411 swap

[oldguy44]

From post dates it would seem as though I am coming to the party a little late. I recently purchased a 97 savanna cutaway van to build a mobile workshop for the volunteer work I do. It has the 4.3 V6 with the 4l60-E trans. I got it cheap and it does everything I need it to do, however................. with gas in So Cal hovering around 6 bucks a gallon a bump in economy would improve my wallets disposition. A friend on the opposite coast suggested the 411 swap. I have been looking for information, the link on this 411 forum is no longer active and I have been unable to piece together a reliable set of instructions. Give me a set of points and a carburetor and I know what to do, electronics not so much. Is there someone reliable (operative word is reliable) that supplies a kit and programming for the ECM? If not is there someone I can talk to that can lead me through it, or pay to do it?

Any help would be greatly appreciated.

 

[L31MaxExpress]

I don't even think it is possible to smog an 0411 in California in a vehicle it did not come in. 4.3 will not gain nearly as much as a V8 will from tuning. For fuel mileage keep the V6 in a good state of tune, maybe a free flowing muffler like a magnaflow and a k&N air filter. Clean the MAF and let it be. Davis Unified Ignition module, Davis Unified coil, MSD cap and rotor and Taylor Tundervolt wires along with Delco plugs gapped at 0.060 gave me the best results. I changed the ignition parts when the stock parts started failing by misfiring. Shorty headers for a S10/Astro van would help too, but I doubt the are C.A.R.B. approved with a matching E.O. number for an Express van.

 

[0xDEADBEEF]

Tuners do not tune for fuel economy. Not saying it can't be done, but I don't think you are going to be in for a quick and easy process.

I'd leave it alone and just keep it in good working order. Keep your tires properly inflated, stuff like that. I would not do any mods at all, more air flowing through the engine means more fuel is burned.

 

[tayto]

I would try contacting Wester's Garage https://www.westersgarage.com/

 

[oldguy44]

Never thought about smog. The issue on these old vehicles is tailpipe emissions but they do plug the ECM into the state database and if the wrong computer id shows up the party is probably over.

Having been putzing with cars for over 6 decades I can tell you without reservation that this thing needs more timing between idle and 2000. I can guarantee that a timing bump would show a measurable increase in economy with a regular distributor and a decent carburetor (probably not a carburetor that GM ever made) but what that might do to the internals of an ECM and how it might compensate I do not know.

I did email Westers garage to see what they might be able to offer.

Ignition upgrades are certainly an option, don't know about a K&N. Don't know where I might fit it in this Blivid. In case you are not familiar with the terminology, a Blivid is 15 pounds of manure in a 10 pound bag, this thing is packed pretty tight. Also not so sure about a magnaflow as this thing has a 3in exhaust from the y pipe back. Probably used the same exhaust regardless of engine size and lack of back pressure can negatively affect fuel economy. More than one person found that out putting headers on a carbureted 454.

Nonetheless, thanks for the responses. Gave me more information to think about.

 

[L31MaxExpress]

Never thought about smog. The issue on these old vehicles is tailpipe emissions but they do plug the ECM into the state database and if the wrong computer id shows up the party is probably over.

Having been putzing with cars for over 6 decades I can tell you without reservation that this thing needs more timing between idle and 2000. I can guarantee that a timing bump would show a measurable increase in economy with a regular distributor and a decent carburetor (probably not a carburetor that GM ever made) but what that might do to the internals of an ECM and how it might compensate I do not know.

I did email Westers garage to see what they might be able to offer.

Ignition upgrades are certainly an option, don't know about a K&N. Don't know where I might fit it in this Blivid. In case you are not familiar with the terminology, a Blivid is 15 pounds of manure in a 10 pound bag, this thing is packed pretty tight. Also not so sure about a magnaflow as this thing has a 3in exhaust from the y pipe back. Probably used the same exhaust regardless of engine size and lack of back pressure can negatively affect fuel economy. More than one person found that out putting headers on a carbureted 454.

Nonetheless, thanks for the responses. Gave me more information to think about.

Tuners do not tune for fuel economy. Not saying it can't be done, but I don't think you are going to be in for a quick and easy process.

I'd leave it alone and just keep it in good working order. Keep your tires properly inflated, stuff like that. I would not do any mods at all, more air flowing through the engine means more fuel is burned.

Not at all true on mods increasing fuel consumption. It would be true if all you did was drive at WOT but at part-throttle reducing pumping loses frees up torque to move the vehicle. I noticed fuel economy gains with tri-y headers, low restriction muffler and a K&N filter. The 4.3 is having to really work to move the weight and anything that can help build torque will help the fuel mileage.

