16.7 knock, is this a problem?

[menace848]

Well, it is obviously a problem but I do not know what could have caused that! It happened when my car just got finished with the atr downpipe and exhaust(no cat) had gone on. I also had gotten a power plate. I wasnt sure where the boost was and when I pushed the car the first time, the crappy stock boost meter read about 10 psi and 8 degrees knock. Well, I knew that couldnt be good but just to see I floored it for a second later on, the boost went past the 15 psi limit and knock to 16.7! I immediately let off, good thing nothing was broken. I had not turned the boost down yet so I am guessing it was probably at 20 or so. But the thing is with 10 psi I had 8 knock? Anyway, I asked someone and they suggested a bad injector so I have gone through 2 tanks with injector cleaner but have not hooked it to the scanmaster yet, and I am running about 10 psi now just to be safe. Anybody see a problem? Also, maybe it could be my chip which I got about a year ago from bowling green customs. Either way I might get a thrasher chip to see if that might help

 

[JDSfastGN]

maybe the downpipe is hitting the frame or the the exhaust is loose. Good luck

 

[tc86gn]

I think you should post a little more info about your setup before opinions can be offered. What kind of fuel pressure are you running? Have you upgraded your fuel pump? I am not an expert but the guys on this board that can help you will need some more info.

 

[DynamicGN]

Originally posted by JDSfastGN
maybe the downpipe is hitting the frame or the the exhaust is loose. Good luck

In regards to that...i noticed my THDP was close to the frame to and might be hitting it...so this could be a cause of knock then? I gotta check that out.

 

[menace848]

sorry I have a 355 walbro pump, and I havent checked the DP clearance and wont be able to until the weekend. I dont know what the fuel pressure is at but if anything its probably high so that shouldnt be the problem. THanks

 

[turbo buicks]

get a real boost guage. the stock ones are bad 99.99999% of the time. my car ra 10 psi when i got it but the guage showed over 15 psi. ive heard you will gain 2 psi of boost w/a 3" DP an/or dump and that you should turn the boost down to compensate for this and then tune it up. also i have a bad injectors and it leans out and will knock at 15 psi so i dont go over 10 psi most the until i get 50's. if your injectors are bad like mechainically or a super clogged and really messed up you need to get them rebuilt or replaced and flow tested or just invest in a new set or injectors. cleaner does nothing of they are really bad like mine b/c ive put 3 kinds of different cleaner through them and they are still the same.

 

[bose]

knock

As you were told you need an accurate boost gauge.What octane did you have.Is your chip a street chip for pump gas or a race chip?Bruce

 

[striker_29]

Dude, splash in some race gas or xylene and see if the knock goes away. If it does not, its false and you need to look at the downpipe. If it does go away, its real and you need to really look at your fuel system.

 

[menace848]

ok I just ordered a scanmaster2 and boost gauge. I was on pump gas 93. I have had the injectors professionally cleaned before.

 

[turbo buicks]

Originally posted by menace848
ok I just ordered a scanmaster2 and boost gauge.

good! your on the right track

 

[Turbo PeppeR]

check your downpipe under heater box and also the body seam under firewall,my atr hit both.good luck...

 

[d0n_3d]

Originally posted by turbo buicks
get a real boost guage. the stock ones are bad 99.99999% of the time. my car ra 10 psi when i got it but the guage showed over 15 psi.

guess i am one of those 0.00001% because my stock led boost gauge and aftermarket vdo boost gauges are EXACTLY the same at 82k miles

it is true that most of the TRs have whack stock rpm and boost led gauges...don't know why they would go bad...

 

[Dan Thompson]

If you don't have an engine tie down get one of those.

My stock DP would hit and I now check it by just hitting the side of the COLD DP at the cat with the side of my fist.

I've had the DP hit the crossover and hit the frame, so you can adjust it by undoing the clamp and moving the pipe in the correct direction. May need to hold it there with a crowbar on piece of wood while the clamp is re-tighten.

Its a FREE test this way. I like FREE.

 

[turbo buicks]

caspers electronics just came out w/some kind of sensor trigger relay thingy to fix the ones that go bad and are usually the cause of bad stock RPM and boost guages in TR's.

 

[menace848]

i have an engine tie-down on but it is very loose, how tight should it be, by loose i mean i can move it 2 or 3 inches back and forth with my hand. I ordered the scan2 and gauges and got a call from ramchargers that they dont have the gauges or pod in stock, that sucks, but I will just tell them to ship me the scanmaster i figure.

 

[bose]

motor mount

I just bought a drivers side poly motor mount and do not have to mess with a strap.Bruce