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-   -   Is E85 with AFR a good idea? (https://www.miataturbo.net/engine-performance-56/e85-afr-good-idea-41225/)

NoMiEzMX-5 Dec 13, 2009 04:01 AM

very impressive numbers for a stock bottom end..what are you using to watch for detonation?

Max_Power Dec 13, 2009 04:36 AM


Originally Posted by NoMiEzMX-5 (Post 494881)
very impressive numbers for a stock bottom end..what are you using to watch for detonation?

I'm using a Link ecu which has a knock sensor.

lycos Dec 13, 2009 06:47 PM

e85 will never knock so when tuning your ignition its better to tune on the dyno and see when the car stops making power to avoid putting stress on the bearings.

Max_Power Dec 13, 2009 07:57 PM


Originally Posted by lycos (Post 495050)
e85 will never knock so when tuning your ignition its better to tune on the dyno and see when the car stops making power to avoid putting stress on the bearings.

It won't knock as early as the 91 but of course it will also knock - that's something that is defined by the RON rating...
In any case the car was tuned for 306 and then re-tuned more conservatively for every day at 302 whp.

webby459 Dec 14, 2009 09:18 AM


Originally Posted by Max_Power (Post 495080)
tuned for 306 and then re-tuned more conservatively for every day at 302 whp.

:giggle:

Dude, you need to turn it down way more than that, you are on borrowed time!

In the meantime, sorry, I can't help with the dyno software, but I am interested in seeing the results. Do you have a printout that you can scan and post? My questions:

1. Again, how is your idle with the 1000s?
2. Can you post data logs from the link? Hopefully they are in a csv or equiv that can be read without link software. Interested in particular in inj duty cycle, IATs at your high boost level, and spoolz.
3. Where was your torque peak? Did you find mbt, particularly in the lower ranges?
4. Would you mind posting your ve and spark tables, and throw in your afr targets while you're at it? Interested in how much spark angle you ran.

I will post my info when I've got the car together, in the meantime your info will help myself and others, we appreciate it.

Max_Power Dec 14, 2009 12:03 PM


Originally Posted by webby459 (Post 495221)
:giggle:

Dude, you need to turn it down way more than that, you are on borrowed time!

In the meantime, sorry, I can't help with the dyno software, but I am interested in seeing the results. Do you have a printout that you can scan and post? My questions:

1. Again, how is your idle with the 1000s?
2. Can you post data logs from the link? Hopefully they are in a csv or equiv that can be read without link software. Interested in particular in inj duty cycle, IATs at your high boost level, and spoolz.
3. Where was your torque peak? Did you find mbt, particularly in the lower ranges?
4. Would you mind posting your ve and spark tables, and throw in your afr targets while you're at it? Interested in how much spark angle you ran.

I will post my info when I've got the car together, in the meantime your info will help myself and others, we appreciate it.

I see your point webby but let's not forget that I'm running E85 and that it makes the possibility of a dangerous know a little bit less likely... in any case if my engine blows up I'll need to face the consequences but I need (at least) this kind of power to be competitive in SSM where most people have 500hp FDs... and I need to drive the car on the street with this power so that I get accustomed to it... so just pray for me and let's hope that this holly BP bottom end will last me for this season.

I wish I had what you want but I wasn't able to open the files (I don't have a print out) and I didn't have the chance to datalog anything yet... in a few days I'm flying to Europe for a few weeks so when I return and I'll post the info you asked...
What I can tell you for now is that the idle is fine... and I'm pretty surprised that the car starts even when it's parked outside at 37F (E85 is not good at cold starts).

webby459 Dec 14, 2009 12:09 PM

Where are you located? I am doing an SSM build also, it seems that there are more than a few building miatas for SSM, glad we'll have a contingent to run against the FDs. I (and I'm not the only one) think that the Miata can go against the best SSM has so far, you just have to add lightne$$ like the CSP guys do. For now, my car is a part time track and street car, so I won't commit to lightness a'la CSP, and I'm not absolutely sure I'll be competing at nationals, but if I can do well in my local tour (Finger Lakes) and Divs, who knows...

