Pentastar power increase

[Badunit]

I have yet to see a dyno chart where I trust the numbers at low RPM, which is the area I am most interested in. Maybe it is because all the tests are looking for peak hp and torque and don't care about low end torque. But, if the numbers in that 3.6L chart are to be believed, the torque from the 3.6L drops fast below 2500rpm and falls like a rock below 1700rpm. Considering 1600-2200 is the common rpm range when cruising around, the chart is showing the reason it has to downshift so much.

The 4.0, on the other hand, is still pulling strong down low. The chart you posted makes it look like it drops off fast but that is because the y axis range starts at 140 lb-ft while the one for the 3.6 starts at 0. It exaggerates it. Below is a chart with both of them on the same scale. I assumed 20% drivetrain loss for the 4.0. I left off the part of the 3.6L curve where it falls off a cliff because it is probably not correct.

My takeaway from this is that the 4.0L is torquier (and therefore more powerful) at cruising rpms where the engine is running 90% of the time (or attempts to be) and the 3.6L is more powerful at higher rpms, like when passing or towing up a hill. Not a jaw dropping conclusion. My butt dyno already told me that.

Sponsored

 

[ShadowsPapa]

I have yet to see a dyno chart where I trust the numbers at low RPM, which is the area I am most interested in. Maybe it is because all the tests are looking for peak hp and torque and don't care about low end torque. But, if the numbers in that 3.6L chart are to be believed, the torque from the 3.6L drops fast below 2500rpm and falls like a rock below 1700rpm. Considering 1600-2200 is the common rpm range when cruising around, the chart is showing the reason it has to downshift so much.

The 4.0, on the other hand, is still pulling strong down low. The chart you posted makes it look like it drops off fast but that is because the y axis range starts at 140 lb-ft while the one for the 3.6 starts at 0. It exaggerates it. Below is a chart with both of them on the same scale. I assumed 20% drivetrain loss for the 4.0. I left off the part of the 3.6L curve where it falls off a cliff because it is probably not correct.

My takeaway from this is that the 4.0L is torquier (and therefore more powerful) at cruising rpms where the engine is running 90% of the time (or attempts to be) and the 3.6L is more powerful at higher rpms. Not a jaw dropping conclusion. My butt dyno already told me that.

My car can walk up a 3-4% grade in 3rd gear (a T5 five speed) at about 1400 rpm and still accelerate if I want it to without hesitating. It's got a truly flat curve.

 

[Charles 236]

I'll never understand why people pull engines out the top. Drop the whole shootin' match out the bottom, roll it out on dollies, build what you want, roll it back under and pull it up, bolt it in.
Maybe that's just posting there in that picture, but even my Eagle all went out the bottom and the modified assembly back in the same way and I did it with 1 arm in a sling (literally, I'd ripped off a bicep and just had surgery to reattach)

In the case of Wranglers and Gladiators, the only way to swap an engine is out the top. Unless you lift the body off of the frame, in that case the engine still has to be lifted off of the frame, since the cross members are welded in.

About 25-28 years ago, I was doing a lot of engine work in the Chrysler Plymouth dealership. I pulled engines from the LH bodies (Intrepid, Concorde, LHS and 300) from the top. It took me about seven hours to finish a swap this way. The shop foreman asked why I didn't just drop it out the bottom on the cradle. I told him it was easier out the top, but I would do one out the bottom to satisfy his desire to see it dropped out. I did, and found that it took about seven hours. I did drop some engines out the bottom, especially out of the J bodies (Stratus, Sebring, Cirrus), so I was familiar with the process.

I still use both methods, depending on the vehicle.

 

[TheRealStreetcommander]

My takeaway from this is that the 4.0L is torquier (and therefore more powerful) at cruising rpms where the engine is running 90% of the time

Yeah, you are right and most certainly the 4.0 has more torque from off idle to around 1800rpm.

I also agree low rpm dyno testing is infuriating. It gets blamed on the transmission not being able to stay in the 1:1 gear at low rpm or being prone to downshifting, but to me that shows a lack of effort by the dyno owners and operators --find a way to make the trans hold the gear you want, or get a job doing something else very poorly. Dyno testing is essentially data gathering and analysis, i.e. science. This circles directly back to your number chasing comment though. Not many people brag about the torque their engine makes at 1000rpm --that's a very special crowd.

A perhaps more legitimate excuse I've heard is that many transmissions don't make enough line pressure at low RPM to create apply pressure's high enough to prevent slippage. This is plausible and I've seen where torque management routines on RAM Cummins for example, will reduce torque in certain gears and RPMs to allegedly save the driveline.

