Nick D

What happens exactly, because I think that it might have happened to mine recently. Strange noises? Loss of power? What does it entail? Thanks.

TheBlurLS1

iTrader: (8)

detonation happens, this causes knock retard, and kicks your timing back, so yes you will have a loss of power.

no longterm damage though, just run it completly dry and fill her up with teh expensive stuff

jaberwaki

i only disaggree with that last part...
the detonation monster gets you at the worst possable time... high rpm WOT ....
alot of long term damage can happen....

long story short... DO WHAT YOUR OWNERS MANUAL TELLS YOU..... 91 oct or higher only

LS1BlackBeauty98

putting anything less than 93 octane in any fbody is like beating ur own child. thats wrong.

Flaminchiten67

I can only get 92 where i live

Now i'm off to whail on my child!

777

iTrader: (21)

the fuel ignites before the spark ignites it...causeing pre-ignition...this = very bad and could possibly destroy your engine...actually it is very easy for it to do that...on a stock f-body it will prolly only reduce timing and be able to run 'okay'...but it will cause a loss in power...but it won't run good or feel right

zamboxl

iTrader: (1)

wrong pre ignition will destroy a high output engine like ours in less than a second. He is getting nock wich is a second detonation, where the exaust gases will spontaneously ignite J-rod did a write up about all this stuff pretty good one to.

racer88

Pre ignition and detonation go hand and hand. Our computer adjust for it if knock retard is present the PCM yanks timing out to reduce any detonation from information caught by the knock sensors. Believe it or not, detonation is bad, but in a stock car slight detonation isn't enough to destroy the motor. The pistons and rods are pretty tough when you can see these motors take a 150 shot of nitrous over and over and over again and still run fine.

Detonation can be detrimental over time due to increased temperatures and cylinder pressure, chaffing to the cylinder walls. Imagine a jack hammer going off on your pistons.

Anyway, if your car 'pings' on 87 simply don't use it. I can run 87 and my car is fine, but it's tuned and it's modified and it never detonates on 87, 89 or 93 octane. I've raced many times with 89 and still trapped my usual MPH. With the gas prices going to 2.17 for 87 and super now 2.29 I have been running 87 in mine and will do so until the prices come down.

Nick D

Thanks for the info, I have never put 87 in mine and have never had thoughts of doing that. I thought there might have been a possibility that 87 was put in because I was having some trouble with a high squealing noise, but I guess that is unrelated. Thanks.

98Z-6Speed

The first LS1 I ever owned, I went out and filled her right up with 87, did not know any better. She started running like crappola, I was really worried. Then this site clued me in, and its been smooth sailing on 91 ever since.

racer88

I ran nothing but 93 in mine when it was bone stock. I usually run 89 most times, barely run 93 in it unless I am headed to the track. But some nights I end up racing with 89 in it, no detonation and no loss of how it runs.

With no cats, a breathing block with full exhaust and careful tuning you can run 87 octane in these cars and never really see a performance loss with stock compression.

GM restricts these motors so bad with the junk headers from the factory and the emissions related stuff makes them worse. Take all that off, you will have a different beast.

jaberwaki

so you lowered your C/R in order to run cheaper gas?
because if you did not then you are not saveing any money at the pump...
if all you did was pull timing advance and richen your a/f to "tune" it for 87 octane then your motor is not running as efficiantly as is was before, chances are you are getting alittle worse mpg, and probably enough that you are making up for value with volume....

knock retard is a "reactive" not "proactive"protection tool... which means by the time it takes effect, your motor has already been hurting itself... but because of the K/R it wont keep hurting itself... however... when the detonation condition goes away then the knock module will give that timing right back to the motor... and guess what starts all over again as soon as the knock returns... long story short, you could be getting detonation several times a day, because your pcm does not pull timing for good(unless you tune it that way) it will always be looking to put the timing right again.. and every time it does its like reseting the timer on a bomb

racer88

My compression ratio is what it was stock. It's tuned well and what MPG? 4.10 gears and mods don't make my car fuel efficient last time I checked how many miles I get to the gallon.

I am tuned, my car runs great for all of it's mods and I can run 87 Octane and have no detonation issues. LS1 edit is a wonderful tool, gotta love the real time numbers with Auto tap too.

Might wanna ask around, my buddy runs 87 in his heads/cam Z that runs 11.1 on motor and he even sprays his car with a 150 shot. Amazing what you can do with a good tune and a breathing motor.

LSWannabe

Continually running 87 octane (a.k.a. cow ****) will cause your engine to spontaneously jump out of the engine bay and kick you in the ******* nuts.

zamboxl

iTrader: (1)

now that would be a sight to see.

