Air filter mod II ?

[Mike Holland]

My original air filter mod was simply designed to ease the path of air through the filter box. It worried me that the induction pipe extended so far into the box, almost up to the outer panel, leaving just a small gap for the air to enter the pipe. When I tied shortening the pipe there, it was disastrous for the performance, so I decided that was a tuned length.
Now I see that the HPE models have a pipe that curls around in the filter box and meets up with the U hole that I chopped in my original mod. It seems to me that this will provide a much smoother flow and, because it is a bit longer, may also improve torque.
Installing this pipe would be a mod just for the pre-HPE GTS300s. I have ordered one from SIP to try out, but it is taking ages to get to Australia. I am not even sure that it has been posted yet.
Just wanted to put the idea out there. Maybe one of you has easy access to one of these new pipes and a pre-HPE scooter to try it on. My gut feeling is that this will give better results than my original mod.
Mike

NB. The part number is 1A011902.

[boggie-one]

Hi Mike

Thanks for sharing ideas.
Do you have a link or some pics of you air box mod and some experiences of the outcome for us to read?

Please point out which mod was unsuccessful.

Regards
Boggie

[bogu112]

Pics will be great

[steelbytes]

Now I see that the HPE models have a pipe that curls around in the filter box

interestingly this is not the case on the Asia Pacific HPE.

(see my posts on MV https://modernvespa.com/forum/post2448307#2448307)

[GTS-Peter]

The difference is that we are talking about the 300 HPE Supertech and the showed filterbox is for the 125 and 150cc IGet engines.

The HPE 300 engines are totally different from the IGet engines.

What Mike Holland is looking for is if someone already has made experience with some air filter modifications on the HPE.

Rob tried something : viewtopic.php?f=17&t=55353&start=75

But he wasn't online since a few weeks.

[steelbytes]

The difference is that we are talking about the 300 HPE Supertech and the showed filterbox is for the 125 and 150cc IGet engines.

the filterbox shown is on my 2019 Supertech 300 HPE bought in Australia. yes it's the same as the 125/150 iGet. yes it's different to the filterbox on a Supertech 300 HPE bought in Europe. Maybe read the *whole* thread on modernvespa ...

[GTS-Peter]

Its really wondering me that you have this filter mounted on your 300 HPE. Can you share a Foto of your engine, shot through the removed storage/helmet compartment? Upload via picr.de

The IGet have a totally different throttle body. Maybe the Airbox is not the only thing different on your 300 HPE.

When I check the Australian model via easyparts.nl it leads me to the same filter box that I find in the European 300 HPEs.

USA model :
https://www.easyparts-rollerteile.de/ex ... 14-d224504

European model:
https://www.easyparts-rollerteile.de/ex ... 46-d223428

EMEA - GSO model :
https://www.scooterselex.nl/explodedvie ... 35-d222029

Your APAC model I can't find in the lists.. Maybe some photos of your actual engine will help more.

[steelbytes]

Its really wondering me that you have this filter mounted on your 300 HPE. Can you share a Foto of your engine, shot through the removed storage/helmet compartment? Upload via picr.de

I uploaded to https://imgur.com/a/UuPIRZA (don't have picr.de)

Maybe the Airbox is not the only thing different on your 300 HPE

you might want to also read my post https://modernvespa.com/forum/topic172875 where I mention the different Engine and VIN numbers


for general pics of the bike see https://www.instagram.com/steelbytes/?hl=en

[GTS-Peter]

OK, I see you have have a totally different engine bay and I can't find it on the databases. Very strange!

What's the additional reservoir on the front? Maybe this is all part of the anti fuming system that's filtering fumes from your gas tank. I know this from cars and bigger bikes and I know that the USA and Canada GTS even have had a additional anti fuming system on the euro3 engines already. But what I see on your HPE looks really new to me.

[steelbytes]

What's the additional reservoir on the front?

Its part of the air intake.
See part 20 on the diagram i linked above.

The air intake starts at the seat hinge and travels through that flat black plastic chamber then down a corrugated rubber hose into the airbox

[GTS-Peter]

Absolutely fascinating. Usually things like this can be easily explained by the drawings in parts catalogues. The strange thing is that there is absolutely no hint for a overseas version of a 300 with this intake system. Maybe some preparation for Euro6 already? Or some sort of Rally modification for whatever reason?

Hope we can solve this!

From my point of view it will definitely improve power to switch to the standard HPE 300 airbox. Look at the hose diameter between throttle body and airbox!

But who knows what kind of mapping your HPE currently runs? It it runs fine now, it won't after the Airbox change without any tuning on fuelling.

[German18t]

these are the photos of the decaire inlet tube of an hpe
https://ibb.co/n0bBV3r
https://ibb.co/7zkrFR9
https://ibb.co/7JDdxhx

[steelbytes]

Absolutely fascinating. Usually things like this can be easily explained by the drawings in parts catalogues. The strange thing is that there is absolutely no hint for a overseas version of a 300 with this intake system. Maybe some preparation for Euro6 already? Or some sort of Rally modification for whatever reason?

Hope we can solve this!

I found that the Vespa GTS 300 IE Super ABS E3 2017-2018 (APAC) also has this style of airbox.

fun note, this model also has the new style wheels and the new horncover (easyparts is incorrect about this)

how did I find this? I saw a 2018 Vespa GTS 300 Super Sport FL in Titanium Grey for sale and asked for the VIN and looked at the photos. the VIN starts with RP8M45710 and I can see the new wheels and this style of airbox and horncover

https://www.easyparts.com/explodedview/ ... 39-d223374

From my point of view it will definitely improve power to switch to the standard HPE 300 airbox. Look at the hose diameter between throttle body and airbox!

But who knows what kind of mapping your HPE currently runs? It it runs fine now, it won't after the Airbox change without any tuning on fuelling.

I see what you mean about the hose ...

I found a pic of an American HPE on topspeed.com and that shows the larger hose. https://www.topspeed.com/motorcycles/mo ... 87875.html

Maybe I should import an airbox from Europe ... but maybe then should change the ECU map ...

[Mike Holland]

Well, it took two months for the air bellows to arrive from SIP to me in Australia. I fitted it the next day, and tested it on my regular acceleration strip. I normally reach 100 kph when I get to a certain point. No change on this test, and I was disappointed - I expected more torque and acceleration.

A few days later I did a test run up a long steep hill on a nearby motorway. My maximum speed up this hill has been 120 kph for the past 15 years, and this is my performance benchmark. On this occasion I managed 125 kph, and today I had another run and maintained 127 kph up this long hill. As I had never exceeded 120 kph before this is a significant improvement.

I can feel the extra power when I get to about 100 kph, lovely for overtaking. So this mod works at high speed, and not the low speed that I expected.

I would loved someone else with a pre-HPE GTS300 to try this and report back. It requires a little more hacking of the filter box's center divide to fit the hose.

Mike

[GTS-Peter]

So you installed the longer, thinner intake snorkel of the HPE to your "old" gts, and it gained some power? Interesting as I doubt the opposite for my HPE 300 and I did it just the other way round and installed the old GTS intake tube to my HPE.