Engine Mods that Do and Don't Work

[bmpcamry09]

I've done some real-time monitoring, but so far in somewhat limited circumstances. I get absolutely 0 timing pull during my hilly commute at ambient temps of 70 degrees or lower. I occasionally see a half to one and a half degrees when temps are a little warmer. I get 0 under light acceleration on the freeway. I'll soon see how the Summer and longer trips go.

You’re lucky if you’ve got 87 in your 2.0 and no knock. What about wide open throttle? Which knock retard are you watching? There are 3, short term, long term, and fuel. Short term and fuel are the ones for what is currently happening. Long term is the learned value applied consistently.

I was making more reference to actual spark advance. As soon as throttle is tipped in I was seeing negative spark timing itself.

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[THAW]

You’re lucky if you’ve got 87 in your 2.0 and no knock. What about wide open throttle? Which knock retard are you watching? There are 3, short term, long term, and fuel. Short term and fuel are the ones for what is currently happening. Long term is the learned value applied consistently.

I was making more reference to actual spark advance. As soon as throttle is tipped in I was seeing negative spark timing itself.

I watch LT, ST, fuel and total. I've seen 1.5° LT blips when total held at 0.

When I tried WOT (uphill) I got 0 total, but funny enough, all the sudden I caught up to a couple police vehicles dealing with a pedestrian on the middle shoulder which slowed everyone down, and I saw a few degrees for a couple seconds when I was forced to abruptly get off the throttle.

 

[SEW]

The statements made on the thread starter are dead on!

After owning a 2015 Ram PU with a Pentastar V6 sold me on the engine (306 hp back then). So, I ordered a 2026 2dr Sport S JL, V6, 6-speed heavily optioned.

The engine was gutless up to about 3,000 rpms. The throttle pedal req’d a lot of depressing to do much at all. Up to 3,000, the engine felt like there was a fuel shutoff under light acceleration and especially at light load. It just felt HORRIBLE! Seemed like it was missing much of the time.

On the highway, I normally drove in 4th and rarely 5th. The engine only reached 2,000 rpms (3.45 diff in Sport/Sport S) at 80 mph in 6th. The Wrangler has a high drag index. The engine/factory tune didn’t have enough power to maintain 80 in 6th and was marginal in 5th. Drag goes up by the square of the speed increase (the drag at 80 is 78% more than at 60. The engine barely maintains 60 at 1,500 rpms and has very little more power at 2,000 so can’t handle 80). The entire drivetrain would jerk with the apparent missing.

Contacted Brad. Discussed. Removed ECU, sent to AP Tuners for an unlock, reinstalled and drove 3 hrs to Brad’s house. Brad thoroughly deactivated Start/Stop, and tuned the ECU for 91 octane. Total time 2-3 hours.

Results: The throttle is very responsive. Significant torque increase from idle to 3,000 and vehicle can easily pull/accelerate from 1.500 rpms . All missing sensations are gone. The power increase above 3,000 is noticeable but not as much as below 3,000. It’s likely 30 hp more overall. 60 on up is very doable in 6th gear.Overall, less down shifting is required. No more driving around in 2nd gear in town. No more emission controlled feeling.

Finally, the Jeep is what I had hoped for.

 

[zouch]

would be curious to see how this applies to the Diesels.

This will be a fun one, but after having a bunch of these under my supervision, I want to make this thread and explain why, not just put out some claims.

DONT WASTE YOUR MONEY ON:

COLD AIR INTAKES

-Our Jeeps do not have a mass airflow sensor, so even with tuning, there isn't much to change to "tune the intake" to your Jeep, a manifold absolute pressure sensor (MAP) is used to calculate aircharge in measurements of MG. I have not seen any measurable differences in aircharge volume from customers with stock intakes or with cold air intakes. The only "benefit" to one is for more sound. In the rare event that the intake is actually pulling in more air, the ECU is going to have to compensate for it by adjusting long term fuel trims, but it will not command more torque or power as a result. Torque ceiling on factory tuning is set to 272 foot pounds, and you will never command more than that on stock tuning. Even if you modify the Neural Network or other injector data within the tune to adjust fuel trims for an intake, I have never seen a measurable increase in torque or power. Metal intakes are even worse, as that metal rides right on top/behind the radiator and is soaking in all that heat, driving up temperature readings at your intake air temperature sensor.

