Question about Renix Stroker
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Joined: Sep 2010
Posts: 21,168
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From: Milwaukee, WI
Year: 1987
Engine: Check
No as I said,
"a msd megasquirt or something like that"
You have to be able to adjust fuel map
And unless ya want to have a ton of tiny resistors all over your sensor wires that have to be changed based on air temp, pressure, water temp, etc then you will need an external comp adjuster.
"a msd megasquirt or something like that"
You have to be able to adjust fuel map
And unless ya want to have a ton of tiny resistors all over your sensor wires that have to be changed based on air temp, pressure, water temp, etc then you will need an external comp adjuster.
Erm, the RENIX 6-242 is computerised, as it runs multi-port electronic fuel injection (and is therefore electroncally-controlled.)
However, the RENIX computer seems to respond rather well to modifications like stroking - or forced induction (although a change of the MAP sensor is required there, and a supplemental fuel controller may be required, I don't know yet.)
The stroker is supported well by a simple fuel injector change - the OEMR RENIX units are spec'd for, I believe, 19#/hr @ 39psig. Generally speaking, going with a "full-on OTS" stroker (meaning the 6-258 crankshaft and bore +0.060", or about 280ci, should work well using fuel injectors rated for 23#/hour @ 39psig, or equivalent rating.) The ECU can usually adjust the fuel curve to fit the engine displacement and operating speed, once the capability to deliver sufficient fuel is in place.
The above leads me to believe that the RENIX ECU has an "open-ended" programme, where it will use programmed tables for baseline values and adapt them according to noted operating conditions (this is fairly unusual, since most electronic engine control setups have hard-coded "lookup tables" for most values at most operating conditions, and limited adaptability. This is what made "blowing PROMs" or "burning PROMs" - flashing the ECU - for GM equipment so popular, you'd actually change the baseline lookup tables. It's easy enough to do with GM, it's more difficult with Ford or Chrysler, and don't get me started with most imports not made by Toyota or Honda!)
You want to stroke your RENIX? Don't let me stop you! Get the stroker parts (258ci crankshaft, 258ci connecting rods, and pistons to fit your (re)bore job; and sufficiently-sized fuel injectors) and build away! The fuel injectors should be easy enough to find - they're standard early Bosch units, which were used by pretty much every and saturate the aftermarket. I'd start with FiveO Motorsports - they sell sets that are balanced for flow and cleaned & tested, and have listings for our beloved AMC six.
ADD'L - Having a bored throttle body can be nice, but isn't essential. A bored throttle body isn't a performance adder on its own, as most OEMR throttle bodies can support something north of 125% of the engine displacement at redline anyhow (RENIX throttle bodies support a theoreticaly 130% of flow of the 6-242, at redline, assuming 100% VE. The VE of the RENIX 6-242 is closer to 80-85%, and you're not adding enough displacement to make up for that anyhow.) The throttle body will give you crisper throttle response (I could go into the geometry of why, but I honestly don't think it's necessary...) but it won't add power capacity in se. Swapping cams and porting your head would give far better results per dollar spent, in terms of actual performance gain...
TANGENT - I'm considering finding a 12-cw crank for a 6-258 (I have a manual transmission, and the extra rotating mass will smooth out shifting and takeoffs,) and having it offset ground to about 4.000". If I can find a RENIX block that will support a 4.000" bore (or +0.125" - which is twice the standard accepted max overbore,) that will net me about 301ci displacement, and net significant power gains.
Considering what else I want to do to that engine, installation will have to wait until I leave CA (damn them for freezing the rolling 30-year exemption from Smog...)
However, the RENIX computer seems to respond rather well to modifications like stroking - or forced induction (although a change of the MAP sensor is required there, and a supplemental fuel controller may be required, I don't know yet.)
The stroker is supported well by a simple fuel injector change - the OEMR RENIX units are spec'd for, I believe, 19#/hr @ 39psig. Generally speaking, going with a "full-on OTS" stroker (meaning the 6-258 crankshaft and bore +0.060", or about 280ci, should work well using fuel injectors rated for 23#/hour @ 39psig, or equivalent rating.) The ECU can usually adjust the fuel curve to fit the engine displacement and operating speed, once the capability to deliver sufficient fuel is in place.
