alky tuning question with knock retard

[TOM J]

First scenario is i ran the car with my O2's at 744 with no knock retard, and ran 12.1 @ 114mph. but the car felt slow compared to runs on street. I pulled plugs @ the track discovered one bad plug, did a blow by test and was leaking into radiator. So i installed new head gaskets and now the car has 14degree knock retard @ 750 02's with no other changes but head gaskets and increasing of alcohol to richen up mixture, my fuel pressure is 43lbs with vac line off recommended by Eric Marshall who's chip i have with 20degrees of timing @ 3rd gear. All scenario's are ran @ 24lbs of boost. Would be greatley appreciated your input on the situation and any suggestions you might have. I plan on taking the car to the track on saturday. Thank you

[Steve Wood]

give it more fuel...not alky-unless you believe your o2 is wrong. That is where I would start. 14 degs of retard and you will be changing hgs by Saturday.

[Steve Wood]

Really be nice to know what your fuel pressure was...should be 67# at 24# of boost, and very nice to know what your egts were.

[TOM J]

why do think there was no knock before the headgasket change and if i change fuel should it be through the chip or fuel pressure first

[TOM J]

i dont have a et gauge and i have to get longer line for fuel gauge , how does alky really affect ex temp. can i just add alky , i am running razor's pac kit , the way i understand it is to try to remove fuel and replace it with alky for better results am I wrong , is it possible that I am getting KR now because before with the leaking cylinder i'm making more power and my requirments change quit a bit and I shouldn,t use that as a reference , shouldn't the alky get rid of the KR are my o2's really that low 740-750's i have seen on these post were people are these o2's and not getting KR please tell me if a i am totally in left feild on this , thanks againe

[Steve Wood]

The alky should cool egts to a certain point, but, it does not have as much heat content as gasoline. No matter which, you have to run rich enuf to avoid detonation no matter what the egt may be.

The original hg got damaged somehow...even tho stock o2s are not reliable with any precision...most here would probably agree that .744s are asking for it.

If the chip will allow you to richen the mixture then go that way. If not, turn up the fuel and see what happens.

Sure be nice to know if your fuel pump was doing its job.

[Razor]

Well see the question is the knock increasing as the speed of the vehicle is increasing or is the knock flashing 14 then coming down. See tranny shifts, suspension, belt tensioner, etc.. the motor has been pulled apart.. how do you know 100% exactly its been put back together with everything in the exact same location.

I would drop boost to like 18 and see if it runs clean there. Noting issues like fuel pressure, BLM', and watching the knock as the speed increases through a gear. Start with higher O2's like 780's and 18 PSI and see if it runs clean. If it doesnt, find out why? If it does then start upping the boost, fuel pressure,.. and watch the knock in the middle of third gear as the speed increases.. should be zero.. or less than a degree.

Every car is different. What one person can do doesnt mean someone else can do. There is a point whereby if you increase the alcohol into the motor it will start losing power. So the idea is to use only enough to get rid of detonation. If you drop fuel pressure and lean the motor out.. then you'll probably have to add alcohol to control the detonation. So in this aspect adding alcohol is fuel replacement.

Tuning on the street I like being conservative at set my goal in the 780-800 range as my safety cushion. At the track I will shoot for 740-760's with a motor thats not heat soaked. Some motors like 780's.. others like 720's.. I do notice the more mods like heads, cams, higher timing.. they tend to run higher O2's. Stockers seem to get away with lower O2's. Just depends. Watch your time slip, how the car reacts from 330, 1/8, 1/4.. and make decisions as to how its picking up. Make those changes accordingly in FP, timing, alky.

Hard to tell based on your post what changed from one day to another. I hope you can figure the issue.. let us know.

I have a lot of people that rely on the recall feature of the scanmaster.. it will record the highest knock registered..but if it happens on a shift??? its a useless number. Watch it rolling into the throttle.. if it comes fast then goes.. its not fueling but mechanical. Guys that run noisy cams know this for example.

HTH

[TOM J]

I added fuel by changing it with the chip the kr went away thanks for the input guys, ounce I get the fuel and alky dailed in and I add timing and if I get kr should adjust fuel first or alky or should just back off on timing

[Razor]

Originally posted by TOM J
I added fuel by changing it with the chip the kr went away thanks for the input guys, ounce I get the fuel and alky dailed in and I add timing and if I get kr should adjust fuel first or alky or should just back off on timing

You'll make more power on boost than timing. And based on turbo will dictate boost levels run.

Example a stock turbo.. once yout at 23-24 PSI... at this point start to add timing.. and alky to control the detonation. There comes a point that no matter what alky you spray will the KR go away. And that goes for leaning it out as well.

You'll have to take the car to the track and monitors what produces the most MPH.. and work at that.

No majic wand.