Headers foe a 94 4.5L FJ80

[80 Cruiser Rod]

I know I will get some answers here. I have without any sucess been able to find Headers for my truck. Is there anybody out there that does make Headers for a 94? I have seen some older LCs with Headers but I can not find any for this year.

 

[blarsen]

here is a link to a place in Au. that sells them..
http://www.jet-hot.com.au/jh_direct.php?amhkcHJpY2VsaXN0LmNzdg==

I have no clue if they are any good..
later Bret

 

[FJ809496TLC]

Try this:https://forum.ih8mud.com/showthread.php?t=114570&highlight=headers. You can also do custom. I was quoted $780.

 

[Beowulf]

Rod,

You should know that the factory Toyota exhaust manifold is very efficient. At least one member (photoman) installed some MAF headers many years ago and he reported no noticeable improvement in performance or fuel economy or anything.

Save your money for the important things and if you need more HP, get the TRD S/C.

One more thing.... your truck is an FZJ80, not an FJ80. The difference between the two designations is the 1FZ-FE engine which you have in your 94.

-B-

 

[cruiserdan]

According to my friend at TRD the 1FZ manifolds are quite efficent and they could not realize enough of an improvement to justify developing headers.

 

[jamisobe]

I have I used headers on other vehicles in the past and I believe that headers will outperform restrictive cast iron manifolds as long as the rest of the exhaust doesn't bottleneck any potential gains.

When I initially inquired into headers for the 80 I was told that headers for the FZ were scarce because of the difficulty in providing efficient non-restrictive collectors (there isn't much room because of the routing to the outside of the frame) that are mass produced. The header kits available came with a collector that is no better or worse than stock. Bottleneckah.

Headers without a good flowing collector may not perform any better than cast iron manifolds. Customize the collector for flow if you want to use headers.

 

[RavenTai]

I have I used headers on other vehicles in the past and I believe that headers will outperform restrictive cast iron manifolds as long as the rest of the exhaust doesn't bottleneck any potential gains.

thats the problem the stock manifolds are not restrictive, if you look at them they basically cast headers.

 

[80 Cruiser Rod]

I have noticed the exhaust manifold look allot like a cast header. The problem is that I just replaced both of my Cats and was told that both of the pipes that sit between the Manifolds and Cats don't have much more life in them. It was suggested that going to headers with custom fabricated pipes would improve performance and fuel efficiency.

I have recently talked to someone and was told that they really didn't improve performance and they where a constant problem needing retightening and gasket replacements.

If I did go to headers I would have replace the entire system to accommodate this modification.

 

[jamisobe]

thats the problem the stock manifolds are not restrictive, if you look at them they basically cast headers.

I'm not seeing it.

The three short runners constrict into one hole the size of the downtube/one individual runner. Then the downtubes are merged in a non-efficient, but practical way. The problem with installing headers is that it is difficult to produce collectors that do not constrict as the cast iron manifolds do by forcing 3 runners (1 at a 90 degree angle) into one downtube.

The stock collector is not very "areodynamic". The flow dynamics of the stock collector are similar to that of the cast iron manifolds which is why headers don't do much. To maximize flow there should be a reduction in resistance where tubes merge to accomodate the increased pressure.

 

[jamisobe]

I have noticed the exhaust manifold look allot like a cast header. The problem is that I just replaced both of my Cats and was told that both of the pipes that sit between the Manifolds and Cats don't have much more life in them. It was suggested that going to headers with custom fabricated pipes would improve performance and fuel efficiency.

I have recently talked to someone and was told that they really didn't improve performance and they where a constant problem needing retightening and gasket replacements.

If I did go to headers I would have replace the entire system to accommodate this modification.

I have not had any problems with tightening. The flanges on my downy headers are very thick which helps. We used the original locking manifold bolts to secure the headers. I use the exhaust to pull myself around when I am beneath the truck. It is very solid.

You may want to print the pictures I posted to show to a fabricator if you go the custom route. I had 2 fabricators turn the work down because they said it wouldn't fit. Its hard to find good help. Not only did it fit but it is up much more tightly in the underbody. It turned out to be a good friend who exhibited the skills.

Notice that the inner fender was slightly cut to fit the collector.