The above leads me to believe that the RENIX ECU has an "open-ended" programme, where it will use programmed tables for baseline values and adapt them according to noted operating conditions (this is fairly unusual, since most electronic engine control setups have hard-coded "lookup tables" for most values at most operating conditions, and limited adaptability. This is what made "blowing PROMs" or "burning PROMs" - flashing the ECU - for GM equipment so popular, you'd actually change the baseline lookup tables. It's easy enough to do with GM, it's more difficult with Ford or Chrysler, and don't get me started with most imports not made by Toyota or Honda!)
You want to stroke your RENIX? Don't let me stop you! Get the stroker parts (258ci crankshaft, 258ci connecting rods, and pistons to fit your (re)bore job; and sufficiently-sized fuel injectors) and build away! The fuel injectors should be easy enough to find - they're standard early Bosch units, which were used by pretty much every and saturate the aftermarket. I'd start with FiveO Motorsports - they sell sets that are balanced for flow and cleaned & tested, and have listings for our beloved AMC six.
ADD'L - Having a bored throttle body can be nice, but isn't essential. A bored throttle body isn't a performance adder on its own, as most OEMR throttle bodies can support something north of 125% of the engine displacement at redline anyhow (RENIX throttle bodies support a theoreticaly 130% of flow of the 6-242, at redline, assuming 100% VE. The VE of the RENIX 6-242 is closer to 80-85%, and you're not adding enough displacement to make up for that anyhow.) The throttle body will give you crisper throttle response (I could go into the geometry of why, but I honestly don't think it's necessary...) but it won't add power capacity in se. Swapping cams and porting your head would give far better results per dollar spent, in terms of actual performance gain...
TANGENT - I'm considering finding a 12-cw crank for a 6-258 (I have a manual transmission, and the extra rotating mass will smooth out shifting and takeoffs,) and having it offset ground to about 4.000". If I can find a RENIX block that will support a 4.000" bore (or +0.125" - which is twice the standard accepted max overbore,) that will net me about 301ci displacement, and net significant power gains.
Considering what else I want to do to that engine, installation will have to wait until I leave CA (damn them for freezing the rolling 30-year exemption from Smog...)
And boom goes the dynamite...
Thread Starter
Member
Joined: Jul 2009
Posts: 153
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From: Kiln MS
Year: 1990
Model: Cherokee
Engine: 4.0 Renix
That's what I was looking for. I had seen something simuliar but couldn't find it on jeepstroker.com
I plan on using a new block for a 96-01 for the beefier internal webbing and using my renix system. Sound OK?
I plan on using a new block for a 96-01 for the beefier internal webbing and using my renix system. Sound OK?
Erm, the RENIX 6-242 is computerised, as it runs multi-port electronic fuel injection (and is therefore electroncally-controlled.)
However, the RENIX computer seems to respond rather well to modifications like stroking - or forced induction (although a change of the MAP sensor is required there, and a supplemental fuel controller may be required, I don't know yet.)
The stroker is supported well by a simple fuel injector change - the OEMR RENIX units are spec'd for, I believe, 19#/hr @ 39psig. Generally speaking, going with a "full-on OTS" stroker (meaning the 6-258 crankshaft and bore +0.060", or about 280ci, should work well using fuel injectors rated for 23#/hour @ 39psig, or equivalent rating.) The ECU can usually adjust the fuel curve to fit the engine displacement and operating speed, once the capability to deliver sufficient fuel is in place.
The above leads me to believe that the RENIX ECU has an "open-ended" programme, where it will use programmed tables for baseline values and adapt them according to noted operating conditions (this is fairly unusual, since most electronic engine control setups have hard-coded "lookup tables" for most values at most operating conditions, and limited adaptability. This is what made "blowing PROMs" or "burning PROMs" - flashing the ECU - for GM equipment so popular, you'd actually change the baseline lookup tables. It's easy enough to do with GM, it's more difficult with Ford or Chrysler, and don't get me started with most imports not made by Toyota or Honda!)
