Dyno Testing Bolt-ons On The 4.0

[Jezza]

I already did a header video. I'll probably release it tomorrow. I also did the 1.7 rocker video as well. That one will probably go out next weekend. I'm shaving head about 0.020" and the block an additional 0.005". That combined with the thinner headgasket should put me up to 9.5:1. The cam is baby, just a small bit more than stock.

 

[GoldenGorilla]

Looking forward to those and curious about the results you found.

 

[macleanflood]

Watched the video this morning and got really confused.

You keep interchanging header and cat back...and I think you're referring to the Banks exhaust header...but cat back to me is just that... behind the catalytic converter...so muffler and pipe over the axle and the tailpipe. Different cat back systems are stock 2.25 or bigger 2.5. Not sure what you did?

You also repaired the banks header...but did you smoke test or water test for leaks? Did you use a new gasket?

Like the exhausting stud kit. I want to pull my intake and get it ceramic powder coated...might replace the hardware.

My banks header is paired with a custom downpipe I made in 2.5" to match the header...short of it's flange...I put an expansion bellows in front of the oil pan and a v band in front of a Magnaflow hi flow cat... installed an O2 bung to retain the factory sensor location...and then a Hooker stainless 2.5 cat back exhaust.

-Mac

 

[BlueC]

The latest video, Episode 9, Exhaust Header

 

[TerryD]

Watched the video this morning and got really confused.

You keep interchanging header and cat back...and I think you're referring to the Banks exhaust header...but cat back to me is just that... behind the catalytic converter...so muffler and pipe over the axle and the tailpipe. Different cat back systems are stock 2.25 or bigger 2.5. Not sure what you did?

You also repaired the banks header...but did you smoke test or water test for leaks? Did you use a new gasket?

Like the exhausting stud kit. I want to pull my intake and get it ceramic powder coated...might replace the hardware.

My banks header is paired with a custom downpipe I made in 2.5" to match the header...short of it's flange...I put an expansion bellows in front of the oil pan and a v band in front of a Magnaflow hi flow cat... installed an O2 bung to retain the factory sensor location...and then a Hooker stainless 2.5 cat back exhaust.

-Mac

He was comparing the dyno run with the header to the dyno run after the cat-back install.

 

[JustDandee]

It has the stock single cat. I might do a video later with the cat removed and strait-piped. I may also do an open header pull as well. Maybe someday if I have time. The header just bolts up to the stock pipe, so the cat will stay.

Episode 9, are you still on the stock catalytic converter? Potential choke in the system keeping the flow relatively static?

You mention SAE correction, wondering if formulation correction for the
Environmental is part of the “loss”.

Taking in your visual observations of the OEM design to the banks, visually it looks like a net zero design. All this as long winded opinion that I would leave it on for the remainder of the test.

On your test drive, how is it feeling from your starting point?

 

[srimes]

I'd take the header off. Ideally, it'd be best to try it again with the other mods done to see if it helps then. But with the information we have so far I don't think it will.

The results were down across the entire rev range. If it was a case the the header doing better at higher flows I'd expect to see a power increase at higher revs, but that didn't happen. Something is wrong. Unless you can find a reason, like a port mismatch or gasket blocking flow, I'd get rid of the header.

 

[Rickyd]

I'd take the header off. Ideally, it'd be best to try it again with the other mods done to see if it helps then. But with the information we have so far I don't think it will.

The results were down across the entire rev range. If it was a case the the header doing better at higher flows I'd expect to see a power increase at higher revs, but that didn't happen. Something is wrong. Unless you can find a reason, like a port mismatch or gasket blocking flow, I'd get rid of the header.

The banks has a larger primary tube size than most. It was the only one I could find that fit my edelbrock head port size for my 97 stroker.

I'm not surprised it isn't optimal for this application. It has been long assumed that the head itself is the main choke point on AMC 6's

 

[GoldenGorilla]

I'm not that surprised the earlier stock headers held up well and there weren't big gains. It seemed like a pretty decent design.

The banks has a larger primary tube size than most. It was the only one I could find that fit my edelbrock head port size for my 97 stroker.

I'm not surprised it isn't optimal for this application. It has been long assumed that the head itself is the main choke point on AMC 6's

This was the same reason I ended up with the AFE shorties. I'm working on a build and am strongly considering the Edlebrock head.

I'd suspect that the later gen with the 2 part cast log manifolds may show more gain, but are even more constrained by the smaller exhaust ports in the 0331 head. An article from some years ago showed good low to mid performance gains with the DT shorties of similar design on an otherwise stock system, but limited gains on the high end. That's consistent with my experience since installing these.

I installed my 1.7 roller rockers before these on my otherwise currently stock motor. I know how my '04 responded to each and I'm curious to see next week's video.

 

[Rickyd]

I'm not that surprised the earlier stock headers held up well and there weren't big gains. It seemed like a pretty decent design.



This was the same reason I ended up with the AFE shorties. I'm working on a build and am strongly considering the Edlebrock head.

I'd suspect that the later gen with the 2 part cast log manifolds may show more gain, but are even more constrained by the smaller exhaust ports in the 0331 head. An article from some years ago showed good low to mid performance gains with the DT shorties of similar design on an otherwise stock system, but limited gains on the high end. That's consistent with my experience since installing these.


View attachment 637284

I installed my 1.7 roller rockers before these on my otherwise currently stock motor. I know how my '04 responded to each and I'm curious to see next week's video.

