Does anybody have experiences (good or bad) with 100 octane in the Z? I am considering running it tomorrow night at the drag strip.

 

If your NA , then it's a waste of money for you. Won't hurt anything , just won't buy you anything. Now if you are FI or NOS, you can tune to 100octane and pull less timing/and or add boost , both of which can add signifiant power with added safety.

 

No, if he does not have a tune in the car to utilize a higher octane then it is useless. All higher octane gas does is prevent detonation.....whether that be from boost, hot spots, too much timing. It doesn't matter whether the car is NA or FI.

If he is on the stock computer tuning and not detonating then it is just wasting money.

 

waste of money unleess you are gonna run more timing

 

When I did my upgrades, they had my motor apart and were looking at the pistons. Usually they said there is a lil carbon on the piston head from normal wear. They think the way I drive and the fact that I always put in 100 oct and mix it with 91 for a 94-95 mix that it kept them clean and shiny.

 

Let me rephrase this, sure with a re-tune specifically for 100octane you can get some benefit , particulary with a more aggressive timing strategy; however, it hardly seems worth the cost given the small improvement, especially given that 100o ctane is not available everywhere at the pump.

 

From what I've heard you drive the car pretty hard , and that alone will generally keep the carbon blown out.

 

I wonder if carbon build up is needed or if a clean piston surface is what is preferred?

 

clean

carbon can stay hot and create embers which can cause premature detonation

running efficient can/will help you stay clean. aka not running pig rich.

nitrous has a way of cleaning it out too

 

For me it helps when its really hot outside because my car always seems to be on the edge of detonation. I only notice the improvement when I am at full throttle from 4500 rpms to redline.

 

I put in a tank of 100 octane a few weeks ago, just to check it out. My expectations about incremental power were very low. Gotta say I was surprised. In "normal" moderate driving it made no difference. However, with WOT high rev mode, it made a difference I could definitely feel. It felt like the cams really took advantage of the higher octane. Could be the usual Cali premium gas is crap at 91 octane.

 

Yeh , it's the crappy 91. You'd see most of the improvement NA (witout reflash) going with 93 if avalable. The OEM program definately de-times on 91.
For those with 93/94 , the jump to 100 would yeild much less.

 

Oh well, Nevada also has crappy 91 octane. So would 100 actually yeild some improvements for me?

 

Some maybe, but if you can get 93/94 it will get you more bang for the buck.
The OEM ECU is not programmed to fully take "timing" advantage of 100 octane.

 

Well I can tell you what was my expirience... on N/A I put 100 oct. gas and the car put 8 whp more on the dynojet (same day, just minute in between) and race my brother Z to see if there was any difference and my car run much better than before... my mods at that time, Exhaust, intake, plenum, pully, cat pipes and headers.

oh btw my brother did the same thing afterwords and make the same results!

 

Thank you, I will try it then. Finally some cold hard proven numbers. I have the same mods with the exception of headers. By the way, is your premium gas 91 or 93 octane where you are?

 

93 oct. we are in Puerto Rico very hot temp. here

 

Ok, well we have 91 octane here in Vegas where it also gets very hot, so it may even yeild more results for me.

 

Sport Compact Car picked up about 6whp by using 100 octane vs running 91 octane on their project 350Z. The gain was mostly realized from 5000-6600rpms.

 

Guys, 100+ octane works, in moderation. Try a 3:1 93:103 octane mixture...the ECU starts to realize how the fuel is burning and feeds you more power gradually.