Funny, that's what the blind guy also said about not wearing safety glasses ...



.

 

Team, when you premix your premix how much fuel are you using? Small amount to get it started or are you filling like a whole gerry can?

I like to stop halfway while filling and dump my premix into the tank then continue filling

 

seeing as you are convinced that caused the issue .... how about trying to explain why ..............


Note : the issue didn't start at all till after about 3/4 hr of normal driving followed by 30mins of track speed driving . And then got steadily worse as I used up the entire tank of gas .

 

I don't know...I have never had that issue either..I usually put in 20L or so...add the premix and then fill it up.

When I add gas at the track it is usually pre-mixed in gascans that I make sure are mixed up...
Are you sure that the filter wasn't just plugged up before and you never noticed it?

 

I forgot to mention ................ the tank had about 15l of gas in it before i dumped the premix in.

The filter was one that came out of a second hand pump that did have about 60000 kms on it . It "looked" clean when I put it in .
I had already done a track day and quite a few thousand kms with that filter and it was fine.
When I pulled it out it after this issue it actually looked fine .... it wasn't till i blew through it that i realised it was restricting flow when compared to another clean filter i had .

I'm convinced it was due to the age of the (1/2 used) bottle of premix.... unless Team can give me reason to think otherwise.

 

I don't see how adding it and then filling up would not mix it up. And I don't see how it sitting would cause it to go bad after 2 years. I have had Idemitsu that has sat that long and it looks just fine, it has not separated or anything. Unless it is open or contaminated or something i just don't see it going bad. The shelf life should be similar to engine oil which is like 5 years.

 

This bottle had been opened , 1/2 used , then sat (with the cap on) for 2 1/2 years in my gge .

IDK ... it's the most plausible explanation that I can think of ...............

 

Yeah well if was opened then it is possible it was contaminated and it is likely that it started to break down.

 

Sitting at a computer half-way across the planet means that there's no way possible for me to know what the cause is. Further, I never said it was the cause. In general it's not considered good practice to pour the oil in and then fill it up. The philosophy goes back decades ago with outboard boat engines etc.

There are a lot of factors involved; tank configuration, starting fuel level, etc. for starters, with a dual saddlebag tank there's no way you have equal oil percentage distribution on each side after fillup. If the tank is low/near empty where does the oil go when you first pour it in? Probably straight down to where the fuel pump is.

Is bad premix oil a possibility? Sure, I don't dispute that at all, but it doesn't change my opionion about pouring oil directly into the tank rather than in whole or at least partially using a separate 5 gallon container to actually pre-mix it prior to going in the fuel tank.

 

Gotya ..... you might not have said it but the implication was pretty obvious.

 

What's obvious is you making assumptions, no different than assuming pouring the oil in first and then pumping gas results in a homogenous mixture.

The truth is you have no firm proof of what actually happened. In that situation the smart course of action is to implement whatever good common sense practices and strategies are possible.

If you had a clear 5 gallon race jug you might have noticed something wasn't right if indeed it was bad oil, but now you can only guess. Making a concentrated premix blend and shaking it up good makes more sense than just dumping oil in the tank. I realize premixing to spec in 5 gallon jugs, 55 gallon drums, etc. isn't convenient for the street, but for racing I wouldn't do it any other way.



.

 

I must remember to make an extra effort to try understand you better next time.

I still doubt it makes any difference but ..............I do take your point.

 

this had me wondering... does premix clogs up the fuel pump filter?
I only premix when tracking and I noticed that my fuel pressure would be lower after that track session. only after I cleaned the filter then the pressure goes back to what it was before the track session.

 

This was mine (120,000+ miles on it in almost ten years) after years of premixing. It looks clogged right? Well it functioned perfectly. It only got pulled and replaced because I put a new pump assembly with the Walbro in as a preventive measure before going turbo.

 

Mine after 1.5 yrs premixing 1/2 oz per gallon. Cleans as a whistle! What's your ratio and how many years specifically?

FWIW good or bad I do the dump and pump method.

 

I think the problem I had was made much worse by the 320lph pump i have installed . I have a feeling the filter is too small for the flow it needs to handle now and the slightest restriction causes the mesh to be sucked in on itself.

 

Do you have an S2 pump housing/filter assembly or S1?

ps: paging dannobre

 

Yes ??



Posted From RX8Club.com Android App

 

I have the S1 assy. Which is kinda the point of the thread .... Making a hi flow fuel pump assy. that works on the track. We know the S2 is better ............ but is there a high flow pump to fit it ?

 

9k, talking about walbro...in addition to the pressure difference:
my walbro would start the whine louder after my track session with premix. after i cleaned the filter, the whine becomes softer. coincidence?

 

seems like I heard that somewhere else before ....

 

LOL....Ya. Getting tired of talking about the same stuff though

I guess I should make a sticky

 

I thought the pumps were the same basic configuration, but it will be easy enough to check since I have a new S2 assembly sitting on the shelf. The fuel pump assembly was completely reworked from the S1 making it easily disassembled and all the OE parts are serviceable/replaceable; pump (13-350A) , sock filter (13-ZE1), bypass (13-280A), etc. The pump drops right out ...





.

 

The actual pump itself is different ...so I'm told . And there isn't a high flow option for the new style pump that we are aware of . But I have not got an s2 pump so not really sure on any of that.

 

Well it's a Denso with a higher flow rating than the S1 Aram pump.

Typically it will one of several standard configurations that most high flow pumps are offered in, but I suppose it could be unique in some way.

Like yourself I don't really know. I'll disassemble it, if not this evening then over the weekend, and document what I find.