I think we should focus on the improved HP ratings after the modifications rather than the actual figures given. The dyno that we (Neal, myself and some others) use in Durban is our benchmark and although it is believed to be reliable, I don't think it is reflecting TRUE REAR WHEEL HORSEPOWER. I found an interesting read here http://www.factorypro.com/dyno/true1.html and find it very difficult to believe that a modified NSR300 or a modified MC21 with NF5 barrels (my bike) could possibly make more "true rear wheel horsepower" than a kitted '98 HONDA RS250. In a previous post I saw that there was mention of an NSR with NF5 barrels (possibly Matt from Tyga's) that made 76HP in the good old US of A. This would be similar to the "not even close to stockish Yam TZ250 00-02".
So with all due respect to all the doctors and gurus out there, I think that horsepower figures should be looked at as an approximate value, not a "mine's bigger than yours" value. At least until everyone in the world uses the same dyno, and that's not going to happen!
In the UK most people use DynoJet dyno's and tend to use the DynoJet calculated HP at the flywheel figure.
This is something like 60bhp for a good, stock, fresh, deresticted NSR 250. Anything up to 66bhp or so for a carefully tweaked one. Steve's F3 monster makes 74bhp. For comparision a stock 1991 RS250 makes 72bhp and 1996 one makes 76bhp.
Some others use DynoPro's, which can either give a true rear wheel HP figure or a DynoJet calculated figure.
Very few other dynos are in use over here. _________________ Please do not PM me technical questions, if you can't find it on the Forum start a thread
I do not have a before reading as the barrels needed to be machined .
I bought my barrels from a local breaker .
I am running a PGM II , the local race guys here open the box and join 2 things together and install a switch . All i know is that it made the graph smoother and more hp . He said it alters the powervale opning . I assume it alters the timing too . I will check my plugs at the track next weekend .
ah i see, no photo required thanks i just wasn't aware of the PGM II modification.
I look forward to reading about how it performs on track! - i've never dynoed my 300 (which is just a 'stock' Tyga kit), my only guage of its performance has been how it compares to other bikes down the straights at trackdays. _________________ After years of moaning about immigrants now i am one...
Yes, that's kind of my point. Those numbers in isolation are pretty meaningless. Not saying that the tool isn't useful; just reinforcing your point that the only really informative use for dyno's is to measure changes on the same bike on the same rig or between different motors on the same rig - running the same settings etc.
That said, I have quite a lot of raw data for different bikes and same-model bikes running on different dynojet and dyna-pro rigs, and there seems to be pretty good consistency between the same kind of rig in different locations if you feed the raw data into the viewer with a set correction factor etc.
I've never encountered one of the Dyno Power rigs though. Are they manufactured in SA? Both look like reasonable power curves of course, which is the most important thing .
I've never encountered one of the Dyno Power rigs though. Are they manufactured in SA?
Hyper Power International rigs are made in SA and I believe they are popular in Australia too.
Did you see the spec on the TZR in question? Its a modified 3XV9 SPR RC Sugo kit (ex Kenny Roberts Track School). Very rare and sought after. I don't agree with the figure on the graph, but I do know that this particular bike is something special and that is all I have to say about that evil Yamathing!
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