Wheelspin knock

[BEATAV8]

My translator did not make this problem any better or any worse, regardless of fueling adjustment. I do not think that this could be real knock. Wheelspin is a light load condition until the tires start to grab, light load is not a knock inducing situation. If it were real knock, my motor and a few others I know of with the same problem would likely have bitten the bullit by now.

 

[87GN&98VET]

GN HEAD, I have not replaced any bushings or control arms. My car only has 14k miles on her, so I doubt it's related to wear. I do not have any wheel hop and Turbolink shows no more than 3 degrees retard, but the Caspers gauge lites up to mid-yellow. So the computer must be filtering the knock signal. I don't understand why it would send the signal to begin with - still have the stock downpipe and I can't see where anything would be hitting. The tires break loose before full boost but it should already be in PE, so it shouldn't be lean. Maybe the gauge is too sensitive?

 

[GN HEAD]

We need more input here, there are several of us having the same problem, there's gotta be a turbo Buick guru out there that has the answer........ What is causing this knock when the tires break loose????

 

[turboaddict2]

I still have the stock control arms and am wondering if new ones would help solve the problem

 

[HRpartsNstuff]

Well, from our experience, 98% of the time it's in the rear control arm bushings. Even low mileage stockers are no match for the power we are making. It was too soft to begin with, and that was before they aged 15 years.

The lower CA's make more difference than the uppers, and the bushings make a lot more difference than boxing them or even new material (tubing). New control arms make the most difference because of the new poly bushings AND the new material that is stronger than even the boxed stockers. BUT, to really cure the problem & get the best performance, it needs to be addressed as a set/combo. Doing part of the job yeilds part of the results.

Basically, that means that boxed upper & lowers with new bushings all the way around is better than brand new lower CA's & leaving the uppers as-is.

For those that are not familiar with us, we make lazer cut boxing kits & custom replacement bushings that have a grease fitting built into them. We also make the strongest double adjustable uppers BAR NONE, and non-adj uppers and lowers new. We have a bushing tool as well to get the nasty bushings out of the top ears on the rearend housing. These are so tough to remove without our tool that many people leave the stockers in there. They never reap all the benefits of a complete system that way.

PS- The Poly motor mounts stop the exhaust from hitting when the motor torques over, but can't help when the rearend/tires shakes the **** out of everything.
Hope that helped.

 

[Vader 87]

Dropping your 60 ft times by at least .15 with the HRParts LCAs is also an added plus

 

[HRpartsNstuff]

Keep in mind, the "rule of thumb" is that a tenth off the 60 foot time = closer to 2 tenths off the 1/4 mile.

Sooo, .15 off the 60 = .3 off the 1/4 mile! It's a LOT harder (and costly) to make the power needed to get that off your ET than by just swapping the bushings out!

My car was probably a "true" 10.90 car when compared to most. Because I had the rear suspension working so well, I got the 60's down to a 1.40 That's about a tenth quicker than most other 10.90 cars, and that's why I went 10.71 with it, not 10.90. Oh what a feeling!

 

[GN HEAD]

Paul, thank you for the reply, all/any input on this is helpful and previous experience is even better.