PEDAL CONTROLLERS

-All of these, I don't care what the brand is, manipulate the 5 volt Canbus signal going from the pedal to the ECU. These manipulate the voltage output to increase throttle response. Yes, they accomplish that, but they do not add power, and it is a risky way to get pedal response, no matter how reputable the company is. $300-$500. If you have to have one, go with Banks Pedal Monster as they have a good failsafe strategy in place. Everything else can fry your Canbus and cause new issues if they go faulty.

THROTTLE BODY SPACERS

-These literally don't do anything, what they do is throw off the air volume calculations that your very advanced ECU is using to power your entire vehicle. Just stop.

FUEL INJECTORS

-Some dude on the JK forums claimed upgrading his JK injectors to JL injectors added a bunch of power, no, no it didn't, it threw off your fuel trims and confused the crap out of your ECU, larger injectors MUST be accounted for in tuning, there are even minor injector tuning differences on various different PUG platforms (IE the injector data from a Grand Cherokee 2.6 is NOT the same as in a JL Wrangler).

THINGS WORTH THE MONEY

Premium Fuel

-These engines prefer premium fuel, period. Most stock 3.6 engines will pull 3-5 degrees of timing at wide open throttle on 87 octane, unless the weather is cold. This 3 to 5 degrees of timing is costing you 10-25 HP/10-25 TQ. I see it over and over and over. Yes, the manual says 87 is fine, but you are riding the knock sensor threshold at all times with 87 in your tank. Remember, just because you can't hear pinging doesn't mean your knock sensors can't hear it. If your in the "I've always run 87 octane and have no issues" crowd, congrats and carry on, but I promise you, your not making advertised power. If you want to run 87 all the time, get custom tuned for. The tune will offset losses from crappy fuel and also provide a bigger safety net. These models have a long term knock retard strategy that will "learn" your octane and continuously pull timing if it keeps detecting knock, making it even more sluggish. ESPECIALLY you 2.0 guys. The 2.0 will pull 10 plus degrees of timing on 87 octane, causing extreme heat build up. I datalogged one this past week locally, and regularly saw -5 to -10 degrees spark advance at cruise, which is insane. It genuinely hurt my feelings. LOL

Custom Tuning

-Surprise, the tuning guy said tuning is worth the money. I shouldn't even have to explain this, but a good tune from a reputable tuner of your choosing (there aren't many to choose from........) will completely transform your vehicle. Forget about raw HP and TQ numbers, I am talking driveability, response, power, and so much more. A custom engine and transmission tune by me, Livernois, or whoever else, will be the best money you spend. Just know that no one is as picky as I am about how a tune feels or looks on a log.

Straight Through Design Mufflers or Muffler Deletes

-I have consistently noticed that customers with good quality exhausts, ones that you can see straight through the muffler or ones that remove the muffler completely, actually are gaining about 5 HP/5 TQ or more across the board. The hot exhaust gasses are allowed to get out of the combustion chamber just a nut hair faster, and this helps reduce detonation/knock/heat and does indeed help.

Heat Management Devices

-Ventilated hoods, cooling fan controllers, colder thermostats, and anything else that helps remove heat is your friend. Stock tuning has very very aggressive heat related timing nannies. You could be losing 20-40 horsepower if your engine temps are north of 210 on a regular basis and everything is getting heat soaked. I see it constantly in datalogs. Important on both 3.6 and 2.0 models, but even more important on 2.0. Colder thermostats, yes, they work. The earlier opening allows coolant to flow sooner, allowing the radiator to start doing its magic earlier.

