[eric schumacher]

Two comments
1-The small air regulators often use for boost adjusters work fine as fuel
regulators.

2- Why would you wonder for one minute if your fuel pump is adequate when it
is so easy to add a simple ashcroft type guage and some nylon line to
measure the fuel pressure under any condition you care to evaluate.  That is
what regulators are for e to take care of variations such as voltage and load.

Lots of Luck Eric

At 10:08 PM 2/23/97 +0000, you wrote:
>	Loyd (and others): Hope you don't mind my replying on the list,
>but I figure this discussion might help somebody else...
>
>>On the Turbo Regal list they talk about adjusting the regulator to the
>>pressure you need under boost, disconnecting the return line, and adding a
>>line to a vessel with a known size. Then energise the pump and measure how
long it takes to fill the vessel.
>
>	Did this yesterday. With the engine off (so batt voltage is
>somewhat lower, thus lower pump output), I got:
>
>	at 43 psi, 1650 cc/ 30 sec.
>	at 58 psi, 1300 cc/ 30 sec. (i.e. 15 psi boost level).
>
>By my calculation at .5 lb/hp hr BSFC, this should support over 450
>hp. Don't think I'm running THAT rich!
> 
>>i'm assuming the regulator is like the on the Turbo Regal, that discharges
>>a volume to the return line to maintain regulated pressure on the
>>injectors.
>
>	Correct. All the Bosch L-Jetronic (and I believe the Motronic)
>has this setup.
>
>>  There is are tricks you can do to a Bosch 233 regulator to make
>>them adjustible.  In the tube where the air inlet hose attaches, thread add
>>a roll pin and a allen head screw with small hole drilled through. 
>
>	I bought a 3.0 bar regulator (for a 728i) which screwed in place
>directly of the 2.5 bar. Since I had increased my engine size from
>3210 to 3453 cc, I needed 7.6% more fuel. It so happens that the
>square root of 3/2.5 is 9.5% more. This and a little tweaking of the
>AF meter spring put me in the ballpark.
>
>>Sounds like you need to get a reading off the O2 sensor during a WOT blast.
>> Need to have around .8 mv otherwise the engine will detonate.  Very tough
>>on piston tops, head gaskets and the top rod bearing.  Hopefully you have
>>instrumentation on fuel pressure, turbo boost pressure etc. if you are
>>pushing this that hard.
>
>	I do. Fuel pressure (and a pyrometer in the exhaust manifold).
>It's interesting how much hotter the exhaust gets when you're getting
>too lean!
>
>>Finally the amount of spark advance should not be so aggresive with NOS,
>>from my reading on various lists.
>
>	True, but 50 hp of NOS/gasoline only requires about 1-1.5 degree
>of extra retard. I have an MSD "Boost Timing Master" which I use
>instead of the distributor diaphragm retard.
>
>>  Is there a way to monitor the amount of retard the ECU performs after
sensing a knock.
>
>	Only my ears. The L-Jetronic '81 doesn't have provision for a
>knock sensor.
>
>>  the only tools you have left are an adjustible wastegate
>
>	Got one of those too (modified it myself for a dashboard
>"horsepower screw".
>
>>Sounds like you should have licked the fuel problem, with a textbook
>>solution of larger line, larger wire for higher current, etc.
>
>	You're right! I'm beginning to wonder if it isn't electrical
>after all...
>
>> members have had problems with
>>electrical gremblins.  Under high load the engine twists and the electrical
>>connections may get stretched.  An engine tie down is recommended, with a
>>check of all cables etc.
>
>	Now _this_ hadn't occurred to me... I'll try it this weekend and
>let you know!
>Thanks to all who replied.
>-Charles
>'81 745i working most of the time ;)
>