My JT is a ZF by the way, and I think the converter flashes at near 2000rpm when unlocked, so I don't ever feel the lack of torque under heavy throttle. It seems to be programmed to downshift before it gets called to apply much torque below 1800 rpm. Stated differently, I don't really ever notice my JT operating in the idle to 1800rpm range unless I'm just fatting around town, and then it doesn't matter

 

[Flyin6]

Hush. I was just trying to get him to spend more money on snake oils.

You're a real funny guy...NOT!

 

[Flyin6]

Darren Parsons figured it out…
??‍ in a home shop in the desert…. Just saying things can be done, even when the internet says no….

What year is that? If it is late 2021 or after then you're on to something, but if it is an earlier JT, then it has the -2 computer and we are no longer talking apples-apples

 

[Flyin6]

Just swap your JT with a diesel version. The power & economy is astronomically different. You could also move over nearly all your modifications without issue.

I have had 3 vehicles with aftermarket forced induction, I've had 3 more with factory FI. As much as I love doing my own work, pushing the boundaries, learning and tinkering; the factory installed platforms ALWAYS perform better, have better drivability, reliability and are better supported.

Swap your stuff to a diesel and dont look back. It'll likely get you bigger power gains than you'll achieve with this route and cost less.

That has been discussed but is a lot harder than you may imagine. Frames are different in 3.0 vs 3.6 jeeps. So it is actually a major undertaking.

 

[Flyin6]

The old adage = "if you build it, they will come"....plays into the game here. You don't need "forum support" - you only need a tuner with a vision. If they need 50-100 "buyers" before they start down the road, then they are lousy businessmen. I can guarantee that there are DOZENS of people on this already - crunching numbers, analyzing viability, watching, listening, and brainstorming. When one of them gets on it, we'll have it. Until then, you have the opportunity to be "the one" and make huge bank. What are you waiting for !! You have the vision!!!!

Ya know I can do a lot of things. Aft wheel landing NVG on mountain ridges: Check.
50 knot cross wind landing at Kennedy international: Check
Mow the grass straight as an arrow: Check
Get into this programming game: Lost as last year's easter egg!

 

[ShadowsPapa]

In the case of Wranglers and Gladiators, the only way to swap an engine is out the top. Unless you lift the body off of the frame, in that case the engine still has to be lifted off of the frame, since the cross members are welded in.

About 25-28 years ago, I was doing a lot of engine work in the Chrysler Plymouth dealership. I pulled engines from the LH bodies (Intrepid, Concorde, LHS and 300) from the top. It took me about seven hours to finish a swap this way. The shop foreman asked why I didn't just drop it out the bottom on the cradle. I told him it was easier out the top, but I would do one out the bottom to satisfy his desire to see it dropped out. I did, and found that it took about seven hours. I did drop some engines out the bottom, especially out of the J bodies (Stratus, Sebring, Cirrus), so I was familiar with the process.

I still use both methods, depending on the vehicle.

OK, mega-brain fart. Geesh, I've even seen how these are assembled in the case of Wrangler and Gladiator - full frame, engine assembly dropped onto frame and bolted to frame, body goes on.
Smack forehead...........

 

[ShadowsPapa]

Ya know I can do a lot of things. Aft wheel landing NVG on mountain ridges: Check.
50 knot cross wind landing at Kennedy international: Check
Mow the grass straight as an arrow: Check
Get into this programming game: Lost as last year's easter egg!

Thank goodness for our differences and our different skill sets.

 

[Flyin6]

The conversation with Livernois continues.

I asked if it is possible to create jumper harnesses to retrofit the GPEC2 into later-model Gladiators. No response on that yet.

If that is possible, then the tuning barrier is gone.

 

[Mr._Bill]

That has been discussed but is a lot harder than you may imagine. Frames are different in 3.0 vs 3.6 jeeps. So it is actually a major undertaking.

No, he was suggesting you trade in the gas truck for a diesel model.

