[Don231]

Hi, I was out trying my new Scanmaster-2 today and when I nailed it at about 70mph in 3rd gear I had about 7.7 degrees of knock. O2 counts were at 820. The outside air temp was 19 degrees. FP was set at 45 line off.I had about a gallon of xelene in full tank of 93.Boost set at between 16+17 pounds. Question is what should do to lower knock? Sorry so long and thanks.

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87-Turbo T TE44 BGC 23 Row innercooler,3in SSDP Hooker duel exaust,Green Stripe injectors,62mm TB,Plenum Spacer,Adjustable reg,Hot wired 340 walbro fuel pump,New kirban valve springs,new timing chain,gears,button,390 Richmond gears. posi rear air bags pinion snubber,10mm Magnacore wires. Never been to track.

 

[TTA89]

Is this when you first stepped on the gas? Did it downshift? Did the know go away if stayed in it?

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Mike Schoenfeld

 

[ES]

First reply is the 1st thing to know.
Is it retard or noise knock.
My drive train is sloppy and I get 4.6 as a high on shifts.
2nd did you watch the boost?
16-17 when normal temps. can go up a couple pounds at colder temps
but you should have been able to handle with your gas setup.
??? chip ???

 

[Guest]

One gallon of Xylene, in the amount of gas in your tank, did nothing to increase octane.
When it's that cold, probably more FP is needed to minimize knock, but even under ideal temps. and conditions, on pump gas, 15 psi should be the safe limit.
It is difficult to tune a turbo car for no knock under your conditions and IMHO, it's not worth it to hammer on a motor until you eliminate the knock, especially at these temps.
However, if you still must, lower boost to 10 psi and if no retard appears, increase it, a lb. at a time till you tickle the knock sensor . Then lower the boost by a 1/2 lb. or so.
ScanMaster may miss a boost spike, so you may have even incurred more retard, assumingly from knock, , which is another reason to boost your motor more conservatively.


Ron

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Ron's Custom Automotive
Certified NJ Emission Repair Facility
1-800-718-7667
GSCA # 2306 / PR Director
www.ronscustomauto.com
[email protected]

 

[ES]

Ron what is your highest acceptable knock?
I know that SM can miss a spike but I will see 3-4 dergees on shifts then the next frame will be .5 - 1.5.

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Thrasher 93 chip
340 walbro hot wired
9 in K & N
Adjustable wastegate / FP
SM 2.1
Autometer tach & boost
2.5 SS duels with loud mufflers.
Other rides
69 - 442 original owner
98 GS

 

[Guest]

Originally posted by ES:
Ron what is your highest acceptable knock?
I know that SM can miss a spike but I will see 3-4 dergees on shifts then the next frame will be .5 - 1.5.

If it were my car, I'd adjust and tune for "0" knock / spark retard. Although the Scanmaster is a wonderful scan tool, I will only ultimately rely on DS for the most positive and complete data stream recall.
Along with this, the sensativity and accuracy of your knock sensor is extremely critical.
DS is a very cheap insurance policy for any T/R motor driven under stressful conditions.

Ron



------------------
Ron's Custom Automotive
Certified NJ Emission Repair Facility
1-800-718-7667
GSCA # 2306 / PR Director
www.ronscustomauto.com
[email protected]