Naji yu have mail. As far as the cams go, I havent seen a bunch of probems with split duration causing knock though I can see why it might. I am running a HKS 280 while I wait on fundage (tax) to get some S1's or S2's.

 

my cams are 264 in, 272 ex. i have extra 272 intake that i'll be installing soon.

 

Naji, i'm not going to blame it on the cams just yet . too many things to consider. plus i am a ricer . i want more powwwwwer!!!!

 

It takes quite alot of power to be too much for a street car. 550hp in a RWD non posi chevy was kinda ghey, so in the spool went along with 295-50-15 drag radials. Makes it a little more streetable these days as long as its dry out.

 

I am glad you have a positive outlook about this I hope to see you next weekend so we can do some logs.

 

Retarding the intake cam will help reduce the tendency for knock by reducing cylinder pressure.

 

Looks very similar to the timing I used to run a few months back. Since then I added a testpipe and set the cams back to -3i -1e and was able to bump the timing some more. I tried -4i -1e and was able to run more timing, but the car did not feel as strong up top as it does at -3 -1 with a degree or so less timing.

 

Ramp from 6500 - 7000 looks a little aggressive for my taste, on my car that would cause knock around 6700 for sure. But every car is unique so if it likes it

 

Thanks for the input, I will tame the timing in that area.

 

nj1266,

I'll pm you one of my more recent maps this evening, don't have access to them at the moment. I've been round and round with knock, in my case the bulk of it was due to a bad injector, but I also think georgia 93 octane is not that great, the cars I have tuned on the dynodynamics all seem to end up with timing similar to what I am currently running so I'll shoot you something to take a look at when I get home.

 

I want to thank all those who have e-mailed me a Rom. I am looking at them and working on making the most tame timing map. I am leaving the fuel map alone for now. I am so appreciative of this forum.

 

Fuel- That brings me to another question. I looked at the log before I sent a rom and saw what the wideband said the AFR's are. However I know at least with a IX that they dont match up with the target map with lean spool active. Are you sure that the WB is trustworthy? Just going by fueling you should be at least 1/2 point leaner or more by the target AFR with lean spool if it were a IX (at any rate). Something to double check as well Naji, it might be lean a little.

 

I will work on the fuel map. I am going to richen it up. I will start very conservative with both timing and fuel. But the first thing I want to do is log the car after the 2nd tune. I was not able to get the data I needed on the dyno for obvious reasons and the tuner does not share his Evoscan logs with his customers. So I will log the car with the current tune. Here is the plan:

1. Change the IC pipe clamps to t-bolt clamps and do a boost leak test.
2. Log, check for knock. If knock still there
3. Change spark plugs to BPR8ES
4. Log, check for knock. If knock still there
5. Flash the utterly conservative map that I am working on
6. Log, check for knock, if still there
7. Go back to stock cams
8. Log, check for knock, if still there

then the best piece of advise I can give is screw 91 octane gas and mix to get 93 octane. That is what the car is supposed to run on in the first place.

 

I just want to update this thread. Today we got a chance to log the car. We changed plugs to BPR8ES and gapped them to 0.025. Then we went out and did 4 back-to-back WOT logs. The spark plug trick seems to have lowered the knock sum to about 6-8 counts dependening on the run. The good thing is that the KS is repeating itself in the same range; 5000-5500 rpm. That is where it starts and then it tapers down from there. There are also 3-2 counts in the logs, but I am not concerned about those.

Here is my question. When the KS hits @ 5-5.5K and then goes down are the Knock sums that are declining residual from the original or are they new KS? The chart below shows that KS hits 6 counts @ 5500 rpm and then falls down to 2 by redline. So do I remove timing/add fuel in the 5500 rpm range only or do I remove timing/add fuel for the entire KS area?



Overall, I am optimistic that we are heading in the right direction. Next step is to change the stock clamps to t-bolt clamps and do a boost leak test. Then we will log again and see the results.

I am also thinking of going to BPR9ES plugs. But that raises the issue of fouling the plugs in daily driving.

 

NJ,

PM me if you want to try something "off the beaten path" that might work.