You want to stroke your RENIX? Don't let me stop you! Get the stroker parts (258ci crankshaft, 258ci connecting rods, and pistons to fit your (re)bore job; and sufficiently-sized fuel injectors) and build away! The fuel injectors should be easy enough to find - they're standard early Bosch units, which were used by pretty much every and saturate the aftermarket. I'd start with FiveO Motorsports - they sell sets that are balanced for flow and cleaned & tested, and have listings for our beloved AMC six.
ADD'L - Having a bored throttle body can be nice, but isn't essential. A bored throttle body isn't a performance adder on its own, as most OEMR throttle bodies can support something north of 125% of the engine displacement at redline anyhow (RENIX throttle bodies support a theoreticaly 130% of flow of the 6-242, at redline, assuming 100% VE. The VE of the RENIX 6-242 is closer to 80-85%, and you're not adding enough displacement to make up for that anyhow.) The throttle body will give you crisper throttle response (I could go into the geometry of why, but I honestly don't think it's necessary...) but it won't add power capacity in se. Swapping cams and porting your head would give far better results per dollar spent, in terms of actual performance gain...
TANGENT - I'm considering finding a 12-cw crank for a 6-258 (I have a manual transmission, and the extra rotating mass will smooth out shifting and takeoffs,) and having it offset ground to about 4.000". If I can find a RENIX block that will support a 4.000" bore (or +0.125" - which is twice the standard accepted max overbore,) that will net me about 301ci displacement, and net significant power gains.
Considering what else I want to do to that engine, installation will have to wait until I leave CA (damn them for freezing the rolling 30-year exemption from Smog...)
However, the RENIX computer seems to respond rather well to modifications like stroking - or forced induction (although a change of the MAP sensor is required there, and a supplemental fuel controller may be required, I don't know yet.)
The stroker is supported well by a simple fuel injector change - the OEMR RENIX units are spec'd for, I believe, 19#/hr @ 39psig. Generally speaking, going with a "full-on OTS" stroker (meaning the 6-258 crankshaft and bore +0.060", or about 280ci, should work well using fuel injectors rated for 23#/hour @ 39psig, or equivalent rating.) The ECU can usually adjust the fuel curve to fit the engine displacement and operating speed, once the capability to deliver sufficient fuel is in place.
The above leads me to believe that the RENIX ECU has an "open-ended" programme, where it will use programmed tables for baseline values and adapt them according to noted operating conditions (this is fairly unusual, since most electronic engine control setups have hard-coded "lookup tables" for most values at most operating conditions, and limited adaptability. This is what made "blowing PROMs" or "burning PROMs" - flashing the ECU - for GM equipment so popular, you'd actually change the baseline lookup tables. It's easy enough to do with GM, it's more difficult with Ford or Chrysler, and don't get me started with most imports not made by Toyota or Honda!)
You want to stroke your RENIX? Don't let me stop you! Get the stroker parts (258ci crankshaft, 258ci connecting rods, and pistons to fit your (re)bore job; and sufficiently-sized fuel injectors) and build away! The fuel injectors should be easy enough to find - they're standard early Bosch units, which were used by pretty much every and saturate the aftermarket. I'd start with FiveO Motorsports - they sell sets that are balanced for flow and cleaned & tested, and have listings for our beloved AMC six.
ADD'L - Having a bored throttle body can be nice, but isn't essential. A bored throttle body isn't a performance adder on its own, as most OEMR throttle bodies can support something north of 125% of the engine displacement at redline anyhow (RENIX throttle bodies support a theoreticaly 130% of flow of the 6-242, at redline, assuming 100% VE. The VE of the RENIX 6-242 is closer to 80-85%, and you're not adding enough displacement to make up for that anyhow.) The throttle body will give you crisper throttle response (I could go into the geometry of why, but I honestly don't think it's necessary...) but it won't add power capacity in se. Swapping cams and porting your head would give far better results per dollar spent, in terms of actual performance gain...
TANGENT - I'm considering finding a 12-cw crank for a 6-258 (I have a manual transmission, and the extra rotating mass will smooth out shifting and takeoffs,) and having it offset ground to about 4.000". If I can find a RENIX block that will support a 4.000" bore (or +0.125" - which is twice the standard accepted max overbore,) that will net me about 301ci displacement, and net significant power gains.
