Another Anderson Spacer thread, install notes, subjective testing. Long post

I received my Anderson Spacer and the install was fairly straight forward. Took me three hours taking my time and triple checking my work.
The kit is well done, and unlike most things I followed the installation instructions. Pictures help, and I added a few steps along the way that were not listed. One of the most helpful was after all the talk about moving the wiring harness I unbolted both the back wiring bracket and the one at the front of the rocker cover. Three bolts gave me all the room I needed.

No Review is complete without a few nits. I don't like the bolts supplied. Mostly for aesthetic reasons. The yellow zinc is just out of place. Functionally I'm sure they are adequate. I traded them out for some allen headed ones that are a little longer and added a thicker washer. The stock bolts have a fairly thick washer that I'm sure were specified for clamping force.

The same issues for the Bracket extenders. They work, but are just not pleasing. Rounding the corners and coating them black makes them blend in better. Nits Picked its a overall just fine.

An interesting note, after the install two of us noticed a change in the sound at idle. The sound was a bit deeper, still smooth but the note was slightly deeper. The shop is very well insulated, sound is deadened and it was very quiet. It was not a huge difference, but enough for the two of us to comment almost simultaneously. Once outdoors its not discernable.

So before I disclose how I tested to determine if I had thrown my money away, or if the product was a miracle cure here is my disclaimer. I am providing my tests and my observations as one point of reference for those interested. The test I performed is not "Scientific, conclusive, exhaustive" or even super well thought out.

I fully expect there will be the typical "Its not a tune" "You Gotta tune" and cries of that's not a good test I wanna see the dyno sheet. You folks shall be ignored.

So what did I do?
First the objective. My goal was to determine if on my next trip from Maine to Fla towing I could improve the hectic shifting syndrome. I feel the truck downshifts too readily. And once this happens the motor wants to rev to the sky. On long grades I cringe. Its really, really bad. yes the motor and trans combo may be more than capable of this. But I want to minimize it.

Before Installing I selected a test method. I chose a very long, steep grade (8%) here locally and hooked up my 5x13 trailer which is loaded to roughly 3800 Lbs. ( Trailer included) I started by keeping the truck in drive and at 55mph at the bottom of the hill. This is just below 1400 RPM on my tach.

My first mark was just as the grade began. I kept the rpms as steady as I could by and waited for the truck to down shift, it didn't take long. In the new gear RPMS are at about 2800 RPM directly after the shift. I took a mark on the spot and kept up the hill until it shifted again. {at about 1800 rpm} Another mark. Two more trips and the results were repeatable.

While I don't normally tow in Drive unless its downhill or flat, I felt it was a good worst case scenario.

Now I repeated the test In S5 which puts the RPMs just above 1600 @55 on my tach. The new marks recorded ( higher up the grade but not as far as I would have liked.) The second mark was further away but not as far as I expected since it had held S5.
Two more runs and again the results were fairly repeatable.

One last run In non adaptive cruise all the way to the top, starting in S5. Two downshifts before the top of the grade. The marks are different where it shifts but not by a lot. within the margin of me trying to hold the RPMs steady im sure.

AFTER INSTALL. ( Next day, so yes conditions were a bit different, but nothing drastic)

Ill get right to the conclusions, In all tests the truck held off from shifting longer. In drive, as expected the shift was still earlier than I would like. A gain for sure, but not great. This Is as I expected as the RPMs are already quite low.

In S5 the change was much more noticeable, Both of my new shift marks were extended, and the second shift was significantly further up the hill.

The cruise control run surprised me, with the truck holding gears longer than with me at the helm so to speak. It was the best run so far.

I ran one more run in S4, which I had no control run to compare it against. It held shifts for longer but of course the RPMs were higher to start. Too high for my liking. But the end of the run was in the same gear, so my only complaint so to speak would be listening to the motor rev higher for longer.

One last note, the truck seems happier trying to get the trailer up to speed. It just feels as if there is less weight trying to gain momentum. I'll take it. It also feels stronger on the flat, like trying to just maintain speed with traffic. Again its subjective, but I am noticing it enough to dismiss the placebo effect.

Around town observations. The feel of the truck at just on throttle is improved. Not sensitive, but less lag so to speak. I feel better crossing lanes with the reduced hesitation.
I have a crossroads on a big hill that I must climb daily, so I am familiar with how the truck feels going from a dead stop to the top of the hill ( which also rounds a sharp bend). The truck is MUCH happier on this climb now. I do swear I can feel / hear the intake making the shift from long to short, which I was never able to discern before. There seems to be a little transition period I never noticed, just like the old days of the Honda VFR and Vtec.

All in all the spacer seems to be doing just what I had hoped. It doesn't add magic HP, clean my whites better than tide, or make me fall asleep faster. But I do think its an improvement for towing.

Now let the "where's my dyno chart because without a tune this thread is useless" crowd have their say.

 

Thanks for sharing this. It confirms what I’ve read in other threads. The spacer doesn’t magically create more horsepower or torque, but rather shifts the peak torque lower in the powerband, where it is more usable. The engine feels more torquey because the torque is available at lower RPM. Many people dismiss the Anderson spacer as pure snake oil. However, it appears to (slightly) improve day-to-day driveability. Now whether such an incremental change is worth $327 ($472 for the aluminum version) is certainly debatable. But pair this with a tune, and you will likely notice a definite change in the Tacoma’s willingness to climb inclines and pass slower traffic.

 

Thanks for sharing I like this more than the Dyno run tests. Most dynos don't accurately provide data in such low RPM ranges, at least around me.

