New exhaust = no power bad milage. (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

D

DJForrestA

Joined
Sep 28, 2005
Threads
27
Messages
158
Location
Twin Falls Idaho
I don't know what to blame this on if anything. I have had my cruiser about 2500 miles now. It runs like a top, Has used 1/4 quart of oil in 2500 miles and is mechanically very sound. THe body is a little rough and it basically had a straight pipe with no cats that ran out under the rear drivers door. I took it to the best shop I've seen for exhaust work. The guy has put duals on my 66 mustang convertible, my scout and numerous other vehicles. His work first rate and very inexpensive for quality custom work. I told him my only concern for this landcruiser was nothing below the frame and very quiet. I have a glasspack under the drivers seat and a small can muffler under the rear passenger seat. Lots of bends though to keep it all above the frame. He used 2 inch pipe. Here are some pics. Could this be the reason I can't seem to get any power until 2900 rpm. I can't cruise 65 or 70 because in overdrive I'm only turning 1800 rpm or so I have to run it in 3rd and I'm turning 3000+. So I don't know if its the exhaust or the rpms I'm turning. Lots of highway use at 65+ for me.
 
Last edited:
listen to me i have a 94 it could make a little difference but i ran straight pipes with a magnflow muffler that is a high flow muffler, no cats either by the way. I dumped the exhaust by the rear passenger tire. i noticed power and gas differences for the better. i have about 6 ft of pipe after the headers if that with just one muffler.
 
Too small is correct. I think the down pipes to the cats are 2" and the y pipe and all other pipes are 2.25 ' Too much restricted flow. Nice looking job though.:eek:
 
2" is VERY small. You have a 4.5L motor there, after all.


Actually he has the 4.0L engine and yeah the pipe is still small.
 
I wondered about that but this motor seemed so gutless I didn't think it would make much difference. Maybye I put it back like it was just a short pipe off the headers out the side. I hate that look though and whoever gets in that door has exhaust blowing on their leg. I was worried one of my little boys would accidentally touch it and get burned. :doh: I'll give him a call and find out what else we can do. We used the smaller pipe so we could stay above the frame the whole way out and above the drivelines. Anyone have pics of their exhaust work?
 
Slow moving gasses can be caused also the number of bends, and the degree to which the pipe is bent.

Later
 
there is some wierd scale for everytime you bend it it is like adding x number of feet of pipe. it would help if i knew the scale but i am sure your muffler guy knows
 
One 90 degree bend = about 3' of straight pipe.

As to a guess why the lower end is loosing power... the length and diameter are causing the exhaust pulses and waves to arrive back at the exhaust valve at the wrong time.

My bet, simply run another 2" pipe along side the existing system.
 
I think your exhaust is part of the power problem. Your rpm problem is not related to the exhaust though. You've neglected to factor in that you are running 33" tires into the equation. That is where some of your power is being robbed from and it is definitely why you aren't getting the rpms needed to pull highway speeds in OD.
 
I'm still running on 31's but I have a set of 33's to bolt on. I ran across some 31x9.50x15 swampers I probably end up running. All five nearly new for 400 bucks. I can't pass it up. I need to call him today and get this figured out before I push the gas pedal through the floor.
 
I work with water flows in 2" pipe and can tell you that a single 90 equals like 20 foot of straight pipe. Compound that with the issue of putting too many bends too close together and the total loss of flow is far more than the sum of the single bends. Don't know if that info crosses directly over to exhaust gases or not.
 
If yours is a 91 you should be able to run duals easily. Get rid of your y-pipe or collector or whatever you have since you do not have cats and add another 2" pipe to collect exhaust from the second pipe. Sound like you have way to much back pressure. A good exhaust man should be able to bend & weld it up for you.

I have a 92 that we put duals on from the cats back. Tossed the y-pipe and the old trash can muffler, ran the duals w/ 2.25" pipe(s) in the original routing positions. Added a dual inlet/outlet flowmaster (which acts as the crossover also) and turned the pipes out behind the passenger wheel. The only modifications we had to make was to the bottom protion of the cat heat shield. Just had to cut the back of it out to accomaodate two pipes since it was designed for one exiting with the y-pipe originally. My cruiser now gets better mileage (on a relative scale), more power, runs cooler, and has a sweeeeeeet sound. Spent $365.00 on mine which was about 75.00 more than what the stock system from the cats back would have been....Good luck.
 
It was installed at Rays Muffler in Burley. Loren is the owner and he really is the man. I told him I wanted it all run above the frame rails and it needed to be uber quiet. It is very quiet but I guess I should have done more research so I knew the limitations. I'm not sure where the factory pipe went but mine snakes through a ton of tight places to reach the back. I'm not sure I could fit a larger or two pipes. you can see from the pics I went obove the rear output on the t case above the frame after the headers and on the passenger side. Some of those spots were super tight squeezes. I called him today he said bring it in and we'll run it straight pipe and test the difference. If there is one he'll re run the entire system however I want for no charge. He's the only honest muffler guy I've ever met.
 
We have a good exhaust guy in Mountain Home. Honest and Fair. He did a high flow cat back system on my 91 for $258. I could ask him which muffler he used. You might have him check the Bosal catalogs. The Bosal Exhaust pieces for the LC are unobtanium but he would have a better picture of how to route it. I wish I had a reason to drive to Twin. I'd try to help you sort through this. It is just to far to go for a drive for no real reason. Are you running cats or not? That could be a problem too.

I saw your other post about the 33s so I thought they were on. That takes that out of the equation then. It almost sounds like you might also have a messed up torque convertor. That would cause a loss of power and your RPMs to be wonky.
 
Forest, I Just Had My Exhaust Done Last Week At Rons Amercian Car Care, I Removed The Cats, And Had A Magnaflow Muffler Installed, So Far So Good If You Would Like You Could Stop Buy Friday, And See How Mine Was Installed
 
sdbrassfield said:
If yours is a 91 you should be able to run duals easily. Get rid of your y-pipe or collector or whatever you have since you do not have cats and add another 2" pipe to collect exhaust from the second pipe. Sound like you have way to much back pressure. A good exhaust man should be able to bend & weld it up for you.

I have a 92 that we put duals on from the cats back. Tossed the y-pipe and the old trash can muffler, ran the duals w/ 2.25" pipe(s) in the original routing positions. Added a dual inlet/outlet flowmaster (which acts as the crossover also) and turned the pipes out behind the passenger wheel. The only modifications we had to make was to the bottom protion of the cat heat shield. Just had to cut the back of it out to accomaodate two pipes since it was designed for one exiting with the y-pipe originally. My cruiser now gets better mileage (on a relative scale), more power, runs cooler, and has a sweeeeeeet sound. Spent $365.00 on mine which was about 75.00 more than what the stock system from the cats back would have been....Good luck.
Click to expand...

You have any pics of your exhaust system? I'm looking to redo mine and get rid of the trashcan muffler.
 
You must log in or register to reply here.

Similar threads

freewill
No Electrical Power
Replies
2
Views
239
freewill
freewill
N
No vehicle power!
Replies
2
Views
456
NelsonCruiser
N
Cruisin94
Exhaust Stud
Replies
12
Views
585
CharlieS
CharlieS
W
No Start, Single Click, All Power goes out (with references)- Solved
Replies
17
Views
2K
Mark W
Mark W

Users who are viewing this thread

Total: 2 (members: 0, guests: 2)

Share this page

Back
Top Bottom