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3rd Gen Ram Tech2002-2008 Rams: This section is for TECHNICAL discussions only, that involve the 2002 through 2008 Rams Rams. For any non-tech discussions, please direct your attention to the "General discussion/NON-tech" sub sections.
LMAO....yes that's all very nice. What you are failing to realize is that there is a reason (probably several) both the factory and aftermarket basically ignored this engine beyond anything stock. You have fun,bubba Steve. I'm sure you'll show us 🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣��🤣
Of course I will share what I learn... always have, good or bad. And I dont think the aftermarket ignored this motor, the crowd just moved on so demand dwindled... fixed your typo...
Edit... Seeing that you're new here, question is, when the data surfaces will you be around to see it?
Figure 4 and Figure 5 show graphical representations of the
effects of plenum size on torque at various engine speeds. At
low RPM, the smaller plenum appears to produce higher torque
than the large plenum although the effect is modest.
Seems to have more of an effect above 7K RPM, though the 4.7 will never see that. At least, not for long.
Of course I will share what I learn... always have, good or bad. And I dont think the aftermarket ignored this motor, the crowd just moved on so demand dwindled... fixed your typo...
Edit... Seeing that you're new here, question is, when the data surfaces will you be around to see it?
Not as new as you'd like to think lol......BUBBA
This engine has been around since 1999 and made it through 2013. The only entity that really did anything with it was Mopar, BUBBA. 14 model years and the best you could ever get was some cams and a blower kit from the aftermarket LMAO. Yes, that's "largely ignored". More importantly, it doesn't matter whether I'll be around to see it or not because either way I won't care. Cheers, Bubba! 🖕😁🖕
Seems to have more of an effect above 7K RPM, though the 4.7 will never see that. At least, not for long.
Look at the bottom of the graph in Figure 5, the step for both plenum sizes, I wonder what was happening at that time. @ 4k both appear to be stable and track well up to about 4500 rpms. For both power & torque it appears the smaller plenum edges out the larger plenum. Figure 15... the smaller the plenum volume the faster its response to WOT changes makes sense. What would have been great to see would be to have the bike on a dyno with a load to keep the rpms at 1k intervals & measure power.
For the two smallest plenums, it is clear that MAP exceeds 1.0 bar even before the throttle is fully open. In fact, MAP appears to overshoot ambient conditions suggesting a ram tuning effect that would ultimately benefit engine transient response. By the end of cycle 2, the other plenums had reached maximum
pressure.
Look at Figure 15... and the 1.2L & 2.4L graphs... I see that the response is different for ea on cycle #1 yet the other 3 larger plenums are not and are similar to the 1.2L.
This paragraph stands out...
While the actual wave dynamics are complex for a multicylinder engine, the intake system can be modeled as a simple Helmholtz resonator [1]. When the intake valve opens and the piston descends, a rarefaction or expansion wave travels upstream in the runner toward the plenum. Upon reaching the runner opening in the plenum, this wave is partially transmitted (still as an expansion wave) into the plenum. At the same time, part of the original expansion wave is reflected as a compression wave that heads back to the cylinder. If the compression wave arrives at the intake valve before it closes, the increased pressure will effectively force more air into the cylinder [2]. This tuning effect or resonant supercharging leads to increased volumetric efficiency and torque. Meanwhile, the expansion waves will travel to the inactive branches (with closed valves) and be reflected as expansion waves back to the active runner. These expansion waves reduce intake runner pressure and have the effect of reducing volumetric efficiency [1]. Typically, intake tuners focus on runner geometry (length and/or cross section area) and plenum size and shape. An excellent overview of resonant supercharging is provided by Benajes et al [3].
To me it seems like to get the runner length could be tuned to work most efficiently with an rpm band. It also makes me wonder if the IM design change in later years to the shorter runners was done to improve efficiency.
Throttle body spacers on a Multi Port fuel injected engine offer ZERO performance gains. This is because only air passes through the spacer. the entire theory behind what makes throttle body spacers work is their effect on increasing the time for air and fuel to atomize. However on a multi Port fuel injected engine, fuel is not introduced until after the air has passed through the throttle body, into the plenum and then down the intake runner where fuel is finally introduced just prior to the valves. They are DYNO PROVEN to cause a 4-5HP loss in HP. I typically recommend to our customers to take the spacer and throw it as far as you possibly can from your truck. The further you throw it, the more HP you will make.
