Got knock haven't had the money for a knock gauge yet, knocks about top of 2nd gear at ~16-17lbs on 93 oct and Red 93 chip, Outside temp was 60. Crap gas? that's what i'm thinking. Don't know how many degrees of knock it's getting, but it's a stock turbo and injectors. Would RJC plate help this? I need a scanner bad i know.
Full throttle audible knock...
- Thread starter Brian Mc
- Start date
Welcome!
By registering with us, you'll be able to discuss, share and private message with other members of our community.
Man, If you can hear the knock then it's severe and it's just waiting to destroy something! Turn the boost down before you go WOT again or you may regret it. The reliability of knock guages has been in question since they came out and this is too important to mess around with. Borrow someone's scan tool to tune your car with until you can afford one of your own and also check your fuel system to make sure it is keeping up, especially if you have a stock fuel pump, which is basically junk unless you never floor it. 16-17 lbs of boost sounds too high for 93 pump gas.
Dave@ramcharger
Senior Member
- Joined
- Sep 24, 2002
- Messages
- 126
Some people say they can hear the knock... on a car with a knock sensor usually if you can hear it, its either too late or you better get out of it cause you are hurting something.
its amazing sometimes people will keep driving the car the same way with large amounts of knock without doing anything.
its amazing sometimes people will keep driving the car the same way with large amounts of knock without doing anything.
Don't ask me how I know, 
but consistant audible knock is above 7.0 KR!
I heard it ONCE when I had the RA93, Walbro 307, stock unmodified wastegate actuator. This was before I got a scanmaster. I got the powerplate and never heard it again until I started to play with boost and tuning alky. That's another story. Also, freeing up your exhaust, aka test pipe, will make a big difference in knock.
but consistant audible knock is above 7.0 KR! I heard it ONCE when I had the RA93, Walbro 307, stock unmodified wastegate actuator. This was before I got a scanmaster. I got the powerplate and never heard it again until I started to play with boost and tuning alky. That's another story. Also, freeing up your exhaust, aka test pipe, will make a big difference in knock.
Running race gas sounds good but you'll still want to tune it with a scan tool to make sure there's no detonation anytime you are setting it for max boost. I'd say it will probably quit making any more power after 20-21 lbs boost though. That's about the limit for the stock turbo. 116 octane is overkill, too. 110 or 112 should do it unless you are talking about mixing it with street gas. That would make a safe boost level anyone's guess without a scan tool. Are you seeing a pattern here?
Ignition retard - Up to but no more than 5 degrees of ignition retard is considered "tickling the knock sensor" when you are setting for kill but for everyday street driving where fuel quality can vary from tank to tank you may want to shoot for no retard at all to be safe.
O2 reading - shoot for mid to high 7's (.750-.799). A higher reading (.800 and up) would mean richer, which some people prefer to be safe, and a lower reading (.749 and down) would indicate leaner. Leaner can be meaner but also can be risky.
To change these readings you have to change your air/fuel ratio by adjusting the boost (more air or less air) and fuel pressure (more fuel or less fuel). All of this is best done at wide open throttle in 3rd gear where the load on the engine is heaviest so you'll need a good long, staight streach of road somewhere with the least amount of traffic possible. It helps to have a buddy along to call out your readings so you don't have to take your eyes off the road but if you see more than 5 degrees of retard then let out and richen the air/fuel mixture by either turning the fuel pressure up or boost down. If you don't have an adjustable regulator then you can only turn the boost down to get a richer a/f ratio and you will be limited to how much boost you can run. If your boost is not adjustable (non-adjustable wastegate and no boost valve installed) and is only controlled by the chip then either run higher octane or put a chip in with lower boost setting and save Red's chip for later. Or call Quad Air (you probably won't get Red, he's a busy man) and see what they say. Whew! Got way more technical than I intended but this is important basics. I'm sure there are other methods or settings that others prefer but this is what has worked for me and my buddies around here.
O2 reading - shoot for mid to high 7's (.750-.799). A higher reading (.800 and up) would mean richer, which some people prefer to be safe, and a lower reading (.749 and down) would indicate leaner. Leaner can be meaner but also can be risky.
To change these readings you have to change your air/fuel ratio by adjusting the boost (more air or less air) and fuel pressure (more fuel or less fuel). All of this is best done at wide open throttle in 3rd gear where the load on the engine is heaviest so you'll need a good long, staight streach of road somewhere with the least amount of traffic possible. It helps to have a buddy along to call out your readings so you don't have to take your eyes off the road but if you see more than 5 degrees of retard then let out and richen the air/fuel mixture by either turning the fuel pressure up or boost down. If you don't have an adjustable regulator then you can only turn the boost down to get a richer a/f ratio and you will be limited to how much boost you can run. If your boost is not adjustable (non-adjustable wastegate and no boost valve installed) and is only controlled by the chip then either run higher octane or put a chip in with lower boost setting and save Red's chip for later. Or call Quad Air (you probably won't get Red, he's a busy man) and see what they say. Whew! Got way more technical than I intended but this is important basics. I'm sure there are other methods or settings that others prefer but this is what has worked for me and my buddies around here.
Thanks, it's clear, but you can't change timing, right? unless of course you change the chip. I have a AFPR and an adj, wastegate, so if it doesn't thunderstorm tonight i'll hook up the tech 1 and the fuel pressure gauge and bump the fuel pressure up, it's at 43 with the line off now. Appreciate the help. got to get the stock Fuel pump out and the Walbro 340 in.
I tried turning the actuator back 1.5 turns last night, but boost isn't lowering. could ported heads and thermal coated manifolds cause a boost increase? i've turned it back 3 turns or so and boost is right where it was before i pulled the engine. 
Matt Weiser
It's an F.U.V.
- Joined
- Dec 17, 2001
- Messages
- 491
Not sure what you mean by "turning it back". You want to LENGTHEN the wastegate rod to reduce boost.
An adjustable wastegate will have hardware threaded into the middle of the rod that will allow it to be adjusted shorter to increase boost or longer to decrease boost. If you just have a one piece rod then turning it won't change a thing. One turn should equal about 1 lb of boost.
blackbuick87
Senior Member
- Joined
- Mar 11, 2002
- Messages
- 3,205
Brian youre a nice guy and I like you a lot.
Your car is VERY close to looking like this:
http://bobdittmar.tripod.com/blown87combobs1987buickgrandnational/id2.html
Little by little your head gasket is being chewed away, until there is nothing left except metal, and then BOOM
Your car is VERY close to looking like this:
http://bobdittmar.tripod.com/blown87combobs1987buickgrandnational/id2.html
Little by little your head gasket is being chewed away, until there is nothing left except metal, and then BOOM
