Alez
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| posted on 7/2/06 at 01:36 PM |
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Red line and long straights
Hi!
I've attended a couple of track days with my Blade. The engine is a stock '97 and the clock red starts at 11000 rpm. I've been
reaching 11000-11500 rpm for upshifts, which feels fine. However, I'm not comfortable with taking the revs so high and making the engine stay
like that steady. I'm not sure if it's a matter of getting used to it, but to me it feels like it will end up burning or blowing up
(although the engine is sound and working great so far, and I take good care of oil level and so on).
What I'm doing just now is I'm taking the car to 190 KPH (or 114 MPH) which is about 10500 rpm if memory serves. Obviously, if I'm
safe to go beyond that, it would give me better lap times without any improvement on my skills (no challenge for me). From the feeling I get when
accelerating, I think I have enough power to reach red on a flat straight (ideally I'd like slightly longer gears but this is what I have just
now), which is about 200 KPH (or 120 MPH) at 11000 rpm, and keep the engine there for quite a few seconds on the longer straights.
What do you track day freaks do to your engines??
Cheers,
Alex
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melly-g
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| posted on 7/2/06 at 01:44 PM |
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Surely the blade engine should be able to rev to about 16000rpm with no problems?
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froggy
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| posted on 7/2/06 at 02:12 PM |
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if you think about it the really high end of the rev range doesnt get much extended use as you normally shift up as you approach that sort of engine
speed and in top gear you wouldnt reach those sort of engine speeds on a bike that quickly as you would be travelling at serious speed to get
anywhere near the redline. most road bikes never get within 2-3 thousand rpm of the redline in top and through the gears touch max revs for maybe a
second before changing gear. not much help to you but if it smells like its in pain then it probably is
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ChrisGamlin
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| posted on 7/2/06 at 02:15 PM |
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It certainly won't rev to 16k melly-g, only a few 600's will do that, let alone 1000cc+ engines.
Alex, 11,750 is where the limiter will kick in, running it up to this in top is fine although once you hit the limiter back off very slightly and hold
it just below so you're not constantly bouncing on and off it.
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ned
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| posted on 7/2/06 at 02:41 PM |
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if it is a regular occurence and its holding peak rpm for a long time maybe its worth looking at the gearing ie dif?
probably a bit drastic though, do as chris suggests and see how long you have to hold top revs for on the straights. Are these relatively long or
short circuits Alex?
cheers,
Ned.
beware, I've got yellow skin
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Alez
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| posted on 7/2/06 at 02:51 PM |
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OK Chris, thank you, so I just ignore the red line (at 11000 rpm) and keep the engine steady just below the 11750 rpm you mentioned, for the quite few
seconds that those straights last. Hmm, I need to change mentality, I keep feeling bad about doing it, even at 11000 rpm steady.
The other thing is 11750 rpm would give about 128.2 MPH so I may not want to go that far or maybe I don't have the engine power anyway..
Thanks!
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Alez
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| posted on 7/2/06 at 02:57 PM |
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Hi Ned, we don't get many opportunities for track days here in Spain, not at all compared to you guys (I'm planning 2-3 this YEAR). So
yes, short tracks are much more enjoyable for my type of car, but I tend to take anything I can down here
What I'm describing is happening tipically once-twice per lap (couple longest strights of the track), for some seconds each, specially on longer
tracks (I haven't measured it really).
Cheers,
Alex
[Edited on 7/2/06 by Alez]
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ChrisGamlin
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| posted on 7/2/06 at 02:59 PM |
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You'll be lucky to pull much over 120mph on all but the longest straights, if I remember correctly your car is a live axle with a 3.54 diff so
the same gearing as my car when I had the blade assuming similar tyre sizes, and only a couple of time did I manage to max it out on the limiter in
top, the rest of the time its so slow to get from 115-125mph that you'll rarely get there on a conventional circuit, but you'll get to
110-115mph very quickly hence why you're having to hold back quite often.
