Tuning Advice

[thbjcb]

Got a powerloger hooked up and looking for an expert to review as I am having some knock. Testing is mostly in 3rd as this is more a true knock indicator from what I have read.

Mods: 3.5" MAF with translator, TT chip for 93 oct, FMIC, 3:" DP and test pipe, 60 LB inj, DW300 w hot wire, power plate, cold air intake. New radiator and dual fans, stock turbo, poly mounts for the engine and tranny, home ported heads with larger valves, 208/208 flat tappet cam, heavier valve springs.

Known issues: A lot of false knock when trying to do burn out on the street. I did found that the bushings for the stock UCA and LCA are totally shot to the point when the car is in park and you push the car forward and back it makes loud noises and you can visually see the slop in the bushings. Whenever I shift the into D it sets off the knock detector. Worse when its cold but this issue has progressively gotten worse. You can hear a loud click noise when shifting that must be the correct freq to set it off. There is also a 1-2 delayed shift that I need to lift up on the gas super quick and it will go in. If I bring it up slowly it will shift at 3K.

Going after the control arms next so hopefully it will fix some of the lower knock but I am starting to wonder if my tranny is the real knock source. Engine runs great otherwise, no idle issues or backfire when rev d .

 

[Turbo6inKY]

Driveline slop will definitely cause false knock. Wheel slip will as well.

Go through the suspension and replace all the bushings, as well as the motor mounts and transmission mounts. Do the body bushings, too, if the car's not too rusty to get it done.

 

[Turbo6inKY]

Also, are your sure your 1-2 is really 1-2? A burned up 2nd gear band will behave like you're describing, except you're not going into 2, you're going 1-3.

 

[thbjcb]

Already did the poly mount for engine and tranny. It still shifts into 2 as I can feel it go from 2 to 3. Ordering new rear Upper and lower control arms soon. What type of body mounts rubber or poly? Still looking for input on the data file.

 

[salvageV6]

Up the octane, 4 gallons of 100 no lead or a gallon of xylene to a low tank of 3 gallons or less of fuel. Retest.

If I had a heads and cam. car I'd definately have an alky. kit and a good
transmission.

I'd run it from idle to / through 3rd gear (depends on KR when to lift) for the powerlogger tests.

Just my .02.

 

[Turbo6inKY]

Already did the poly mount for engine and tranny. It still shifts into 2 as I can feel it go from 2 to 3. Ordering new rear Upper and lower control arms soon. What type of body mounts rubber or poly? Still looking for input on the data file.

There is no reason not to go Poly on the body mounts.

 

[TurboTGuy]

Driveline slop will definitely cause false knock. Wheel slip will as well.

Go through the suspension and replace all the bushings, as well as the motor mounts and transmission mounts. Do the body bushings, too, if the car's not too rusty to get it done.

Though good for the car in the long run, that's a LOT of work if just looking to eliminate possible false knock. Don't you think?

 

[Turbo6inKY]

Though good for the car in the long run, that's a LOT of work if just looking to eliminate possible false knock. Don't you think?

Not really. It's maintenance that should be done on every car. Especially if you intend to flog it hard enough that slop in the suspension and body is causing false knock.

These cars are all old enough that if this work hasn't been done, it should be.

 

[TurboTGuy]

Not really. It's maintenance that should be done on every car. Especially if you intend to flog it hard enough that slop in the suspension and body is causing false knock.

These cars are all old enough that if this work hasn't been done, it should be.

Agreed. Everything but the body bushings has been done on mine, if I have to go that far, I'm realigning the body to sit square on the frame, too.

That will move just about, well, everything.........

 

[Turbo6inKY]

Agreed. Everything but the body bushings has been done on mine, if I have to go that far, I'm realigning the body to sit square on the frame, too.

That will move just about, well, everything.........

A couple of ratchet straps and a whole lot of cussing...

 

[TurboTnZ06]

Ported heads and a cam, on pump 93, you need to turn the boost down. Like 12-14psi and see if it knocks then. Then move up in boost. At most I could see 16 psi on mine and get KR sometimes, and pull back timing too.

 

[thbjcb]

take a look at my data attached file and you will see knock occurs at about 11 lbs, which seems kinda a low. I have a can of boostane on order so we will see if that helps.