BREEZE1 Posted September 18, 2008 Share Posted September 18, 2008 I just wanted to see if someone could start a sticky with renix performance mods. Yes a lot of us have renix’s in our mj and they SUCK in a stock application. At least I think so, Ive had a few 4.0L HO’s in my time and damn I wish I had that power in my mj! I know for a fact you can search all over the net and you come up short when your looking for renix performance mods! So If someone would be so kind to take a little time and make a sticky with all kinds of performance mods that would be sweeeeet! And if you can fix it were it won’t get messed up from other people asking questions that would even be better! I’m sure there is a collage kid out there or someone with noting better to do, so hook your fellow brethren up with some info! Make it so good that when someone types in “renix performance” on yahoo or google that it brings up your link. I mean I want to see the Dead Sea scrolls of renix performance mods! You can do it!!!! I’m sure I speak for a lot of other guys when I say this “if you start doing this link I will buy you endless brews when we meet up one day”!!!! GOOD LUCK!!!! :cheers: Link to comment Share on other sites More sharing options...
BLHTAZ Posted September 18, 2008 Share Posted September 18, 2008 I don't know about making another "sticky" as they start piling up and it gets to be too much. Maybe a post in the DIY forum with this type of info. I personally don't think the Renix is that bad. I own an HO as well and I was quite pleased with the power of the Renix when we got it as I was expecting a pig, but found it quite impressive. Link to comment Share on other sites More sharing options...
Akula69 Posted September 18, 2008 Share Posted September 18, 2008 After a short "renix lesson" that mine taught me, I have been please with mine as well. Now I just need to buy a few more parts from BLHTAZ, and it'll be even better! :D Link to comment Share on other sites More sharing options...
Pete M Posted September 18, 2008 Share Posted September 18, 2008 You want performance from a Renix system? Gears. Gears, gears, gears, gears, gears. Also keep up on the regular maintenance. And at the ages of our trucks, that includes sensors too. Link to comment Share on other sites More sharing options...
Jeepman Posted September 18, 2008 Share Posted September 18, 2008 As said already Gears will help... Rusty's Makes a TB spacer and Cold air intake and you can always add a header and if you ditch the Clutch fan and go electric that will help with power and fuel... I Scrapped the Renix Engine in my 89 MJ and Swapped in a HO engine... I added a 91-up radiator and Twin 10" electric Fans with a Rugged Ridge Header and 03 TJ Intake as well as Added 2.5" Exhaust fromt the cat back (need to get a Front pipe Made still) Cold air intake and soon to be TB spacer... HP has shot up like crazy as well as my Fuel ecoonomy... Link to comment Share on other sites More sharing options...
BookspanS Posted September 18, 2008 Share Posted September 18, 2008 As said already Gears will help...Rusty's Makes a TB spacer and Cold air intake and you can always add a header and if you ditch the Clutch fan and go electric that will help with power and fuel... I Scrapped the Renix Engine in my 89 MJ and Swapped in a HO engine... I added a 91-up radiator and Twin 10" electric Fans with a Rugged Ridge Header and 03 TJ Intake as well as Added 2.5" Exhaust fromt the cat back (need to get a Front pipe Made still) Cold air intake and soon to be TB spacer... HP has shot up like crazy as well as my Fuel ecoonomy... How would you get cold air intake on an '86? Link to comment Share on other sites More sharing options...
Jeepman Posted September 18, 2008 Share Posted September 18, 2008 Here is the Rusty's Kit.... http://rustysoffroad.com/mm5/merchant.mvc?Screen=PROD&Store_Code=rustys&Product_Code=RP-AT11-XJ&Category_Code=PER_AIR You will Have to make the Shroud to keep the Hot air out if you want a true Cold air intake... If your 86 is Carbed then your out of Luck but you could just install an open element filter... Link to comment Share on other sites More sharing options...
BookspanS Posted September 19, 2008 Share Posted September 19, 2008 Its a 2.5 Fuel Injected....Or atleast that what my tailgate tells me Link to comment Share on other sites More sharing options...
BREEZE1 Posted September 19, 2008 Author Share Posted September 19, 2008 dang! I'm more or less talking about tips and tricks you can do to your engine to give it more power or better fuel economy. Every thing is so scattered out its hard to find a lot of things in one area. I know gears really help out, when my jeep was 2wd and had the stock gears it was like slower than a turtle in peanut butter. But now that I have 4:10’s under it I can hardly move it in my garage with out the tires barking. Odds are ill be knocking it up to 4:88’s one day. But I still want links on how to improve my power plant. Link to comment Share on other sites More sharing options...
mvusse Posted September 19, 2008 Share Posted September 19, 2008 One way to get more performance is to swap out your Renix engine for a Chevy 383 stroker. I know a few people have swapped in a 350. If a 350 fits, a 383 would as well, since it's the same block. Link to comment Share on other sites More sharing options...
