This might be a newb question, and Im going to appologize already just in case.

I have an h2b eg and I tuned on 100 octane with a stock intake manifold and made 263 with 178 tq which was nice for my setup.

12.5:1 comp with a slightly decked head, less than .030 and I have flat valves. I'm thinking the comp is around 12.8:1-12.9:1 so its not super high...

Last night i did some base runs with 91 octane, my tank was empty and all I had was 91 octane in the area so I had to tune with it. I did a baseline: somewhere around 253 and 170tq.

I swapped out intake manifolds and put on a skunk2 intake manifold and base lined at 262hp and 174 tq with a slightly weaker curve than before. After tuning, DNR was able to bring it to 266hp with 173tq and a better curve than I had before.

My question is, would it be worth tuning again with 100 octane, have people seen dramatic differences with pump gas vs 100 octane or higher? Should I be running 100 octane with my compression or is 91 still considered safe? Any help is appreciated. Thanks in advance!

 

if u can advance the timming without any engine pining or denating, then i wouldn't see why u'll need the 100oct.

 

I'll compare my old dyno sheet to my new one and maybe ill post it in here to get more feedback...

 

Can you list your setup?

 

Setup:
92 h2b EG

Block:
95 mm crank with h22 rods
88mm 12.5:1 CP pistons with custom relocated wrist pin.
IB ultra light rods

head:
ported by blacktrax performance
supertech flat valves
portflow Ti retainers and valvesprings
blox B cams
Milled .020 at the most.

Skunk2 Pro Series Intake manifold and STR 70mm TB.
camp 1320 h2b header

Trans:
2000 b16 with an obx diff...


Thats it for the most part...




Modified by DSRxCandyh22EG at 2:28 PM 10/6/2008

 

the rule of thumb i was always taught was use the lowest octane fuel that you can without pinging for the best power