 

[Flyin6]

From Livernois:

Even if we did a supercharger on a 3.6, they only make about 280ish to the wheels and it’s a $15k job for a magnuson on one of those so you’re already half the cost of a HEMI swap, with half the horsepower as well. We’ve always been the first people to tune vehicles, such as the 23 EcoBoost trucks, and any new vehicle on the market. We’ve got the best engineers working on cracking the -5 computer, just like every other tuning company out there. The only roadblock with the -5 is not the connections, but the code to crack the encryption. There’s billions of possibilities for the encryption and it might take 6 months or it might take 6 years to crack them. FCA strengthened their encryption on the -5 computers tenfold compared to the -2A computers so it’s almost near impossible to crack them. Unfortunately right now, the only two options you truly have for the gladiator is 1) leave it how it is and hope in the future the -5 gets cracked or 2) Hemi swap. By the time you do a supercharger, ported heads, throttle body, and possibly upgrade some of the internals, you’re right at the price point, if not more of a HEMI swap. Even if you didn’t do the internals, you’d still be around $5k short of doing the AMW 505 swap. I used to work at a dealership and we worked with AMW closely, and having the opportunity to drive both a 505 swapped gladiator along with a Rocky Ridge or Black Widow gladiator that were both on 37s, I would choose the AMW and spend the money on a conversion every day of the year. Even with the factory gearing and 37s, it was slow and wasn’t fun to drive at all because there was no power to get up and go. The 505 on the other hand had no issues turning those 37s and never shifted constantly. From personal experience, even if you got an extra 50wtq from the motor, it wouldn’t do what you expected it to do as the gearing internally is vastly different from the suburban. The gladiators 8 speed trans is made to shift more frequently than the 4 or 6 speed in your suburban. Heck, I’ve got a 2018 F150 5.0 with the 10 speed on oversized tires and even with 3.55s, if I’m going up a slight incline on the highway, it downshifts down to 7th, otherwise the trans will cook itself, which is also why the trans on the gladiator downshifts so frequently. If you had a little more torque, even if it kept the trans in the same gear, your temps would skyrocket which would eventually cook the transmission. The stock computer will automatically downshift the trans that far to keep the fluid moving and keep the trans at a good operating temp.

-Hunter

 

[Flyin6]

No, he was suggesting you trade in the gas truck for a diesel model.

OK, Copy that
Can't...Spent WTM ( WAAAAAY too much) on the AEV I own.

 

[Mr._Bill]

From Livernois:

Even if we did a supercharger on a 3.6, they only make about 280ish to the wheels and it’s a $15k job for a magnuson on one of those so you’re already half the cost of a HEMI swap, with half the horsepower as well. We’ve always been the first people to tune vehicles, such as the 23 EcoBoost trucks, and any new vehicle on the market. We’ve got the best engineers working on cracking the -5 computer, just like every other tuning company out there. The only roadblock with the -5 is not the connections, but the code to crack the encryption. There’s billions of possibilities for the encryption and it might take 6 months or it might take 6 years to crack them. FCA strengthened their encryption on the -5 computers tenfold compared to the -2A computers so it’s almost near impossible to crack them. Unfortunately right now, the only two options you truly have for the gladiator is 1) leave it how it is and hope in the future the -5 gets cracked or 2) Hemi swap. By the time you do a supercharger, ported heads, throttle body, and possibly upgrade some of the internals, you’re right at the price point, if not more of a HEMI swap. Even if you didn’t do the internals, you’d still be around $5k short of doing the AMW 505 swap. I used to work at a dealership and we worked with AMW closely, and having the opportunity to drive both a 505 swapped gladiator along with a Rocky Ridge or Black Widow gladiator that were both on 37s, I would choose the AMW and spend the money on a conversion every day of the year. Even with the factory gearing and 37s, it was slow and wasn’t fun to drive at all because there was no power to get up and go. The 505 on the other hand had no issues turning those 37s and never shifted constantly. From personal experience, even if you got an extra 50wtq from the motor, it wouldn’t do what you expected it to do as the gearing internally is vastly different from the suburban. The gladiators 8 speed trans is made to shift more frequently than the 4 or 6 speed in your suburban. Heck, I’ve got a 2018 F150 5.0 with the 10 speed on oversized tires and even with 3.55s, if I’m going up a slight incline on the highway, it downshifts down to 7th, otherwise the trans will cook itself, which is also why the trans on the gladiator downshifts so frequently. If you had a little more torque, even if it kept the trans in the same gear, your temps would skyrocket which would eventually cook the transmission. The stock computer will automatically downshift the trans that far to keep the fluid moving and keep the trans at a good operating temp.

-Hunter

My read is that he is trying to politely tell you they are not going to spend any more unless someone else finds a way to overcome the obstacles preventing them from going forward. He put a lot of effort into justifying an engine swap. My interpretation, don't call us, we'll call you if we are able to come up with something in the future.

Sponsored