 

[L31MaxExpress]

Never thought about smog. The issue on these old vehicles is tailpipe emissions but they do plug the ECM into the state database and if the wrong computer id shows up the party is probably over.

Having been putzing with cars for over 6 decades I can tell you without reservation that this thing needs more timing between idle and 2000. I can guarantee that a timing bump would show a measurable increase in economy with a regular distributor and a decent carburetor (probably not a carburetor that GM ever made) but what that might do to the internals of an ECM and how it might compensate I do not know.

I did email Westers garage to see what they might be able to offer.

Ignition upgrades are certainly an option, don't know about a K&N. Don't know where I might fit it in this Blivid. In case you are not familiar with the terminology, a Blivid is 15 pounds of manure in a 10 pound bag, this thing is packed pretty tight. Also not so sure about a magnaflow as this thing has a 3in exhaust from the y pipe back. Probably used the same exhaust regardless of engine size and lack of back pressure can negatively affect fuel economy. More than one person found that out putting headers on a carbureted 454.

Nonetheless, thanks for the responses. Gave me more information to think about.

K&N filter will drop in the stock box. If you can find a diesel van air box the air inlet snorkel is full width. For a few bucks at the scrap yard the diesel inlet let my 350 breath better too. Cost me all of $2 to get the diesel snorkel at the u-pull it yard.

Gas

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Diesel

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Diesel air inlet

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[0xDEADBEEF]

Not at all true on mods increasing fuel consumption. It would be true if all you did was drive at WOT but at part-throttle reducing pumping loses frees up torque to move the vehicle. I noticed fuel economy gains with tri-y headers, low restriction muffler and a K&N filter. The 4.3 is having to really work to move the weight and anything that can help build torque will help the fuel mileage.

Air and fuel are burned at roughly stoich in closed loop non-WOT, so more air can only use more fuel. You have to restrict air coming in/out to burn less fuel, or tune for lean burn above stoich.

Even if you can achieve more pumping efficiency while moving the same mass of air, I can't see it adding up to much difference until you get into heavy load. No OEMs have gone to headers and K&N type filters to try and achieve CAFE standards. I think if it worked they would have done it as they are really under pressure to meet those standards, and of course they would prefer a simple and cheap solution.

I actually think long tubes are one of the best mods you can do, but not for economy, for the HP.

 

[MIHELA]

Air and fuel are burned at roughly stoich in closed loop non-WOT, so more air can only use more fuel. You have to restrict air coming in/out to burn less fuel, or tune for lean burn above stoich.

Even if you can achieve more pumping efficiency while moving the same mass of air, I can't see it adding up to much difference until you get into heavy load. No OEMs have gone to headers and K&N type filters to try and achieve CAFE standards. I think if it worked they would have done it as they are really under pressure to meet those standards, and of course they would prefer a simple and cheap solution.

I actually think long tubes are one of the best mods you can do, but not for economy, for the HP.

They may not have gone to K&N filters, but many OE manifolds are basically headers now. They also use VVT to reduce pumping losses.

 

[L31MaxExpress]

Air and fuel are burned at roughly stoich in closed loop non-WOT, so more air can only use more fuel. You have to restrict air coming in/out to burn less fuel, or tune for lean burn above stoich.

Even if you can achieve more pumping efficiency while moving the same mass of air, I can't see it adding up to much difference until you get into heavy load. No OEMs have gone to headers and K&N type filters to try and achieve CAFE standards. I think if it worked they would have done it as they are really under pressure to meet those standards, and of course they would prefer a simple and cheap solution.

I actually think long tubes are one of the best mods you can do, but not for economy, for the HP.

I guess you have not looked at many imports in the last 20 years. Almost all Nissans use a header style manifold or manifolds.

It absolutely can help fuel economy. I recently put a Volant air intake, plenum spacer, and JBA shorties on my Nissan Pathfinder with the 4.0L. While it had tubular manifolds they were log style without a decent functional collector. One cracked on me so it was a perfect excuse for real headers. It gave a very noticeable torque increase. I use less throttle in normal driving and my fuel economy is up to about 16.5 average in town from 14.6. Thats nearly 2 mpg average in a SUV that does not get driven with a light foot. You want the engine to breathe, its a self-powered air pump. The less it has to work to move air/fuel into it and exhaust out of it the more torque it makes and the better the MPG when it is lightly loaded. Lean a/f mixture also gives better mpg because it decreases pumping loses by throttling the engine via torque reduction rather than a throttle plate, same as EGR, cam phasing, and multiple displacement systems.

Nissan OEM 3.7L manifold...Yet NONE have gone with headers according to you.

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