Most spacers made today claim to create a small spinning tornado that is supposed to spin all the way into the plenum where it breaks off into 8 separate baby tornado as they head down into each intake runner where fuel is finally introduced... the reality is your plenum is a very violent place where air is pulled and pushed in a complete chaotic atmosphere. Worse yet, to create these small tornadoes of spinning air, they need to create a restriction in order to promote the spin... this takes energy away from the incoming air flow... the spacers become a restriction at best.
With that said, throttle body spacers can in fact have an effect on power of a carbureted or throttle body injected engine because both air and fuel are introduced PRIOR to the spacer. Now please note, I mentioned that the spacer can effect power... I didnt say increase. This is because nearly all engines will react differently. I have built identical Pontiac 350 engines that reacted completely different to throttle body spacers. One really liked the 2" spacer, and the other lost about 10HP with the spacer and performed best with no spacer at all. So they are not a one size fits all mod and are typically used for fine tuning.
On a multi Port fuel injected engine, there just is no bennifit to extending the throttle body with a spacer. I understand you are speaking about port matching it to your throttle body. I promise you, you will see ZERO gains if just using it as a spacer. HOWEVER we used to port match throttle body spacers and install nitrous jets into them... In that case, port matching them removes the restriction and makes for the perfect place to install a nitrous jet. just be mindful of the direction of the jet is spraying as we have had customers freeze the throttle body shaft causing a temporary stuck throttle...
This is a 2002 4.7L throttle body placed over a throttle body spacer...removed after a dyno day where it lost 5hp. 5 hp was promptly gained after removing it.
I forget the brand, but they all center around the same sales gimmick, I still have it kicking around the shop, I couldn't force myself to sell this garb to a customer. They are all SNAKE OIL on a multi port fuel injected engine! Run away!
SPEED SAFE, AIR RAM PERFORMANCE
LMAO....yes that's all very nice. What you are failing to realize is that there is a reason (probably several) both the factory and aftermarket basically ignored this engine beyond anything stock. You have fun, bubba. I'm sure you'll show us 🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣��🤣
Well, easy now... LOL
Actually, there where over 3 million 4.7L engines built and sold between 1999-2013 (250,000 average per year) . it was installed in everything from Dakotas, Rams, Durangos, Jeep Grand Cherokees, Jeep Commanders and a few Mitsubishi's ... so it had a decent run and is well known today for being a very reliable engine. The main reason the factory gave the 4.7L little love was because they didn't want the smaller V8 engine with a full liter less to compete with their very cheap to build 5.7L. The 4.7L cost about $1,000 more to build & they up charged 1,500 bucks for the 5.7L option. So they made over 2500 bucks (Cash in pocket profit) for every HEMI sold... and they sold a lot of them. The 4.7L never made it into a car because if it had, the aftermarket would have come to its side and HEMI sales would have taken a rather large hit. The factory underbuilt/detuned the 4.7L intentionally as not wanting it to to compete with HEMI sales, this is why the 4.7L responds very well to mods and can easily make HEMI power with bolt on's and tuning... while displacing a full liter less than the 5.7L.
All that to day, throttle body spacers are dyno proven to lose HP on a 4.7L... and they are DYNO proven to react differently to every Carb or TBI engine. Some like 2" spacers, some like 1" spacers, some like 1/2" spacers and some dont like spacers at all. Spacers are a tuning aid for Carb or TBI engines.
what's the point in posting a topic and asking questions if all you are going to do is shoot down every reply that someone that is trying to help you gives you? the guy above has made it clear about the 4.7. I have one with HO cams HO intake upgraded rockers springs headers high flow cats flow master exhaust ngk coils, upgraded injectors e-fan you name it. it is what it is. NOS, blower, or turbo is all that's left and I aint doing that. I could have just bought one with a hemi or did a hemi swap and still came out ahead. just trying to help.
