cheapcherokee93
<----boat-manche
- Location
- Guadalahabra, CA
As some of you saw in the Mod Tech section, i've been recently displeased with the power output of my mostly stock 4.0. thread can be seen here: http://naxja.org/forum/showthread.php?t=1110999
Lately i've been exploring options for gaining a significant amount of power out of my jeep, whether that includes a stroker, forced induction, or a drivetrain swap. To make this even more difficult, I live in beautiful Southern California which means our glorious SMOG rules come in to play. Awesome right?
So i'm making this thread in order to go over all performance options in relation to CA (and maybe other states) smog rules. For me, this is not limited to having a system that can be removed once every 2 years to have the smog check done, because thats something i'm willing to do (within reason). Money also plays a factor here, ultimately i would like to find a balance between dollars spent, horsepower gained, time spent, and reliability in the long run.
I also think this thread doesnt have to only be about my set up, but any one else looking for some major HP while still complying with their states emissions rules. Its too bad not everyone can live in a state where you can bolt on a supercharger and not have to worry about passing a smog check. some of us can only dream
With that said, here is the set up I am dealing with and my thoughts and questions on all the different options out there. Feel free to correct me if I'm misunderstanding something.
1988 Jeep Comanche
Renix 4.slow
AW4
231
33s
4.10s (4.56 or 4.88 is on the list)
lots 'o weight
no A/C
Option #1: Forced Indution
Superchargers:
My thoughts here are making an "easily" removable supercharger set up that can be swapped out every 2 years for smog checks. I have no AC, so ideally the pump location would be used for the supercharger. The main benefit i see to a supercharger is the engine does not have to be removed to receive the power increase, which means less work (maybe).
Since the Renix system has no check engine light and no way to communicate with the ECU, CA smog checks dont include scanning the computer for renix jeeps. Theoretically I want to run MegaSquirt (somewhat hidden in the stock harness) for tuning both the N/A and supercharged set ups. Bolt on supercharger- upload boosted tune, take off supercharger- upload smog tune. MegaSquirt is reasonably priced and works well, and since the renix system has no CEL i should be able to get away with running it. The exact model i'm looking at is actually the MicroSquirt setup, since its super small, already assembled, has spark control capabilities and uses an external MAP sensor. Obviously this also requires the use of a wideband O2 sensor. Here are my perceived Pros and Cons of the different types of superchargers:
1-Centrifugal
Pros: Easier Packaging and tuning (swap out compressor wheels). Somewhat easy to find (there are a good amount of vortechs on craigslist)
Cons: custom mounting (but this is true of almost all superchargers for the XJ), not as much boost at low RPMs
2- Roots
Pros: Higher boost at low RPM, easy to find (M90, M62),
has experience with them
Cons: custom mounting, packaging issues
3- Screw
Pros: Excellent boost
Cons: Packaging, Availability, Cost
Turbos:
I won't get much into turbos because of their obvious problems with needing to remove it for smog.
Pros: highly adjustable through different turbo sizes and adjustable wastegate, simple, easily available, potentially inexpensive (say you could re-use a factory turbo from an older vehicle that came with one stock)
Cons: packaging packaging packaging, especially with the exhaust! i think it would be extremely difficult to have a turbo set up that could be removed with reasonable effort.
Option #2: Stroker
The stroker is probably the easiest set up as far as long term goes. Why? lets see, the engine bolts right in, re uses all the factory sensors and can pass CA smog so long as the factory air box is used and it passes the sniffer. There is no way for the smog tech to know its stroked out which makes this a very appealing option. There are some downfalls that i have noticed though.
These are things that i have witnessed based on either forum posts or through a close friend of mine who purchased a 4.6 stroker through a very reputable company and his experiences:
-more prone to over heating
-decreased reliability
-cost $$$$$$
-other random issues
I have not been very impressed with strokers, based on what I have read online and through personal experience with my friends jeep. However I have seen a few very reliable stroker set ups on here. What i really want to know is, what makes one stroker more reliable than another? Quality of parts used? Quality of machine work used? Both? Some magic combination of parts + prayer?
