I had an increase of knock in my grand prix with a set of bad spark plugs and spark plug wires. I also notice that too big of spark plug gap can cause misfires.

 

are you sure that its detonation, and not just your imagination. I can swear I hear deto all the time, but nobody else can.

 

LOL... u need sleep Naz. Now you're hearing things

.

 

i dont know, i dont hear it under part throttle or 0-1psi, anything over that and full throttle you can hear that pinging noise that old cars make when they go up hills, its not HUGE but noticable...

I cant figure it out, i was adding and adding fuel until it started boggin of too much fuel, i took out a ****load of timing.>>WTF?

I guess we will see at the dyno this weekend, where i can stand right in front of the car and listen, but i dont think its my imagination

 

True. Dyno doesnt lie.

Good luck man... Keep us posted.

 

tic...tic...tic...tic....Booooom! Shhhhhhhh did you hear that?

Just kidding you might want to check your plugs though.

 

I hear some vibrations (appears to be exhaust)when ever i first get on to boost. It rattles a bit sounding like mild detno but goes away quickly. The only way i can tell is on a dyno standing outside or having some one drive and me hang out the window. Still the best way i can think of is checking if there are no other alternatives are the spark plug condition.

 

will be checking plugs tomorow, and will tie the exhuast down better and try it again, it just doesnt make any sense to be detonating.....

 

Carbon build up internally causing hotspots & premature iginition?

Naz, have you tried the sample Focus Turbo map that comes with the software?

[ 12-04-2002, 09:56 PM: Message edited by: PhilM ]

 

but wouldnt the compression check show this?

I will check my compression again tomorow, but i checked it a few days ago and it was dead on at 180-181

I will check it again tomorow

 

Naz what you are prob. hearing it preignition not detonation with the type of static compression you have and adding boost you are going to need better fuel not more fuel

Oct. boost is a bunch of crap and a waist of time and money DONT trust your engine on it

To go to a cold plug and im not talking the motorcraft ones eather this may help some the gap will have no bearing on deto. or preignition

to make the big power even if you lower your compression to 8.5 you will have to use 100oct or better

Taking lots of timing out and adding lots of fuel is only going to cause major problems some where else stop why you are ahead

just my thoughts

tom

 

i agee about the octane but i think there is still alot that can be done even on 91 octane

Jon is runing 270whp at 12psi on 91 octane with good tuning, so it is possible, and he is doing it on stock , 9.5:1 compression, he can have even more with lower compression and stronger parts.

Sure if he had 100 octane on every corner, he can get even more, but im just saying that it is possible to still make decent power

And im not boosting 20 psi tom, im onlt at 5-7psi right now, so it should be able to work without any problems. It did for a while, but now i think i hear deto....

Hell, i never even heard deto when i first installed the pectel without hooking up fuel pressure, so it was WAY lean, now with the a/f pegged and very little timing, it still pings a bit, or at least i think it does...im gonna check the plugs and compression tomorow

 

would a damaged piston or ring or something cause it? Meaning should i worry about the compression check?

Its really weird, the car just isnt the same all of a sudden, i used to be able to push it hard in 3rd through 5th gear to redline, no prob, now its actin up, almost like something is not working right, or unpluged or something....something weird.

Its not a manifold leak, i sprayed carb cleaner all over it, the idle didnt change at all....im stumped

Im gonna try it on some race gas and seee if that solves it that way i know if its octane or not....damnit, stupid cali with their 91 octane

[ 12-05-2002, 12:57 AM: Message edited by: nazthug ]

 

Here is a dumb question... Naz, have you shined a light down through the spark plug hole to look at the top of the pistons? Would detonation or runnig too lean for prolonged times cause deformation of the piston surface area? just a thought....

Also Tom i thought preignition and detonation were the same thing. They both are causing the fuel to combust at the wrong times due to exces heat build up.

Thanks,
Boris

 

naz, I wouldn't street tune, which is what it sounds like your doing to a degree, listening for deto.