Throttle body spacers on a Multi Port fuel injected engine offer ZERO performance gains. This is because only air passes through the spacer. the entire theory behind what makes throttle body spacers work is their effect on increasing the time for air and fuel to atomize. However on a multi Port fuel injected engine, fuel is not introduced until after the air has passed through the throttle body, into the plenum and then down the intake runner where fuel is finally introduced just prior to the valves. They are DYNO PROVEN to cause a 4-5HP loss in HP. I typically recommend to our customers to take the spacer and throw it as far as you possibly can from your truck. The further you throw it, the more HP you will make.
Most spacers made today claim to create a small spinning tornado that is supposed to spin all the way into the plenum where it breaks off into 8 separate baby tornado as they head down into each intake runner where fuel is finally introduced... the reality is your plenum is a very violent place where air is pulled and pushed in a complete chaotic atmosphere. Worse yet, to create these small tornadoes of spinning air, they need to create a restriction in order to promote the spin... this takes energy away from the incoming air flow... the spacers become a restriction at best.
With that said, throttle body spacers can in fact have an effect on power of a carbureted or throttle body injected engine because both air and fuel are introduced PRIOR to the spacer. Now please note, I mentioned that the spacer can effect power... I didnt say increase. This is because nearly all engines will react differently. I have built identical Pontiac 350 engines that reacted completely different to throttle body spacers. One really liked the 2" spacer, and the other lost about 10HP with the spacer and performed best with no spacer at all. So they are not a one size fits all mod and are typically used for fine tuning.
On a multi Port fuel injected engine, there just is no bennifit to extending the throttle body with a spacer. I understand you are speaking about port matching it to your throttle body. I promise you, you will see ZERO gains if just using it as a spacer. HOWEVER we used to port match throttle body spacers and install nitrous jets into them... In that case, port matching them removes the restriction and makes for the perfect place to install a nitrous jet. just be mindful of the direction of the jet is spraying as we have had customers freeze the throttle body shaft causing a temporary stuck throttle...
This is a 2002 4.7L throttle body placed over a throttle body spacer...removed after a dyno day where it lost 5hp. 5 hp was promptly gained after removing it.
I forget the brand, but they all center around the same sales gimmick, I still have it kicking around the shop, I couldn't force myself to sell this garb to a customer. They are all SNAKE OIL on a multi port fuel injected engine! Run away!
SPEED SAFE, AIR RAM PERFORMANCE
Thank you! Some 1st hand experience with them. I have also discovered my son in law is an advocate for them... he experienced a 2 mpg bump on one ford engine (I forget which it was) and a 1.5 mpg on an older ford F150 he had (port injection). Most of the motorheads looking for performance changes want that 5 hp bump at the top peak and anywhere else they can find it... on a dyno. The dyno runs show what the max power is and are max only state, one that my trucks never see. Where I look for performance gains are in the 3000 rpms & below range at part throttle, where my trucks live day in & day out. My research led me down a path that showed me that the reflected pressure wave back into the port runner is where the gain actually is when it comes to the intake manifold runner length. Helmholtz resonators were studied (I think it was linked in this thread by HeyYou) to see how that could be leveraged for more top end power. That study unfortunately was on a motorcycle engine reving up past 10k rpms. There was a graph in there that showed the bottom end torque (starting at 3k rpms) had a significant improvement with the different sizes, but again, that is at WOT. Again, my trucks dont see WOT and live in the part throttle world.
On the Ram when I did it's 11 year makeover (documented on cumminsforum.com, same user name), I learned how small changes can be leveraged to work with other mods. One example is the fan drive pulley... The ram has a Fluidampr on it, a 1st gen version. This version required the dampr be removed to allow a belt swap. This was done every 100k miles at its service interval. Someone made a smaller fan drive pulley to get around this problem so I jumped on it. It weighed less than the OEM one & was a tad bit smaller in diameter. The first drive was an eye opener with improved throttle response (truck is detuned and a manual trans so small changes are felt easier). Enough for me to go research which other pulleys could be swapped. Swapped in the idler pulley next and had had a similar experience, then came the power steering, had to swap pumps so I went to a newer pump and again did the pulley. Each time I tweeked the tune to match my needs which meant injection timing changes and rail pressure tweeks.
