Ns power.

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Luciano
Posts: 156
Joined: Sat May 10, 2003 1:01 am
Location: Sweden, Malmö

Post by Luciano »

Hi All.
Here is what I can contribute with:
NS from Germany when I put it on the dyno completely standard NS with 37554 km on the clock. It got impressive 46.8 SAE Horsepower...
The mechanic told me that he got 1 hp when he put oil on the chain. But I do not know if it was before or after this dyno run...

So I believe is that the NS has standard on the rear wheel approximately 50 SAE hp.
Best regards, Luciano.
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Torque over the whole register.

Alastair
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Post by Alastair »

That illustrates quite nicely why the bike is at its happiest at 100mph in top gear.

It would be great to get some graphs of a totally standard engine with Shepherd pipes, Jolly Motos and finally the Lomas pipes. Karl might be able to supply the latter? Any takers?

Mat Grant
Posts: 357
Joined: Mon Sep 09, 2002 1:01 am
Location: Sandhurst

Post by Mat Grant »

Hi,

I've got a dyno chart here that came with the Rothmans NS, it says 'standard engine swarbrick end cans' I'd forgotten about that as I've taken them off.

There is no date on the chart, so I can't tell if it's with or without the BDK 'adjustable' ignition that is on the bike now.

The peak it at just over 52 bhp, maybe 53. So it must have ben a good one(?) Sadly I have no chart for the bike with the 500 kit on, but it had the standard pipes so it probably wasnt making much power.

I'll scan it in and try to attach it.

Mat.
Mat Grant

Mat Grant
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Post by Mat Grant »

Hi,

While on the subject of NS power - Steve Moore emailed me, he said his NS500 engine made 90.2 bhp on the dyno before he owned it. He doesn't have a chart though. It sounds believable to me, it's only 30 bhp per cylinder. You can make RD125s go up to around 30bhp....

Mat.
Mat Grant

Alastair
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Post by Alastair »

If Steve D is getting 70hp and having to use YPVS reed valves to do that ,presumably to flow more air, I'd suggest talk of 90hp is a little fanciful. Could be wrong though! Surely you'd have to do some major work on crankcase volume somewhere along the line to go significantly over 70hp and that would take you into the realms of redesigning the whole engine. Further, given the fragile nature of the gearbox with a standard 50hp, trying to ride it with 90hp at rear wheel would be suicidal.

Thinking of those that chose to use the NS powerplant as an alternative to a 250cc unit in an RGV or similar chassis, one has to ask the question, why if in stock trim it produces only slightly more power? Surely a more modern 250cc motor could be tuned to produce more than the NS lump?

gumball
Posts: 312
Joined: Sun Jul 20, 2003 1:01 am

Post by gumball »

Elmarie wrote:Further, given the fragile nature of the gearbox with a standard 50hp, trying to ride it with 90hp at rear wheel would be suicidal.
A stronger metal should be used. The shaft in particular which holds in the gears in place. Stronger clutch springs to hold the gear in and over sized dogs.
HIGH RPM IS WHERE IT IS!
Tread With Caution

Mat Grant
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Location: Sandhurst

Post by Mat Grant »

I think the limit for an RGV is about 70 - 75 BHP. I used to have a Stan Stephens race tuned RGV, it made a load more power than standard, but only for 500 rpm, then stopped dead at 12,000 rpm. In the 500rpm wide powerband it really zipped forward, it was like having two powerbands, but it was difficult to use.

My project bike 'felt' like about 65BHP, but the difference was that it went from about 7000 to 10500 in useable power. As I'm not the worlds greatest rider this makes it loads easier to go fast on :) . At uni I had an RGV and on slimy winter roads it was virtually unuseable in the power.

I think the limit to air flow is not the reeds, but the carbs. I have had a few disscussions with Terry Shepherd on this subject, he did a load of development with a guy in Florida that raced an NS, tried loads of different reeds and it didn't make any difference. Changing to Lectron carbs was the only thing that made a big difference.