Considering what else I want to do to that engine, installation will have to wait until I leave CA (damn them for freezing the rolling 30-year exemption from Smog...)
Member
Joined: Dec 2010
Posts: 164
Likes: 0
From: SoCal
Year: 1990
Model: Cherokee
Engine: 4.0
Just because it doesn't store codes doesn't mean you can't mod it. Basic electronics, bro.
Member
Joined: Dec 2010
Posts: 164
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From: SoCal
Year: 1990
Model: Cherokee
Engine: 4.0
If 5-90 is correct, and he usually is, the computer can adapt the injector map all on its on with the right injectors. Personally, I would still be inclined to put a wideband O2 sensor in there so I KNOW exactly what's going on in my engine. And like I said before, you could easily add a trim pot to your MAP, coolant temp, or IAT in order to tweak the input. That's my 2 cents. My Renix is getting a turbo, I will be sure and post a write-up for all you curious folks to see how it goes.
Member
Joined: Feb 2012
Posts: 218
Likes: 0
From: springs
Year: 1990
Model: Cherokee
Engine: 4.0
Originally Posted by desertdog
Just because it doesn't store codes doesn't mean you can't mod it. Basic electronics, bro.
I said it doesn't store codes or can be programmed.
Quite a difference
But thanks for your positive and helpful post
Link to a writeup or your website you have it posted on????
No?
Awwww
What a bummer.
Again, If you want full control of your comp an not just a wideband o2, get a megasquirt or something comparable.
Fully controllable with downloadable maps for your setup (usually)
Or you could take dude aboves advice,
Get a degree in electrical engineering,
Read everything about renix,
Decipher the layout,
Rewire it to do what ya want,
Test,
Redo it all again.
????
Last edited by AnoniWeezy; Feb 15, 2012 at 12:38 PM.
CF Veteran
Joined: Mar 2009
Posts: 1,208
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From: Watha,NC
Year: Jeepless at the moment
FWIW, the Renix, with knock sensors is actually a PLus, as you say you been on jeepstrokers, you probably read about the pinging issues. This can be solved many ways, but if you already have the ground work.....
Thread Starter
Member
Joined: Jul 2009
Posts: 153
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From: Kiln MS
Year: 1990
Model: Cherokee
Engine: 4.0 Renix
CF Veteran
Joined: Sep 2010
Posts: 21,168
Likes: 5
From: Milwaukee, WI
Year: 1987
Engine: Check
CF Veteran
Joined: May 2008
Posts: 3,018
Likes: 23
Year: 1988
Model: Cherokee
Engine: AMC242
If 5-90 is correct, and he usually is, the computer can adapt the injector map all on its on with the right injectors. Personally, I would still be inclined to put a wideband O2 sensor in there so I KNOW exactly what's going on in my engine. And like I said before, you could easily add a trim pot to your MAP, coolant temp, or IAT in order to tweak the input. That's my 2 cents. My Renix is getting a turbo, I will be sure and post a write-up for all you curious folks to see how it goes.
And, you're spot-on with what I meant about "open-ended programming." Having a WHEGO AFR monitor isn't a bad idea, and installing one would be simple - just have an exhaust shop weld a HEGO bung in the collector about two inches away from the OEM location (you do need to mount a second sensor, but the HEGO uses a standard thread. M18-1.5, as I recall.) A good exhaust shop should have a boxful of the bungs for their custom work, and it will probably cost you only a bit to have the manifold drilled and welded (I had to get a flange welded up a while ago by a local shop, and I took it in in hand. It cost me a six-pack of Sam Adams, as I recall - he didn't want money for the job, since it only took two minutes...)
@v8eater - Hm. I do like the idea of the 1996-up main bearing cap brace, but that can be easily retrofitted to an earlier block (just use the later main bearing cap screws. DO NOT SWITCH THE CAPS THEMSELVES - bearing caps like that are machined with and matched to their location and orientation.) However, I've heard of far more RENIX blocks able to survive an overbore to 4.000" (+0.125") than the OBD-I or OBD-II blocks, and the NVH revisions done to the 6-242 block have made it progressively lighter (most weight lost was in the deck thickness, cylinder wall thickness, and the main webs.)
