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Discussion Starter · #1 ·
Hi guys I have been driving my ultra on 87 octane for like the past year... I kind of have always known that I should be running 91 in it but with the prices of fuel being so ridiculous I have just kept my foot out of it. So, I am not looking to do a high output build but rather add some components that may or will knock down the knock down. yes, I am wanting to reduce knock retard. My thoughts

1st install 3" down pipe and resonator into 2.5 dual exhaust. 2nd add intercooler. and while I'm at it 3rd change to a gen 5 supercharger. I am thinking the exhaust will relieve back pressure which I would hope help alleviate some KR. I know the intercooler will keep inlet temps down and consistent. I am not sure if the gen 5 supercharger will help or make it worse. all the reading I've done says the gen 5 is 20% more efficient then the gen 3. The question is whether or not the efficiency drops heat or increases flow and heat or a compromise. I have thought about putting larger rockers on but I'm really not wanting to lose fuel milage...

i recently connected an obdII scanner and found the ecm retards the ignition from a dead stop 9 degrees wile floored for first 60 feet then nothing the whole way up. if i punch it at 60 it retards like 2 degrees. of course, air temps are in the 60s so it probably worse in the summer. my normal driving doesn't even retard the motor.

just wondering if anyone else has done any mods with 87 octane in mind or is it just taboo...
any thoughts or help would be appreciated.

thanks Andrew K.
 

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Remove s/c belt when wanting to run 87, replace when you can afford 91+. Free and not trying to make something odd work for more than the $5-10/tank difference you're avoiding. Did this during the last price surge ~15yrs ago when I was tight on cash. Car is going to be a dog for acceleration (it's just an 8.5:1 N/A car now), but you're guaranteed to not have a risk of knocking on junk gas.
 

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There was probably millions of L67 powered cars driving around only using 87 octane blindly for years, but it will wear down the motors faster as its fighting against itself with the knock.

IMO your better off sticking with the higher octane fuel and doing mods that would help the engine breathe better which will help you with getting better mpg (of course in conjunction with an easy driving style). Start with the basics the colder spark plugs like you mentioned, intake, larger diameter exhaust piping (maybe zzp power logs), 180* t-stat (to help with KR) & a tune.
 

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Discussion Starter · #5 · (Edited)
I am going to do just that and see what improvements i may see with kr on 87. like I said right now if i keep my foot out of it and drive normal there is no kr happening with normal driving. all the improvements I do are just what everyone else is doing to improve hp and torque. but I want to see what real world effects it dose for a daily driver.

my scanner stats right now are: pedal to the medal 9deg kr. at 65 deg and 183 deg engine temp.

my scanner is showing 180 to 185 deg engine temp what is typical temp for a 180 stat?
 

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As mentioned elsewhere, t-stats aren't a digital item, so they'll hold to a range in normal operation, with elevated temps in harsher conditions.

Dunno why you want to spend all this money to not spend money on octane, risking more of that piston-chipping KR you're already exposing it to. I suggest math'ing out the number of fill-ups at $0.50-60/gal difference you can stomach vs. a $500-800 exhaust upgrade, $800-1,000 intercooler, and so on.

Like I said, I've been there, and by taking the time to wait until I was financially ready, got to a place where I could go all out with what I put into my car a few years later. Patience and planning works when it comes to this stuff, there's nothing to race against except potential issues you invite upon yourself.
 

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Stop messing around and park it until you can afford to drive it again. All this stuff is not worth the time and effort just get a cheap hooptie or sell it. They drive like absolute dog crap without the blower belt on.
 
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