Nate,
Welcome aboard the great Roller Rocker shoot-out!!!
I guess I shouldn't have sent out another Question so soon, I had not
intended for it to be the 13th.
No matter though...the RPM's vs power thing was meant to find the ones
who know their engines.
Three have responded correctly.
P.S. I have no idea what the answer is to your question. A 250 is the
earliest model Triumph I've owned so I could only speculate as to why
the gearbox works better with earlier models.
-----Original Message-----
I attempted to answer all of the earlier questions, but somehow, my post
did
not make it onto the list. !@#$%^ Hotmail perhaps, this list is far too
valuable for my spambox... gotta change that.
Anyhow, I will try again, with this question, as it seems most of the
original 12 have now been answered with responses close to those I would
have provided ( I may add some of my own thoughts at a later time).
#13) At what RPM does a stock 6/250 stop producing power? I'm not
talking
about whether or not it will achieve redline...I want to know when the
engine stops making power, at what point is it futile to hold the
accelerator any longer before shifting. This is a drivers
question...get it within 100RPM's. Think about what I've said, go
drive your car if need be!
I don't know what I was thinking when I said within 100RPM's. 300 would
have been fair. Sorry! Jim
My TR6, an early 73, seems to produce little more meaningful than noise
beyond 4200 RPM. The factory published 4500 as a peak figure, and given
the
pathetic stock timing curve, I have no reason to doubt that. I have
done
considerable tuning with ignition advance, making great gains in
drivability
and fuel economy in the 1500-4000 RPM range. No matter what I have
done,
fuel or ignition wise, 4200 seems to be about the limit of the stock
cam.
Note should be made here that I run basically straight pipes for exhaust
(too loud) and modified individual filters with a 3/8" radius funnel
into
the carbs. The filter mods make noticeable increases over no filters at
all. Optimum acceleration times seem to come by shifting at 4800 or so.
No
point in revving to redline with the stock setup.
I bet a stock TR engine might still be making some power at 8000 RPM
when
the big bang theory would dictate no further power would ever be
produced by
that engine. Didn't try that though!
Nate Steiner
CF140U
P.S. Here's one for you Jim, and others as well. Why does the same
basic
gearbox shift nicer in a TR2, 3, or early 4 than in a TR6. Lets leave
the
hydraulic issues out of it, there is at least one other reason. Sorry,
no
free parts from me (but I'll make a heckuva deal on an 1800 DOHC Fiat
motor).
Robert Lang
In a stock car, I'd have to say things "stop happening" at around 4500,
more or less. Change to K&N's and it does up a tad, maybe 150 RPMs.
Mitch Seff
I would have to say "peak " horsepower is reached at 4500 rpm, for later
models @ 104hp. After this the hp falls off even though rpm's still
climb.
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