Fortunately, most 6-242 hard parts are mechanically compatible, so mixing and matching is entirely possible. What I want to do:
- RENIX block, bored to 4.000"
- 12-counterweight 6-258 crankshaft (ideally offset ground to 4.000" stroke)
- Ported, polished, and massaged #7120 head.
- If I don't get silly and make something, I'll use a 1999-up intake and either a stock OBD-I exhaust manifold or a tuned equal-length header (tune it for optimal scavenging at 2600-2800rpm, if I can.)
I'd like to put a Whipple in on its side - which would probably require that I build a MegaSquirt (for the degree of programmability) or adapt the GM V6-DIS to the 6-242, and I'd probably end up fabbing an intake to keep it all below the hoodline. Round it out with water/MeOH fogging, and run it up around 0.75-1.0atm of boost. Have a manual wastegate so I can force the blower OFF if I need to (like one of my boys wants to borrow my truck, for some reason. It's not like I even let valets park any vehicle I own...)
If you've got questions on parts compatibility, start a thread somewhere and let me know about it. I'm trying to finish Swappology - but it's uphill work, and I get questions anyhow. Perhaps having a single thread for people to refer to would save me answering the same question six times on the run (I may end up doing that everywhere I go, if I don't get beaten to it. I'd call the thread "Swappology," after the book I'm working on...)
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Joined: Dec 2010
Posts: 164
Likes: 0
From: SoCal
Year: 1990
Model: Cherokee
Engine: 4.0
>>[QUOTE=AnoniWeezy;1539626]I never said it couldnt be modded, bro
I said it doesn't store codes or can be programmed.<<
Can't be programmed? It's no different from an OBD computer other than the code storing and availability of aftermarket piggyback chips. And, if you actually READ your previous post, you DID say "no modifications can be done to it".
>>Again, If you want full control of your comp an not just a wideband o2, get a megasquirt or something comparable.
Fully controllable with downloadable maps for your setup (usually)<<
Define "full control"...as far as I'm concerned, if I can adjust and monitor my final AFR and the computer is still handling ignition advance, that is about as much control as I need. This is Jeeping, not Formula One.
>>Or you could take dude aboves advice,
Get a degree in electrical engineering,
Read everything about renix,
Decipher the layout,
Rewire it to do what ya want,
Test,
Redo it all again.<<
Actually, since you brought it up, I DO have a degree in electronics, and I bet if I was motivated I could get inside the Renix brain and teach it all kinds of tricks. However, simply adding a rheostat to manipulate the signal from the MAP sensor sounds a lot easier to me. So, I'm sorry if you did not find my advice helpful, but I am here to prevent the spread of disinformation such as "You can't mod a Renix computer." Capice?
I said it doesn't store codes or can be programmed.<<
Can't be programmed? It's no different from an OBD computer other than the code storing and availability of aftermarket piggyback chips. And, if you actually READ your previous post, you DID say "no modifications can be done to it".
>>Again, If you want full control of your comp an not just a wideband o2, get a megasquirt or something comparable.
Fully controllable with downloadable maps for your setup (usually)<<
Define "full control"...as far as I'm concerned, if I can adjust and monitor my final AFR and the computer is still handling ignition advance, that is about as much control as I need. This is Jeeping, not Formula One.
>>Or you could take dude aboves advice,
Get a degree in electrical engineering,
Read everything about renix,
Decipher the layout,
Rewire it to do what ya want,
Test,
Redo it all again.<<
Actually, since you brought it up, I DO have a degree in electronics, and I bet if I was motivated I could get inside the Renix brain and teach it all kinds of tricks. However, simply adding a rheostat to manipulate the signal from the MAP sensor sounds a lot easier to me. So, I'm sorry if you did not find my advice helpful, but I am here to prevent the spread of disinformation such as "You can't mod a Renix computer." Capice?
Last edited by desertdog; Feb 16, 2012 at 12:01 PM.
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From: Milwaukee, WI
Year: 1987
Engine: Check
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From: Kiln MS
Year: 1990
Model: Cherokee
Engine: 4.0 Renix
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