Hi.

What is the top power that you guys have got out of an nsr? I've been over at the rgv forum and it seems their top HP is around 68-69 and with fairly narrow curve.

So
1.what the top HP figure and
2. what the average race tuned HP?
3. how narrow a powerband is this?

cheers,
Max

RGV power curves are laughable!



One of the better MC21's... on Esso's finest 97/98 pump fuel! No AVGAS/race fuel required!

Just shy of 75rwhp.
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Andy.
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maxsummers1 wrote:
2. what the average race tuned HP?

There was to my knowledge one NSR regularly racing in the UK last year - mine, it's pretty stock and should make around 62bhp when I've re-ringed it. It made 60 and a bit on a tired 2nd hand front barrel/piston/rings fitted for a trackday just after the season ended.
I'd like more go but while it's tune the engine or pay to enter races, I know which I'll choose.

VJ22 RGV's? Didn't see any stay togeather for a whole weekend.
Aprilia RS250's? Freddy Pett's makes 6bhp more than a piped/wireplaced MC21 and about 4 more than an Aprilia challenge cup spec RS250 at the Krazykat dyno, so that should be around 68bhp, it also ate it's gearbox several times.
Dave Reynolds Aprilia made a tad under 70bhp on the dyno used for the graph in Andy's post.

So they can be good but you put a fairly stock NSR on a dyno and you'll get a graph like this, try it with an RGV and you get one like this, which would you rather try to wind on at full lean?
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Andy when you say "RGV power curves are laughable!", do you mean in the sense that they don't have the same potential to make as much maximum power as an NSR, or that the shape of the curve isn't as good?

Edit: How much work do you have to do to squeeze just under 75RWHP out of an NSR!?

Indeed the nsr does have a nice curve. The thing that gets me with the rgv with the guys on the rgv forum with how they continue to try to find more revs with thier already PEAKY engine! TBH I want a bike that still has a bit of midrange as I'm not quite rossi.

How strong is the crank and gearbox in an mc21? How reliable is that mc21 andy?

is there a pressurised airbox readily avaliable for the nsr?

How much room is there within the frame around the carbs? Can you compare this with an rgv (as i've worked on one of them)-is there more or less free space?

What the standard squish? How tight is run on the race-prepped engines? How well designed are the combustion chambers?

Sorry for all the questions guys-just trying to get started on developing a bike

Hi , I race against a vj22 , my bike made a few more hp than the vj on the same dyno . I agree that his power was all upstairs and not much low done . BUT - his bike would pull away out of the corner with his close ratio box , he could get through the gears quicker .
I hope to have solved this problem now with my own closer ratio box .

Neal

Major_Tom wrote:
Edit: How much work do you have to do to squeeze just under 75RWHP out of an NSR!?

Erm, quite a lot. That's 3 bhp more than a stock 1992 NF5 RS makes!

A more realistic figure for an NSR running stock crank, modded cases, ported barrels and optimal compression might be very high 60's bhp.

Other questions;

I've never heard of an NSR gearbox problem, it's very similar to an RS box, the crank is good too but needs someone who really knows what they're doing to rebuild it and the bearings are hard to get.

You can get pressurised airboxes for the NSR, Gecko Racing (on this forum) has made some very good replica's of ther JHA ones made.

The NSR in F3 type form is heaven to work on next to an RGV, no airbox, no oil pump, no carb solenoid plumbing etc. and of course all NSR's have their carbs attched to each other to the rear of the top barrel like this and they come off togeather.
A main jet change is about a 15 minute job in total. Top barrel (the awkward one) takes an hour at the most.
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