Brettus

iTrader: (2)

heh - so was I (until a few years ago ) . It does make you less prone to believe stuff unless it can be proved beyond any doubt .
I've read these forums extensively - taken in all the BS and dissected it and concluded there was enough evidence to suggest premixing was beneficial . Keep reading , you will get there ....

PBlue

iTrader: (1)

dont patronize me. you want to believe it, go ahead. I've read most of what you have i bet. I'm just more skeptical than you. Of course everyone is going to say that their product will help you, so you buy it. and no two people treat their engine the same, just like no two engines are exactly alike.

The lightweight wheel issue is similar. In theory they should improve over heavy wheels in every way. Isley even did an article in the SCCA mag where they did various tests and showed that lighter wheels with the same tire were faster in all categories... albeit not by very much. But nonetheless the performance advantage was proven... and then i bought my lightweight wheels for looks moreso than weight loss.

while we're at it... i have some magic lugnuts that will make your rims and tires last longer. wanna buy? why not... right?

Brettus

iTrader: (2)

Some things that helped me make a decision :

*Racing Beat's tests on premix showing power advantages
*Various reports from motor rebuilders suggesting the centre of the apex seal wears out first
*hundreds of motor failures earlier on - put down mainly to insufficient lubrication of apex seals
*Evidence that premix was found to disguise premature apex seal wear
*Mazdas own admission of guilt by increasing injection rates and introducing a centre injector in recent model upgrade
* race teams who would not even think of racing without the use of premix
*Reports of increased gas mileage


That's all i can think of right now but there comes a time when it just becomes accepted as good practice - you obviously have not got to that - does that make you right ?
Oh that's right you are an engineer so if Mazda designed it that way it must be right cause they know way more than anybody here ....
Yeah right !

Mr. Pockets

Now, I haven't been around forever, but I do seem to remember a gentleman who worked at the engine rebuilding facility and posted pictures. I remember the main culprit being carbon buildup causing the seals to stick.

chiketkd

iTrader: (5)

+1

I also remember someone asking him in that thread whether to add premix (or any other additives) to their fuel, and he said to follow the offcial guidelines from Mazda.

Brettus

iTrader: (2)

Yes he did say there were a lot of carboned up engines (caused by nanny driving no doubt) . However many of the early failures were from wear evidenced in part by the fact that Mazdas cure for the problem was to up the injection rate .

As for the quote above , of course he would say that . He is basically Joe Bloggs picked off the street and trained how to rebuild rotaries - how would he know any different than what Mazda tells him ?

PBlue

iTrader: (1)

and you are an expert because.... you can read other people's opinions?

Brettus

iTrader: (2)

/\ my opinions tend to be formed by hearing the same things over and over from several "in the know"people who are dealing with this stuff on a regular bassis along with thinking about it from a commonsense engineering background with a bit of first hand experience thrown in - how about yours ?

chiketkd

iTrader: (5)

Well I remember someone asking him in that thread about whether fuel additives (e.g. Chevron Techron) were okay to use in a rotary engine. His response was no b/c of the risk of dislodged carbon build-up migrating to another part of the engine and causing serious harm. So not all of his answers in that thread were follow what Mazda says, some were based on his experience as a rotary engine tech.

Brettus

iTrader: (2)

he is not a rotary tech - he is a guy hired to rebuild engines .
But yeah I dare say he has learnt a lot about what he does and would now have a few clues .
I think what you are refering to were his thoughts on using decarb proceedures like seafoam etc

PBlue

iTrader: (1)

Hearing the same thing over and over doesn't make it true.
The common sense is that its easier to claim something works when its extremely difficult to prove that it doesn't. Do you have proof that ***** pills don't work? no, so why dont you buy them... me... its because im huge already... wait... what was the point of all this? oh yeah... and thats the true meaning of christmas.

done... unsubscribed

robrecht

Good summary, B. Except maybe for the race teams, don't they usually remove the OMP and therefore need to premix. Not sure, but I think this may also be true of RB's tests, but keep in mind that they did only saw power advantages with a rather large dose of premix, much more than most use.

robrecht

But keep in mind that while some rebuilders see premix as a cause of carbon build-up, others recommend 2-stroke alone as a way of reducing carbon build-up. Not to mention that many of us add FP+ to our premix as an added remedy for carbon build-up.

robrecht

That was me. Actually, I tried to engage sleepy-z a couple of times on the topic of premix. He basically declined to really address the issue because he's speaking as a Mazda employee and said he can only give the Mazda party line.

robrecht

True. There's not enough irrefutable evidence to convince everyone to premix. I try and listen to the really smart guys and follow their experience and instincts. BTW, you have the best color RX-8 but I don't care about the size of your *****.

shaunv74

Do the test yourself instead of stirring up another thread about premix.

You can determine if it improves the engine with two methods:

1) Take a vacuum reading before adding premix
2)Add premix and drive around for a few gallons of gas
3) take a vacuum reading and if it has increased you have increase the engine vacuum due to better sealing of the seals due to more complete oil coverage. If it doesn't then it's snake oil.

2)If your commute is very repeatable and your gas mileage very consistent try it for a couple of tanks and see if you get an increase or not.

Try it for yourself and decide. that's what I did and I pre-mix.

That's what others did and they don't.

robrecht

I think that might be a good test if your seals are already worn enough to affect compression and vacuum. But if your engine is in good shape, don't expect premix to do much if anything. Doesn't me it's snake oil if it might be helping protect your engine.

Apexin

I did not intend to start a pre-mix war. Just a simple question. If it's not legal then it's not legal. Problem solved. I want win by ability, not by bending the rules. And I just got a new rule book, which solves my other problem. Thank you for all of your help. Happy racing.

shaunv74

Nope. It's a good test either way. I started premixing right after I broke in my new engine and saw a gain in mileage right away.

robrecht

And increased vacuum? I started right away also but didn't see any improvement. I just premix for extra protection.

mwood

I know premix has to lower octane, question is how much? If significantly lower, that might answer a number of the power related questions...

Brettus

iTrader: (2)

/\ sweet FA

Flashwing

Where was I "calling" anybody out on the rules? I simply asked if that was true because fuel additives are not something that can be detected nor proven.

Whoa, people...this wasn't meant as a personal insult. I know how seriously people who are competitive within SCCA take the rules. Believe me, I've already been flogged on local autocross forums because I was placed into street modified due to my carbon fiber hood and mid-pipe nevermind that neither item increases the performance of my vehicle in any manner.

I guess it's going to be up to the OP as to what's more important. Pre-mixing has no proven performance value.

StealthTL

iTrader: (1)

Some hydrocarbons have octane nubers as low as minus 160, but of course, pre-mix blenders tend to avoid them.

If you assume a worst case of your oil having 'zero' octane rating - then ten gallons of good 93 rated gas mixed (very rich) at 100:1 with would give an overall rating of 92.07....

S

ULLLOSE

iTrader: (1)

You called me out when you directly asked me, "I'm just curious if you're being facetious or being truthful." If you can't take the answer, don't ask the question.

As far as your mods.... It would be sad to think that you got a carbon fiber hood that weighs more than stock, and does nothing to improve cooling or intake airflow - I think in this section of the forum we might refer to that as useless bling. WOW, a mid-pipe that flows worse than stock, money well spent.

btw the mid-pipe does not put you in SM, a catted pipe is legal in STX/U, and a catless is legal in BSP.