How much work is it to install a larger throttle body?

Drivetrain upgrades, engine upgrades, or any other mods to gain speed or acceleration.

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Valiant
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How much work is it to install a larger throttle body?

Post by Valiant »

Well, I need to put in a 31mm throttle body, a throttle cable(2015 uses dual cable, I had to order a 2013 single cable), 31mm manifold, and larger intake pipe(to the airbox).

My scooter shop(specializes in custom mods for mopeds & scooters) had my PCX for over a week. To the best of my knowledge, they didn't do any work on it for the entire period, and they seem to be lying to my face about it. I plan to stop by tomorrow and if I can't find any evidence they even started on it, I plan to take it back.

So I wanted to see if this installation can be done with only removing the seat if possible, as I don't have a private garage and can't completely disassemble the panels unless I can finish the work all in one day.
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Re: How much work is it to install a larger throttle body?

Post by Pcxdemon »

If you can use existing throttle cable than yes you can install it by just lifting the seat out. It would take about 1/2 hour if the air box connecting tube goes straight in to the air box. Otherwise I'm thinking that the new tube is bigger than the hole in the airbox and you will need to take the box out and enlarge the hole to fit in new tube. It's not a hard work or complicated at all, I'd say put aside couple of hours to muck around..
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Re: How much work is it to install a larger throttle body?

Post by Valiant »

I was told I'd have to buy a single throttle cable because that's what the larger throttle body uses. I assume the throttle cable installation necessitates removing a lot of panels because you actually need to secure that cable to the frame itself.

And yes, the new tube is larger and a larger hole needs to be cut into the airbox. Kind of wondering if a hole saw bit could do the job on a hand drill.

I'm just not too sure what all the tools I would need are. This wasn't covered by Dave's how-to on his BBK because he didn't put in a larger throttle body, I have literally zero mechanical experience, and I'm not sure what tools I would need to unbolt everything.

My brother knows the co-owner and he tells me that the owner doesn't want to work on my PCX because he thinks I can't be satisfied. Well the reason why I kept going back was because of the transmission issue that limits my speed to 60 mph, which is less than stock. I don't see why that's a satisfaction problem, as it's more of a "something's wrong with it" problem. I'm also clueless as to why someone would agree to work on it, take my PCX, and do absolutely nothing for over a whole week.
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Re: How much work is it to install a larger throttle body?

Post by Alibally »

Is it low in power when accelerating or does it pull well but peters out at 60?
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Re: How much work is it to install a larger throttle body?

Post by Valiant »

The current transmission issue has the speed going up to 60.5 mph, and from there the rpms shoot straight up, but I don't gain any speed.

If the missing TB is causing any issues, I'd say I lose power at the high end without it.
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Re: How much work is it to install a larger throttle body?

Post by Pcxdemon »

Just thinking about this, sounds like your weights are too light! I wouldn't trust much for that workshop work on your scooter..
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Re: How much work is it to install a larger throttle body?

Post by Valiant »

Pcxdemon wrote:Just thinking about this, sounds like your weights are too light! I wouldn't trust much for that workshop work on your scooter..
Probably. They had a good rating, but upon closer inspection I did note a slew of 1-star(out of 5) reviews that describe some of the problems I experienced.

The guy did kind of give me that look and asked me what I wanted to do. Kind of had to shake my head and ask him what he thinks the problem is. It's only my opinion that maybe that 11% center spring is a LOT stiffer than the listed percentage would have you think. I've moved up to 13g weights, but while I lost some acceleration, it isn't exactly "slow" per se when accelerating.
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Re: How much work is it to install a larger throttle body?

Post by Valiant »

Okay, so my mechanic said he installed all the parts yesterday(didn't exactly see the PCX myself).

He said it was running richer all around now than it was prior to the installation of the intake parts. Is that even possible? All that should've been installed were intake parts, the fuel injector should be exactly the same.