 

[MTNRAT]

Look guys there are alot of people here who have looked into this in depth. The bottom line is the stock manifold exhaust system is NOT restrictive for the stock engine. Even those with SC have noticed little or NO improvement with less restrictive exhaust(me included) and have gone back to stock. On many engine applications headers and a better exhaust will give good gains. The FZJ is not one of those engines. Only cruiser experts will know, and they have spoken.
Cheers,
Sean

 

[jamisobe]

Look guys there are alot of people here who have looked into this in depth. The bottom line is the stock manifold exhaust system is NOT restrictive for the stock engine. Even those with SC have noticed little or NO improvement with less restrictive exhaust(me included) and have gone back to stock. On many engine applications headers and a better exhaust will give good gains. The FZJ is not one of those engines. Only cruiser experts will know, and they have spoken.
Cheers,
Sean

Experts? Meh. I can show you experts that disagree on a countless number of subjects. That line is so passe. I'm an expert, he's an expert, wouldn't you like to be an expert too!

You should of tried dumping your stock style collector. ...But that would entail thinking outside the box.

An expert has spoken.

 

[MTNRAT]

2 minutes, not bad.
Cheers,
Sean

 

[jamisobe]

2 minutes, not bad.
Cheers,
Sean

Is that what she said?

 

[LX_TREME]

Stock manifold looks very restrictive to me compare to these

 

[jamisobe]

Stock manifold looks very restrictive to me compare to these

Werd.

 

[80 Cruiser Rod]

I'm not seeing it.

The three short runners constrict into one hole the size of the downtube/one individual runner. Then the downtubes are merged in a non-efficient, but practical way. The problem with installing headers is that it is difficult to produce collectors that do not constrict as the cast iron manifolds do by forcing 3 runners (1 at a 90 degree angle) into one downtube.

The stock collector is not very "areodynamic". The flow dynamics of the stock collector are similar to that of the cast iron manifolds which is why headers don't do much. To maximize flow there should be a reduction in resistance where tubes merge to accomodate the increased pressure.

So with all things considered was it reeaaalllly worth it. If so, what were your gains?

 

[jamisobe]

So with all things considered was it reeaaalllly worth it. If so, what were your gains?

Absolutley, I would do it again even though it was a challenge to design and find the right fabricator.

As far as gains there were several:

1. My highly trained internal seat-of-the-pants accelerometer felt a noticeable difference in pick up throughout the entire power band and especially a discernable pull at higher rpms. These are heavy vehicles with heavy accesories, but a consciousness towards weight reduction will also help gain in this area.

2. The sound is very impressive and I have recieved many compliments. It was loud before the 70 series Big Block Flowmaster and it had a resonate drone at speed before I tuned it with the after-cat silencer. It is fairly quiet until throttle is applied and then it sounds very high performance without causing an earthquake.

3. It has given me much better clearance. It no longer hangs down below everything else.

4. I like the way it looks under the hood and in the passenger wheel well. It looks racey - chakowwww!!

As far as gas mileage goes I have never been that concerned. I assume that it improved but I can provide no empirical evidence. I expect that the performance gains are in line with what "experts" or performance junkies expect from an effective header upgrade.

 

[80 Cruiser Rod]

Absolutley, I would do it again even though it was a challenge to design and find the right fabricator.

As far as gains there were several:

1. My highly trained internal seat-of-the-pants accelerometer felt a noticeable difference in pick up throughout the entire power band and especially a discernable pull at higher rpms. These are heavy vehicles with heavy accesories, but a consciousness towards weight reduction will also help gain in this area.

2. The sound is very impressive and I have recieved many compliments. It was loud before the 70 series Big Block Flowmaster and it had a resonate drone at speed before I tuned it with the after-cat silencer. It is fairly quiet until throttle is applied and then it sounds very high performance without causing an earthquake.

3. It has given me much better clearance. It no longer hangs down below everything else.

4. I like the way it looks under the hood and in the passenger wheel well. It looks racey - chakowwww!!

As far as gas mileage goes I have never been that concerned. I assume that it improved but I can provide no empirical evidence. I expect that the performance gains are in line with what "experts" or performance junkies expect from an effective header upgrade.

By the way good job with all of the info. I think I'll wait until I have to replace my whole exhaust. I put out a good chunk of change replacing my Cats, complete Brakes including Rotors and Emercency Brake Shoes and Hardware with a NEW set of Sneakers too.

Thanks for the Post,
Rod

 

[RavenTai]

Stock manifold looks very restrictive to me compare to these

and those stockers are a lot better than what typically passes for an exhaust manifold