Edited to add: I don't want to beat a dead horse, but your rods don't care that you're running E85. I hope for the best for you, but I will personally feel good knowing that my bottom end is pretty well bullet proof when I hit the track the first time in 2010!

Max_Power Dec 14, 2009 01:16 PM


Originally Posted by webby459 (Post 495297)
Where are you located? I am doing an SSM build also, it seems that there are more than a few building miatas for SSM, glad we'll have a contingent to run against the FDs. I (and I'm not the only one) think that the Miata can go against the best SSM has so far, you just have to add lightne$$ like the CSP guys do. For now, my car is a part time track and street car, so I won't commit to lightness a'la CSP, and I'm not absolutely sure I'll be competing at nationals, but if I can do well in my local tour (Finger Lakes) and Divs, who knows...

Edited to add: I don't want to beat a dead horse, but your rods don't care that you're running E85. I hope for the best for you, but I will personally feel good knowing that my bottom end is pretty well bullet proof when I hit the track the first time in 2010!

I know what do you mean... I'm located in California and I have been co-driving with Bill Schenker for a year and I know how fast a csp nationally champion car miata can be... I just wanted to add more power to it...
The problem is that the FDs are not really pigs - there are just a little bit heavier and with almost double the HP... but I still think that a good driver on a fast miata can give the FDs a run for their money ;)
My car is purposely built for SSM - there are still 40-60 lbs that I can shave but that's about it. I first need to see how heavy is the car and then I'll proceed - let's not forget that our weight limit is not as low as CSP.
I currently have backdated the dash to 93, I have removed PW, PM, AC and I only kept the PS which I believe that I need. The car's front end is made out of kevlar and it's about 11-12 lbs total for bumper and two fenders... Rear bi-plane wing is half aluminum and half dry carbon, the racing rad was swapped for a stock plastic mazda unit, soft top is not there anymore and the roll bar was gone too - I with all these I wish I'm relatively close to the 2060 lbs limit.

PS The rods don't care for E85 but they don't like knocks and E85 is more detonation resistant. In any case it's not too much fun for me pulling the engine out and spending a bunch of money if I don't have to... so I'm following the rule of "if it doesn't break don't mess with it"...

Rushin Dec 17, 2009 12:23 PM

I run e85 with my set up. I notices EGTs way lower than on 93. Before i would see about 1400-1450 on highway in 5th and now its about 1000-1100 same rpm same 13.8-15.5 afr. And after hard driving i can still put my hand on the tail pipe and its not too hot. So the engine for sure runs cooler. And the power feels more linear than before and no more nasty smell from the tailpipe and no smoke either.

I had to add about 30% fuel across the board and i run out of fuel when driving pretty fast.

i have 600cc injectors, on 93 i was running at about 50-60% duty cycle no i am near 85%.

Max_Power Dec 17, 2009 12:32 PM


Originally Posted by Rushin (Post 496853)
And after hard driving i can still put my hand on the tail pipe and its not too hot. So the engine for sure runs cooler. And the power feels more linear than before and no more nasty smell from the tailpipe and no smoke either.

Thanks for your feedback Rushin!
You know ... I didn't realized it, but you are right - after the hard dyno session I removed one of the exhaust's v-bands (grabbed it with my bare hand) and I didn't get burned...
+1000 on the smell, I really like it, it smells like burned alcohol - like if I was lighting up shoots at the bar :giggle:

Rushin Dec 17, 2009 12:36 PM


Originally Posted by Max_Power (Post 496864)
You know something... I didn't realized it, but you are right - after the hard dyno session I removed one of the exhaust's v-bands (grabbed it with my bare hand) and I didn't get burned...
+1000 on the smell, I really like it, it smells like burned alcohol - like if I was lighting up shoots at the bar :giggle:

Yeah, the smell is much better than burned gas. Still does not cure burning oil tho, lol.

Its just safer fuel for boosted cars. And its a bit cheaper too, however you do use more of it because its got less BTUs and requires more of it to produce same amount of energy as gas.


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