tooter's next manifold adventure...

[tooter]

It might take a few cold start cycles for the ECU to relearn the new operating properties. On the dyno, the spacer lowered the torque peak from 4,100 rpm to 3,700 rpm, which is a difference of a little under 10%.



Without a tachometer that might be more difficult to detect, especially with the transmission torque converter fluid coupling compensating for the engine load. Let me know your driving impressions and gas mileage after driving it around for a while. :)


Greg

[j-san]

Greg, I believe you mentioned the Weapon-R header you have also helped lower the torque curve a few hundred RPMs as well. I also recall you have a Magnaflow custom exhaust as well?

I am thinking of a header being the next mod. Looking at either the DC Sports or Weapon-R. Whichever header will help lower the torque curve further would be preferred. I have the JDM TRD muffler, but I don't think that contributes much for low end torque. A mechanic friend told me the issue with small engines and exhaust pipe diameter isn't an issue of backpressure, but that of exhaust gas velocity. Smaller pipes allow for higher gas velocity, which then improves the scavenging ability of the passing pressure wave, and helps low end torque. Larger pipes reduce the gas velocity, but allow for greater flow volume, which can improve high-end HP. Makes sense to me.

I just wonder if the mods are somewhat of a wasted effort with the auto tranny. Like you said about the fluid coupling, I would bet the tranny is responsible for a reduction in effectiveness. Still, the mods are fun to do and I enjoy getting under the car or hood and learning more about the workings of the Yaris.

I put about 35 miles on the spacer since install. I did notice the tranny doesn't downshift as readily while trying to accelerate on the on-ramp to highway speeds. Surprisingly, I am able to get a up to speed even in 3rd gear and not have to either force the tranny into 2nd or mash the gas pedal. Hope it gets better with more miles.

[tooter]

Originally Posted by j-san

Greg, I believe you mentioned the Weapon-R header you have also helped lower the torque curve a few hundred RPMs as well. I also recall you have a Magnaflow custom exhaust as well?

Wow... you just brought up an interesting point that I hadn't even considered.

The stated peak torque of a factory stock Yaris engine is 4,200 rpms.

Both dyno runs on that chart were done with the Weapon R exhaust header and the Micro Image Magnaflow center exhaust.

The peak torque on the run without the spacer is 4,100 rpm. So that means the header lowered the torque 100 rpms while the spacer lowered the peak by 400rpms. The two together produced the 3,700 rpm torque peak, 500 rpms lower than the stock peak.

I believe the 100 rpms are because there is such a short space in which to fit a header and yet retain the original position of the rest of the exhaust. So the tubes simply aren't long enough to make much difference.

On my Tacoma, I put a long tube header that uses folded runners to fit into the same space as the factory stock short tube header...




...and it lowered the torque peak by 650 rpms because there was enough room to pack long runners into a short space.

I am thinking of a header being the next mod. Looking at either the DC Sports or Weapon-R. Whichever header will help lower the torque curve further would be preferred.

From the dyno results you can know that the Weapon R is good to lower the peak 100 rpms. There's no way of knowing about the other headers, because I don't believe that anyone has ever tested them.

I have the JDM TRD muffler, but I don't think that contributes much for low end torque. A mechanic friend told me the issue with small engines and exhaust pipe diameter isn't an issue of backpressure, but that of exhaust gas velocity. Smaller pipes allow for higher gas velocity, which then improves the scavenging ability of the passing pressure wave, and helps low end torque. Larger pipes reduce the gas velocity, but allow for greater flow volume, which can improve high-end HP. Makes sense to me.

You're spot on. Axle backs can help performance without reducing the low end torque because the factory cat, tuned resonators, and the small diameter midpipe all work together to retain exhaust velocity.

I just wonder if the mods are somewhat of a wasted effort with the auto tranny. Like you said about the fluid coupling, I would bet the tranny is responsible for a reduction in effectiveness. Still, the mods are fun to do and I enjoy getting under the car or hood and learning more about the workings of the Yaris.

Yeah, because the fluid coupling is constantly altering the drive ratio to compensate for engine load, it muffles your perception of the effects. However, they're still there.

I put about 35 miles on the spacer since install. I did notice the tranny doesn't downshift as readily while trying to accelerate on the on-ramp to highway speeds. Surprisingly, I am able to get a up to speed even in 3rd gear and not have to either force the tranny into 2nd or mash the gas pedal. Hope it gets better with more miles.

That is an effect you can perceive. With slightly more torque, the transmission automatically shifts in to a higher gear sooner because it senses the engine is able to pull in that higher gear.

