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Vic Wasteland Thread

R31Nismoid

By R31Nismoid,
in Victoria

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joeyjoejoejuniorshabadoo
joeyjoejoejuniorshabadoo

probably worth more than your D1R's

Mohsen
Mohsen

i kinda want one. name him al pacacino.

Birds
Birds

You laugh now, but when I'm at a formal occasion with a shitty DJ and they need someone to drop Dre beats...I have something up my sleeve.

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Birds Grand Master

Birds

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guys, sometimes i dont understand how f**king stupid some people can be.

im in the office doing some quotes, all the doors are closed, gates are locked shut.

dude just rocked up.

called the lane line- no answer, called me, no answer. then tried to push the gate open.....

omg this shit makes my hair hurt.

You sure that wasn't your mate looking for a place to stash all his profits

Leroy Peterson Grand Master

Leroy Peterson

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Nismo 555s checking in with 2 years of pump E85 usage and not a single blocked injector was had that day

are they top feeds?

(or am i coming from the SR world where side-feed is normal and top-feed is like the injector master race that is not always attainable)

Birds Grand Master

Birds

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are they top feeds?

(or am i coming from the SR world where side-feed is normal and top-feed is like the injector master race that is not always attainable)

Side feed

Converting to top feed is like wearing a mini skirt

You're asking to get raped

Come at me feminists

Odium Grand Master

Odium

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Miguele and I finished throwing my turbo back on last night / today (and swapped his subi turbo for a better one)... My baby lives!!! Idles like a boss again :) Only issue is I snapped a bolt (1 of 3) that holds the turbo elbow on so will need to source a replacement for that (and hope it's not snapped down too low to grab it with some vice grips).

Then Sandown and BOOOOOOOSSSSSTTTTT!!!!

Borci88 Veteran

Borci88

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I'd be replacing all your rubber fuel lines Tony. I know people say they don't break down, but you've got black "goo" in your injectors. So it's either rubber, or some sort of molecule that came from the fuel. Better to be safe than sorry seeing as biofuel hose is cheap.

blah_blah Grand Master

blah_blah

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Well this is what i found on an analysis from another forum. I made a thread in the forced induction section.

Hi,

I don't post often on this particular forum but I just came across this thread and the other one in the alternative fuel section. I am an engineer, and I have been following industry developments in alternative fuels.

I doubt many of you are aware of this, but GM had a production port injected turbo flex fuel engine all the way back in 2007. It was a Saab variant of the Ecotec engine family. Saab did extensive testing on a lot of boosted E85/Flex fuel issues and published some work on it. See Bergstrom, "The New ECOTEC Turbo BioPower Engine from GM Powertrain," 2007 and Bergstrom, "Alcohol Based Combustion Engines - Challenges and Opportunities," 2007. Deposit formation is one of the dirty little secrets of E85; another is pre-ignition.

GM found the exact deposit problems many of you are experiencing. I have read a lot of different ideas on here about the nature of the problem and I have read a lot of speculation about solutions for it. Here is what we know for sure about the deposit issue, based on GM's internal research.

Chemical Origins of the Deposits

The deposits primarily consist of "Poly Iso Butylene," or PIB, a cleaning additive in the gasoline portion of commercial E85 blends. As far as we know, the ethanol itself doesn't directly cause this type of problem with injector and valve deposits. This PIB additive was never designed for use in high ethanol concentrations.

PIB is designed to soften engine deposits, but below a certain concentration (by total fuel volume) it is actually counter-productive. What happens is that with insufficient PIB by volume, the normal valve deposits don't soften. The PIB actually combines with these normally occurring deposits and makes build up worse.

Running PIB-free E85 is basically impossible in a practical sense. GM engineers ordered special batches of PIB-free E85, but in the real world the E85 still becomes contaminated with PIB because the entire fuel refining and transport infrastructure has traces of it. Still, with this very low PIB concentration E85 deposits can still occur at similar rates.

A lot of people on here have speculated something along these lines.

Effect of Drive Cycle

Deposit formation is highly dependent on vehicle use and overall drive cycle. This whole issues is complicated, but aside from the makeup of the actual E85 blend, drive cycle is the #1 factor in these deposits.

Bergstrom, "The New ECOTEC Turbo BioPower Engine from GM Powertrain," 2007, Internationales Wiener Motorensymposium 2007, p. 29

On the left is a multi-hole type (not pintle type) fuel injector after 15,000 km running a GM in-house designed drive cycle to simulate major stop-and-go city driving. On the right is the same type of injector after 60,000km in a high-speed (mostly highway) drive cycle. Both engines were running the same commercial E85 blend in Sweden, consisting of 95 RON fuel and denatured ethanol.

Drive cycle variations may not explain absolutely everything but it is a reasonable hypothesis for why two vehicles running the same E85 blend can have such variability. This can also partly explain why somebody doing a lot of highway driving (rural driver or suburban commuter) who always runs E85 may never experience noticeable deposits.

Using Fuel additives and Normal Gasoline blends

There are a lot of fuel additive blends out there and they change all the time so I can't speak for all of the various formulations. What we do know based on GM's research is that PolyEther Amine or "PEA" , which can/used to be found in Techron products, cleans valve deposits but does not clean injectors with this problem. In fact, too much of fuel system cleaner could make the problem worse.

So how do we clean up the deposits if an engine is prone to them for whatever reason? Put "normal" gasoline blends in the tank and it will go away within 1 tank. You don't even need to pull the injectors.

Most of you already knew that. It's not really news; it just confirms with reliable sources what has been widely understood.

Conclusion

So yes, I didn't have any earth-shattering solutions to present, but I did clear up some of the mechanisms for this deposit formation. The deposits are caused by the gasoline portion of E85. The two biggest factors in deposit formation are the additive mix in the fuel and the way you drive the vehicle. Fuel system cleaner products are innocuous at best, counter-productive at worst. The type of injector or fuel system you run might matter some but they are not part of the mechanism of deposit formation.

So if you figure out that your engine is prone to these deposits, be mindful of stop-and-go traffic and put gasoline in your engine sometimes to clean it out.

Hope that helps.

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