The secret to more power....

[UselessPickles]

You make it sound like it's as simple as adjusting some screws and suddenly you have a 400+, or even 800+ hp 4BT.

I did some browsing around on a couple 4BT forums, and the common relatively easy, affordable mods get you into the low 200 hp range without opening up the engine. Beyond that seems to start requiring serious engine mods (pistons, rods, machining heads, valve springs, aftermarket studs, crankcase bracing, bigger turbo, twin sequential turbos, etc., etc.).

I've also noticed that the diesels with huge power at the drag strip need to brake-boost for about 5-10 seconds to pre-spool the turbo before fully staging to begin the race. They do the same thing on the dyno too. That leads me to believe that there would be some serious turbo lag during daily driving if you wanted to tap into that big power.

Yes, a 4BT can make some huge power. But it takes quite a bit of money/work, especially if you want good reliable power. The same can be said for many engines. There's nothing magically secret about diesel for getting more power.

The Pentastar could likely make some similarly huge power if it was modified to the extent of these huge power small diesels. The stock pentastar already makes quite a bit more power than a stock 4BT. Bolt-on forced induction puts the Pentastar into the power range that the 4BT requires being rebuilt internally to support.

What the huge power modded diesel gives you though is insane low rpm torque. I know some Jeep people think low rpm torque is all the rage, but I'm pretty sure it would be safe to say that 800+ ft-lbs that requires loading up the engine to spool up the turbo to get there... would just be absolute complete overkill for off road driving in a Wrangler. That kind of torque is what you use for hauling *very* heavy loads. I know it's hard for you to remember, but this is a Wrangler forum. Wrangler's don't weigh as much as your deuce, so they don't need ridiculous amounts of low-end torque just to move around acceptably.

Final point: if the 4BT is so easy to turn up to 600, 700, 800+ hp as a reliable and good daily driver, and would be amazing in a Wrangler, then why isn't Bruiser doing it? Why does Bruiser only talk about being able to "turn it all the way up" to the 250-300 hp range? Maybe you need to call up Bruiser and let them in on your secrets to more power!

[KaiserBill]

You make it sound like it's as simple as adjusting some screws and suddenly you have a 400+, or even 800+ hp 4BT.

I did some browsing around on a couple 4BT forums, and the common relatively easy, affordable mods get you into the low 200 hp range without opening up the engine. Beyond that seems to start requiring serious engine mods (pistons, rods, machining heads, valve springs, aftermarket studs, crankcase bracing, bigger turbo, twin sequential turbos, etc., etc.).

I've also noticed that the diesels with huge power at the drag strip need to brake-boost for about 5-10 seconds to pre-spool the turbo before fully staging to begin the race. They do the same thing on the dyno too. That leads me to believe that there would be some serious turbo lag during daily driving if you wanted to tap into that big power.

Yes, a 4BT can make some huge power. But it takes quite a bit of money/work, especially if you want good reliable power. The same can be said for many engines. There's nothing magically secret about diesel for getting more power.

The Pentastar could likely make some similarly huge power if it was modified to the extent of these huge power small diesels. The stock pentastar already makes quite a bit more power than a stock 4BT. Bolt-on forced induction puts the Pentastar into the power range that the 4BT requires being rebuilt internally to support.

What the huge power modded diesel gives you though is insane low rpm torque. I know some Jeep people think low rpm torque is all the rage, but I'm pretty sure it would be safe to say that 800+ ft-lbs that requires loading up the engine to spool up the turbo to get there... would just be absolute complete overkill for off road driving in a Wrangler. That kind of torque is what you use for hauling *very* heavy loads. I know it's hard for you to remember, but this is a Wrangler forum. Wrangler's don't weigh as much as your deuce, so they don't need ridiculous amounts of low-end torque just to move around acceptably.

Final point: if the 4BT is so easy to turn up to 600, 700, 800+ hp as a reliable and good daily driver, and would be amazing in a Wrangler, then why isn't Bruiser doing it? Why does Bruiser only talk about being able to "turn it all the way up" to the 250-300 hp range? Maybe you need to call up Bruiser and let them in on your secrets to more power!

Simple is relative. You don't make 800hp or even 600hp at the crank shaft without some internal modifications:

1) Reduce Compression ratio from I believe it is 17:1 possibly 18:1 to 13-14.5:1 ratio (it will be a little harder to start, but still doable.). New pistons about $1000.00 maybe less depending type used.

2) Blue Print and Port The Engine That has to be done. Depending on how well built your engine is from the factory will determine how much this will set you back but it should be under $3K if you can do most of the work yourself.

3) Fuel injector pump have it rebuilt so you can get at least 800PSI to the injectors they will do the rest of the work for you. You want high volume and high pressure. So you need to have your injectors blue printed-- depending on the number and specs you have probably set you back with the injector pump another $2000-$2500

4) Turbos-- You start off with the first stage using the stock 4BT turbo then you put on either a Cummins 8.3 turbo or maybe one from L10 enigne either one will probably be more than enough to get you to the magic boost number of 200+ PSI!!!! Used pull out about $500-$1000-- rebuild kit runs about $250 to $500 depending on requirements.

