I am going to get a racegas tune but!! What octane should I use for a race tune??
I know the stock turbo can only push so much psi before it just starts dieing out and making heat!! Anyway I want to turn it up to peak 30psi...I know it won't hold!!! So what do you guys think?? THANKS,,,
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ARP HEAD STUDS
255 F/P
3'CAT DELETE 3'CATBACK
INJEN UICP WITH HKS FILTER
MBC
ACT/HDSS

 

30 psi is way beyond the peak efficiency of the stock turbo. 25-26 should be enough. How about using what is readily available to you in your area?? 110 oct should be plenty.

 

Limp -- Sorry but you are incorrect....There are many IXs hitting 25 peak on 93 Octane (I am one) and I know several that hit 30+ with Meth...

Back to the question -- probably want to tune the car to the octane you have readily available at the tracks you frequent...Or E85

 

It is not what the turbo can get up to, but where it's "sweet spot" is. I doubt the 30 psi is in it's effective range. my 2c

 

30psi is WAY out of its efficiency range..

The easiest way to "guess" is to see what the highest boost you can maintain at high RPM.. Typically if you spike at 30psi, you taper to 23-25psi.. So I'd guess that 25psi might be the limit of its efficiency.. Not very scientific, but it works..

 

Ok so I guess I'll use 100 octane since I can get it at the pump!!!! 24/7....
Thanks,,,

 

I run a 50/50 blend of 93 and 110 leaded. When on race gas, I run stock timing table, leaner 12:1 AFR, and I spike to 27psi falling fast towards redline.

Most of the power comes from the stock timing (which normally has 3-4* pulled out of it) and the 3-4lbs of additional boost from 5500-7800.

Race gas usually runs about 4mph faster in the 1/4.

 

I tune my car for 100 octane, which is the only gas my evo sees now that it isn't my daily driver. I can get it from the pump locally and also at the track.

With a open track tune, my car gained 20whp, 30wtq running 26psi peak. 11.3 AFR. It's a beat on it all day long tune.

Nice thing about unleaded is that you don't have to worry about it killing your stock and wideband 02 sensors.

 

Yea I used to run street blaze 103 but it was $10/gallon. I get 110 leaded for $4.50/gallon. Even if I have to replace the O2 sensor one a year it still turns out to be significantly cheaper for me. Oh and it smell good too!