e85 - do I want some?

[JohnnyT]

Tom initially informed me of a recent tune (I believe Jordan did) on a damn-near bone stock CX-7 running e85 using the CP-e standback. Provided great results and netted 30whp.

The CX-7 owner's thread with dyno is here: http://www.mcx7.com/showthread.php?p=52967#post52967

I was immediately intrigued. I don't know a ton about the stuff, and with all the speculation I wanted to see if you had any hard-driven facts because it seems to work well for 'most' cars, but as you guys likely found out, the DISI MZR is not included in that category.

I'm damn near fully-bolted now, and I have upgraded fuel pump internals coming to me tomorrow (fuel was the CX-7 owners biggest issue - with these internals I should flow about 1900psi @ WOT).

Do you guys foresee any long-term issues with the high pressure fuel pump, the fuel lines, or the injectors?

I think e85 would be great to combat the knock and net a solid amount of power. I do have a Cobb AP (I know, they suck to tune on) with AcessTUNER Race, and I figure if I'm doing a custom tune that I'd at least consider this option and get your guys' thoughts.

Thanks for the help.

 

[Workdawg]

BOOOO E85, from a strictly political and social standpoint.

 

[JohnnyT]

*JohnnyT says NO thank you to Workdawg for this un-useful post*

 

[Picklz]

I'm not sure how much additional fuel the CDFP internals allow you to flow, but the thing with E85 is you usually have to flow more fuel (sometimes as much as 25-30% if I remember right) for a given HP. I think our injectors would be fine but I have no idea if the fuel system would keep up or not.

The only E85 knowledge I really have is carb based and they generally replace a lot of the orings and such with a different material that the e85 won't eat away at, I'm not sure what all in the DISI would have to be replaced.

But I'm with Dan, E85 is a sham and while it is sort of a poor mans race fuel I hope it goes away, or the price goes up to what it actually costs (rather than us subsidizing it).

 

[maperformance]

I just copied Jordan on this he will get you the info you need as far as the tuning goes.

 

[maperformance]

Do you guys foresee any long-term issues with the high pressure fuel pump, the fuel lines, or the injectors?

I think e85 would be great to combat the knock and net a solid amount of power. I do have a Cobb AP (I know, they suck to tune on) with AcessTUNER Race, and I figure if I'm doing a custom tune that I'd at least consider this option and get your guys' thoughts.

Thanks for the help.

Yes we tuned the cx-7.

I see no long term issues as long as the fuel is used and cared for correctly.

Yes e85 is great at defending against knock.

We have no experience with tuning the AP's though.

 

[shadyspeed3]

I just copied Jordan on this he will get you the info you need as far as the tuning goes.

Also ask jordan how he feels about tuning with the cp-e standback unit now! i have the same unit and talked to him about it and he told be not to bother and get the cobb ap.

ive got the unit in and want to get it tuned. pm me a quote for tuining if you could!

Thanks,
John

 

[JohnnyT]

Yes we tuned the cx-7.

I see no long term issues as long as the fuel is used and cared for correctly.

Yes e85 is great at defending against knock.

We have no experience with tuning the AP's though.

Hmm...does anyone local with an AWD dyno have experience with it?

 

[shadyspeed3]

Hmm...does anyone local with an AWD dyno have experience with it?

check the local skubaru forums. they use the cobb units. they may have an idea who can tune.

can't you just set the ebrake a notch and it turns fwd? lol more or less kidding but isn't that true?

 

[JohnnyT]

check the local skubaru forums. they use the cobb units. they may have an idea who can tune.

can't you just set the ebrake a notch and it turns fwd? lol more or less kidding but isn't that true?

I bet DB out in Rogers can do it. I'll talk to them.

You're kidding. We'll just leave it at that haha.

 

[niterydr]

Tom initially informed me of a recent tune (I believe Jordan did) on a damn-near bone stock CX-7 running e85 using the CP-e standback. Provided great results and netted 30whp.

The CX-7 owner's thread with dyno is here: http://www.mcx7.com/showthread.php?p=52967#post52967

I was immediately intrigued. I don't know a ton about the stuff, and with all the speculation I wanted to see if you had any hard-driven facts because it seems to work well for 'most' cars, but as you guys likely found out, the DISI MZR is not included in that category.

I'm damn near fully-bolted now, and I have upgraded fuel pump internals coming to me tomorrow (fuel was the CX-7 owners biggest issue - with these internals I should flow about 1900psi @ WOT).

Do you guys foresee any long-term issues with the high pressure fuel pump, the fuel lines, or the injectors?

I think e85 would be great to combat the knock and net a solid amount of power. I do have a Cobb AP (I know, they suck to tune on) with AcessTUNER Race, and I figure if I'm doing a custom tune that I'd at least consider this option and get your guys' thoughts.

Thanks for the help.

From a technical standpoint E-85 is more corrosive than regular gasoline. It can take out some aluminum and rubber part.