5) Intercooler-- Probably air to air you can get one for about $800- $1000.

6) Water-Methanol System about $950.00

7) Wrap and insult the exhausts and turbos for each stage as well as the intakes. $500.00


How do you make the power: Compound (Two Stage) Turbo Charging. You use the smaller 4BT stock unit to as the primary turbo with a by pass value that is boost operated-- it reaches say 24PSI Manifold pressure bam it closes and spools up the bigger C8.3 unit or L10 Unit that then pushes up to the 60-200psi manifold pressure zone.
Again the price of the final product all depends on your ability to find good prices on things and perform a majority of the work yourself. Otherwise the price goes way up. But, to me this is easy.





This how Borg-Warner does it. A home-built setup will have more tubing and so on but it will work out the same way. Massive HP!!!!

Why doesn't Bruiser do it? Simple reliability always suffers with massive hp an torque. They want customers that want novelty but aren't exactly people who fix things on their own. So they keep the HP low and the Torque lower and this makes for greater reliability in all aspects of the vehicle.

[UselessPickles]

Thanks. I think you've just proven my point. And that's all on top of a $21k conversion. And there's a lot of assumptions of "do all the work yourself" (bolt-on kits are one thing, removing and rebuilding an engine is on a whole different level of skills/tools necessary), and assumptions that you actually know what the hell you're doing with matching all the right components and settings up to support the big power (there isn't a simple complete kit for this). More realistically, you're going to need to work with a performance shop that has experience in modding the 4BT, and prices for various portions of the process will skyrocket. And in the end, reliability is a concern.

For about the same amount of $$$, you could do a 6.1 or 6.4 hemi conversion (pay someone else to do it, that is), add a bolt-on supercharger *kit* from a reputable manufacturer, no engine mods necessary, be in the same ballpark of power output, and have an engine that can be diagnosed/serviced by any Chrysler dealer. Plus the Hemi sounds much better. The 4BT sounds like a school bus or garbage truck. Not impressive :-p

[KaiserBill]

Thanks. I think you've just proven my point. And that's all on top of a $21k conversion. And there's a lot of assumptions of "do all the work yourself" (bolt-on kits are one thing, removing and rebuilding an engine is on a whole different level of skills/tools necessary), and assumptions that you actually know what the hell your doing with matching all the right components and settings up to support the big power (there isn't a simple complete kit for this). More realistically, you're going to need to work with a performance shop that has experience in modding the 4BT, and prices for various portions of the process will skyrocket. And in the end, reliability is a concern.

For about the same amount of $$$, you could do a 6.1 or 6.4 hemi conversion (pay someone else to do it, that is), add a bolt-on supercharger *kit* from a reputable manufacturer, no engine mods necessary, be in the same ballpark of power output, and have an engine that can be diagnosed/serviced by any Chrysler dealer. Plus the Hemi sounds much better. The 4BT sounds like a school bus or garbage truck. Not impressive :-p

I said it was simple-- I didn't say it was a bolt on kit- i.e. idiot proof... And yes it does require more skills and understanding of the engines than bolting on a turbo kit. However, the rewards are so much greater to he who knows the secrets of the dieselly goodness!!!! As for reliability anytime you add a turbo or change the the chip-set in engine you reduce potential reliability. When you put the Prodigy kit on your Jeep reliability was compromised. This would be potentially more likely to have a failure. But, odds are a 4BT operating under its normal rpm with about 80PSI of manifold pressure would have a nice long life.

Myself, I would put a 4-53T Detroit Diesel in the Jeep with Compound turbo unit and I'd tweak the RPM to 2800-- which would add a little more complexity and then I would throw out the stock transmission and put in a Eaton Fuller 6spd model (maybe even an older Spicer 5+4 unit if I could it under it) and put in a heavy duty divorced Transfer Case and swap the axles out for U1400 series Portal Axles...


http://www.powerlinecomponents.com/l...automotive.pdf



My theoretical build would sound like Satan Himself Pulling Up To Your Doorstep For Your Soul! The best part is I could make it roast any 6.4Hemi build from AEV on the Dyno pretty much any engine that isn't 100k in price playing with pump gas would be a loser to this engine on the dyno. Not to mention being stroke the torque curve would be nearly flat. So, it would be epically overpowered on or off the road.

[Timmy]

Myself, I would put a 4-53T Detroit Diesel in the Jeep with Compound turbo unit and I'd tweak the RPM to 2800

Then why don't you put the 4-53T Diesel in your Jeep? Go for it, then write up a posting with step-by-step so we can all learn how to put one in a Jeep. Toss it on the dyno when you're done and share your results.

[KaiserBill]

My company car is a Jeep Liberty-- It won't fit. I've thought about it.