Back to your dyno experience... you commented that you gained back 5 hp after removing it. That makes total sense because of the airflow change, but what did it do to part throttle performance? And what about the adaptation relearn? Someone (might have been you, I forget who it was) spelled out a process for clearing out the adaptations so it will re-adapt quicker. How long does that take (the relearn process)??? Did you wait that amount of time before doing the follow up dyno runs? IMO the only way to truly eval that or any part change is to do a before dyno run, log the environmental conditions along with the engine sensors at the time of the baseline test then install the change and give it the time it needs to re-adapt. Once that is done then it would be valid to go back to the dyno on a day that has similar enviro conditions and re-test it.
Back in the 2001~2002 range I stumbled on fuel cooling, used it to solve a problem I had with a chip I installed on a bmw 325. Saw the cause & effect and ran one on every vehicle after that. All of them showed the same benefit. Posted up the experience on vwvortex.com during a conversation and got blasted for it. Several guys said the same thing, it will do nothing for performance... even though I stand there with 1st hand experience using them. So, being a test engineer, I came up with a plan to head to the dyno and do 3 runs w/o a cooler and then 3 runs with. The averaged runs showed an 8% gain in both TQ & HP at the peak and a 13% max gain in both TQ & HP. Those numbers may also be questioned with the adaptation argument, did not know about that back then. I dont recall how the conversation in that thread went after posting the data & graphs... Edit: Hey the data is still there... Fuel cooler dyno #'s | VW Vortex - Volkswagen Forum
My investigation on one would start with a before and after test that measured the runner flow out of the intake manifold ports. Get a manifold, spacer and stock TB (have one since I'm now using the 70mm one) and fab up a test setup that would allow me to base line the flow thru the manifold & TB in multiple TB openings. First would be to measure the flow out of each port in a stock config, then establish repeatability. Once that is done, then install the spacer and measure the delta. A couple of ways of doing that would be to 1 use a MAF sensor (my 1st choice) or use a manometer (have one).
Anyways... lost my train of thought... work time.
Last edited by steve05ram360; Jan 21, 2022 at 09:44 AM.
Actually, there where over 3 million 4.7L engines built and sold between 1999-2013 (250,000 average per year) . it was installed in everything from Dakotas, Rams, Durangos, Jeep Grand Cherokees, Jeep Commanders and a few Mitsubishi's ... so it had a decent run and is well known today for being a very reliable engine. The main reason the factory gave the 4.7L little love was because they didn't want the smaller V8 engine with a full liter less to compete with their very cheap to build 5.7L. The 4.7L cost about $1,000 more to build & they up charged 1,500 bucks for the 5.7L option. So they made over 2500 bucks (Cash in pocket profit) for every HEMI sold... and they sold a lot of them. The 4.7L never made it into a car because if it had, the aftermarket would have come to its side and HEMI sales would have taken a rather large hit. The factory underbuilt/detuned the 4.7L intentionally as not wanting it to to compete with HEMI sales, this is why the 4.7L responds very well to mods and can easily make HEMI power with bolt on's and tuning... while displacing a full liter less than the 5.7L.
All that to day, throttle body spacers are dyno proven to lose HP on a 4.7L... and they are DYNO proven to react differently to every Carb or TBI engine. Some like 2" spacers, some like 1" spacers, some like 1/2" spacers and some dont like spacers at all. Spacers are a tuning aid for Carb or TBI engines.
SPEED SAFE, AIR RAM PERFORMANCE
Originally Posted by ole buck
what's the point in posting a topic and asking questions if all you are going to do is shoot down every reply that someone that is trying to help you gives you? the guy above has made it clear about the 4.7. I have one with HO cams HO intake upgraded rockers springs headers high flow cats flow master exhaust ngk coils, upgraded injectors e-fan you name it. it is what it is. NOS, blower, or turbo is all that's left and I aint doing that. I could have just bought one with a hemi or did a hemi swap and still came out ahead. just trying to help.
Thought provoking discussions can lead to ah-ha moments... most zero in on the max gains and dont think about the driving experience... which is at part throttle.
