89' 3.3L 10.6:1 dyno

[yamahaSHO]

The car will only adjust timing up as far as it is programmed. Therefore, you will NOT benefit from higher octane with your stock SHO.

Carbon build up will lead to higher compression as it cakes onto your pistons.

 

[SeanMc]

I can't run 87 on my 10.5:1 3.3L, it'll ping to all ****, and even after driving for a while, it never shut up.

 

[SuperchargedSHOguy]

I can't run 87 on my 10.5:1 3.3L, it'll ping to all ****, and even after driving for a while, it never shut up.

exactly...

 

[SHOtime2511]

big oil gets enough of my money. ill keep my 87.

 

[JEM]

big oil gets enough of my money. ill keep my 87.

I look at it this way: back when 87 was $1.09 a gallon, the step between grades was typically a dime, so 91 (the best we get out here in the benighted People's Democratic Republic of California) was nearly 20% more than 87.

Now, with 87 at $3.50 or so, the steps between grades is still not much over $.10, so now it's only 7% or so more than 87.

A bargain...

 

[adidas_kn]

I can't run 87 on my 10.5:1 3.3L, it'll ping to all ****, and even after driving for a while, it never shut up.

Thats what i would think but its not. Its quiet as can be. I've never ran only 87 through it. Its always been a wierd mixture of 93 and 89 and 87 I usually fill it up with about 1/4 tank of the old chit left in it. I have 90 octane in it right now with some octane booster and it runs fine. I'll start running the Mucho Expensivo 93octane in it from now on. I should have my Accel coil here soon then I'll put my 8.2 Thundervolts on it and see if she runs any better. I wish I could find a dyno local here in florida soo we can throw it back on afterwards to see if it made a difference.

 

[SuperHO]

big oil gets enough of my money. ill keep my 87.

I'll start running the Mucho Expensivo 93octane in it from now on.

I believe I've covered this once before, but here's one more again.....



Typical SHO has an 18.4 gallon tank. Premium unleaded is $.20 more a gallon than regular.


math time!!!


18.4 x .20 = 3.68!!


Don't break the bank on your next tank of premium vs. regular...

 

[SHOtime2511]

I believe I've covered this once before, but here's one more again.....



Typical SHO has an 18.4 gallon tank. Premium unleaded is $.20 more a gallon than regular.


math time!!!


18.4 x .20 = 3.68!!


Don't break the bank on your next tank of premium vs. regular...

i understand you POV. but to me i never have noticed a diffrence in MPG's or performance. if i can save $3.00 by simply selecting the handle on the left rather than the one on the right,ill do it. money is money,it all adds up. if you use one tank a week you would save $191 and some change for the year.

 

[SuperHO]

Wow...$200 on a year? Over the course of 12 months? AIn't that something like $.50 a day?


maybe you've never noticed, but I can certainly tell on either of my SHOs when someone's put the cheap shit in. I'll go ahead and splurge that extra lil bit and get the good stuff.

 

[SinisterSHO]

Wow...$200 on a year? Over the course of 12 months? AIn't that something like $.50 a day?


maybe you've never noticed, but I can certainly tell on either of my SHOs when someone's put the cheap shit in. I'll go ahead and splurge that extra lil bit and get the good stuff.

I'm sure you can tell the differences in different brands of oil too, right? FWIW, I've been running 87 in my cammed 93 for the past 2.5 out of 3 years I've owned it Never noticed any problems with it.

 

[zak]

I can't run 87 on my 10.5:1 3.3L, it'll ping to all ****, and even after driving for a while, it never shut up.

How does it do on 89 octane? What do you have for cams (its dynamic compression, not static, that effects timing/detonation). Dynamic compression changes with cam overlap.

 

[SeanMc]

How does it do on 89 octane? What do you have for cams (its dynamic compression, not static, that effects timing/detonation). Dynamic compression changes with cam overlap.

Running the SHOShop stage2 cam.

 

[thecrew2999]

The car will only adjust timing up as far as it is programmed. Therefore, you will NOT benefit from higher octane with your stock SHO.

Carbon build up will lead to higher compression as it cakes onto your pistons.

yes that is true about carbon buildup making more compression as it cakes to the pistons... but.... but.... when the valves cant shut 100% they are more about 80 - 90 % closed... all that gained compression from caked pistons... gone...

when i said the carbon leading to the valves shutting that crap in there and pitting i ment simply even if you clean the carbon off so the valve shuts all the way they still will lose compression because the pits now are letting air pass threw them..

trust me on this one i just lapped the valves on my 3.0 heads on my 3.2 build and the pits made me wanna say screw it and go bigger valves on the DD.
the amount of pits on the seats (remember these seats are very very hard metal) shocked me from olny 134k on those heads.

so yet again i said you guys can run the cheaper fuel i really dont care.. not changing my life any.. im just saying you do this at risks.
remember that little writting near the tach, premium fuel recommended? think about why possibly.

 

[yamahaSHO]

It is very unlikely your valves will not shut all the way without a major failure. Even if you look at the worst of valves, the seat is still clean. If your valves weren't closing all the way, you'd have a poorly running SHO that you would notice.

It sounds like your engine was tired to begin with, which proabably shows in other places too.

 

[38SHO]

I've always run premium in my SHO's

Chris if ur reading this I always did in the 94, here and there I might have put in 87 and didn't really notice a difference... but I liked the engine and just decided to pay some extra cents and get the premium....................

now with my 93.... oh boy

you put 87 in it, the thing will run like complete crap.............. **** you can hear it

now that I put the superchip back in it, I haven't tried anything less then premium.. its probably worse on 87 now but who knows.... with the premium it never has a problem

 

[SuperchargedSHOguy]

Todd, I ran 93 in it the first 2 tanks and then switched to 87 and did not notice any difference. Now it will always need to run on 93

 

[thecrew2999]

It is very unlikely your valves will not shut all the way without a major failure. Even if you look at the worst of valves, the seat is still clean. If your valves weren't closing all the way, you'd have a poorly running SHO that you would notice.

It sounds like your engine was tired to begin with, which proabably shows in other places too.

boy jason its hard to make examples without you breaking down every part

no the engine was actually in real good shape and had some 60ks it looks like. just the seats were crap with pits.. noting major just looked like someone sand blasted it with large bead

 

[SHOtime2511]

no the engine was actually in real good shape and had some 60ks it looks like. just the seats were crap with pits.. noting major just looked like someone sand blasted it with large bead

chances are that wasent from gas.

 

[revhardSHO]

There are stock shos with stock y-pipes making that much HP. The magna-flow ypipe should at least flow as well as stock, so there is something else going on there. But the torque is there, thats all that matters.

 

[SHOtime2511]

any updates on this yet?