I don't know about afe's but the banks headers for the 0331 head will work with the older model port location and size on the edelbrock head.

 

[ColoJeep]

I'm not that surprised the earlier stock headers held up well and there weren't big gains. It seemed like a pretty decent design.



This was the same reason I ended up with the AFE shorties. I'm working on a build and am strongly considering the Edlebrock head.

I'd suspect that the later gen with the 2 part cast log manifolds may show more gain, but are even more constrained by the smaller exhaust ports in the 0331 head. An article from some years ago showed good low to mid performance gains with the DT shorties of similar design on an otherwise stock system, but limited gains on the high end. That's consistent with my experience since installing these.


View attachment 637284

I installed my 1.7 roller rockers before these on my otherwise currently stock motor. I know how my '04 responded to each and I'm curious to see next week's video.

I noticed the factory tube manifold is a " tri Y " type construction which typically adds some power low to mid range . The Banks is more like a "4-1" V-8 header typically adds power at the upper end. Even if the primary tube size was a little large , you would think it would be Okay at the top end . It's a little odd to me that Banks lost ground everywhere. Normally Banks stuff is a well thought out power adder .

 

[GoldenGorilla]

I don't know about afe's but the banks headers for the 0331 head will work with the older model port location and size on the edelbrock head.

The aFe headers do too. They're made from a thicker gauge of stainless than the Banks headers (and most others) and I chose them primarily for that reason with the hope of avoiding cracking collectors.

The exhaust port locations are effectively the same on all the 4.0 heads, they're just smaller and rectangular on the 0331 heads, so the late manifolds won't cover the larger old style ports. I wanted/needed to retain the mini-cats where I live.

 

[Jezza]

Watched the video this morning and got really confused.

You keep interchanging header and cat back...and I think you're referring to the Banks exhaust header...but cat back to me is just that... behind the catalytic converter...so muffler and pipe over the axle and the tailpipe. Different cat back systems are stock 2.25 or bigger 2.5. Not sure what you did?

You also repaired the banks header...but did you smoke test or water test for leaks? Did you use a new gasket?

Like the exhausting stud kit. I want to pull my intake and get it ceramic powder coated...might replace the hardware.

My banks header is paired with a custom downpipe I made in 2.5" to match the header...short of it's flange...I put an expansion bellows in front of the oil pan and a v band in front of a Magnaflow hi flow cat... installed an O2 bung to retain the factory sensor location...and then a Hooker stainless 2.5 cat back exhaust.

-Mac

I get the confusion. I did the catback exhaust in the last episode, and I have been comparing each new episode to the previous episode's numbers. Perhaps I should have done something in between to reduce confusion.

I sewed up a few cracks in the collector. Nothing serious, and I did use a new gasket.

I am still running the stock downpipe to the cat. I think they are like 2.25" or so.

 

[Jezza]

The latest video, Episode 9, Exhaust Header

Thanks for posting. I was busy getting my ass kicked by this engine all weekend.

 

[Woodrow]

I get the confusion. I did the catback exhaust in the last episode, and I have been comparing each new episode to the previous episode's numbers. Perhaps I should have done something in between to reduce confusion.

I sewed up a few cracks in the collector. Nothing serious, and I did use a new gasket.

I am still running the stock downpipe to the cat. I think they are like 2.25" or so.

On my ‘97, the stock (I think) exhaust was 2.5” to the cat and 2.25” after.

 

[ColoJeep]

Thanks for posting. I was busy getting my ass kicked by this engine all weekend.

THANKS FOR ALL YOUR HARD WORK JEZZA ! It is appreciated by many !

 

[astjp2]

I am hoping for a spreadsheet that summarizes the upgrades and what power and torque did for each mod. Maybe we need to add a stroker crank? Hmm? I like that idea!

 

[Jezza]

Latest and greatest is up.

 

[GoldenGorilla]

Thanks @Jezza. I think your results actually do land in the range I'd expect in WHP if they were delivering around 9hp at the crank which is in the range I thought they'd deliver in a 4.0L. 30% driveline loss would put that at 6.3hp. I don't think I've ever found a documented good direct 1.6 stamped to 1.7 roller result on an engine dyno before, but I thought 9-12 at the crank was reasonable based on the lift and all the examples of V-8s I could find. I also found these made the most difference on the top end in my '04. There are bunch of differences between our heads, and ECMs and all sorts of other stuff but I never bothered put my jeep on the dyno before making changes to know the numbers for sure.

Above 3500 my stock 4.0L used to make a bunch of noise, but didn't seem to make much more power. That was the issue that instigated finally starting to mod my TJ. In my 5 speed, the rpms in 4th were too low to hold speed on a steep high altitude climb on I-70 and shifting to 3rd would be revved way up without doing much. That has all seemed MUCH better on the road where it accelerates well in 3rd if desired up through 4500rpm since installing the 1.7s. Going from 4.10 to 4.56 had a big impact too.

I went with Harland Sharp's 1.7 because they were in stock at the time. I can confirm they also fit under the stock steel valve cover.

 

[GoldenGorilla]

Prior to these changes I also got 13.x mpg no matter whether I was on the highway or around the city. With the changes I've made, my around town mileage ranges from 13-14.5 depending on how much I push on that skinny pedal coming out of the stop and go. Over the weekend I got 16.2 mpg on some longer 55-65mph byway driving. First time I ever remember seeing 16 mpg in the 21 years I've been driving this.