Just throw it on a dyno, and tune it. That's the only way to solve your issue. I highly doubt your detonating tho, it might just be misfire(s), or preignition like Tom said.

If you had damaged piston rings, you would get blow by like hell, and the only way to tell if you have blow by is a leak down test, or unless of course your smoking like a pig out of boost too.

Throw it on a wideband and tune.

[ 12-05-2002, 07:59 AM: Message edited by: damius ]

 

Boris, the two are intertwined. Pre-ignition will cause detonation, and detonation can cause pre-ignition. I really don't think of them seperately at all. Tick noise=bad. That's all that matters. The only difference between the two is that they have slightly different root causes, so if you knew which one it was you could solve it easier.

Naz, I'd look at your engine. If you chewed up your pistons or something like that, it could cause hot spots that would make it more prone to detonation.

 

ROB: If i chewed up a piston, wouldnt it show on the compression check?

I checked it this morning again, all 4 cylinders at 180.

I also checked the plugs, something weird about them though.

They are all nice and dark from running rich, but the ends of them, the little arms that come out(electrode?) and curve around, the tips of them on the side that the pistons fire at, are rusty looking....WHAT DOES THIS MEAN?

THe part that looks al nice and white when new, is dark, theres no rust there, im talking about the very end of the spart plug that extends into the cylinder

 

im gonna try a gallon of toluene with about 8 gallons of 91 today to see if that makes a difference, at least that way i will know if its just octane

 

be careful with that stuff, i've read many posts about it eating away at seals and gaskets

 

Originally posted by nazthug:
im gonna try a gallon of toluene with about 8 gallons of 91 today to see if that makes a difference, at least that way i will know if its just octane

<font size="2" face="Verdana, Arial">Your not going to increase the octane that much with only one gallon of toluene. Toluene is rated at 114 or so I think. (114+ 91*8)/9 = 93.55 octane. You should try less 91 octane gas and more tolune to see a higher octane # as, I don't think that current octane different will help. You can try 4 gallons of 91 with one gallon to toluene, which will be around 95.6 0ctane.

[ 12-05-2002, 02:26 PM: Message edited by: lourenco ]

 

Originally posted by nazthug:
im gonna try a gallon of toluene with about 8 gallons of 91 today to see if that makes a difference, at least that way i will know if its just octane

<font size="2" face="Verdana, Arial">Naz,

Are you using a cat? If not, go get a few gallons of blue gas (100 LL) at your local airport and see what happens.

 

94 octane is what im gonna shoot for for the test, 94 is a HUGE difference over 91octane, enough to tell a difference i am sure.

Just gotta find some now

BTW< the car is running better, i think its to do with temperature, at night its colder and it detonates more for some reason, now i redid the program, started from teh base jon sent me, and its running much better, and better fuel economy, because i set timing back to over 30* while cruising i have it at around 38* so it runs and responds better

 

that doesnt make sense...wouldn't it be less likely to detonate at night when its cold?

 

how much colder is it at night, because colder air is dencer, meaning you would need less bost at a consiterble drop in temp to keep the same programing, i think the air temp has more to do with it then any one seems to mention...... try placing air temp prob infront of intake see how much colder it is when you hear it

[ 12-05-2002, 06:22 PM: Message edited by: TaCman2001 ]

 

well at night it would need more fuel though, so maybe my air temp fuel multiplier is off

anyways, i got me 5 gallons of TOLUENE, i put 1 gallon in to about 8-9 gallons thats in there now, so i didnt do it first before a fill up, but hopefully it will mix, i took it out for a few twisties to make sure it mixes in, we will see how it does a bit later....

my pectel works with a air temp sensor in the itnake pipe, so i ALWAYS have exact intake temperatures....now they are in the 60's, the intercooler must be working, after i drive, even if hard, i pop the engine, the intake pipe is ice cold

[ 12-05-2002, 07:32 PM: Message edited by: nazthug ]