The other thing which 'should' help flow on the inlet side is the removal of the Bridge on the inlet port - if you look at CR125s etc, in fact most two strokes, they have much more inlet area and a proper boost port. The only two sets of those I know of are the knackered ones I've got and Wavy Davys (used to be Hakan Olsons).

Also the HRC NSR250 kit involves either removal of the airbox lid or putting holes in it, and the removal of the filter, there is probably some restriction here as well on the NS400.

So we need Wavydavy to come up with a dyno chart(!)

I really think that if you had a 500cc NS with fully tuned ports for top end power, bigger carbs, rejetted for no airfilter or airbox lid, programmable ignition with a bit more advance, debridged on the inlet port, you'd get a lot of power.

A bit like how an RG500 makes about 75 bhp as standard, but can be made to produce loads of power, with development the NS could be much higher than 70bhp.

But this is all speculation... ie bullshit :lol:

Mat.
Mat Grant

wavydavy
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Post by wavydavy »

So we need Wavydavy to come up with a dyno chart(!)
I will, gladly, if someone can point me in the direction of a shop with a Dynojet 250(preferably, but others may be considered - just I know the 250 is supposed to be more accurate and able to calculate compensation factors better) in reasonable riding distance of Cahors...

That's about 600km South of Paris, Departement 46 (handy if you like Rossi, not so if you don't 'cos you have to have a '46' on your numberplate).

Closest I know of is Nimes, about 100km, but they only have a 150.

Dave

steve d
Posts: 66
Joined: Sun Feb 27, 2005 12:46 pm

ns power

Post by steve d »

ns power

Hi,
I'd agree (mostly) with Alastair. but if there is such a thing as a 90 bhp ns I'd certainly like to know its full spec.
I,d think you would need a new full ignition - not easy on a road bike.

70 bhp is where im at now. A few more bhp I think I can find , but 90?- seems a bit out of reach.

As Mat says, a few more ns dyno graphs would help.
(mine has bridged inlets,Mat).

Ns motors have a fair spread , compared to a 250.
Check out my tzr rc , run on the same dyno, same day, as the 400 graph shown earlier.
A good peak figure, but ns makes a better road bike.

Steve.
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Alastair
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Post by Alastair »

Mat Grant wrote: A bit like how an RG500 makes about 75 bhp as standard, but can be made to produce loads of power, with development the NS could be much higher than 70bhp.
Mat.
Steve D wrote:Ns motors have a fair spread , compared to a 250.
Fair point about the spread of useable power, but if you are going to all the expense of a motor swap, why the hell go for the NS motor when you can get equal or more power than a tuned NS from a standard RG500 or RZ500 motor :shock: Then you get even better useability and the option to tune for even more stink with better reliability and no Russian roulette with the gearbox.

I'm getting a little off the original dyno graph topic here........[/quote]

Mat Grant
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Post by Mat Grant »

Well in my case it was a case of going for the RGV conversion rather than going for the engine choice, as I already had the engine. The other reason for going for the NS is it is a lot cheaper. How good it is depends on whether you think of it as an NS400 with upgraded frame, wheels, brakes, suspension etc or as an RGV with a different engine.

Having owned four NS400s, one of which ended up in the RGV frame, as an upgrade to an NS400 it is an excellent upgrade. It is definitely loads better handling and braking, loads more grip, loads more feedback.

If you're starting from scratch, then it is a different question, I was thinking of doing an RG500 conversion, but they are so expensive and hard to get hold of, plus they aren't perfect in the handling department. Also a much more expensive conversion.

Before I wasted £1300 on the (broken) 500 conversion (which to be fair includes a whole Rothmans NS400 which I may sell and get some of that money back), the bike was motd and on the road for about 2 grand (this includes selling the left over bits from the NS and RGV).

If I saw that bike for sale for 2 grand I would definitely buy it, so it was a good value conversion.

To be honest all this kind of stuff is quite mad when you think for about 4 or 5 grand you can buy a modern fireblade / cbr600 etc that will be very fast and reliable.

