -- all aluminized. If you wanted something that would outlast your truck, go with stainless, but expect to pay 2.5 to 3.0 times more. With mine, I wasn't sure if I was gonna like it, or take it off, so I went with aluminized. Hope this helps.
Eric -- http://photos.yahoo.com/jes_96
|
Lurkin
Dodge Dakota
JOIN HERE
3/03/2005
15:53:19
| RE: 4.7L exhaust
IP: Logged
Message:
I did exactly what JES did, only my cost was $60 for the Magnaflow, and $30 to get it installed.
Don't expect any more then a sound difference though. Opie's given you some words of wisdom also. Plan what you want to do ahead of time and you won't waste too many $$$$.
|
Bullock
Dodge Dakota
JOIN HERE
3/08/2005
21:30:06
| RE: 4.7L exhaust
IP: Logged
Message:
found magnaflow number 14615, might try it. all the pipe in already mandrel bent. should be okay
|
Old Fool
Dodge Dakota
JOIN HERE
3/09/2005
07:07:56
|  RE: 4.7L exhaust
IP: Logged
Message:
The factory 'Y' Pipe is more than just a small restriction, it is a darn hindurance. If you leave the factory 'Y' don't look for any gains from any type of exhaust mods, just a sound difference. And the factory 'Y' IS NOT mandrel bent, in fact it has crimps in it that almost close the driver side off completely. I went to true duals and removed the 'Y' completly, removed the 3rd cat and left the precats and picked up 3/10ths in the 1/4 mile. Good Luck.
Later,
|
Tnjones
Dodge Dakota
JOIN HERE
3/09/2005
17:58:40
| RE: 4.7L exhaust
IP: Logged
Message:
Hey Old Fool,
You've got the 4.7L? I've read here and elsewhere that true duals hurt the low end tork in the 4.7 even though it does reduce the restriction. Just like with the HO cams its trading tork for HP.
|
Old Fool
Dodge Dakota
JOIN HERE
3/09/2005
19:01:21
| RE: 4.7L exhaust
IP: Logged
Message:
Well, I don't know about loosing low end torque, and if I did, THANK GOD. If i smash the gas on dry pavement or asphalt here in South Texas at any speed under 55 mph in any of the lower gears I have to be careful that my ass end doesn't smack the car in the lane beside me. I also have 295/50-16s on the back, so the tires aren't to small. I'm pretty sure the people that post about the torque loss has never done the HO cams and true duals or they wouldn't post that. I have both and the pipes are 2.5" all the way back past the glass packs which are 2.5" centers.
LAter,
|
Kowalski
GenIII
3/10/2005
16:30:47
| RE: 4.7L exhaust
IP: Logged
Message:
The HO cams don't trade torque for HP either. Suppoesedly most of the torque gain of the whole HO package can be had just by changing to the HO cams; felt like a gain throghout the whole range when I swapped.
Lead, follow, or get out of the way
|
Opie
Dodge Dakota
JOIN HERE
3/11/2005
10:20:02
| RE: 4.7L exhaust
IP: Logged
Message:
Big ditto to all the "HO Cams + True Duals" 4.7 people. I did it on mine and then added the Superchips programmer and I regularly get put back in my seat. The big meats on the truck help to adjust the gearing so that the new power isn't wasted on wheel spin.
Based on other dyno results, the combination on these trucks of the NA mods (true duals, intake, HO cams, Fastman TB, and Superchips) yields at least 305 ft lbs of torque at the rear wheels. I have all of these, but it is on a 4X4, which robs me of a bit of performance loss due to more spinning metal and more weight. I can't imagine how much fun it would be to have a 2 wheel drive and these mods...
|
QQQ
Dodge Dakota
JOIN HERE
3/11/2005
10:39:52
| RE: 4.7L exhaust
IP: Logged
Message:
Question about true duals: I have a 2000 4.7 which has only 1 converter. Do those that have put on duals keep their converters? Buy a second? (If 2000) or just keep them off.
|
bmac86
Dodge Dakota
JOIN HERE
3/11/2005
13:32:23
| RE: 4.7L exhaust
IP: Logged
Message:
hey opie check your numbers on that rear wheel torque. doest it start at 295 at the fly wheel?
|
Old Fool
Dodge Dakota
JOIN HERE
3/11/2005
23:00:04
| RE: 4.7L exhaust
IP: Logged
Message:
Yeah the STOCK torque is 295, but with the mods he has that almost mirror mine he is putting 305 to the rear wheels which means some place near 370+ at the crank. Sounds pretty darn close to me.
