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18psi off boost on 92 octane

pont1230

pont1230

Well-Known Member
what's up guys just wanted to know if it was safe to run 18psi off boost on 92 octane,not looking for anything crazy just want to make the car a little quicker maybe 12,s .What do you guys think I need to do,the car is all stock,thanks guys...:burnrubber:
 
18 lbs should be fine and I do it all the time, just make sure if you hear it detonating to not drive it hard and you won't blow a head gasket.
 
You need some form of knock detection, if you are hearing knock that is like 10+ degrees, too much of that and your bearings minimally will be toast. Also too easy to not hear it, especially if you have alot of wind noise around the windows. Being able to run 18# on pump gas has alot of variables to work with no knock. Mainly the timing in the chip, if its a stock chip, then the stock 16.5# is too much on todays crap gas no matter what the octane is due to the excessive timing in the stock chip.
 
straight gas no ethonal 17 should be fine I still wouldn't trust it get an alkycontrol.com kit
 
have an adjustable wastebgate ,boost gauge, knock gauge ,fuel pressure regulator,and turbo tweeck 5.7 chip on the way.No scanmaster yet.
 
Rob is spot on, in my opinion. Simply relying on hearing detonation as the one means of defense is the fastest way to wreck the main bearings, and frankly I have never heard my car "rattling" yet I have a handfull of blown headgaskets to prove it has happened.

Bearing failure is that slow death of the TB engine that is on the ragged edge of small to moderate knock retard.
You read the stories all the time...a couple blown HGs here, big knock detected there, and then sure enough you've got single digit idle oil pressure and your cramming 20w50 oil with some wiz-bang oil additive to get 12 psi of idle pressure.

Because the 2 are seemingly unrelated we discount the possible bottom end damage from detonation, but it happens....the crank flexes because of the stress and those meager 2 bolt main caps cant contain it...among other things.

I cant speak for everyone here, but my car wouldn't tolerate 16 psi of boost on today's 93 octane gas....it would have at least 1* to 2 * of retard.

Methanol is the only reason I can boost past 22 PSI safely and frankly, that's a risk...I only rely on my scanmaster for accurate detonation detection and I do have an audible knock detector too. But it's my opinion that knock detectors are somewhat unreliable and that's why I feel it's the scanmaster that is required to truly know what the ECM is seeing and reacting too in the arena of detonation.

And I recognize that some people will say thier car will take upwards of 20 psi of boost without methanol and I don't doubt them, but mine wont and probably the vast majority of stock-ish TB powered cars will not tolertate it either.


...
 
I was not condoning the fact of him not getting all the fancy scanmasters and such in the future, but I am just stating that if you are running a stock configuration that you should be safe running 18lbs of boost with 93 octane if you drive and listen to your engine. You can do anything with money, but you can also get into the low 12's by being smart and using common sense. I ran high 11's back in the late 90's and we did not have alky or scanmasters. If you are just starting out use common sense and don't mash the throttle if you hear detonation is all I was trying to state. :)
 
I hear you mike ,no I am not new to the buick engine I,just wanted to hear some opinions from you guys,going to take small steps.I guess this is like 50/50,i remember when I had my gn back in 1990 I was running 18 psi on 93 and never had a problem for the next seven years, then it got stolen and there were no scan master back then so everyone is intitle to their opinion thanks guys:burnrubber:
 
Agreed with everything above....One point I guess I didn't make clear was that my particular car won't tolerate 16 psi on today's pump gas 93 octane, even with a conservative TT chip .... oh, but I tried.....I tried everything to avoid a progressive alky kit,but had to succumb to using it because NO unleaded race gas is available near me (I tune with a wideband).

I didn't own a TB powered car till 2007 so I can't offer testimony to the way things used to be in th early 90's....wish I could, because I suspect gasoline was much better back then.


Also, I've come to realize that no 2 TTA's, or GN's for that matter, can be compared to each and expect the same results.

..
 
pont1230 said:
I hear you mike ,no I am not new to the buick engine I,just wanted to hear some opinions from you guys,going to take small steps.I guess this is like 50/50,i remember when I had my gn back in 1990 I was running 18 psi on 93 and never had a problem for the next seven years, then it got stolen and there were no scan master back then so everyone is intitle to their opinion thanks guys:burnrubber:
Click to expand...

So from 1990 to 1997 you didn't have a problem with 93 oct, and now you do?...:shock:
 
no I I dont't have a problem with 93oct but its been a long time,and I hear a lot of people saying you can't do much with 93 and its not safe,etc.Just wanted to hear it from you guys,thanks all...
 
Also the comparison between the GN and TTA with 18# is very different in stock form. TTA compression is slightly more, heads are a little different making the combustion chamber a little different. TTA even has more timing in the stock chip than the GN stock chip, so the GN could tolerate more boost than a TTA with any gas with all else being equal. And as mentioned, no 2 cars seem to behave the same so what works in one may not work in the other.
 
Around 1990-93 I used to run 20 psi with "octane booster" or whatever the local track had for race gas mixed in with 93 pump gas and crossed my fingers. I also probably was overfueling with a piggyback reg, my idea was that I would rather be rich than lean. Was before specialized chips and adjus. regs. or scanM or gauges for this and that. Was guessing. 7.90's in the 1/8th @ 86 mph-ish consistently. Heads never been off still to this day.

Gas prolly does suck more these days so I'm running 100 unleaded and alky inj. on the Sunday drives in the country or whatever else drive to the grocery...
just in case some wipper snapper wants a beat down...:boxing::wheelchair:
 
I agree with you guys that fuel stinks now with all the additives and such. I really don't beat on mine too much these days, but I still listen for detonation and such. I make sure I watch things more on cool dry nights when the car rips compared to the hot muggy days when it feels like a Prius sometimes. lol I guess I will have to watch things when I start building the new car since I will want to beat on it a lot more when I get it running right. In the end, nothing beats a Scanmaster, Alky and some common sense to keep heads from going Kaboom!
 
Yeah at $600 a Alky kit is alot cheaper than rebuilding a motor, and you can throw alot more than 18psi at it... which is where you will see a difference anyhow.
 
I can get 100% 93 no ethanol and 100% meth ,,, if that don't work I got 110 gallons of c116 ... ill never push a car to the limits on 93 and 100% meth .... c116 is a lot cheaper than burnt pistons an blown headgaskets ... its your car do what u want but im not a tuner just a video/jukebox tech who know how to cover pool tables if I have to
 
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I can't make over 14/15 without methanol on 91 octane pumpgas and a conservative timing tables.

Just don't get greedy with it.
 
I might be wrong but I think grumpy said a dp wasn't needed till 10's .. plz correct me if im wrong
 
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