Detonation??

[themeanest240]

the other day i was driving my 240 with a redtop sr20, all it has done to it is gt2871r, 550cc injectors, z32 maf, enthalpy rom tune. ive been running off the actuator (7lbs), i decided to turn it up to 12lbs to see what she did and a heard a bunch of ticking/knocking. forsure coming from motor.but when i turn it back down to stock boost, i dont hear anything like it.also my wideband is telling me 12.3-12.7 wot.i only hear it when boost is turned up past wategate, it sounds so bad i dont wanna drive it.i have an safc2, scott just told me to take it out, im pretty sure it can read knock? should i get a fpr to see what thats at? turn it up to get rid of knock or detonation, i dont really know what to do/please help me!thanks

[slidestyle69]

well on your fpr idea, that would be a choice if your having fuel cut, are you? when it knocks and what not, does it cut out and fall on its face or just make noises's?

what amount of boost is your ecu tuned to?

remember detonation is a leading cause for broken ring glands on a sr(BEWARE),

[Sil80315]

I doubt its your fuel pressure. 12.5 isnt that bad. yeah 11.5 is the key figure but running around 12.5 wont cause it to knock unless its something internal.

Sounds like a rod bearing or wrist pin.. Sometimes when they go you will only hear it at a given RPM or power range and by adding more boost pressure to the cylinder it will make it worse. I bet if you took a stethoscope at idle you would prolly hear it all the time

Modified by Sil80315 at 6:46 PM 7/28/2009
Modified by Sil80315 at 6:47 PM 7/28/2009

[xrproto07]

Well im also hearing a ticking sound from my engine, but I have an S14 SR and it usually has to do with the VCT when an s14sr starts doing that. And sounds like a dam diesl lol.....im almost positive redtop sr's have VCT though...

[themeanest240]

should i try retarding the timing to see if its just detonation? or would you even hear detonation?ill try the stethoscopeif it is bad rod bearing how do i pinpoint which one? if it is i will replace all, just need to check for scoring on the crank.can i replace them by just dropping the oil pan?also can it really be that bad right now if i only ever hear it when turn up the boost?thanks so much guys!

[Sil80315]

rule of thumb. If your going to replace 1, replace them all. You have to pull the motor to be able to get to all the rods esp seeing the upper oilpan is about an inch from the K frame and its also bolted to the block from inside the bell housing.

to rebuild the bottom end you can just buy rod and main bearings but I would take the crank to a shop to have them polish it and check it out. I say this because my sr ran fine till i got a rod knock. It only took about 5 min of a slight rod knock and it heated up the bearing and warped my crank.

its only going to cost you like 200 bucks to rebuild the bottom end..thats if you dont replace the head gasket or replace the piston rings.

[themeanest240]

Well i didnt hear any knock with the stethoscope. i figured if its never heard unless im boosting past 7lbs i wont hear it, and its kind of hard / impossible to use a stethoscope boosting past 7lbs.Would i hear a bad wrist pin at all times? I wasnt too sure about the sound i was getting from the oil pan and block so im going to take it to work and have a few machanics listen. Im still thinking it might be from timing or something, but it the afr's are all good that should be fine right? i had planned on putting my apex-i head gasket in, but more boost will create more problems.maybe loose exhaust stud or something like that could cause the know sound, but i made sure i tightned and re tightened everything.Any other ideas?thanks again!!!

[C-Kwik]

Unless you're able to hear it under load (i.e. while accelerating) you're not going to hear the knock, even with a stethescope. Knock doesn't occur all the time. It occurs when heat and pressure are too high. close throttle and low throttle applications are unlikely to produce knock as the amount of air and fuel going into the motor are so small.

That said, knock/detonation is best described as soundling like ball bearing in a can. The intensity of the sound can vary with the intensity of the knock, but ultimately, the sound is similar. It also tends to feel more random where as mechanical knocking noises like rod bearings will have spacing between sounds that are uniform and proportional to engine speed.

[shift_SRDETuser]

yeah why dont you trash the eprom tune and get a power fc.. They rule and they also can detect knock and retard timing. Also you have to be careful because several things can be knock other than actual knock. I had an oil pressure plate and it would pick up knock from it-- so you can pick it especially when you boost to 18 lbs or so and if you have small amounts of fuel left.