This statement from Cal is what has me curious:
Even if I knew the recipe for a reliable stroker, its probably out of my price range. There are also the extra parts needed to tune the stroker correctly, whether that be running the renix ECU with bigger injectors and an adjustable FPR, or running a stand alone like MegaSquirt. IMO cost adds up real quick here, by the time you build the stroker and buy all the accommodating parts to make it run correctly. I'm not saying getting a significant power upgrade should be cheap, but that this could be the most expensive option depending on how you build it. Obviously the main benefit of this route is the fact that its the easiest for smog checks.
Option #3: Engine Swap
I must say this option is probably EASILY the one that requires the most time to perform. To legally get an engine swap to pass CA emissions you must go through a smog referee and get it approved. The full requirements can be seen here: http://www.bar.ca.gov/80_barresources/07_autorepair/engine_change_guidelines.html
Basically all original smog equipment from the donor engine must be re used, and a functioning OBD port and Check Engine Light must be used. The engine must be functioning as if it were in the original vehicle, which means if it came with EGR, the EGR must be reused in the jeep, and so on.
The general benefits i've seen with engine swaps are:
-increased reliability
-more power (obviously!)
-more readily available performance parts (depending on engine choice obviously)
and the major downfalls that i have found are:
-harder to keep cool = fitting a bigger radiator or purchasing super expensive big money huge aluminum radiator.
-packing, everything has to be custom from motor mounts to exhaust
-a different engine also means a different transmission and t-case in most cases = even more time + money
-retrofitting newer/different engine electronics onto jeep body
-pleasing the smog referee
With that said, these are the engines i've considered:
Small Block Ford 5.0
these are cheap, simple, very reliable and stupid easy to get the fuel injection running in any vehicle. performance parts are cheap and everywhere, however factory power ratings are not very spectacular for a v8. The engine is also very compact which makes fitting in a jeep simple. Unfortunately this limits you to only Ford automatic transmissions and transfer cases, something i'm not too fond of. There are no aftermarket mounting solutions for this engine in the MJ, so everything must be fabricated. Cooling might not be so bad with the Jeep's radiator as this is a smaller V8.
Small Block Chrysler
I'm talking the "newer" 5.2 and 5.9 found in ZJs, Dakotas, Durangos, and Rams. Overall impressions are its a harder engine to come across, however donor vehicles are cheap where you could have an entire drivetrain to swap in. Sadly this engine does not have cheap aftermarket support or performance parts on craigslist everywhere. Factory power ratings are decent, but behind these engines are the generally unreliable 44 and 46RE transmissions. the later model engines dont have EGR, which makes fitting it easier. These engines are also not considered as reliable as the small block ford or LSx engines.
so potentially this could be a cheap engine swap using a cheap donor vehicle and using its whole drivetrain.
LSx
By far the most popular option today. The LSx series engines are readily available, can be upgraded with ease, and are somewhat cheap in CA though not as cheap as in the east coast it seems. Maybe i just dont know where to find the cheap stuff. These engines accept power upgrades very well and have a plethora of aftermarket and info. There are conversion motor mounts available which means less fab work. There is more info on this engine swap into a jeep than any other V8. The issues i see are packaging, mainly with the intake and pulleys clearing the hood. getting the factory EGR manifolds to clear the MJ unibody looks like a challenge, although what do i know. Getting factory gauges to work can also be trouble, but nothing aftermarket gauges cant fix. There have been some smog legal swaps in CA, so i know it can be done. Cooling also seems to be an issue once again, so a bigger radiator needs to be shoehorned in. This engine also requires the use of a GM automatic transmission, something else to be aware of.
I see it like this swap provides affordable, reliable power with lots of room to upgrade in the future. i'm also under the impression the automatics used behind the LSx (4L60?) are reliable and upgradeable, so thats good. Aftermarket motor mounts are a huge plus. Wiring looks like a huge chore. Lots and Lots of work to get this thing CA smog approved, but is it worth it?