Quality Engine Oil

-I have tuned several Jeeps now that showed knock/detonation on one log, then I tell them to change their oil, and the knock goes away. Fresh oil every 3000-5000 resists heat and low speed preignition (LSPI), the SN and higher rated oils are a must have as the technology has evolved over the years a lot, I LOVE Valvoline Restore and Protect, Valvoline Advanced Synthetic, and Penzoil Ultra Platinum. Use 0w20 if you'd like, but I use 5w30. Not trying to start that war here.

I also like the Baxter oil filter adapter, and plan on adding one to my 2025 soon. I like the idea of keeping oil in the top end of the engine on start up so that the engine can jump out of high lift mode (defaulted on start up) as fast as possible and reduce center lobe camshaft wear. But I wouldn’t call it a performance mod.

 

[bmpcamry09]

would be curious to see how this applies to the Diesels.

I have virtually zero diesel experience outside of from when I owned a 6.blow Ford. Wish I had some insight.

 

[SRH76]

Yep. That stumble is engine going into high lift. No way around that on factory tune.

I knew it! LOL! Thanks for the confirmation!
I notice that 'burble' in the exhaust right around that spot, and guessed it was likely the VVL kicking in. Do you know if there's an issue with hovering around that transition point? Sometimes when I'm coasting along a side street (23 Rubi 6SPD) I can hear it burble 'in and out' around that RPM if i let the revs get up while slowing down.

 

[bmpcamry09]

I knew it! LOL! Thanks for the confirmation!
I notice that 'burble' in the exhaust right around that spot, and guessed it was likely the VVL kicking in. Do you know if there's an issue with hovering around that transition point? Sometimes when I'm coasting along a side street (23 Rubi 6SPD) I can hear it burble 'in and out' around that RPM if i let the revs get up while slowing down.

I’ve been pretty vocal that I believe that whole system and the way it operates contributes to camshaft failure on 2018 and up models. Almost every cam failure reported is an intake cam, with the center lobe (hi lift lobe) being damaged. I think the high lift system is a poor design and that rough engagement and the way it operates (there is no roller on the high lift side) speeds up failure. The system is not needed. It is not used for power, it is used for emissions and efficiency reasons, although I’ve proved that disabling it and tuning around it actually enhances efficiency and drive-ability, with the factory emissions remaining in tact. Every JL and JT I tuned gets this system shut off now. Unfortunately, the system will always be in high lift mode for a second or two on cold start because of the mechanical limitations while waiting for oil pressure.

 

[SRH76]

I’ve been pretty vocal that I believe that whole system and the way it operates contributes to camshaft failure on 2018 and up models. Almost every cam failure reported is an intake cam, with the center lobe (hi lift lobe) being damaged. I think the high lift system is a poor design and that rough engagement and the way it operates (there is no roller on the high lift side) speeds up failure. The system is not needed. It is not used for power, it is used for emissions and efficiency reasons, although I’ve proved that disabling it and tuning around it actually enhances efficiency and drive-ability, with the factory emissions remaining in tact. Every JL and JT I tuned gets this system shut off now. Unfortunately, the system will always be in high lift mode for a second or two on cold start because of the mechanical limitations while waiting for oil pressure.

I'll call that a solid 'yes'.
I knew it was a sketchy system, but I appreciate you laying out the detailed operation above. A tune would definitely sort it out I'm sure, but between being in CA and still under full warranty, I'm not keen on poking around to that level just yet.

 

[bmpcamry09]

I'll call that a solid 'yes'.
I knew it was a sketchy system, but I appreciate you laying out the detailed operation above. A tune would definitely sort it out I'm sure, but between being in CA and still under full warranty, I'm not keen on poking around to that level just yet.

Let me know if you have any questions. I actually have done several CA vehicles and no issues with emissions or safety inspections to report yet. I tune within factory parameters and don’t change any emissions related settings and there is no indication of tuning from a dealership standpoint other than “flash counter” which no tech pays attention to. Can flash stock tune back at anytime also to alleviate any possible concerns on that end.

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