Shane Pendergrass

Does mandrel vs pressure bent exhaust pipe make a huge difference? Everywhere I'm reading online says that mandrel should be used and that any reputable shop should have a mandrel machine. However, I've checked about 12 different exhaust shops around me as far as 80 miles away and can't find any shops that can do mandrel bends.

I'm wanting to get the exhaust set up and do it right because I'm having to replace a rusted out muffler that's about 6 years old already. I'm willing to pay a little bit more for the mandrel if it's possible but not wanting to pay double to triple the price. At this rate, I can't find anyone to do it though and it looks like I'll have to do pressure bent.

Has anyone else had the same experience trying to get mandrel bent pipes? Did you just get pressure bent?

GREEN16

If you're talking performance or flow differences you might find this video interesting.


I wouldn't pay the extra...

Shane Pendergrass

Thanks I'll watch it. Performance might help a little but I'm more interested in hopefully getting better mileage back. I've not gotten good mileage at all the entire time I've had the truck. After doing research, not having an x pipe and having an off brand flowmaster may be what's hurting me.

I'm fixing the broken muffler to two magnaflows and adding an x pipe at the same time. I just wanted to do everything to get mileage back if possible. If it's not the exhaust that's causing the bad mileage, that's fine since I've had the truck for years. If it's a simple fix to get it slightly back up, it would be nice though.

bigred90gt

I hate to say it, but wherever you did your research to come to that conclusion, I would never go back there again. I've heard a lot of strange things regarding vehicles, but "not having an x pipe and having an off brand flowmaster" causing bad gas mileage has to be up there with one of the strangest.


There's a lot of things that could be causing gas mileage issues, but I'm fairly certain neither of those are it. What are you driving? Year, mileage, engine? What kind of mileage are you getting, and what are you expecting?




To your original question, unless you are building an all out race car, you will never notice a difference between a mandrel bent exhaust vs one bent in a standard crimp bending machine like exhaust shops have.

Shane Pendergrass

For the vehicle, I have a 2wd 2005 f150 4.6 xlt supercab. Would like to get 13-15 mpg, sometimes get as low as 8-9 when I feel it should be a little higher. I have a diablosport predator tune on it and the truck has 285/70/17 tires installed. It has 224000 miles and I've recently replaced many parts. Within the last 500 miles, it's had a new serpentine belt, spark plugs, pcv valve, lower control arms, upper control arms, sway bar link ends, inner and outer tie rods, struts, front rotor/hub assembly/wheel bearing, rear shocks, tires and was aligned. Shouldn't have parts in the front end causing resistance because of wear.

As for the muffler itself, I've actually read a lot on this forum, f150online forum and ford150.net and that's where my research was from. Quite a few threads and also engine masters is where I came to that conclusion. The muffler in particular being chambered vs the straight through design should allow more exhaust through vs the flowmaster. Being a no name brand, I've read that they fall apart quicker and usually have smaller airflow allowed through them. For example, if a muffler has a 2.5 inch pipe on the outside, it may only have 2 inch on the inside. Sometimes companies use the same muffler shell for all their mufflers and only change the outer pipe for different models.

Having two dual pipes (no y pipe), going into the dual in muffler I've read on all three forums is not good. From my research, having the different length of pipes makes one side of the engine work harder and it needs some type of crossover. All this combined makes the engine work harder to push the exhaust out and having rusted holes in the exhaust I'm sure doesn't hurt. I may be wrong on all this and that's why I'm here asking questions.

white_dc

iTrader: (12)

Mandrel bend machines are expensive, which is why it will be hard to find a shop that has one.

If you are dead set on a mandrel bent exhaust, find a race car or fabrication shop near you. They should be able to order several different pre-bent mandrel bent pipes and fabricate an exhaust from scratch.

Trust me, it wont be cheap. Otherwise I would just have someone use a regular crimp bender.

RLXXI

With almost a quarter million miles on it, it's likely the only way you will up the economy is with a complete overhaul. Sounds like to me it's just tired/worn out.

Machines do wear out.
.

Shane Pendergrass

Yeah, I've had it since it had 160,000 miles on it. The guy I got it from was a Charter contractor and towed an enclosed trailer with it everyday pretty much. I tow about a third of the time with my mowing business. The trucks had a hard life and not just highway miles haha. Part of the reason why pretty much the whole front end was replaced.

Any ideas what would be done with a complete overhaul? Not sure if it'd even be worth it to me. Like I said, I've dealt with the mileage for a long time.

Shane Pendergrass

Sounds like it won't make a difference at all for me. The current exhaust is pressed pipe. I just wanted to make sure it wasn't something that would make a big difference. I have an appointment for tomorrow at my normal shop now after watching the posted video.

white_dc

iTrader: (12)

with 225k miles on the truck I dont see the need for a mandrel bent exhaust. Since you are complaining about MPG, Id check to see if your cats could be clogged and the o2 sensors since they will be under the truck anyways. but if your cats were clogged there would be a noticeable lack of power.