Racing fuel in a Z

ianthegreat

Oops *104-105

I cannot comment on his car as I do not own a 370z. I've not ridden in it w/ fuel nor seen it run at the track w/o fuel. It just seemed quicker, but you are right.. could be a placebo effect.

I've never run fuel in a NA engine before. Admittedly, I know little about it other than it's improving my cars performance.

My AFR's are fine. Stock compression ratios are already high. I may make a switch from fuel to meth though as fuel is just getting way to expensive. I am consistently trapping higher on fuel - 109mph vs. 112.9mph over nearly 30 runs. I am tuned though, but none of my logs have shown me knocking on 93oct. I'm actually riding the factory knock sensor - the tune is not adjusting timing at all.

I need to go back and review the logs, maybe try different parameters, and see if I can see anything.

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ianthegreat

My buddy and I go to the strip a lot. He drives the 370z. If anything you are advancing the timing due to the octane - it wouldn't hurt.

We basically coast our cars on empty then fill w/ around 3-4 gallons on VP109 (101 octane). BIG improvement.

Your ECU needs time to adapt. A couple WOT pulls should be good.

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lovethe370z

The engine's VVEL is pure awesomeness

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2010 370z Coupe
Touring, Sport, Nav
6MT Red/Black

kannibul

Placebo

Do a few drag runs with 91, then do a few with 101.

ChrisSlicks

VP109 is oxygenated and is 105 octane (R+M/2). Given that you can't advance the timing or increase compression most of the gain will be from the oxygen content.

370zdub

From my understanding you want to run as low as possible of octane fuel you can with out knocking. Lower octane burns hotter and faster, hence the reason it can create detonation in high compression engines or those that have been force inducted. To run a high octane fuel in an engine not designed for it can lead to carbon build up on the pistons and valves.

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2010 Ford 6.4L Power Stroke Diesel: 588whp/1082wtrq
2007 Dodge 6.7L Cummins Diesel: 788whp/1405wtrq, runs 12's @ 7400lbs, Still miss my 370z!

RCZ

Higher octanage will not hurt your motor...it will not make more power... its just going to be safer. If you are driving on the street, you are wasting money. I run 50/50 mix of 93oct and 98oct (at least) on the track for that extra safety margin...specially on our motor that likes to run hot..

Blown32

What mods have you made for the need of the "extra safe margin"?

KillerBee370

To the OP's origianl question: Nothing will happen. Although I can't see anyone "accidentally" putting something other than what they intend to into the tank.

On a side note, I have 5 gallons of 100 octane oxygenated fuel in my car right now (topped up with pump 91) and it seems to be running just fine.

RCZ

Anytime you are running at the track your engine experiences more stress than usual. More stress and higher revs over an extended period of time lead to higher cylinder temps. Sometimes hotspots are created within the cylinders which can ignite the fuel mix pre-tdc. , aka detonation, pinging, knock, whatever you want to call it.

I have intakes and a full exhaust, which can lean the car out a little bit. I am tuned so I know where my AFR is so that's not that big of an issue. Either way its always safer to run higher octane when your are putting your engine under that much load. This engine normally runs really hot, I would even think about running some meth or WI later on for extended sessions. Specially if I am going to eventually run a supercharger.

Its funny, but I think you were expecting me to not know what Im talking about. Knocking isnt only caused by higher compression and boost like you said. If you are near the knock threshold because of your AF mix, simply filling a bad batch of gas can cause knocking. Bad batch of gas being something with lower octanage than what is advertised. It happens...

Did I mention I live in Florida and sometimes I track the car in 100+ degree weather.

Blown32

Whats funny is that you believe I was questioning you because" I didn't think you new what you were talking about"?Not at all because I noticed you tracked your car and actually assumed you had the knowledge but was curious as to any mods you may have had?
As for a bad batch of gas possibly with a lower octane rating causing detnation is quite obvious but thanks for informing me that you was aware of the that.
As for me saying that detonation is caused by high compression and boost it is a fact! If you read correctly you will now see that I never used the word "only" in that statement to simplify matters for readers not familiar with the science involved.I also stated there is a science to this but didn't get in dept because I wanted to make it very simple to be understood without to many variables and confusing for any readers that want to learn.
So thanks for informing me that you understand what I'am talking about.Its always good to know that someone picked up on some good info.
My post was to try and help understand the needs for race fuel with simplicity for anyone that doesn't understand.