I kind of get the feeling that something might have gone wrong somewhere, as it doesn't make the least bit of sense to me. Unless I was sent the wrong parts, the airflow should be significantly increased, so it should run leaner if anything. I also don't have an O2 sensor on there, so I'm not exactly sure where it's at when he says it's running "rich". If it's running 13.5 AFR at low to mid rpms, that's rich, but it's not problematic in the least.
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Re: How much work is it to install a larger throttle body?

Post by Reaper »

Valiant, you could buy this afr meter http://www.webike.vn/shopping/products/21551774.html
It is cheap, small size, and works just fine. It plugs to your existing honda oe afr meter. on wot it shows sharp numbers, on half-throttle the numbers are jerking but you definately will see what's going on.
And you could buy a small tachometer, from Koso or any other brands. I stick to KOSO because they are very small, I don't want my panel to looks like this : http://www.youtube.com/watch?v=LCq9pL_JiHk

I like how looks like this : http://www.youtube.com/watch?v=9IKj0cSM6ps Thanks Pcxdemon for sharing this.

If you are in a world of modding, you should have some gauges anyway.
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Re: How much work is it to install a larger throttle body?

Post by Valiant »

Reaper wrote:Valiant, you could buy this afr meter http://www.webike.vn/shopping/products/21551774.html
It is cheap, small size, and works just fine. It plugs to your existing honda oe afr meter. on wot it shows sharp numbers, on half-throttle the numbers are jerking but you definately will see what's going on.
And you could buy a small tachometer, from Koso or any other brands. I stick to KOSO because they are very small, I don't want my panel to looks like this : http://www.youtube.com/watch?v=LCq9pL_JiHk

I like how looks like this : http://www.youtube.com/watch?v=9IKj0cSM6ps Thanks Pcxdemon for sharing this.

If you are in a world of modding, you should have some gauges anyway.
That's... a temperature gauge o_O .

I did see the KOSO AFR from somewhere else, though Reggy from Yuminashi recommends a good wide-band O2 sensor for accurate readings. Price was about $300 for a good one, but I figured for another $300 more I could buy the Bazzaz self-mapper and not have to deal with manual adjustments along the way. Really though I'm just putting that off and hoping I don't have to resort to that as of yet.

That, and I'm pretty sure any gauges that are on the thing might get yanked right out by loitering homeless people/drug addicts, as I already had a saddlebag cut off my PCX.
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Re: How much work is it to install a larger throttle body?

Post by Pcxdemon »

Disconnect the battery for a few minute, then reconnect and go for a little ride. Let the computer relearn new parameters...
It will be fine valiant, 13.5 afr is very good, you only need to worry going 16+ but you will never go there as you don't run 196cc kit..
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Re: How much work is it to install a larger throttle body?

Post by Valiant »

They did that, but I'm not sure how long it takes the ECU to adapt. And more importantly, I'm not sure if that Enigma EFI Bluetooth unit is going to interfere with that adaptation.

I did note that whenever I alter the fuel map settings(which is admittedly like throwing spaghetti at a wall and seeing what sticks), the PCX dies on idle pretty much immediately afterwards. But after starting it up again(typically have to hold down the starter for about 10 seconds), it doesn't do that again. Not sure if that's part of the ECU adaptation, as I was under the impression that most piggyback units work by tricking the stock ECU into reading different values. I was told that resetting the map values to all 0s would make it run the stock settings though.
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Re: How much work is it to install a larger throttle body?

Post by Valiant »

Oh, and speaking of adaptation...

Is it best for me to personally do that reset myself? Because I figure there might be some subtle differences if my 200 lbs fat ass rides it, and if some skinny 150 lbs guy rides it.
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Re: How much work is it to install a larger throttle body?

Post by Pcxdemon »

Personally, I would use bigger injector only ( you do have bigger injector?) without enigma..stock computer will adapt no worries with your kit. Has enigma got any pre maps to select from?
Also, you need to put in at least 50-60 miles to settle it all in stock computer that is..
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Re: How much work is it to install a larger throttle body?

