Noise... Wastegate bottoming audible in car?
04-04-03, 09:10 AM
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Noise... Wastegate bottoming audible in car?
What I hear sounds like detonation. I'm almost certain as much as I've heard it and kept my foot in it that it would have let go by now if it was in fact detonation.
Only thing I can think of would be the stock internal wastegate opening to it's limit and bouncing against the stop.
???
DISCLAIMER: I DO NOT reccomend keeping your foot in it if you hear "bad" unusual noises.
'87 TII, boosting ~6-6.5psi with TID, gutted precat, no main cat and free flowing cat back. Cleaned 550's and 680's. Have ran boost controller to 8psi, 14.2@98mph back to back. With boost controller have spiked repeatedly to 9-10psi on the highway without ANY sounds before, never a hiccup or hesitation as long as I have the magic R5671-A plugs gapped nice and tight and the timing isn't too far retarded.
Only thing I can think of would be the stock internal wastegate opening to it's limit and bouncing against the stop.
???
DISCLAIMER: I DO NOT reccomend keeping your foot in it if you hear "bad" unusual noises.
'87 TII, boosting ~6-6.5psi with TID, gutted precat, no main cat and free flowing cat back. Cleaned 550's and 680's. Have ran boost controller to 8psi, 14.2@98mph back to back. With boost controller have spiked repeatedly to 9-10psi on the highway without ANY sounds before, never a hiccup or hesitation as long as I have the magic R5671-A plugs gapped nice and tight and the timing isn't too far retarded.
04-04-03, 12:41 PM
#3
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at 10psi you should have no problem with 680's...
stock fuel pump??
if so get a biger one. and change your fuel filter.
and I hope you are running 91+ oct
stock fuel pump??
if so get a biger one. and change your fuel filter.
and I hope you are running 91+ oct
04-04-03, 01:33 PM
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New fuel filter last night and no less than 91 octane. After a little top up of 93 last night and the new filter, no change. Since November actually it's only had 93 octane in it.
Stock fuel pump...But I know I'm not near it's limits. I WOULD shove a walbro back there and run some fat wire to it, but I'll be parting this car out before too long.
The noise.....Well, tomorrow I'll have some video clips posted with better audio. If anyone would like me to email them the clip that I have I'd be glad to, but it's not QUITE as clear in it's current format as it will be when I rip it the right way later tonight.
Definetely a "tink tink tink" and now I've found if I keep in it past 5 grand it starts to pick up frequency with RPM. Last night right around the rev buzzer it sounded almost EXACTLY like popcorn popping.
Stock fuel pump...But I know I'm not near it's limits. I WOULD shove a walbro back there and run some fat wire to it, but I'll be parting this car out before too long.
The noise.....Well, tomorrow I'll have some video clips posted with better audio. If anyone would like me to email them the clip that I have I'd be glad to, but it's not QUITE as clear in it's current format as it will be when I rip it the right way later tonight.
Definetely a "tink tink tink" and now I've found if I keep in it past 5 grand it starts to pick up frequency with RPM. Last night right around the rev buzzer it sounded almost EXACTLY like popcorn popping.
04-04-03, 01:57 PM
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Guess I can regulate the air compressor down to 8-10psi and cycle it to the wastegate actuator.
I wonder if a tiny exhaust leak right after the turbo might get noisier once the wastegate starts to open. Un-dampened by the turbine wheel that bit of exhaust could sound different from anything else leaking there.
Not that I can even hear/detect a leak, but it is possibly up there.
I wonder if a tiny exhaust leak right after the turbo might get noisier once the wastegate starts to open. Un-dampened by the turbine wheel that bit of exhaust could sound different from anything else leaking there.
Not that I can even hear/detect a leak, but it is possibly up there.
04-04-03, 02:01 PM
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Doesn't answer any of your questions sorry, but when I had detonation in both cases there was hesitatiion...both the popcorn and the metal on metal clanking...
May not be detonation...but it'd be early to rule that out.
How many miles on the engine/injectors?
May not be detonation...but it'd be early to rule that out.
How many miles on the engine/injectors?
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04-04-03, 02:06 PM
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Miles.... Probably less than 2-3k on the cleaned injectors, and the engine....Lets see...... Should be around 70k but not sure. Interesting story, that.
The plugs in it are cold cold, no worries at all that a hot plug is bringing this on. I think there are 9's in the T and 10's in the L now.
The plugs in it are cold cold, no worries at all that a hot plug is bringing this on. I think there are 9's in the T and 10's in the L now.
04-04-03, 02:10 PM
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How do you know you are not near the limits of the stock fuel pump. You'll max the pump out way before you max out the stock injectors. I dought those 680's are doing anything for you. You need a bigger pump. The noise your describing I sounds like detonation.
04-04-03, 02:24 PM
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Last summer I stuck a fuel pressure gauge and adjustable regulator in the return loop. Squeezed it off to 55psi static pressure and ran it HARD through the top of 3rd and pressure never dropped. There were only 550's in it at that time but I know it was pushing more fuel through the injectors (and RAW out the exhaust!) than I'm using now.
If I can't track it down, I'll throw a pump in it. Actually, might toss a gauge in it tomorrow just because I'm curious.
If I can't track it down, I'll throw a pump in it. Actually, might toss a gauge in it tomorrow just because I'm curious.
04-04-03, 05:57 PM
#11
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Harmonic heatshield or ? vibration?
I've got a heatshield loose somewhere that will sound like detonation at certain loads/Rs.
It's really infrequent but the first time I heard it was during a high-gear, WOT, coming up on 130 or so. Freaked the **** outta me.
I can also induce it in the driveway when the Rs are coming down from 2.5 or 3k.
I've got a heatshield loose somewhere that will sound like detonation at certain loads/Rs.
It's really infrequent but the first time I heard it was during a high-gear, WOT, coming up on 130 or so. Freaked the **** outta me.
I can also induce it in the driveway when the Rs are coming down from 2.5 or 3k.
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