revtothelimit - motorbike forum

Mr. Dazzle wrote: Sat Jan 30, 2021 10:04 pm Old Brit Twins were doing Big Bang while Doohan was a glint in his Dads eye

Twins tho'

The NSR and R1 were fours.

I always understood that the crossplane R1 wasn't a true "Big Bang" motor, more an "Uneven Bang". As Mr Dazzle said, the power delivery is the same as a 90° V4 with a 180° crank, (i.e. the Honda VFR800), which isn't considered to be "Big Bang".



This from Bennetts:
"The motor was the biggest advancement for the 2009 R1, however it was also the area that caused the most confusion. Importantly, the crossplane engine (CP4) is not a ‘big bang’ engine, it is something very different."

https://www.bennetts.co.uk/bikesocial/r ... yers-guide

And this from MCN:
"Don’t get too caught up on how the new R1 works, with its crossplane crank and irregular firing order, which is the same as Rossi’s factory YZR-M1 (it’s not a ‘big bang’ motor - we’ll explain all in this week’s MCN for the techies among you), all you need to know is the new engine has transformed the R1 into one of the best sportsbikes I’ve ever ridden."

https://www.motorcyclenews.com/news/fir ... irst-ride/

Maybe weeksy will buy one if we all stop calling it Big Bang.

Mr. Dazzle wrote: Sun Jan 31, 2021 7:29 am Maybe weeksy will buy one if we all stop calling it Big Bang.

Call it whatever you like, it's not getting bought.

We've completely moved on.... Well she has... i'm still eyeing up a shellsuit



https://www.ebay.co.uk/itm/KAWASAKI-ZX6 ... SwxoxfKEPs

But when i spoke to him about 8 weeks back on this one we were £500 away from eachother.

Mr. Dazzle wrote: Sat Jan 30, 2021 9:21 pm

Yorick wrote: Sat Jan 30, 2021 8:56 pm When Yamaha made the very first big bang engine, you could hear the difference.

Honda recorded it, then slowed it down to analyse it.

Dunno about MotoGP, but in F1 it's common practice to record the sound of the other teams and run it through a computer to work out what gear ratios they're running, what their VMAX will be (they have a rev limit in the rules), when they're lifting in corners etc.

The Honda engineers in particular are always hanging around the sound tests on scrutineering day, recording noises, checking DB levels themselves etc. You'll then see the same guys at various points around the tracks with the same equipment.

Here you go....mostly to prove to myself that I'm not going nuts, VFR800 and Cross Plane R1. They sound very similar to my ears, although it's a little bit misleading cause the R1 revs a few thousand rpm higher. I dunno, maybe it is cause i am expecting them to sound the same?

Love how the R1 wheelies past the super cars

'cept for the bit around 2:20 where it sounds like they're hard on the power but the car is still pulling away. It's a McLaren though, and those things are naffing quick.

Holy thread resurrection, Batman... (blame Weeksy for linking to this thread). Nerd city incoming...

I've owned two of the early (RC24) VFR750s, a 1989 FK model I owned from new and the 1988 FJ model I still own. In between those two I owned an 1996 FT RC36/2 model and I always felt that the exhaust note on the FT was 'flatter' than that of the FJ/FK models. I put this down to the exhaust firing sequence being subtly changed to cater for the different layout on the later bike due to the single-sided swingarm (the earlier models ran a conventional double-side swingarm). Also the FT ran a 4-2-1 system whereas the FJ/FK ran a 4-2-1-2 layout.

Cylinders on the FJ/FK were numbered as follows: #1 back left, #2 front left, #3 back right, #4 front right. Firing order was 1 3 2 4, and firing intervals were 180° - 270° - 180° - 90°, represented in binary as 1-0-1-0-0-1-0-1. This is subtly different from the VFR800 layout shown above, but would it account for the difference in exhaust note that I observed all those years ago?

BTW the VFR800 engine was actually based on the RC45 motor, and was a definite departure from the earlier 750s.

What QS have you got? The Translogic that’s fitted to my 1000 is the best I’ve used yet out of all the aftermarket ones and I’ve used them all.

You can’t go wrong with the GSXR, parts are relatively cheap as well especially spare wheels with wets