Post by Valiant »

Pcxdemon wrote:Personally, I would use bigger injector only ( you do have bigger injector?) without enigma..stock computer will adapt no worries with your kit. Has enigma got any pre maps to select from?
Also, you need to put in at least 50-60 miles to settle it all in stock computer that is..
No, that's kind of the problem. I'd need a fuel map(Throttle Position VS RPMs) the stock ECU uses on top of something from the Kitaco i-Map or Takegawa FiCon2 and overlay both maps on top of each other in order to actually make adjustments to it, otherwise I'd be flying blind. Thus far I haven't been able to find any of the 3.

But do you happen to know if piggyback units would interfere with that adaptation?

If not, I'll see if I can't convince my mechanic to just release the PCX to me as it is, as I don't believe anymore information exists regarding the fuel map, and I'm kind of past the point where I can remove the throttle body, as he already drilled into the airbox.
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Re: How much work is it to install a larger throttle body?

Post by Pcxdemon »

Valiant wrote:
Pcxdemon wrote:Personally, I would use bigger injector only ( you do have bigger injector?) without enigma..stock computer will adapt no worries with your kit. Has enigma got any pre maps to select from?
Also, you need to put in at least 50-60 miles to settle it all in stock computer that is..
No, that's kind of the problem. I'd need a fuel map(Throttle Position VS RPMs) the stock ECU uses on top of something from the Kitaco i-Map or Takegawa FiCon2 and overlay both maps on top of each other in order to actually make adjustments to it, otherwise I'd be flying blind. Thus far I haven't been able to find any of the 3.

But do you happen to know if piggyback units would interfere with that adaptation?

If not, I'll see if I can't convince my mechanic to just release the PCX to me as it is, as I don't believe anymore information exists regarding the fuel map, and I'm kind of past the point where I can remove the throttle body, as he already drilled into the airbox.
All piggy back controllers bypass ecm. They have all been tuned for tps/rpm values. When you hook them up, they steal crank wire signal for rpm and throttle position wire so that's how the piggy back knows where it is and runs its mapping. Injector Wiring is looped thru the piggy back so the ecm is non the wiser for the fuel alteration. ECM still thinks it's running the show while piggy back is doing all the work with its pre-set mapping. Because the mixture is right, the O2 sensor never goes in to the fault to tell computer something is wrong hence no engine management light lights up and ecm couldn't correct mapping if it would want to as it has no control of the injector...
When you install bigger injector, the ECM doesn't know there is a bigger injector. It just fuels like it has with the smaller original one. It fuels per time duration set for tps/rpm in the ecm, so smaller outlet on smaller injector only can fuel so much. Enter the bigger injector in to the game and with ecm nothing is changed, all it is, is that bigger injector has bigger opening so for that time duration sprays more fuel to combust hence it works ok for bbk. But stock ecm mapping is always set for slightly leaner mapping, it's more fuel efficient and enviro friendly. The O2 sensor does try to always keep the mixture at the ideal economic afr of 14.7 as it has small amount of adjustment.. So when you run a bbk and more heat with it, it's advisable to get most out of your fuelling dropping that afr between 12 to at least 13 or so but also get maximum power out of the combustible burn. To do that , you would need piggy back to override the ecm and just increase the fuel up by a smidge, but it's ok if you don't have one..at 14.7 it will still run fine..
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Re: How much work is it to install a larger throttle body?

Post by Valiant »

Again, that's a bit confusing. Because the Enigma has the option to run the stock map, I'm not sure if that also allows for O2 sensor adjustment, or if that's purely a wiring issue and I would have to remove the unit.

On the other hand, I'm still not sure why the intake parts installation would cause it to run richer. From what I understand, the intake pipe is larger as well as the throttle body compared to stock, but the manifold is supposed to be narrower than stock. Now presumably that works like a funnel to shove air into the cylinder at higher speeds.

But Reggy's explanation is a bit confusing to be honest:
The larger the intake pipe, the less airflow velocity you have.
If you would use a smaller pipe, then you would have with the same bore and stroke a higher airflow velocity.