The benefit is the higher octane for starving off knock and the ability to run extra timing.
Another benefit is the colder burning nature of the fuel with the ethanol in it. This can help to lower IAT's..not sure if a direct injection motor will see much gain from that.
Cons are it has less energy (heat) than regular octane so it requires more of it to make the same amount of power. This is the 30% more fuel you hear tossed around a lot (and it is typically between 10-40% more fuel, depending upon what your car is doing)

 

[Workdawg]

First off, I know just about nothing about tuning so I could be completely wrong...

but it seems to me that if the problem with getting BIG power out of the DISI is that you pretty much can't push enough fuel into the engine, wouldn't using a E-85 (which requires more fuel for the same power) pretty much just hurt ya? Assuming you're getting to the point where you need as much fuel as possible (fuel pump upgrades, etc) pushing more gasoline in would give you more power than an equal amount of E-85.

I understand the CX-7 got 30hp out of it, but how much more fuel did it require? It's stock otherwise, so it probably isn't pushing the limits for fuel.

If you're really planning on going for big numbers and fuel is the big restriction, then it doesn't really make sense to me.

 

[goodhart]

check the local skubaru forums. they use the cobb units. they may have an idea who can tune.

Most of the Subie guys stay away from the AP's. Some because OTS maps for the Subie's suck, others because there is a few free tuning programs that are way better like Open ECU and Rom Raider.

 

[niterydr]

First off, I know just about nothing about tuning so I could be completely wrong...

but it seems to me that if the problem with getting BIG power out of the DISI is that you pretty much can't push enough fuel into the engine, wouldn't using a E-85 (which requires more fuel for the same power) pretty much just hurt ya? Assuming you're getting to the point where you need as much fuel as possible (fuel pump upgrades, etc) pushing more gasoline in would give you more power than an equal amount of E-85.

I understand the CX-7 got 30hp out of it, but how much more fuel did it require? It's stock otherwise, so it probably isn't pushing the limits for fuel.

If you're really planning on going for big numbers and fuel is the big restriction, then it doesn't really make sense to me.

Kind of what I was getting at. I am not sure how much fuel the cx-7 took, but when I was using a standback on a ms6 a few years ago, the injectors were around 1/2 duty cycle around 6k. So with the E-85 figure 70-80% duty cycle. Doesn't really give you much more headroom for more boost or a larger turbo.
I don't remember what the fuel pump flow was like and if the ability to adjust fuel pressure has been achieved yet.

 

[JohnnyT]

First off, I know just about nothing about tuning so I could be completely wrong...

but it seems to me that if the problem with getting BIG power out of the DISI is that you pretty much can't push enough fuel into the engine, wouldn't using a E-85 (which requires more fuel for the same power) pretty much just hurt ya? Assuming you're getting to the point where you need as much fuel as possible (fuel pump upgrades, etc) pushing more gasoline in would give you more power than an equal amount of E-85.

I understand the CX-7 got 30hp out of it, but how much more fuel did it require? It's stock otherwise, so it probably isn't pushing the limits for fuel.

If you're really planning on going for big numbers and fuel is the big restriction, then it doesn't really make sense to me.

I don't have to run 100% e85. I can easily use a mixture with 93 as well. However, I'd have to log first and see what my pressures are like, as well as duty cycle on the injectors. I'm not really going for big numbers though, it's more for safety - but the added power benefits of e85 are enticing me more than water/meth injection.

 

[dmention7]

The point is, there will be no added power benefits if you can't deliver enough fuel...

IMO tuning and relying on ethanol content for safety, then running a mix of e85 and 93 sounds like a huge PITA, if not a recipe for disaster.

 

[JohnnyT]

Kind of what I was getting at. I am not sure how much fuel the cx-7 took, but when I was using a standback on a ms6 a few years ago, the injectors were around 1/2 duty cycle around 6k. So with the E-85 figure 70-80% duty cycle. Doesn't really give you much more headroom for more boost or a larger turbo.
I don't remember what the fuel pump flow was like and if the ability to adjust fuel pressure has been achieved yet.

We can adjust pressures pretty easily with the AP (the standback can do it too), but we still do not have control over the pulse width of the injectors. The pressure isn't the problem, it's volume of flow. If I do this, and I'm not seeing enough fuel into the injectors, I can easily mix with 93 to find that 'sweet spot.'

 

[JohnnyT]

The point is, there will be no added power benefits if you can't deliver enough fuel...

IMO tuning and relying on ethanol content for safety, then running a mix of e85 and 93 sounds like a huge PITA, if not a recipe for disaster.

Understood, which is why you tune and log to see if you really can deliver the fuel.

Recipe for disaster? People have done it sparingly and religiously with zero issues.

 

[Workdawg]

Whatever ya wanna do is up to you, but I'd find it really annoying to be mixing gas at the station.

 

[dmention7]

Don't mean to jack your thread... but having to run a precise mix of two pump gases on a daily driver sounds like a huge PITA.