[themeanest240]

well i have no money for pfc, or money to tune the thing.

Like said before i dont hear the knock any other time, besides more then 7lbs of boost, so its detonating.when people have pfc and they get detonation they add fuel or retard timing. correct? if i get a frp wont that be adding fuel, and cant i retard my timing by 5 degrees or so, and put a bkr8eix plug in?

the mechanics at my work said if it was something mechanically broken like a rod bearing or wrist pin it would have been heard with the stethoscope, while detonation from more boost, you'll hear with more boost.

any other ideas?thanks guys!

[Sil80315]

You know.....do me a favor.. Check your plugs. check to see if they are cracked. For some reason sr's like to crack plugs and if there is a small crack in the porcelain it will buck like its mis firing and will act all weird.. so just check that for me.

I had a set of plugs that one had a small crack and it only effected the motor when the car boosted.

[themeanest240]

ok ill check and even put in my colder plugs today i just got them.the thing is i can boost 7lbs all day, its just when i turn it up.stock timing can take more boost cant it?thanks for all the input you guys, this is driving my nuts

[shift_SRDETuser]

then it is in your

ok ill check and even put in my colder plugs today i just got them.the thing is i can boost 7lbs all day, its just when i turn it up.stock timing can take more boost cant it?thanks for all the input you guys, this is driving my nuts

then it is in your fuel MAP... You should contact the ROM writer who made the program and go over your setup again

[themeanest240]

thats something else i thought of, i already emailed him a few days ago just waiting for a reply, he's a busy guy. (Enthalpy)is it forsure the fuel map?is there any way to check this?thanks again!

[shift_SRDETuser]

thats something else i thought of, i already emailed him a few days ago just waiting for a reply, he's a busy guy. (Enthalpy)is it forsure the fuel map?is there any way to check this?thanks again!

I had large amounts of knock when I got it back from the tuner and while the oil plate I was running played a little part in it -- I can not remember what lean plugs look like thinking shiny white but anyway check those. I bet you do not have enough fuel up top and this is causing the detonation. My car did it until I took it back to my tuner and he had his laptop while I drove and street tuned it by adding more fuel to the tables up top and this fixed the issue. If you have ever heard detonation it is like pingiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii

no kiddin that breaks the sound barrier and it is some serious stuff. You need to not run your car into high boost until you get this addressed

[bansheeracer2003]

turn the boost up then turn the car off and let it sit over night so it cools down alllll the way then while its cold drive it around on high boost and see if it still dose it. (u have a about 2-3 min to do all of this)

also look at the plug gap on ur car!and o yea also turn the car on and while it running pull the plug going to the coil packs one coil at a time and see if u could hear it start making the noise , if u do then u have a prob in the bottom end on the cyl that u pull the plug on.

also every one check out http://www.silverminemotors.com

-Ron
Modified by bansheeracer2003 at 5:25 PM 8/3/2009

[themeanest240]

so what if i dont hear the knock when its really cold, i did that and im pretty sure i didnt hear it.does that mean its a rod bearing or what?thanks again!!

[bansheeracer2003]

just starrtt thr car and pull the plug wire it should magnafi the soundif it does not then its ur tune bro

check out http://www.silverminemotors.com

-Ron

[themeanest240]

well i figured it out, will Enthalpy figured it out.They are absolutly awesome!it was my timing, almost ten degrees advanced.motors running strong, tune is 100% !!thanks for all the help guys.

I highly recommend R.S. Enthalpy, awesome tunes, back with the AWESOME customer service!!

[400whps13coupe]

your rom tune could easily be the prob but if RS ENTHALPY did your tune get back with them and they will go over you mod list with u and try to figure it out you can piggy back your rom tune with a safc2 and get a finer tune thata way so you can adjust a lil timing and fuel. if you are anywhere near the atlanta area LETHAL INJECTION will do a safc2 tune for 250 bucks and you will leave a happy man . as far as Power fc's go i have a S13 set up with hand cammander and dattaloggit software i will let go for 600 bucks give me a shout if interested 1 205 227 8343.