wheel spin knock....

[JDSfastGN]

Ok Ive done the search (although using google works as a better search than the one on here) It got kinda testy before in some previous threads regarding this topic so lets keep that crap outta here. I don't believe its real knock to state my opinion, at least in my case. It will happen at the slightest 10 psi spin of the tires. This is a problem with our T. It has a double pumper, dual nozzle alky etc.... Well at lower speeds (65 and below) traction is not always there. The knock spikes to 15+ and it seems to pull so much timing that the car gurgles and can't burn the fuel/alky thats being put in there and just kinda falls down and sputters. So other than knock ignore, has anybody found a fix for their own vehicle? Something with pinion angle, or other suspension geometry? The car has street tires and thats not gonna change for now unfortunatly. From a 70 3rd gear roll its fine and pulls hard and clean. Here are a couple runs. One is from a 55ish roll with tire spin/peddling and the car not pulling clean even after the knock clears up. Other than the really bad TC efficiency the car is running great. Don't know if the files will help at all but I did find it interesting at how the a/f dropped off into the 9s when the knock got high enough for me to back off (fell on its face) At the track the car is fine. Any ideas or theories would be great. Thanks yall. BTW its a LC1 wideband and I had to put smoothing on medium to get any kinda useful data.

edit: give me a few so i can find a way to upload these powerlogger files

 

[Jerryl]

Ok Ive done the search . . . . powerlogger files

6300 RPM?
I know you do it all the time but DAMN you go khahunas!

TTT :wink:

 

[mikestertwo]

There isn't really much you can do about it other than not spin the tires. I have the same issue. Knock determination is frequency dependant. Apparently the vibration frequency caused by the spinning tires is at the same frequency the knock module considers engine knock. I have noticed different tires/air pressure show different amount of knock.

 

[m233roller]

JD,
There's a real easy fix for that. DON"T SPIN the TIRES !!! Sorry for being a smart AZZ just kidding with you. There are about 6 of us here that had the same thing going on. Some worse then others. Most of us have just went to Mickey T's drag radial. LOTS !! better as you hook so much better and these tires ride NICE ! as they are nice and soft. Of coarse if you nail it from the get go they'll go up in smoke but MOST the time in second and third they hook well and you don't get that darn false knock. What kind of tire and air pressure are you running?

 

[JDSfastGN]

thanks guys... im running 275/40/17 nitto 555s.... just a straight up street tire. they are almost new unfortunatly

 

[m233roller]

Nuff said JD. Won't hook worth a S--T.

 

[Razor]

Get an electronic boost controller that can slow down the ramp how hard the boost rolls in.

If the boost ramps in fast.. it blows the tires.. it sets off the knock sensor.

Boost rolls in slower.. you can control wheel spin and problems resolved.

The question does anyone make a boost controller with two different settings that can be activated through a switch.. like street/race. At the track with slicks you'd want fast buildup. Street.. slow.

Hows that?

 

[dr_frankenstein]

Get an electronic boost controller that can slow down the ramp how hard the boost rolls in.

If the boost ramps in fast.. it blows the tires.. it sets off the knock sensor.

Boost rolls in slower.. you can control wheel spin and problems resolved.

The question does anyone make a boost controller with two different settings that can be activated through a switch.. like street/race. At the track with slicks you'd want fast buildup. Street.. slow.

Hows that?

I thought ISAC had provisions to run such a setup..........

breaks my heart I cant get one.... I really really really want an ISAC.

but at the same time sounds super "fast & furious"

"I hit my boost control switch for the track man... "

LMAO

A.j.