Dyno Testing Bolt-ons On The 4.0

[ColoJeep]

Very informative . Great Job Jezza ! The protocols you use make real world sense . On the upcoming HP tune mods , could you pass emission testing ? How hard is it to return to " stock " settings for emission testing? Thanks man , Great testing/videos !

 

[JustDandee]

I have an episode planned for fans.

Only fans?

 

[Jezza]

Very informative . Great Job Jezza ! The protocols you use make real world sense . On the upcoming HP tune mods , could you pass emission testing ? How hard is it to return to " stock " settings for emission testing? Thanks man , Great testing/videos !

I am not going to be modifying any parameters on the emissions. The tune will just optimize the fuel and spark.

 

[Bammo68]

Great video!

Question on editing...

So it's always difficult to provide constructive feedback when someone has gone to a tremendous effort and not appear to be a Negative Nancy so kudos to you Mac for managing this. Some really useful tips there for those of us just starting out on the YT journey.

Its probably obvious to all of us but the camera work, script and pacing of the words to camera are all equally as important (if not more so) than the content itself. Jezza's content is absolutely fantastic and the camera work and scripting is already well ahead of the curve so hopefully feedback like this will help him tweak it to be even better...

 

[macleanflood]

So it's always difficult to provide constructive feedback...

Amen! And someone tear into my videos...I often fall in love with all the footage I took, especially since you work so hard to get shots... it's really hard to cut, cut and keep cutting.

-Mac

 

[Rickyd]

Question: you're testing the 4 hole injectors but the stock ones are arguably 250k plus originals? For an apples to apples comparison shouldn't you replace filters and flow test the originals?

It has been said more than once that any difference in idle quality,etc is from fresh injectors. Not how many holes they have

 

[Jezza]

Amen! And someone tear into my videos...I often fall in love with all the footage I took, especially since you work so hard to get shots... it's really hard to cut, cut and keep cutting.

-Mac

I welcome the feedback. Part of my situation is balancing the quality vs time input. I work full time running another business, and just make these for fun and to plug my website.

 

[Steel City 06]

I am not going to be modifying any parameters on the emissions. The tune will just optimize the fuel and spark.

If you have cash to burn, might be worth testing new high-flow (e.g., Magnaflow) catalytic converters compared to gutted factory catalytic converters. Might help disprove the myth that properly functioning catalytic converters kill power.

Heck maybe they'd sponsor you with a product if you compare it to plugged factory cats...

 

[Wildman]

If you have cash to burn, might be worth testing new high-flow (e.g., Magnaflow) catalytic converters compared to gutted factory catalytic converters. Might help disprove the myth that properly functioning catalytic converters kill power

I thought that myth had been pretty much put to bed after they'd come out with better highflow cats? I mean YES I know old 70's & early 80's cats weren't good but after that?

 

[Steel City 06]

I thought that myth had been pretty much put to bed after they'd come out with better highflow cats? I mean YES I know old 70's & early 80's cats weren't good but after that?

Still a lot of people gutting the 3rd cat on later TJ models. (Though maybe that's more about being cheap and less about power.)

Theoretically if you used a sufficiently robust catalytic converter before a turbocharger, you could actually gain power and efficiency...

 

[Jezza]

If you have cash to burn, might be worth testing new high-flow (e.g., Magnaflow) catalytic converters compared to gutted factory catalytic converters. Might help disprove the myth that properly functioning catalytic converters kill power.

Heck maybe they'd sponsor you with a product if you compare it to plugged factory cats...

I was considering testing a "track pipe" maybe later down the road. I personally think the gain would be minimal, but I have been proven wrong before.

 

[Wildman]

I was considering testing a "track pipe" maybe later down the road. I personally think the gain would be minimal, but I have been proven wrong before.

Be interesting just to see.

 

[Steel City 06]

I was considering testing a "track pipe" maybe later down the road. I personally think the gain would be minimal, but I have been proven wrong before.

That could be interesting. I would expect a significant difference if the factory cats are partially plugged, but if they're in good condition, I agree it should be minimal.

 

[GoldenGorilla]

Might help disprove the myth that properly functioning catalytic converters kill power.

I've consistently seen independent tests show modern catalytic converters (mid-90s and onward) only affect power by 1-3 hp and on most engine dynos that's within the margin of error and less than the fan, AC, alternator and maybe even the water pump. We didn't have it figured out in the 70s and 80s, but that was only part of the restriction in the systems of that era.

