What is the difference Senna 02 and Evo3 SPR? And is the SPR a limited edition? How many will they make? And, if the Evo3 F4S and the SPR have the same engines why the big power difference?

Thanks

-- luca (luca@omnimail.sm), March 20, 2003

Answers

From my studying of the website information, it appears that the main differences are the new SPR has a new closer-ratio gearbox with a longer 1st gear ratio than Senna, and of course the paint scheme.Asfar as the Evo3 and SPR engines, they state cams, compression, and porting. However it appears that the SPR comes with the racing header pipe, which will also account for a 3-4hp power increase, and it is hard to decipher from the spec sheet, but it seems that the SPR power rating is shown as 146 crank hp "with RG3 pipes and eprom" installed. So if that is correct, then the SPR is about 141 crank hp in stock form(without RG3/eprom). This 4hp increase over EVO3 standard engine may actually come from the standard inclusion of the racing header pipe, which they specify will increase hp by approximately the same amount. One major difference is the additional 600rpm at redline that the SPR has(13,900). The "possible result" of all this, could be that the SPR is simlar in hp, but gets a boost from the racing header/RG3/eprom, and the engine mods provide a longer power delivery band at the top of the rpm range, and this is tapped-into by a changing of the gearbox ratio to maximize the use of this additional powerband and revs at the top end. If this is so, this additional 600rpm band would be at the peak hp levels, and allow the motorcycle to remain in the peak hp powerband continuously via use of the close ratio gearbox. It is likely that this would be of little consequence to a street rider, unless he is really tempting fate. For track days, it would be great. This is based upon the assumption that I am reading the spec sheet correctly, which seems to say that the power for SPR is 146cv "with RG3 and eprom". If I am reading it wrong, then the power level is even better, and will put the crank hp at over 150hp with the RG3/eprom installed, which would mean that this is really one helluva mean and nasty machine. That would give about 135hp at the rear wheel, which puts it right at R1 levels. That is quite alot for a 750. It is very hard to tell some of this stuff, because nobody has one yet, and the spec sheets are cryptic. From the photos of the SPR on the MV website, it appears obvious that there is an exhaust change, because the header comes up under the footpeg as a single pipe, and branches into 2 as it transitions into the slip-ons. On the regular F4S, it is clearly seen that there are 2 pipes under the footpeg. Upon inspection of the optional racing header, it is clear that this is the configuration seen in the SPR photos. This is definitley where some of the additional power of the SPR is coming from. If this bike really can get over 150 crank hp with RG3/eprom installed, and can stay at that power level with that gearbox without dropping off peak hp, then this is going to be a real threat at the racetrack.

-- Tom Lyons (twlyons@juno.com), March 20, 2003.

look at the 2003 f4 s TOM,there's only ONE pipe under the footpeg like all the 2003 models!

-- dauly alex (alkatraxx@yahoo.fr), March 20, 2003.

Alex, I am looking at the MV USA website, and they show the single pipe under the footpeg configuration only on the SPR and the Ago. Their photo of the F4S still shows 2 pipes under the footpeg. Where did you see this photo? Maybe the MV USA site has some old photos? Could this mean the racing header is used on all these models, or is there some other exhaust change, that only appears to look like it? I'm confused about this. I'd really like to know what the real story is, because I'm about to make the purchase of one of these bikes, and it would be nice to know what the hell I'm buying!

-- Tom Lyons (twlyons@juno.com), March 20, 2003.

For what it is worth; I own a F4S EV-02 and a SENNA. My Senna has the SPR engine, the close ratio box with long (145Kkm/h) first gear and single pipe under footrest. The F4S is the nicer bike of the two on the road. However, the Senna SPR engine is awesome and once you're going is fantastic.

-- Jan Roestorf (janr@formax.co.za), April 21, 2003.