The downside from a smaller pipe would be that it would choke at higher RPM's which would cut your performance off.

You need a wideband O2 sensor as I said before and based on this you can check if you can work with your actual controller or if it is rubbish.
Again, it sounds to me like that narrower manifold was supposed to increase airflow velocity. But if it's running richer because it's not sucking in enough air(if that's the problem), I'm not sure why that would be different at higher rpms. It's kind of like trying to breath through a straw when you're jogging.
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Re: How much work is it to install a larger throttle body?

Post by fish »

This, and many other, PCX modding threads should make informative reading for people thinking of buying a PCX for thrift/economic/appearance reasons - while really hoping & expecting to cruise at over 60MPH on a small scooter.
$3500 will buy a lot of pretty fair sized lightly used motorcycles and/or larger CC scooters....that will safely & easily cruise much faster than 60mph without reworking what the manufacturer's engineers have already put in place. Few folks working in a parking lot, or a heated home garage or a dealership service bay for that matter, can build a better & more reliable scooter than did the manufacturer. If so, you've purchased the wrong brand of scooter from the get-go.

If you're after some fun and tinkering and have the expendable cash....that's a whole different bucket of monkeys.
Better? Nope.
Me thinks...
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Re: How much work is it to install a larger throttle body?

Post by Pcxdemon »

Valiant wrote:Again, that's a bit confusing. Because the Enigma has the option to run the stock map, I'm not sure if that also allows for O2 sensor adjustment, or if that's purely a wiring issue and I would have to remove the unit.

On the other hand, I'm still not sure why the intake parts installation would cause it to run richer. From what I understand, the intake pipe is larger as well as the throttle body compared to stock, but the manifold is supposed to be narrower than stock. Now presumably that works like a funnel to shove air into the cylinder at higher speeds.

But Reggy's explanation is a bit confusing to be honest:
The larger the intake pipe, the less airflow velocity you have.
If you would use a smaller pipe, then you would have with the same bore and stroke a higher airflow velocity.

The downside from a smaller pipe would be that it would choke at higher RPM's which would cut your performance off.

You need a wideband O2 sensor as I said before and based on this you can check if you can work with your actual controller or if it is rubbish.
Again, it sounds to me like that narrower manifold was supposed to increase airflow velocity. But if it's running richer because it's not sucking in enough air(if that's the problem), I'm not sure why that would be different at higher rpms. It's kind of like trying to breath through a straw when you're jogging.
Just ride it without enigma, I'm sure it has a switch where you can restore it's original mapping where ECM actually runs the show, all piggy back units have that option.
Bigger injector will do the job but needs time to adjust it self so you need to ride the thing, just start slow and easy...
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Re: How much work is it to install a larger throttle body?

Post by Valiant »

Pcxdemon wrote: Just ride it without enigma, I'm sure it has a switch where you can restore it's original mapping where ECM actually runs the show, all piggy back units have that option.
Bigger injector will do the job but needs time to adjust it self so you need to ride the thing, just start slow and easy...
Not quite a physical switch no.
http://dilts-japan.com/faq.html[quote]
The numerical value of all of the MAP is set to the "0" at first in a state of being connected to the motor bicycle.
How do I how to understand this numerical value?

ENIGMA is a "sub-controller".
You can not see the inside of the ECU MAP of normal.
ENIGMA performs the increase / decrease of the fuel injection time for this ECU invisible MAP.
MAP data "0" is the same as normal data(ECU injection time).

When the injection quantity input field and the chart screen is all zero,Do I have to enter a value before the engine start?
Is the ENIGMA possible to write and read the data except PC?

Fuel MAP data "0" is the same as normal data.
You can drive the motor bike soon.
You can use the ENIGMA by a smartphone(Android or iOS) except for model of USB connection.
A PC and a Smartphone has the same function.[/quote]
In short, all 0 values = stock. But as mentioned, I'm not sure if it still tosses out input from the stock O2 sensor in that state.
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