 

Well said . For the most part I feel the same way with the spacer . Not a huge improvement but it teams well with all my other bolt ons and tune

 

I installed mine yesterday and while I didn't do as scientific of a test as you did there were a couple of hills on my commute that would cause it to unlock the converter then shift from 6th to 5th to maintain speed before the spacer would now just unlock the converter to maintain the same speed. I also feel like it's got more grunt off the line requiring less input on the gas pedal. Other than an OTT tune, the spacer is the only engine performance mod I've done.

 

I got to make my first trip north pulling the quad with the Anderson intake spacer and it was definitely a noticeable improvement. Since it moves peak torque from 4000 rpm to 3000 rpm it puts it right where the engine is running if it's in S4 and running 65-70 mph. I'm pulling a 750lb ATV on a 400lb 5x8 trailer and I've done this trip several times with this load so I've got a good baseline of how it pulled before. I picked up about 1 mpg too. Overall it was a much more pleasant trip with the torque coming in lower and makes me feel better about spending that much money on a piece of plastic. I figured this might be useful info to some of you.

 

Still enjoying mine

 

I do wanna say when doing spark plugs on driver side, it is now easier with the addition of the spacer . More room.

 

Thanks for the detailed metrics.

From manufacturer: After installation, the additional length of the intake port air flow path allows for the 2GR engine to reach max torque at a lower engine speed.

Can someone explain how this works? Just a greater volume of air by an inch or so length?
Intrigued that a manifold intake spacer could make a noticeable difference.

If adding a small volume of available air (under 21% combustible O2) makes a difference, does that suggest the engine is starved for air? Wouldn't putting a small fan on the air intake increase the partial pressure and accomplish the same thing? That's essentially what the Turbo (on steroids) does if I'm not mistaken.

 

I’m assuming it’s because the acoustics of the longer intake have a resonance at a lower frequency thus reaching peak airflow at a lower rpm.

Airflow in an internal combustion engine is not constant or laminar. It flows in pulses that cause pressure waves. An intake can be tuned to a specific frequency of pulses that can increase air pressure entering the engine to be greater than atmospheric pressure despite the the absence of forced induction (ie turbo charger or super charger).

I’m guessing there is a trade off that I would rather not take. I trust the Toyota engineers have done me well. No offense intended towards the Andersen engineers. Maybe they are smarter.

 

Thanks gudujarlson. Did a lot more reading and found a 2021to2023 TW thread with much more info. I could be swayed to do this mod.

Someone mentioned getting an electric fan upgrade instead (on radiator I assume. ) How could that help engine power?

https://www.tacomaworld.com/threads/anderson-engineering-manifold-spacer.797477/page-4#post-28626002


https://mechanics.stackexchange.com...unner-length-effect-the-power-curve-of-a-car#

 

My unscientific guess is that the trade off is more torque at lower rpm, in trade for slightly less peak power (HP) at the top of the RPM curve. That being the case because the longer intake manifold is no longer tuned for max airflow at the highest pulse frequencies (high rpms,) so max airflow at high rpms is (slightly) restricted compared to stock.

 

An electric fan upgrade is not even slightly related to intake resonance nor do I think it will increase performance. The best it could do is keep your engine cooler in extreme conditions. Deserting racing trucks often have fans and radiators behind the cab to prevent them from getting clogged with dust. I doubt this would be a game changer for you.

 

I'm sure many of us who have worked hands on jobs like being a mechanic have seen engineers make some pretty poor design choices. Adding intake runner length is a tried and true method of shifting engine torque down the RPM band. In a pickup truck or SUV it makes sense for it's intended usage for the peak torque to be a bit lower in the RPM band than it is on these trucks. Think about how much less technological advancements we'd have in vehicles if there wasn't end users "improving" on the designs of the engineers.

 

They're definitely smarter than you. (I mean, at combustion & mechanical engineering.)

But they're operating from a different & more complex set of priors & design goals than pretty much any individual user.

For example, they have emissions regulations to meet. IDK how the spacer may or may not affect the overall emission profile of the engine. They also have fuel-economy goals to meet. If 95% of Tacoma drivers don't really need extra torque down low, maybe it saves some fuel to tune the torque band higher. They also have marketing concerns, i.e. being able to advertise a higher max horsepower is probably marginally more important than making torque lower in the rpm band.

The same is true of the 3º exhaust-cam gear mod; reportedly it improves power somewhat over stock, possibly without tradeoffs or downsides, but it probably increases emissions a little bit. Not something the individual enthusiast Taco owner cares about very much, but makes an incremental difference when considering, say, 50,000 Tacomas spread across the Los Angeles basin / air quality district.

 

I should have left the part out about the trade offs.

It wasn’t important. I was just thinking out loud about my personal opinions about modifying my intake.

Anyone have comments about the first 3/4 of my post?

 

Nope. It's correct.

@GilbertOz 's comment about Toyota engineers having to balance a myriad of requirements (at scale) rings true. I am willing to give up a fair bit for better torque and drivability.

 

Does anyone have a decent pair of dyno plots for before and after this mod? The ones I’ve found are crap. The manufacturer claims the gains are in the 2900-3100 rpm range but none of the plots have this range or they are obviously nothing but noise in that range.

 

For example, I found these plots and I’m very skeptical that the damped out oscillation at the low end is real. It looks like a poorly executed test to me.

https://www.tacomaworld.com/threads/anderson-engineering-manifold-spacer.797477/page-3

 

Most dynos start measure above 3K range.
I swear they description of the range has changed since the beginning. IIRC, the range was close to 4K. I remember putting out my histogram on other thread with my normal day to day driving rpm range