To premix or not to premix, that is the question

[Milos_Balunovic]

Love the Ipone oils for that. Or some with Banana scent (i think it was motul)

[Milos_Balunovic]

...Just a thought off the back of this, I saw a video on Youtube by 'Driven By Madness' who said it's best to stop premixing a few months before your MOT emissions test or you won't pass it. Is this correct? MOT is due at the end of July.

He came in to YT with intention to make money. He lacks the technical knowledge that he is trying to push in to the world. Though he got nice money for the few videos that he did. (know the guy personally)

[hachiroku]

Just a thought off the back of this, I saw a video on Youtube by 'Driven By Madness' who said it's best to stop premixing a few months before your MOT emissions test or you won't pass it. Is this correct? MOT is due at the end of July.

Well, he's not based in the UK, so not sure how he would know about the UK MOT for starters.
I think you're worrying about nothing, mine still had half a tank of premixed fuel when it went for MOT the other month, and it passed just fine, I wasn't about to "waste" half a tank just to be rid of the premix oil in it!

[rotatopotato]

I've not heard of anyone having issues with premix on their MOT, and I've personally been through two with a fairly rich premix with no issues whatsoever.

[Michael73]

I've been premixing since I bought the car in 2019 and I've never had a problem with the MOT's. Passes every time. I get exactly the same readings for NOX etc every year and when I compare it to the bundle of MOT's that came with the car I see no difference in the results. Obviously I don't know if the previous owner pre-mixed or not, but I guess that either way it answers the question!

[Brundish82]

Hi guys got a good one here, just got me a rx8 and was the first time I opened the bonnet today and thought what the hell is this... the guy I bought it of said its always premixed so... there's this container attached in front of the washer fluid tank with a window, has liquid inside it and smells like it could be 2T. Now I traced the hose and it goes to the air intake hose, the air filter is all aftermarket too with a cone behind the bumper. Is this some weird premix injection system as I don't think you would want anything else going into the engine. Thanks for reading will try and post some pictures later.

[PaulAV]

Might want to post a picture, however it sounds like an oil catch can(would normally be another hose going to it) the only other normal option would be a sohn adapter where 2 stroke is fed into an adapter on the oil metering pump

[Brundish82]

There's a oil catch can on the other side next to the brake fluid and I think its wrongly fitted as it has a mini air filter on it and has been pissing oil over the place too. The previous owner sold it due to this oil leak. Going to try and upload some pics.

[Brundish82]

Some don't loop the catch can back into the intake, which should be fine unless the oil is overfilled, or the rotor side seals are leaking.

My guess is a Sohn tank for the first one.

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[Milos_Balunovic]

Some don't loop the catch can back into the intake,

which should be fine

unless the oil is overfilled, or the rotor side seals are leaking.

My guess is a Sohn tank for the first one.

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if I'm not mistaken it is illegal. That is directly messing with emissions controls and is same as having a de-cat etc... also its hella dangerous as its letting al the fumes right in to the cabin ventilation...

[Milos_Balunovic]

In many US states (e.g. California) even fitting a catch tank correctly in a closed circuit is illegal.

In the UK there's nothing I can find in the current MOT test that would specifically cause a fail, and I have see cars (other than 8's) with the entire breather system removed and replaced with either an open-ended pipe or a filter, let alone a can and a filter.
e.g. https://www.westwalesrallyspares.co.uk/ ... -breathers

I'm not saying any of the above is a good idea for our cars, just that people do it, so you might come across it.

[Milos_Balunovic]

It could be its not checked on the MOT but..

I have seen a lot of cars as well and for some cars it very beneficial (DI engines) but but...

[Brundish82]

Just waiting for my membership to update and then can add pics. As I've been investigating it looks like it has a lot of stuff done, had a rebuild done about 6 years ago with a aggressive street port and looks like its got d585s fitted ac removed, seems to have had a mini map as doesn't rev pass 5k when started/cold. Will keep investigating and start a new post ASAP.

[Brundish82]

Just waiting for my membership to update and then can add pics.

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You have the power now

[Brundish82]

Here are some pics, hoping to look at her later this week so will post what I find lol.

[PaulAV]

That is weird piping, the 3 outlets from the air intake should have specific places to be piped to, none of them should have either oil or water reservoirs

[ChrisHolmes]

Hmm! The tank on the washer bottle is labelled “Water Level” but could well just be its original use. Where does the blue pipe finally connect?
The tank next to the brake servo is a catch can but appears to have a pipe going down past the inlet manifold which is not usual.
There is no AC pump drive belt fitted.
What do the red and black wires coming from the MAF sensor connect to?
You seem fairly well clued up on rotary terminology so communication should be good.

[ChrisHolmes]

I see the throttle body warming circuit has been removed, which is asking for trouble in normal British weather.

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[Brundish82]

Like you said PaulAV before maybe it is a catch can of some sort but why would you have two on the car, it doesn't make sense its funny what people do to cars lol, will check all the questions tomorrow if not Wednesday and really have a good dig around in there. Thanks for the replies guys

[Elmotheewokking]

Rudimentary watermeth injection kit is my guess.

[Brundish82]

Rudimentary watermeth injection kit is my guess.

Interesting, that does make more sence but I thought these where more beneficial for turbocharged engines or am I wrong. There must be a pump somewhere then and a controller for it.

[Elmotheewokking]

Rudimentary watermeth injection kit is my guess.

Interesting, that does make more sence but I thought these where more beneficial for turbocharged engines or am I wrong. There must be a pump somewhere then and a controller for it.

The amount of other mods done to it, the fact it's a water/fluid reservoir, with a pipe leading to the intake. It's pretty much all it can be.
I've seen mention of people fitting them to NA cars, in order to keep the engines cleaner from carbon build up. But largely pointless from what I've come to understand.

[HarSc]

I see the throttle body warming circuit has been removed, which is asking for trouble in normal British weather.

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As far as I know, Revs seem to not connect this back up on rebuild... Or at least, the two R3s I've owned that were built by them shortly before I got them had the same setup with coolant not running through the throttle body... Never had any issues, and if they do this on most builds, i'd have expected something to creep up by now if there was something catastrophically wrong

[Milos_Balunovic]

The Throttle body can freeze up at low temps due to high air velocity pressure drop. It also helps evaporate and moisture that might have found its way in to the motor/sensor... Sadly shops have been known to pretend as smart only to do the opposite than as advertised/imtended.

Fun fact moto GP engines often suffered from the carb freezing up before they introduced it as mandatory to have the carb heated (nowadays throttle body). There were pictures of ice surving the stuck WOT throttle. Funny is that it didn't hurt (at all) the performance of a 480whp/L engine yet some beleive it is heating up the charge air and reduces performance on street engines....

[Lemon]

Carb freezing was also a big problem on the old Renault 5 turbos