Martingale

Lots of stock LS1's have had or currently have detonation issues, they don't destroy themselves in less then a second. The knock sensors will start pulling timing at the first hint of detonation. If you do blow something it will most likely be a head gasket.

jaberwaki

your statements dont make sence.
you dont run 93 octane cause it costs too much, but you dont care what your mpg is.... when i was cam only(with full bolt ons) 4.11 gears (9") i got 23-25 mpg. while making 395 rwhp

a 9" has more perisitic loss then a 12bolt, my cam was bigger, and bolt ons more complete. you should be getting better mpg then i did... (enter correct octane statement)

your car came with HEADERS from the factory???!!!??? i must have gotten ripped off... mine only came with exhast manifolds

sooo... how did you do the "breathing" block mod... last time i checked an ls1 block was an ls1 block...whats the rpo code for the "breathing" option?

so, your car is "tuned" for 87 octane, you run 89 most of the time, and you run 93 at the track.... wow... thats great... you must keep 3 tunes in your car at all times and switch depending on what gas you put in that day...lol

if you are "tuned" for 87 octane. then 93 will actually HURT your performance.not help it.


ls1 edit and auto tap are basic tuning tools... no magic there. your best et is middle road for your mods.

hahahahahaahaaa... is that suposed to be the shocker??? there are cam only cars running 10's right here on this site... there are Stock internals guys here running low 11's. right here on this site... its amazing what you can do with the correct octane gas for your compression ratio.
if what you say is true about your buddy, then he could put 93 octane in bump up his spark advance, lean his a/f and run 10's all day long... (why run slower if you dont have too?) follow the same advice and you'll see a 11 sec time slip

https://ls1tech.com/forums/etdb.php might wanna read this before you brag for your friends... you dont get to his times till page 6....

look i am not here to bust your chops... but dont hand out info to people that could potentially damage there ride, and expect not to get called out on it... whoever taught you what you are doing is wronge... for following there advise, you are not making as much power as you could be, you are running gas that contains more deposits, and you are spending MORE on gas because of lost mpg. tell you what. there are SEVERAL very very good tuners on this site.. dont believe me, run it by one of them...

racer88

My 2000 Trans am went back to GM for a detonation issue that was a defect somewhere in the motor that was not computer related. Car was rich as a pig and still detonated. Thank god I sampled the oil and had it analized, I had tons of copper in it amongst other things. My 2001 has been fine for 62K hard driven miles and track passes in the 400 pass range if not more.

A cars tune can depend on what gas you can use in it. Factory PCM tuning sucks ***, it's there for EPA ratings and emissions. Change the exhaust and let those cubes breath!

HEY Jaberwaki, don't be a DICK. You wanna come on down here and see my car and others run? I get **** for gas mileage on the street, not highway. Sorry about the headers, I meant the stock manifolds.

What a ******** you are. I've been around this site since 2001, trust me if I was doing all that wrong my Man would be the first to say something HE does all the work on my car and others cars. He was surprised when I told him my cars been fine with 87.........He knows this LS1, he builds them (bare block out), mods them, tunes them. Now what? Wanna challenge me on this too?

'IF' I was doing something detrimental to my motor he'd be the first to say so. My car has gone 11.9's before not bad for living at or below sea level most days around the year, might get lucky here to swing out a 12.2 on DRAG radials on a negative DA of -400........you beat my times in Florida I will pay your airfare back to the Country.

Mike98WS6

iTrader: (5)

That just about sums it up.

jaberwaki

if you were properly set up you would not be getting **** for milage at all...

ok..
thanks
well, color me impressed
i've been racing,building ,and setting up cars for 11 years now... more then some less then others...


challange YOU on what? your MANS knowlage? or YOURS?
this is not a sex thing, i know some woman that have forgotten more about racing then i will ever know, this is about you giving poor advice based on poorly researched information.

thats not what your sig says...

you really should stop .... your making it worse... let me give you a free class, the lower your alivation, the dencer your air is. lets just say dencer air means more hp. DRAG radials is what my cars run on the street, et drags is what they wear at the track... and - DA's... again.. a GOOD THING!!! who the hell told you they were bad??? the same person that told you 87 octane in a 10.1 to 1 C/R motor was a good thing?

in whos car? yours or mine? if you want me to hook my car up to my truck and comedown there to race you , then you would have to pay for gas not airfare... and you better be a whole lot faster then 12's (i haven't updated my sig in a while,those numbers are just a little off )

look around, i am not the only one telling you , that you are wronge... (infact,absolutly no one has backed you up on this AT ALL... shouldn't that tell you something?)

Look, you came to a gun fight with a pickle... you have been told ALOT of things wronge from what i can tell so far, the little tidbits you picked up here and there are not staples for you to be spreading around without the slightest clue if they are even correct. I dont have anything against you personally,(thats why i haven't returned the childish name calling you threw at me) what i have a problem with is ANYONE that overhears something in a shop and misquotes it here as gosple. Be honest, its the first step to doing this right.
the TRUTH is ,

you have a nice car, and have learned how to drive it(see look a compliment)
you have a desire to learn more about your car (another good thing)
you know more about your car then alot of the newbies on this site(another compliment)

but, you are not "queen of the racers"
your car is not fast.
nor is it fast for the mods you have done.
87 octane has no business in a higher compression motor(repeat this 3 times)
you have no clue how to "tune" a car, because you dont know the first thing about fuel mapping, spark advance,and static compression or how your fuels octane effects them.

you want to look smart... there is nothing wronge with that.... but if thats a goal of yours, then LEARN.... before you try to TEACH.....

reply if you want... but i'm done with this thread.