Knock will bump your fuel curve a little
which will make a difference on racing fuel if
you are just pinging slightly, but may not make a
difference with pump gas. I use EGT and Knock
sensor to dial in my car that runs racing fuel,
and strictly go by KR on my pump/gas and alcohol
car. Unless you have a Speed Pro, using 02 is about useless for
tuning on our cars because a 1 wire readout varies a bunch vs EGT. Many
people notice the 02 coming down toward the end of the run......because
the EGT is going up. Unreliable. However, some guys have success
with 02 because it establishes a "pattern" and they recognize that
pattern and can associate it with the way the car runs.
Unless you
have an odd size bore
or need a lighter piston to spin the motor higher, stay with the stock
tight fitting pistons. They were designed along the lines of diesel piston's, specifically
designed for our application of abuse. The top ring sits in cast iron
and have shown to be superior in reliability to a common forged in dyno
detonation/failure tests. Also, to eliminate valve train noise
possibilities, stay with the stock cam with 82.5 pounds(factory specs)
of valve seat pressure. It is much better to be overturboed and
undercammed. It is fairly easy to be able to run High 10's with the
stock cam. Besides that, after market cams have a tendency to go flat.
If you are not happy with high 10's and put a larger cam in, you
may experience false knock and you will have to program the kr sensor
out and be prone to failure due to knock so you must, or should, run racing fuel.
Another problem you will run into is the
reliability of the block. You can take it to the "edge" with a stock
cam, so why go bigger if you want something that is going to be
reliable. Lately I have observed 2 motors with the webbing blown out,
with steel caps on the mains. Based on this observation, I have formed
the opinion that it is better to put a girdle over the steel caps, if
you already have them, or the stock caps, like I did and possibly avoid
having to line bore the motor. The idea here is to build a motor that
will go 100,000 miles rather than an after market short block that might
go 20,000 miles. Spend a few more dollars up front and save a bundle
down the road. Buick specs for clearances are fairly tight. My motor
runs 1.5 on the mains and rods, and like Ruggles told me, it is critical
to keep it tight and maintain oil pressure from the stock pump. He has
several reasons why not to use the hi volume pump.
Heads
are another concern. The stock torque-to-yield head bolts were specifically
designed for our application. I would never consider using studs, or
anything else with iron heads. Lawrence Conley once said, when "Black"
was just into the 10's that stock head bolts with 1 steel shim 85 gasket
coated with clear Permatex RTV silicone gave him reliability. The gasket
is much thinner than stock. The fatter the gasket, the easier it is to
push it out. I followed Lawrence Conley's advice and have not had a head
gasket problem since on my black car.. The factory head bolts are not
designed to be used over, so always use new ones. The heads really are
not "lifting", but rather the combustion surface is flexing up into the
water jacket due to lack of webbing on the back side. This is when it
tries to push the gasket out. You may have observed that the gasket
likes to come out under the intake or on the exhaust side. This is where
the deck support webbing is the least. Staking the heads by putting pins
in to hold the combustion surface from flexing, may be a partial
solution to the problem. Champion Heads is the only company I know that
does it.
One of the neatest things about the cars shown in the
picture section is the the fact that they repeat from run
to run, from week to week. Once
these cars were dialed
in, we didn't have to touch any of the parameters again. That's one of the keys to being able to have more fun
and
reliability, in the sense that you don't have
to waste a bunch of
runs dialing it in. Everybody
knows that every time you jump on one of these
motors, the fuse gets a little shorter. The key to it
is following the rules, and the rules are keep everything the same. Keep the boost fixed, and keep the same gas in
it all the time. Jeff hasn't had to touch anything
concerning the engine or thumbwheel position going
on 4 years now on his 10.01 car. For that matter,
the transmission is going on its 4th year now as
well. The white car can sit for a month, and I can
jump in it, and it will have 26 pounds of boost and
never miss a beat. When you set a car up to repeat,
you can anticipate a map sensor pretty easily. The
manufacturers have been doing that with their toys
for years.
As far as the block learn is concerned, there are a
bunch of "cells"that the 02 sensor teaches on a
typical car. These cells provide a fuel air ratio
correction for various loads on the motor. The
larger the injector, the tougher it is for an 02 to deal
with
an increasingly erratic fuel curve. Basically
it gets pretty tough to take a single chip and do it
all in any car using closed loop. When I say that, I
mean cars with large injectors and cams
and what
not, and expect them to provide a peak fuel curve with
drivability and idle quality. It can be done, but its just
a lot more messing around than I care to do, not to
mention
continuosly fouling out the 02 with
lead. The MaxEffort allows you to program the cells
up yourself
and forget it. The
timing is fixed for a reason, and the reason is: You can pretty much dial your boost accordingly, and a lot of
times end up with the same results as going up and
down with the timing.
I have observed that a lot of people are bound
and
determined to run these things on pump gas. Well, years
of experience has taught me that after X amount of
cylinder pressure, combined with X amount
of cylinder temperature, is going to cause detonation. I would
never consider jumping on my black car without
straight C16 in it, and in my pump gas
car I would
never consider jumping on it without lots of alcohol,
and keeping it dialed back from the edge a little.
That's how I got 120,000 miles on that thing without
pulling
a valve cover, and it has had a John Craig TA63 turbo on it for quite some time
now.
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