tooter's next manifold adventure...

[tooter]

Originally Posted by malibuguy

Im pulling together to get some funds set aside for this. Just dropped my trans off for the Malibu to get rebuilt, sent the cam and lifters to get WPC treated as well. Too many projects!

It's ok, Malibu...
There are still two available from this production run. And if there is still any interest after this run sells out, I can always have another run machined.


Greg

[Kaotic Lazagna]

My local Chevron said they switched to summer blend, but didn't say when they did.

[tooter]

Originally Posted by Kaotic Lazagna

My local Chevron said they switched to summer blend, but didn't say when they did.

That makes sense. My mileage has been better lately but I don't date my fillups. Same with my motorcycle. It goes over 70 mpg on Summer blend, and the last couple of fillups have all been 70+.


Greg

[tooter]

I'm down to the last spacer now...

[DJYojimbo]

Originally Posted by tooter

I'm down to the last spacer now...

Greg, is there anyway you can hold the last one for me? I'm just waiting to finish my clinicals and waiting for the hospital to hire me which is very soon! anyway i can put a down payment?

[tooter]

Originally Posted by DJYojimbo

Greg, is there anyway you can hold the last one for me? I'm just waiting to finish my clinicals and waiting for the hospital to hire me which is very soon! anyway i can put a down payment?

Don't worry, man...
Even if the last one sells out before you're ready to buy, I should be able to have a few more made within a month or so. The worst that could happen is that you might need to wait for just a little while.


Greg

[DJYojimbo]

Greg you are the man!!!! Once my first big check from the hospital arrives, i'm using it to buy a tooter!!!

[DJYojimbo]

i think i'm going to buy this and the trd rear sway bar and hold off on the dc sports header haha!

[DJYojimbo]

is anybody using this tooter spacer with an automatic tranny?

[tooter]

Originally Posted by DJYojimbo

is anybody using this tooter spacer with an automatic tranny?

The one that shipped today is going to a guy with an auto. So as far as I know, he'll be the first to experiment with it. My best guess is that an auto trans will shift at slightly lower rpms because the stronger intake manifold vacuum signal will indicate less engine load, but I have no idea exactly what will happen. With my manual it easily short shifts at 2,000 rpms, and pulls in the next higher gear from under 2,000 without lugging the engine. That helps the gas mileage not needing to rev the engine as much in normal driving. Now if I could just get my wife not to rev the engine so much!


Greg

[j-san]

That would be me. Unfortunately, my Yaris lacks a tach, but I do have a ScanGaugeII. I'll try to see if I can't keep track of when the tranny shifts and compare that to after the spacer install. I'm hoping the tranny will keep up with any torque gains lower in the RPM range and shift accordingly. I hope this mod would end up giving me a little more low end power and squeeze out another MPG or two. I'll post up my findings after driving around with it a little.

[tooter]

You might be able to tell any difference of when the transmission shifts by feel. You already kind of know when it's going to shift according to how much you press on the gas pedal, and how much engine load there is such as grades. Gas mileage is a good indicator as it's sensitive enough to respond to more subtle factors.

It'll be really interesting to see what happens as this is uncharted waters. So if after driving with the spacer you feel that the benefits aren't worth the cost, please feel free to return it undamaged and I'll be happy give you your money back.


Greg

[j-san]

That is very generous of you, Greg! I guess we will see how it goes and I hope my experiment with it will be of some use to you. Wish I had a manual tranny, but the wife just doesn't want to learn how to drive one...

[tooter]

I'm still trying to get my wife to rev the engine less so we can get better gas mileage. It's a lost cause.


Greg

[j-san]

Finally got the Tooter spacer installed today. Took me a while to get the time needed to do the install and I had to do a couple runs to the hardware shop for some tools. All together, the install was fairly straightforward and simple. I had to lengthen a couple hoses, but the other hoses seemed to have enough slack to make the move. I used the stock airbox without any issues. Greg has an excellent kit put together and the spacer is very well made - a perfect fit.











I let the battery remain disconnected during the install, which took about an hour. I had to remove the bolts that hold the coolant fill cap section to the throttle body and offset it in order to make the move. I was able to reconnect the fill cap section to the original mount using just one screw and made sure nothing was rubbing the hoses.






With the decorative engine cover back on, it looks virtually stock - especially with the stock airbox. Despite being only held on with 2 screws instead of the usual 4, the cover didn't rattle and the front edge was actually supported by the flange of the intake manifold.






Driving the car after the install was pretty much the same as before. I have an auto tranny and there were a few instances where the shifts came late at lower rpms. The tranny hung in the gear a little longer than what seemed like usual, but it stopped doing that after I got out of the residential roads and started going 50mph. I did not notice any change in how the car drove. I did test out the acceleration on highway onramps at WOT and it almost seemed like the car got up to highways speeds a tad faster than before, but then again, it could be the placebo effect taking hold. No info on fuel mileage yet since this is the first drive with it, but I can update this thread with my MPG with auto tranny once I have a few fill-ups done.

[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