One major sensing element of engine load is intake manifold vacuum, which is a function of how hard the gas pedal is being pressed. When an engine produces more torque at lower rpms, the gas pedal is pressed slightly less, and the intake manifold vacuum is slightly higher. When a certain threshold of intake manifold vacuum is reached sooner, the transmission is signaled to shift to a higher gear sooner. That's what you're feeling.


Greg

[j-san]

There is a slight power increase in the mid-3000RPM range. I kept an eye on the Scangauge whenever I was accelerating on the on-ramp and the car maintained a 3rd gear constant acceleration that was decent. I drive a regular route to work and back and frequently have to force the tranny into 2nd just to get an appreciable increase in speed.

For this first this first tank, it seems to be right in the norm for mileage. I usually get about 95 miles before the first bar in the gauge disappears. With the spacer on, I got 98. I usually go till the pump auto-stops for a consistent fill-up. I'm not expecting massive gains here, especially for the first tank, but we will see.

I wonder if a dyno sheet for an auto tranny would look much different from yours, Greg? I think you said your dyno run was done by putting the car in 3rd and then mashing the gas pedal?

[Kaotic Lazagna]

http://www.fuelly.com/car/toyota/yar.../07Vios/183168

Before I traded Vios in. I installed the Tooter spacer on entry 46. As you can see, every tank after that saw an increase of 2-3 mpg.

[tooter]

Originally Posted by j-san

There is a slight power increase in the mid-3000RPM range. I kept an eye on the Scangauge whenever I was accelerating on the on-ramp and the car maintained a 3rd gear constant acceleration that was decent. I drive a regular route to work and back and frequently have to force the tranny into 2nd just to get an appreciable increase in speed.

For this first this first tank, it seems to be right in the norm for mileage. I usually get about 95 miles before the first bar in the gauge disappears. With the spacer on, I got 98. I usually go till the pump auto-stops for a consistent fill-up. I'm not expecting massive gains here, especially for the first tank, but we will see.

I wonder if a dyno sheet for an auto tranny would look much different from yours, Greg? I think you said your dyno run was done by putting the car in 3rd and then mashing the gas pedal?

Yes, an auto trans dyno run would be different because when you mash the pedal the transmission kicks down to a lower gear. So the run would always begin recording at way higher rpms.

It might just be a coincidence, but making the runners 10% longer yielded a 10% lower torque peak. Although it's highly likely that relationship would break down pretty rapidly if continued.

Our mileage gets shot to hell because my wife drives the car, but when I drive it's easy to short shift at 2,000rpms without straining or lugging the engine.


Greg

[tooter]

Originally Posted by Kaotic Lazagna

http://www.fuelly.com/car/toyota/yar.../07Vios/183168

Before I traded Vios in. I installed the Tooter spacer on entry 46. As you can see, every tank after that saw an increase of 2-3 mpg.

That's pretty impressive...
I did get to drive with the spacer when we took a trip and my best mileage was 42.1 mpg at 65-75 mph on the interstate. But just driving around town with no freeway, my wife has only been averaging 37.5 mpg.


Greg

[j-san]

Hey Greg,

I know you run a short ram intake with cone filter. Did you have to do any mods to get that to work with the Tooter manifold or the spacer? I'm considering an intake like the AFE or maybe the K&N Typhoon. I doubt it would make serious gains, but I'm more curious about it improving MPG and perhaps a little performance increase.

On the other hand, I've also read that the stock intakes are engineered to deliver more flow than the engine could ever use and they also maintain a standing volume of still air within the box, ready to be sucked into the engine. Perhaps I should just look into a higher flow filter that fits the stock air box and go with that?

[tooter]

Originally Posted by j-san

Hey Greg,

I know you run a short ram intake with cone filter. Did you have to do any mods to get that to work with the Tooter manifold or the spacer?

Just cutting the tube short so that I could fit the oversized BLOX velocity stack filter under the hood. The nice thing about an SRI is that it can easily be moved right along with the throttle body when it's relocated by the spacer.






When the engine is running at low rpms, any intake is underutilized, even the stock air box. I put a mini velocity stack on mine when I ran it.







I'm considering an intake like the AFE or maybe the K&N Typhoon. I doubt it would make serious gains, but I'm more curious about it improving MPG and perhaps a little performance increase.[/quote]

They do make a nice sound... but that's about it.

On the other hand, I've also read that the stock intakes are engineered to deliver more flow than the engine could ever use and they also maintain a standing volume of still air within the box, ready to be sucked into the engine. Perhaps I should just look into a higher flow filter that fits the stock air box and go with that?

I tried all sorts of intakes, and none of them really made much difference when compared to manifolds, spacers, throttle bodies, headers, and exhausts.

