Re: Homemade larger HFM tube, was fuel pressure regulators.

[jkerouac@xxxxxxxxxxxxx]

I anticipated some controversy over making my own larger HFM tube with 
the stock US spec sensor.
Its clear there are different philosophies and approaches to performance.
My HFM tube at 3/8 larger than US spec, 1/4 inch smaller than euro, will 
not increase max HP at higher revs as much as the 3 1/2 diameter Euro 
HFM.  Euro HFM setups to me felt peaky.     Based on prior dyno day 
tests of a euro HFM, I believe I _will obtain more torque.  This is the 
same idea as using different venturi sizes in a carburetor.  Its not the 
biggest venturi you fit in the carb, its the one that puts the power 
curve where you want it to be.  A street car power curve is not what I 
would want if I was one of you track guys.  Nor do I want a track car 
power curve on a street car.
As a street car, its the midrange torque and throttle response rather 
than absolute top high end that I'm concerned with.

Btw, this morning in 53 degree air wiht a cold engine, it started up and 
idled fine.  Seems the slight occasional variance at idle (<50rpm, 
versus rock solid needle before) is with a hot engine when idling right 
after fuller throttle driving.  then the system stabilized again. 
 Having driven many thousands of miles with Weber sidedrafts in the 
past, to me this is not a concern.

More important, after another drive with the larger tube today, no check 
engine light and the spark plugs still look fine.

If nothing else, I'll modify my own FPR for about half a bar higher 
pressure.  Internally these can't be different to modify than the old 
bell shaped and E30 styles.

The DIY approach to mods is not always successful, however when it is, 
its where innovation originates.
Some people's approaches is where other's people's profits stem from.
We are each happy with our own approaches.
Some people get off on expensive bang for the buck.  With my car, I 
prefer the intimacy of doing it myself.
Carpe Diem,

'jk



alex.fadeev@domain.elided wrote:

>jkerouac@domain.elided wrote:
>  
>
>>re:  Homemade larger HFM tube, was fuel pressure regulators.

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