Many many options here, lots to think about. I would love to hear input on any of the options, why one would be better than the other, why one sucks, why im crazy for trying to do this amidst CA smog nazis, or maybe something i havent thought of yet? Hopefully this thread can be a tool for others as well.
thanks,
Matt
Lately i've been exploring options for gaining a significant amount of power out of my jeep, whether that includes a stroker, forced induction, or a drivetrain swap. To make this even more difficult, I live in beautiful Southern California which means our glorious SMOG rules come in to play. Awesome right?
So i'm making this thread in order to go over all performance options in relation to CA (and maybe other states) smog rules. For me, this is not limited to having a system that can be removed once every 2 years to have the smog check done, because thats something i'm willing to do (within reason). Money also plays a factor here, ultimately i would like to find a balance between dollars spent, horsepower gained, time spent, and reliability in the long run.
I also think this thread doesnt have to only be about my set up, but any one else looking for some major HP while still complying with their states emissions rules. Its too bad not everyone can live in a state where you can bolt on a supercharger and not have to worry about passing a smog check. some of us can only dream
With that said, here is the set up I am dealing with and my thoughts and questions on all the different options out there. Feel free to correct me if I'm misunderstanding something.
1988 Jeep Comanche
Renix 4.slow
AW4
231
33s
4.10s (4.56 or 4.88 is on the list)
lots 'o weight
no A/C
Option #1: Forced Indution
Superchargers:
My thoughts here are making an "easily" removable supercharger set up that can be swapped out every 2 years for smog checks. I have no AC, so ideally the pump location would be used for the supercharger. The main benefit i see to a supercharger is the engine does not have to be removed to receive the power increase, which means less work (maybe).
Since the Renix system has no check engine light and no way to communicate with the ECU, CA smog checks dont include scanning the computer for renix jeeps. Theoretically I want to run MegaSquirt (somewhat hidden in the stock harness) for tuning both the N/A and supercharged set ups. Bolt on supercharger- upload boosted tune, take off supercharger- upload smog tune. MegaSquirt is reasonably priced and works well, and since the renix system has no CEL i should be able to get away with running it. The exact model i'm looking at is actually the MicroSquirt setup, since its super small, already assembled, has spark control capabilities and uses an external MAP sensor. Obviously this also requires the use of a wideband O2 sensor. Here are my perceived Pros and Cons of the different types of superchargers:
1-Centrifugal
Pros: Easier Packaging and tuning (swap out compressor wheels). Somewhat easy to find (there are a good amount of vortechs on craigslist)
Cons: custom mounting (but this is true of almost all superchargers for the XJ), not as much boost at low RPMs
2- Roots
Pros: Higher boost at low RPM, easy to find (M90, M62),
has experience with them Cons: custom mounting, packaging issues
3- Screw
Pros: Excellent boost
Cons: Packaging, Availability, Cost
Turbos:
I won't get much into turbos because of their obvious problems with needing to remove it for smog.
Pros: highly adjustable through different turbo sizes and adjustable wastegate, simple, easily available, potentially inexpensive (say you could re-use a factory turbo from an older vehicle that came with one stock)
Cons: packaging packaging packaging, especially with the exhaust! i think it would be extremely difficult to have a turbo set up that could be removed with reasonable effort.
Option #2: Stroker
The stroker is probably the easiest set up as far as long term goes. Why? lets see, the engine bolts right in, re uses all the factory sensors and can pass CA smog so long as the factory air box is used and it passes the sniffer. There is no way for the smog tech to know its stroked out which makes this a very appealing option. There are some downfalls that i have noticed though.
These are things that i have witnessed based on either forum posts or through a close friend of mine who purchased a 4.6 stroker through a very reputable company and his experiences:
-more prone to over heating
-decreased reliability
-cost $$$$$$
-other random issues
I have not been very impressed with strokers, based on what I have read online and through personal experience with my friends jeep. However I have seen a few very reliable stroker set ups on here. What i really want to know is, what makes one stroker more reliable than another? Quality of parts used? Quality of machine work used? Both? Some magic combination of parts + prayer?