Eagle Posted September 19, 2008 Share Posted September 19, 2008 I just wanted to see if someone could start a sticky with renix performance mods. Yes a lot of us have renix’s in our mj and they SUCK in a stock application. At least I think so, Ive had a few 4.0L HO’s in my time and damn I wish I had that power in my mj! Your problem is in confusing optimum operating range with "power." The actual torque and horsepower ratings for the Renix and HO engines are very close, but the Renix has a torque peak around 2200 RPM and the HO has a torque peak around 4,000 RPM. The Renix is a true Jeep engine, intended to produce good usable torque at low RPM for off-road applications. If you try to drive it like a passenger car engine on the street, winding it out to 4,000 or 5,000 RPM before shifting, you're only fooling yourself. The optimum shift point for a Renix is around 2500 RPM, but most people don't believe that because they think revving up to higher RPM "should" produce better performance. If you wish to turn a Renix 4.0L into a passenger car engine, you need to port and polish the head, install larger valves, install a true header, replace the camshaft with one that has a higher torque peak, and install larger injectors. You'll end up with an engine that feels stronger above 3,500 RPM, has lousy low-end torque, and gets crappy gas mileage. Personally, I prefer the Renix. I have an 88 (Renix) and a 2000 (post-HO) XJ, both 5-speeds. On the normal route to work, there are two stretches with 30 or 35 MPH speed limits. In the 88 I can motor along both in 4th gear with no problem. In the 2000, I have to be in 3rd gear for those stretches. Link to comment Share on other sites More sharing options...
SoloCamo Posted September 19, 2008 Share Posted September 19, 2008 Your problem is in confusing optimum operating range with "power." The actual torque and horsepower ratings for the Renix and HO engines are very close, but the Renix has a torque peak around 2200 RPM and the HO has a torque peak around 4,000 RPM. The Renix is a true Jeep engine, intended to produce good usable torque at low RPM for off-road applications. If you try to drive it like a passenger car engine on the street, winding it out to 4,000 or 5,000 RPM before shifting, you're only fooling yourself. The optimum shift point for a Renix is around 2500 RPM, but most people don't believe that because they think revving up to higher RPM "should" produce better performance. Exactly. People always assume that the HO is so much stronger, but in reality it only "feels" that way due to the higher RPM the power/torque is being made at. Like Pete said Gears gears gears....Renix is all low end power in stock form and if you throw in some lower gears I think it would be a blast to drive, even in stock form. 3.73's-4.10's would be perfect for an auto and 3.55's are good for a stick. 4.10's are stretching it a bit for stockers because it's going to kill your highway mileage but I'm sure it would be fast as hell from a dig...if you can manage to get traction that is. I personally feel a stock Renix would have zero problem beating a HO to 30mph and at the least hanging dead even with the HO to 60mph. Once you start getting up there in terms of MPH, the higher HP/TQ at higher RPMs show the difference between motors. Link to comment Share on other sites More sharing options...
project88mj Posted September 19, 2008 Share Posted September 19, 2008 i got an 88 4.0 (renix)auto not sure that tranny never really needed to know but i wanted to know how much 4.10 would cost me and how much of a difference i would see from the stock 3.55 i got in there? Link to comment Share on other sites More sharing options...
Pete M Posted September 19, 2008 Share Posted September 19, 2008 and how much of a difference i would see from the stock 3.55 i got in there? It'll put a smile on your face so big it might never go away. :D Seriously though, if you want to get better gears, I recommend looking for junkyard axles with them in it already. In the long run it's cheaper. Plus I never ever condone sinking any money into a dana 35 (which is likely the rear axle you have now) beyond brake pads and gear oil. They're weak and I hate them. :mad: Also, the auto trans in your truck is an AW-4. :cheers: Link to comment Share on other sites More sharing options...
project88mj Posted September 21, 2008 Share Posted September 21, 2008 how can i tell that is the trany? wasent there 3 dirrerent kinds Link to comment Share on other sites More sharing options...
Eagle Posted September 21, 2008 Share Posted September 21, 2008 how can i tell that is the trany? wasent there 3 dirrerent kinds Nope. Not automatics behind the 4.0L. Only one -- the Aisin-Warner AW4. It's one of the best automatic transmissions ever made, so don't worry about searching out something else tp "upgrade." Link to comment Share on other sites More sharing options...
project88mj Posted September 22, 2008 Share Posted September 22, 2008 compair it to the chevy allson 6 speed auto trany (my dad has one) i know mine has olny 4 gears but i meen what can it handle? Link to comment Share on other sites More sharing options...
BREEZE1 Posted October 13, 2008 Author Share Posted October 13, 2008 I know some of you old birds are going to cut on me for this. But back to modifying the renix. I have been thinking of replacing my intake manifold with a 99+ and throttle body. I’m assuming this can be done because they put the HO manifolds on the renix motor, and I know the 99+ manifolds work on the old HO motors. I wasn’t sure If I needed to change the cylinder head to an HO head to do this or not. I also plan on replacing my clutch fan with an electric fan. I want to get the best gas mileage I can. I really love my truck and I wish I could drive it every day. I know a lot of yall say don’t mess with the renix because it has great low end torque. Well I like to build my jeeps so that I could drive it every day if I wanted or wheel it when ever. Face it, who goes wheeling every day? I would love to be able and go once a week. I use to go around 3 times a week when I was in college but those days are long gone. :redX: Link to comment Share on other sites More sharing options...
KillerCOM Posted October 13, 2008 Share Posted October 13, 2008 i'm looking into boring out stock Renix throttle bodies, once i buy my lathe that is....i can do HO no problem. the Renix is gonna be trickier if it can be done. Link to comment Share on other sites More sharing options...
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