Greg

[dragoonmc]

Hey all,
So my install of this spacer was on an auto trans.
I found that it actually hurt my mileage even after it re learned its stuff.
I had about a 2 mpg drop from last summer so i took it off and the mpg came back up to match last year

[tooter]

Do you realize that the spacer can't alter your air/fuel ratio?

It just makes the intake runners longer. So it's obvious that there is something else going on besides the spacer.

But if you're not satisfied and feel that it is to blame for your gas mileage, simply return it undamaged with its gasket and all of the hardware and I'll refund your money.

Greg Mamishian
21444 Entrada Road
Topanga, CA 90290

[Kaotic Lazagna]

Originally Posted by dragoonmc

Hey all,
So my install of this spacer was on an auto trans.
I found that it actually hurt my mileage even after it re learned its stuff.
I had about a 2 mpg drop from last summer so i took it off and the mpg came back up to match last year

Were there any gaps between the spacer and the manifold and/or head?

[tooter]

That would very likely cause the ECU to throw a code.

I know this by personal experience because at the time I installed the prototype, the new gaskets hadn't come in yet. I was really anxious to run it and used an old gasket that was laying around. It triggered a fuel trim code because it leaked.

There's something else going on that we don't know about. But I won't argue with the guy. If he's not happy with his gas mileage and feels the spacer is the cause, he gets his money back.


Greg

[Slitwrist Smile]

Originally Posted by tooter

Do you realize that the spacer can't alter your air/fuel ratio?

It just makes the intake runners longer. So it's obvious that there is something else going on besides the spacer.

But if you're not satisfied and feel that it is to blame for your gas mileage, simply return it undamaged with its gasket and all of the hardware and I'll refund your money.

Toot - you may want to remove your address for privacy reasons. Just trying to look out for the well being of forum members. Everyone on here might be a good person, but outside of YW, you don't know what scammers might try to do. You might want to edit your post (i removed the address from the quote I am posting) and PM it to the user it was intended for.

[j-san]

I've now put a few tanks through my Yaris with the Tooter spacer. I did not notice any significant change in MPG. One tank was worse by about 1.8MPG and two tanks were better, one by 0.4MPG and the second by 1.1MPG. I think it has more to do with the variations in traffic and how heavy my foot is than the spacer. Sometimes I am running late and need to get moving faster and other days I am early and take my time accelerating and do more coasting. I imagine the ECU has learned what it needs with the spacer in place. I cannot feel any difference in daily driving, but it just seems like the tranny is more hesitant to downshift than before. I would understand that to mean the engine is probably pulling with a little more torque and thus, feels it does not need to downshift unless I force it or mash the pedal. I guess I still need to run more tanks to see if there is a greater change in MPG beyond the standard deviation. So far, everything runs as it should.

[tooter]

Originally Posted by Slitwrist Smile

Toot - you may want to remove your address for privacy reasons. Just trying to look out for the well being of forum members. Everyone on here might be a good person, but outside of YW, you don't know what scammers might try to do. You might want to edit your post (i removed the address from the quote I am posting) and PM it to the user it was intended for.

Thanks for your concern.

I've been posting my name and address for years and have never had any problems being a public business . No one can scam me anyways.


Greg

[ezhacker1]

I was able to install the spacer and keep the heat shield on the AFE intake.

Did an initial test 6 mile test run city/hwy after ECU reset just to make sure car runs fine.

1. Idle warmed up RPM is lowered ~25rpm from 620 to 595.
2. Blipping the throttle is sensitive, like having the throttle controller on.
3. Letting the engine lug the car forward is much stronger. Sure the car is shaking but works stronger on my slight inclined driveway.
4. Although idle RPM is lowered, fuel consumption/hour hasn't changed, still 0.125/HR

Manual Transmission
Related Mods: AFE Intake, DC Sports axle back

[tooter]

Originally Posted by ezhacker1

3. Letting the engine lug the car forward is much stronger. Sure the car is shaking but works stronger on my slight inclined driveway.

I call that the "tractor effect". If you've ever driven a tractor, the engine does exactly the same thing... the high torque low rpm engines vibrate harmonically as they pull because the time between each power stroke is so long. We have a steep driveway that I measured with an inclinometer at 10%. I have fun going up it in my truck at below idle 500rpm. It just vibrates right up the hill like a tractor without lugging or bucking.

This is one of the strange attributes of the intake manifold spacer that doesn't show up on the dyno runs because it's "below the radar".

Off idle partial throttle performance is superb. If you have a manual transmission there's less clutch slipping needed just to get the car moving.

Greg