Good point. My thoughts on PI are similar after reading a number of replies
to the PI issue from others on the list. The PI system in of itself gives
you no more horsepower gain on an otherwise stock engine than bolting on
triple webers or any other method of delivering more fuel. The UK model
TR6's gained most of their horsepower through the higher compression ratio
and more aggressive cam profile. The PI system is simply another method of
feeding fuel into the engine. If the engine doesn't have the compression or
cam to use it all, then it seems that adding PI doesn't accomplish anything
at all. As someone replied to me, its only when you get the engine modified
to the point where it can burn more fuel than the strombergs deliver that
you gain from another method of introducing fuel (such as PI or triple
webers).
Regards, Greg
76 TR6 (totally stock for now)
68 MGB/GT
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From: Janssen, Lee K [SMTP:lee.k.janssen@lmco.com]
Sent: Monday, January 18, 1999 3:50 PM
To: 'triumphs'
Subject: TR6 PI power gains
It is interesting to note the power gain achieved by replacing the
Stomberg
carbs with PI as reported by Kastner:
4000 rpm - 5.5% increase
5000 rpm - 9.4% increase
6000 rpm - 12.3 % increase
IMHO low rpm power should be nearly identical for both fuel systems.
The 2.5 PI generated most of the power increases through higher
compression
and a longer duration cam.
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