This statement from Cal is what has me curious:
Even if I knew the recipe for a reliable stroker, its probably out of my price range. There are also the extra parts needed to tune the stroker correctly, whether that be running the renix ECU with bigger injectors and an adjustable FPR, or running a stand alone like MegaSquirt. IMO cost adds up real quick here, by the time you build the stroker and buy all the accommodating parts to make it run correctly. I'm not saying getting a significant power upgrade should be cheap, but that this could be the most expensive option depending on how you build it. Obviously the main benefit of this route is the fact that its the easiest for smog checks.
Option #3: Engine Swap
I must say this option is probably EASILY the one that requires the most time to perform. To legally get an engine swap to pass CA emissions you must go through a smog referee and get it approved. The full requirements can be seen here: http://www.bar.ca.gov/80_barresources/07_autorepair/engine_change_guidelines.html
Basically all original smog equipment from the donor engine must be re used, and a functioning OBD port and Check Engine Light must be used. The engine must be functioning as if it were in the original vehicle, which means if it came with EGR, the EGR must be reused in the jeep, and so on.
The general benefits i've seen with engine swaps are:
-increased reliability
-more power (obviously!)
-more readily available performance parts (depending on engine choice obviously)
and the major downfalls that i have found are:
-harder to keep cool = fitting a bigger radiator or purchasing super expensive big money huge aluminum radiator.
-packing, everything has to be custom from motor mounts to exhaust
-a different engine also means a different transmission and t-case in most cases = even more time + money
-retrofitting newer/different engine electronics onto jeep body
-pleasing the smog referee
With that said, these are the engines i've considered:
Small Block Ford 5.0
these are cheap, simple, very reliable and stupid easy to get the fuel injection running in any vehicle. performance parts are cheap and everywhere, however factory power ratings are not very spectacular for a v8. The engine is also very compact which makes fitting in a jeep simple. Unfortunately this limits you to only Ford automatic transmissions and transfer cases, something i'm not too fond of. There are no aftermarket mounting solutions for this engine in the MJ, so everything must be fabricated. Cooling might not be so bad with the Jeep's radiator as this is a smaller V8.
Small Block Chrysler
I'm talking the "newer" 5.2 and 5.9 found in ZJs, Dakotas, Durangos, and Rams. Overall impressions are its a harder engine to come across, however donor vehicles are cheap where you could have an entire drivetrain to swap in. Sadly this engine does not have cheap aftermarket support or performance parts on craigslist everywhere. Factory power ratings are decent, but behind these engines are the generally unreliable 44 and 46RE transmissions. the later model engines dont have EGR, which makes fitting it easier. These engines are also not considered as reliable as the small block ford or LSx engines.
so potentially this could be a cheap engine swap using a cheap donor vehicle and using its whole drivetrain.
LSx
By far the most popular option today. The LSx series engines are readily available, can be upgraded with ease, and are somewhat cheap in CA though not as cheap as in the east coast it seems. Maybe i just dont know where to find the cheap stuff. These engines accept power upgrades very well and have a plethora of aftermarket and info. There are conversion motor mounts available which means less fab work. There is more info on this engine swap into a jeep than any other V8. The issues i see are packaging, mainly with the intake and pulleys clearing the hood. getting the factory EGR manifolds to clear the MJ unibody looks like a challenge, although what do i know. Getting factory gauges to work can also be trouble, but nothing aftermarket gauges cant fix. There have been some smog legal swaps in CA, so i know it can be done. Cooling also seems to be an issue once again, so a bigger radiator needs to be shoehorned in. This engine also requires the use of a GM automatic transmission, something else to be aware of.
I see it like this swap provides affordable, reliable power with lots of room to upgrade in the future. i'm also under the impression the automatics used behind the LSx (4L60?) are reliable and upgradeable, so thats good. Aftermarket motor mounts are a huge plus. Wiring looks like a huge chore. Lots and Lots of work to get this thing CA smog approved, but is it worth it?
Many many options here, lots to think about. I would love to hear input on any of the options, why one would be better than the other, why one sucks, why im crazy for trying to do this amidst CA smog nazis, or maybe something i havent thought of yet? Hopefully this thread can be a tool for others as well.
thanks,
Matt