At the end of the day if the engine lunches itself at 11,500rpm then there was probably something wrong and it was only a matter of time before it
lunched itself at 10,500rpm anyway, because it should be able to sit at those revs all day long without doing damage. If you've not hit it
before have a hunt for the rev limiter in the lower gears so you know what it feels like and are confident that it exists so next time you're on
a fast straight you can relax and not have to watch the needle all the time.
[Edited on 7/2/06 by ChrisGamlin]
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UncleFista
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| posted on 7/2/06 at 03:00 PM |
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How about a couple of slightly larger wheels/tyres specially for track days ?
It'd up your ratio's and be cheap and easy to change ?
Just a thought...
Tony Bond / UncleFista
Love is like a snowmobile, speeding across the frozen tundra.
Which suddenly flips, pinning you underneath.
At night the ice-weasels come...
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Alez
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| posted on 7/2/06 at 03:17 PM |
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Excellent advice Chris, thank you.
Yes I did a few calcs for increasing the wheel size but going from 13" to say 15" didn't improve top speed so much, and I was not
too keen on the change anyway because of unsprung weight and overall weight.
Anyway, following Chris' advice gives me A LOT more top speed, probably more than I can handle (or the engine power can handle) so it may be
just fine already
Chris, I can't remember my diff ratio, you know more about my car than myself!!  All I know is I do 190 KPH at 10500 rpm on 185/60R13 If
you can remember any relationship of this kind for your car I can do the math very easily and check diff ratios..
Cheers,
Alex
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cossey
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| posted on 7/2/06 at 05:34 PM |
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also with 135bhp ish blade in a locost the aerodynamics will limit you some what so even at very fast circuits you arent going to be above 11000 for
that long.
the newer litre bikes are hitting 13k+ and they arent that much different internally so you unlikely to have a problem
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mad-butcher
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| posted on 7/2/06 at 07:41 PM |
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my offspring had the blade on the limiter all the time at the last aintree despite me kicking his arse round the paddock all day sounded great the
first couple of times the way it popped. if the R1 is as safe an engine as the blade I'll be a happy bunny.
tony
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Alez
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| posted on 8/2/06 at 07:51 AM |
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Aaaallright guys!!
Cossey my engine spec is 128 bhp stock, so yes both power and aerodynamics are dictating top speed.
quote:
the newer litre bikes are hitting 13k+ and they arent that much different internally so you unlikely to have a problem
I think at the end of the day it's all down to heat sinking, pretty much like semiconductors (lots of people overclock their Intel
microproccessors). The engines look very similar, but may be that either they can handle a slightly higher internal temperature in steady regime or
they incorporate some slight improvement to take more heat out.
Cheers,
Alex
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cossey
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| posted on 8/2/06 at 08:31 AM |
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the temperature of the engine wont be much higher on the newer engines even though the blocks themselves are practically the same as the old ones.
revability depends on pistons speed (determined by the stroke) the weight stiffness and balance of the crank/rods/pistons and the breathing abilty of
the head (this is more that the valve train must be able to work without bounce at the higher revs)
if you compare the 2002-2003 r1 with the 2004-2006 r1 the blocks are very similar but although they are the same capacity the later engine has a much
bigger bore and smaller stroke so eventhough the engine revs to 13750rpm as opposed to 11750rpm the piston speed isnt that much higher.
the later engine also has lighter rods and pistons.
the m ain change between them is the head which is much better on the later engine so it can flow better at higher revs (essential to keep volumetric
efficiency high).
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Alez
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| posted on 8/2/06 at 11:14 AM |
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Hmm OK, so you know what you are talking about!! As opposed to.. myself, talking random sh1t3!! 
Nice one, thanks!
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Hellfire
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| posted on 8/2/06 at 12:52 PM |
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Alez, also bear in mind that the blade engine makes peak power at revs short of the red line, so ideally you shouldn't be anywhere near the rev
limiter on upshifts. And like Chris says, you'll struggle to hit the limiter in sixth anyway unless you're on a really long straight.
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Alez
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| posted on 8/2/06 at 02:10 PM |
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Cheers Hellfire
Well, first test already: as suggested by Chris, took it to the limiter in a lower gear, checked.. it has a working limiter, and it triggers at about
11750 as expected
Cheers,
Alex
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