STX Build + E85 Tune = Which Class?
 

I have an OFT and am thinking about tuning for E85 next season. Everything else on my FRS complies with SCCA STX rules currently though. If I switch tunes, which class would that put me in? I'm guessing Street Modified, but just want to verify.

Either SP or SM.

Street Prepared (CSP, I believe)

See 3.6.B

"In addition to fuels which are allowed by Section 3.6.A, Street Prepared, Street Modified, Prepared, and Modified category vehicles may use diesel fuel, any grade of gasoline, or Federally-approved E85. ..."

This is correct, E85 puts you in *SP and the twins specifically fall into CSP.

This rule makes me sad.....


Its not like E85 is a race fuel. Its available at the local gas station, is cheap, renewable, etc... Ya, some cars can't run it. But, some cars in some classes can't fit the tires allowed in that class.

Actual E85 might as well be race fuel. What you're picking up at the pump, when you don't have it actually delivered to you, is not controlled that tightly. Pump E85 is actually pretty rare out here.

But yeah. CSP is where you land. Healthy power bump, iirc. How important it is to the OP to be competitive kinda drives the rest of the decisions. Personally, I'd kinda like to see someone go nuts on a CSP build to see if it has anything for the miatas.

[QUOTE=TrqlessWonder;2459636]Actual E85 might as well be race fuel. What you're picking up at the pump, when you don't have it actually delivered to you, is not controlled that tightly. Pump E85 is actually pretty rare out here.

QUOTE]



In the winter we get anywere from the high 40 to maybe 70%. Starting in April the Ethonal % increases and most stations average around 80-82%. I picked up 94% ethonal in Nebraska in May.


You can run "race fuel" in ST*, just up to 100 ocate IIRC.

[quote=ka-t_240;2459690]That's a lot of variability. I'm not sure exactly how much trouble that actually introduces, though.

And even though we put ~10% ethanol in the regular gas around here, the nearest e85 pump is 65 miles away from me. So, real nationwide availability isn't there just yet.

If I recall correctly, the 100 octane thing wasn't intended, but it's just not readily/cheaply policed. e85 exhaust smells pretty distinctly different, so it's easier to single out. So, it has been. Not all of the rules make sense.

[quote=TrqlessWonder;2459739]
Most of the locals swap to 91 over the winter, or store their cars. The summer consistancy is pretty solid. Most of us attemp to use the same 1 or 2 stations to help make sure demand is noticed as we are loosing stations in the midwest as well.


Our 91 is terrible, most vehicles knock on it. So, its hard to even trust that.

You'll probably be more competitive in SM. Depends on local region a lot, in some regions I run my STX raw times the SM field so you might be ok.

e85 was banned from ST classes a few years back- people started getting "good " e85 and then trailer ing st cars. Kinda kills the whole premise of a street class.

Given the choice between SM and CSP, I'd rather run in SM. In my region there's a lot more drivers in that class and I've been reasonably competitive with them in raw times. I do realize that running an 86 in SM nationally would be suicide, but regionally it would probably be fun.

Not suicide, you just need to dump $30k into the car :)

I still street drive the crap out of mine on E, doesn't matter to me. Its been much cheaper than running 91. The tuning shop in town ends up pulling timine on most vehicles, cause out fuel sucks that bad in ND.


Class doesn't matter to me unless I am going to a big national event. I was 1-3 in raw times in almost every locan event I went to this year. That what matters to me ;)

I think the main reason they took e85 out was because some cars stand to make massive amounts of power off of e85 with no mods, like ours. Other cars you have to do new pump, new injectors things like that but aren't legal to do in stx.