Detonation

[Bleachboy]

I have been getting a lot of detonation in my integra. i have it supercharged at 9 psi. i know thats a little much but im getting hondata soon and am going towards new pistons and rods soon (dropping compression ratio to 9.0:1). I was wondering what i can do to avoid the detonation that i am geting now. I have already gotten cold 7 plugs and have dropped my timing to 12 degrees instead of the stock 15 degrees advance. I am on my way to getting a 160 degree thermostat instead of the stock 180. what else can i do to get rid of the detonation that im getting? it typically only happens when i am putting a load on the engine in a gear that is too high and/or accelerating all the way through the rpm range (more near the top of 7-8k rpm). i have a digital 6 ignition system with a blaster ss coil and plug wires. I have a stock exhaust manifold right now, but am going to get a dc soon. i have a fuel pressure regulator and its set at 40 psi at idle and i also have a rising rate regulator from jackson.

[Mickee]

maybe ur ocatne rating.. you should use the highest possible in ur area....

[Bleachboy]

im already running 91 octane because i was required to run that even before i supercharged due to the vtec but the charger says to use minimum of 92 but the highest i can buy at the pumps is 91 and thats what i buy. i am trying to use some 100 octane but that costs so much. is there anything else that you can think of bro?

[Sniper]

if you had a AFPR, you could bump up the pressure a little bit for some more fuel.....but other than that, a couple bottle of octane booster shouldn't be much of a concern for what you dropped on the SC kit:confused:........

[turbo2.3]

A bottle of octane booster will every fill-up should take care of the problem for now. Also, try running some fuel system cleaner thru your car, you may have carbon deposits that are causing it.

[SarasotaGTP]

You should REALLY drop the boost pressure with your CR and 9psi out of that JR kit. At 9 psi, in the upper RPM range, you are running into supercharger outlet temps nearing 200* (not to mention donating damn near 30 horsepower to spinning the blower). The BEST option (if you plan on staying with the Eaton blower would be to purchase some form of intercooler to bring down those oulet temps. Not only would this lower your minimum required octane rating, but you would also be able to run more timing advance, gaining even more power.

Alex

[fusionsport]

Originally posted by SarasotaGTP
You should REALLY drop the boost pressure with your CR and 9psi out of that JR kit. At 9 psi, in the upper RPM range, you are running into supercharger outlet temps nearing 200* (not to mention donating damn near 30 horsepower to spinning the blower). The BEST option (if you plan on staying with the Eaton blower would be to purchase some form of intercooler to bring down those oulet temps. Not only would this lower your minimum required octane rating, but you would also be able to run more timing advance, gaining even more power.

Alex

that is a most inciteful post- and absolutely correct, and shows the biggest reason I dislike superchargers vs turbochargers- throwing fuel/reducing timing at your detonation problem will help, but a really good idea is to add the intercooler- doesnt have to be a big one- and maybe alcohol/water injection- reducing the c/r isnt a bad idea, but you can run 9 psi with it- one of the bigger reasons that a turbo is a bit more(in my experience) tolerant of higher comp is that it isnt using so much power add adding additional load to the motor, which on a 4-banger means something-
check into that i/c, more fuel, and maybe a slight reduction in timing, and your motor might live- also DO NOT EVEN ATTEMPT to tune this motor without a dyno, unless you like replacing motors

[xjdm94x]

Originally posted by fusionsport
DO NOT EVEN ATTEMPT to tune this motor without a dyno, unless you like replacing motors

[Bleachboy]

first off what is a c/r. sorry i may sound like a complete idiot, but im just kinda new to the F/I market. and as to an intercooler you cant really do that unless you are just planning on putting it before everything. i was already thinking of trying that. J/R only makes an after-cooler for the miata and not for any other car. i am already running a cool air intake, and i dont know if i can really fit an intercooler in my car but i can try.

[Wolf]

CR is compression ratio. It's the ratio of the volume of your cylinder with the piston at the bottom of it's stroke compared to the volume when the piston is at the top of it's stroke.

You could go with water injection. :smokin: :smokin:

[Bleachboy]

i figured out what C/R meant about an hour ago, boy do i feel stupid. i have heard that water injection isnt all that great. but how does it work i might give it a shot.

[fusionsport]

I just had a thread on alcohol/water injection- just look for it

[AWD_Dan]

Octane boost can reduce mild detonation as well, and a little cheaper than a gallon or so of 100 octane. I cant imagine what your EGT temps must be! If I were you, I'd be reeeeal nice to that motor till you have new internals to install. No sence in damaging the valvetrain in the process. Gotta sacrafice a little boost/speed for longevity, otherwise, hose sum more rustangs @ 9psi and enjoy crackin your block open :bam:

Knock = ALL BAD :rolleyes:

Good luck!
-Dan

[turbo2.3]

Originally posted by AWD_Dan

Knock = ALL BAD :rolleyes:




knock + boost = engine parts lying around

[Bleachboy]

thanks for the reassurance. I have got it down to only detonating in high gears at low rpms. i put in the 255 lph fuel pump and it is running great now. only one problem now and thats that the JR pulley nut keeps coming loose(loctyte).

[FenrirTheDevil]

Dagnabit. Am I the only fucker on here who is 100% pro propane? :D

Hell, Hank Hill says it's good. For $2.25 a month you can get a safe injection that will give you octane ratings in the low 120's.

In all honesty...until you figure it out I would add 100octane. The intercooling system, like fusion and sarasota said, should still be your number one priority. Knocking = lean condition. you can throw more fuel at the engine but it will only alliviate the problem teomprarily. Your ambient temps are killing you; and when summer really hit's it is only going to get worse. This is a problem you should get on ASAP.

[djprefix]

Ok, I don't know anything about hondas/acuras, so what compression ratio are you running right now? My camry has a 9.3:1 c/r and is running 10psi with no knocks.

[Bleachboy]

my integra runs stock 10:1

[djprefix]

damn, 10:1 compression + 9psi; you're damn near insane for running that on pump gas. Get some NOS octane booster on every fill, hopefully that will help.

[Wolf]

Yeah, that's the problem. If you can, swap in a larger SC pulley to lower the boost as a temp solution until you can drop the compression ratio. The longer you drive it as is, the more damage you're going to cause to the engine.

[Bleachboy]

what would you guys recomend for a CR. I was thinking 9.5:1 or maybe even 9:1. the higher the better (without detonation). Anyone got any input on this.

[djprefix]

You might be able to get away with 10psi on 9.5:1 compression. If you get an intercooler you should be able to. I haven't had any problems with 9.3:1 with 10psi.

[Angel5]

I'd go with the lowest compression ratio you could. Even something like 8.5:1 wouldn't be bad. You do lose a little power going with less compression, but you make it back up with the extra boost you will be able to run safely.

[SLpornSERIES]

Thought about running some boost timing retard like on the MSD or even a J&S safegaurd? Try making some home made race gas and see if you are still knocking. Like Toulene or Xylene can give you almost a 100 octane rating that is alot cheaper than buying strait race gas. I run 10lbs of boost of my b18b motor and it actually runs too rich with the boost FMU. I'm going to run 8.5:1 comp pistons on my built b20z with more boost :banghead

[maRiSaX]

9 Psi without and upgraded ecu, fuel components and stock internals is not very smart

ive even seen an Si at 10psi w/ hondata and fine tuned still blow a piston

fuck im only pushing 6psi and my car is dying:(