Later, 8)
|
pat f.
Dodge Dakota
JOIN HERE
3/12/2005
20:23:56
| RE: 4.7L exhaust
IP: Logged
Message:
opie....stupid question,ho cam and fastman tb does this mod. work void warranty????
|
Opie
Dodge Dakota
JOIN HERE
3/14/2005
15:26:39
| RE: 4.7L exhaust
IP: Logged
Message:
The HO cam is a MOPAR part. I had mine put in at the stealership for a very reduced price (because of some broken promises when I brought it in for a recall). They continue to guarantee the warranty. I had them put it in writing. John "The Fastman" stands behind his product 110%. He will echo the LAW when it comes to modifications. The Stealership and DC must prove beyond a shadow of a doubt that a particular mod caused a problem with your engine. Read on:
The Fastman TB is a natural step that should be taken when opening up your intake and exhaust. Look for bottle-necks in your engine and open them up. All the ram-air cold air intake ice-box mods you do won't help if the TB is too small to suck in all that air. With the intake, the bottle-necks include the multiple bends in the intake piping, accordian tubing, poor filters, small TB, and intake ports that aren't smooth. The exhaust has it's own problem with an exhaust manifold that collides engine pulses, 3 catilitic convertors, a "Y" pipe that collides more pulses, and a huge muffler. You can fix all of this and still stay in compliance with state/federal regulations as well as DC warranty.
The Fastman TB should be installed IN COMBINATION with relocating the incoming air temperature sensor. This does two things:
1. Makes the computer think that the air coming into the intake is cooler (therefore more dense) than it really is.
2. Richens up the fuel/air mixture to maximize the benefit of the mods.
You are increasing the air flow into the truck, but the computer has no way of measuring how much air is really going into the engine after your upgrades. It senses the temperature only. If you shove a bunch of air into the engine and don't compensate with more fuel, you are running lean and aren't getting all the power you should. If you make the computer think that the air is cooler, it adds more fuel to the mix and makes the combination right.
I think the GM engineers have the right idea with their Mass Airflow Sensor in their vehicles. It senses both air velocity and temperature. It is a two-dimensional approach to a two dimensional issue. The DC single-diminsion thinking with the combination of IAT and TB did't predict that owners will modify thier vehicles to breathe better and bring in colder air.
|
Allan
Dodge Dakota
JOIN HERE
3/15/2005
02:58:32
| RE: 4.7L exhaust
IP: Logged
Message:
The 4.& V8 have a Manifold Air Pressure sensor that tells them how much air is in the manifold. Chrysler is big on the MAP sensors. My 1995 Intrepid had one as well.
|
Opie
Dodge Dakota
JOIN HERE
3/15/2005
15:22:53
| RE: 4.7L exhaust
IP: Logged
Message:
Allan:
I didn't know that. Interesting. I'll have to look into that one.
|
rgathright
Dodge Dakota
JOIN HERE
3/16/2005
14:25:38
|  RE: 4.7L exhaust
IP: Logged
Message:
http://www.reubengathright.com/2004DakotaExhaust.html
A year later, I wonder why I drove my truck 1 mile with the stock exhaust, oh that's right, I had to get to the muffler shop somehow. :P
|
Tnjones
Dodge Dakota
JOIN HERE
3/17/2005
16:58:04
| RE: 4.7L exhaust
IP: Logged
Message:
So what did you guys with true duals do with all the sensors along the original exhaust system?
|
FLDak
Dodge Dakota
JOIN HERE
3/18/2005
08:38:10
|  RE: 4.7L exhaust
IP: Logged
Message:
Tnjones;
The only thing stock about my true dual exhaust system are the exhaust manifolds. I used Thefastman o2 simms to replace the downstream oxygen sensors which allows you to lose the cats.
|
| | P 1 Next Page>> |