My wife and I were cruising a back road in the mountains and passed an old CJ2 or CJ3 and she commented about the smell. Heresy warning. Even if I had a pre-cat era car now, I'd think about installing a modern converter if viable just to not have that exhaust stink. Lots of compact configurations are available. I used to reek of exhaust after taking my old Fiat 850 spider or Honda CB750 out and personally don't really have a positive nostalgic feeling towards that aspect of those vehicles, fun as they were.

 

[srimes]

I've consistently seen independent tests show modern catalytic converters (mid-90s and onward) only affect power by 1-3 hp and on most engine dynos that's within the margin of error and less than the fan, AC, alternator and maybe even the water pump. We didn't have it figured out in the 70s and 80s, but that was only part of the restriction in the systems of that era.

My wife and I were cruising a back road in the mountains and passed an old CJ2 or CJ3 and she commented about the smell. Heresy warning. Even if I had a pre-cat era car now, I'd think about installing a modern converter if viable just to not have that exhaust stink. Lots of compact configurations are available. I used to reek of exhaust after taking my old Fiat 850 spider or Honda CB750 out and personally don't really have a positive nostalgic feeling towards that aspect of those vehicles, fun as they were.

x2. Also, I've seen tons of complaints about annoying exhaust drone when cats are removed.

 

[macleanflood]

I've got a high flow Magnaflow 2.5 in my 97.

-Mac

 

[GoldenGorilla]

Speaking of cooling fans, clutched stock vs electric fans, this old Engine Masters episode popped up in my YT feed. The numbers were really surprising. The specific engine and clutch fan they were using took 7 lb-ft torque and 14 hp. And they got way worse with the non-clutch ones.



Has me thinking alot more about @Steel City 06 's thread on the SPAL electric fan conversion.

Thread 'Cooling fan upgrade comparison: Explorer 11-blade fan and HD clutch versus SPAL 19" 850-watt electric brushless fan'

May 31, 2024

Figured since I have tried both with success, I would post a brief overview and review/comparison of these cooling fan options for anyone looking for something bigger than stock.

Option 1: Explorer 11-blade fan and HD Clutch
This option consists of swapping the stock mechanical fan and clutch with one out of a Ford Explorer. Like the OEM fan, it simply spins onto the water pump, and the clutch acts just like an OEM clutch, though it is more sensitive. For this you only need two parts:

1. HD Fan Clutch: I used Hayden 2794; any "heavy duty" clutch from a 2001 Ford Explorer...

• Steel City 06
• Replies: 412
• Forum: TJ General Discussion

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Not sure it would be enough gain, especially considering how fickle the TJ cooling system is, but 14hp not a small number on this motor. Even 5hp down in the lower RPM range would help the highway performance. According the factory dyno charts the engine is around 100 hp down in the 2500 rpm range giving a solid 5% improvement. Look forward to @Jezza testing with no fan if possible.

 

[MikeE024]

x2. Also, I've seen tons of complaints about annoying exhaust drone when cats are removed.

My used turbo kit came with a gutted precat, so I gutted the other just to see how it would run. I already had the third cat removed.

I didn’t like the smell, but my god the sound was flat out awful. I was very happy to slap on my flow master pre cats.

 

[Rickyd]

I'd happily give up a couple hp to not have a headache from noxious fumes at the end of a trail ride. Something as short as a jeep you can't get away from it.

I had a gutted cat and no muffler when I got my tj. I wasn't impressed

 

[lBasket]

I've consistently seen independent tests show modern catalytic converters (mid-90s and onward) only affect power by 1-3 hp and on most engine dynos that's within the margin of error and less than the fan, AC, alternator and maybe even the water pump. We didn't have it figured out in the 70s and 80s, but that was only part of the restriction in the systems of that era.

My wife and I were cruising a back road in the mountains and passed an old CJ2 or CJ3 and she commented about the smell. Heresy warning. Even if I had a pre-cat era car now, I'd think about installing a modern converter if viable just to not have that exhaust stink. Lots of compact configurations are available. I used to reek of exhaust after taking my old Fiat 850 spider or Honda CB750 out and personally don't really have a positive nostalgic feeling towards that aspect of those vehicles, fun as they were.

Yeah that go-kart smell gets old fast IMO