Final point on BHP - the nearest parallel I can think of is the 350LC / ypvs. I've seen a few of these with up to 70 bhp from 350cc. The NS500 has this plus 1 more cylinder. So if you got the NS up to the state of tune/efficiency that a ypvs is at, you'd get over 90bhp.

YPVS Porting, reed sizes, carbs etc are all similar to the NS, the difference is (I think) that there are millions of people with them and loads of tuners developing them. For example in the next village from me where I lived in Leicestershire, there was a guy who built a 350lc with Nitrous oxide and dry clutch which was dynod at around 80bhp. When I had my first NS there was only one other I knew about - and that was in Nottingham, I only knew about it because he got it fixed at the same Honda dealer as I got mine from.

If the NS had been sold in the same numbers as the YPVS I think there'd be loads more tuning/trick parts available.

An NS400 is basically three 125 eninges. If you can get 30bhp out of a 1980s 125, then you could get it from an NS if yuou worked on it enough.

Reliability - I've only had one problem with an NS, and that was a bearing. If you were to go on the RGV forum and ask how many people have had engine melt downs, or the NSR forum, you'd find it's a big number. One of the recommended actions on buying an RGV is to strip the powervavles and check / clean them. My first NS I had for about two years, it was about 7 years old then, I thrashed it mercillessly, I put good oil in it, and in never had any problems.

Mat.
Mat Grant

bloodnut
Posts: 334
Joined: Sat Jul 03, 2004 1:58 am
Location: New Zealand

Post by bloodnut »

"Fair point about the spread of useable power, but if you are going to all the expense of a motor swap, why the hell go for the NS motor when you can get equal or more power than a tuned NS from a standard RG500 or RZ500 motor :shock: Then you get even better useability and the option to tune for even more stink with better reliability and no Russian roulette with the gearbox.

I'm getting a little off the original dyno graph topic here........
Because the ns 400 motor has the following advantages over an rg or rz500.

- Its a proper 90 degree v twin
- It has reed valve induction
- It has a big bang firing pattern easily and cheaply adapted to modern ignitions
- It is compact and light
- It doesn’t blow cranks all the time
- It doesn’t blow clutches when modified
- It costs less to modify than a 4 cylinder
- It is Honda reliable.
- Its fits into the RGV chassis like a glove.

It beats an rgv motor because they blow to bits above 70 hp and that’s a very peaky 70 hp, the ns motor produces gorgeous torque to rip you out of corners from 6000 on.

It is the purest design of the three gp reps.

IMHO

Cheers
Jared
Last edited by bloodnut on Fri Jan 27, 2006 11:08 pm, edited 1 time in total.
if all else fails - gas it

drive2fast
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Joined: Wed Aug 06, 2003 1:01 am
Location: Germany

Post by drive2fast »

The Lomas Pipes add around 8 PS with atac in place, that's the last info
I have, which is already some month's old, so that could have changed.
I have the dyno graph somewhere, will try to find it.From what I remember
my bike had 52 PS on the dyno in standard configuration, with the JL pipes
it was around 60-61 PS.

I'm the owner of the bike JL build the pipes with (the bike you can see on http://www.rg500.com .
I haven't had a chance to test the pipes on the road myself yet, as the bike is still at Jim's place, over the winter I don't need it anyway.
Once the bike is back, I will post some pictures and my impression (sorry I don't have a dyno).
Maybe Karl can post an update on the pipes.

steve d
Posts: 66
Joined: Sun Feb 27, 2005 12:46 pm

ns power

Post by steve d »

ns power.

Hi , more recent dyno. stuff.

Note now without ypvs reeds.

Steve.

ps it's still not quite set up right - note the power fade in 5th and top
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Mat Grant
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Post by Mat Grant »

Hi Steve,

Interesting - any major changes since the last dyno other than the ypvs reeds? Actually one thing I was thinking was that if the ypvs reeds are the same as banshee reeds there may be some wacky 'double reed' type thing out there that may be useful(?).

Cheers, Mat.
Mat Grant

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