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HRC Carbs

Posted: Fri May 04, 2012 8:16 pm
by jb1000rr
Is it worth fitting a set of HRC carb vacuum pistons and the HRC carb air funnels to a standard road bike with a normal airbox and filter fitted? It's not a Race or track day bike so I don't need to or want to run the bike without the air filter and is only really used during the summer, on fine days.

However, I understand that the HRC carb vacuum pistons, with the extra holes in the bottoms would give a better throttle response, which can only be advantageous, but would there be any negatives?

Again I guess the shorterned HRC air funnels allow more air to get into the carbs without restriction, if you were using the HRC funnel and carb tray, etc etc. With the airbox fitted, I know not as much air can get in but would they have any adverse effect if an airbox/ air filter was fitted?

Thanks.

Re: HRC Carbs

Posted: Fri May 04, 2012 8:19 pm
by Drunkn Munky
Slides yes but i doubt you'd notice any difference, the stacks no it wouldnt be worth it there designed to make power at the top end

Re: HRC Carbs

Posted: Fri May 04, 2012 11:56 pm
by Cammo
jb1000rr wrote:Again I guess the shorterned HRC air funnels allow more air to get into the carbs without restriction, if you were using the HRC funnel and carb tray, etc etc. With the airbox fitted, I know not as much air can get in but would they have any adverse effect if an airbox/ air filter was fitted?
As well as making a shorter inlet tract to shift peak power higher in the rev range, the hrc stacks shroud the air jet on the carbs which is critical to the hrc open carb setup. On a standard bike this will throw all of the jetting out significantly - not recommended!

Re: HRC Carbs

Posted: Sat May 05, 2012 8:17 am
by jb1000rr
Thanks Drunkn Munky, Cammo.

So its ok to run the HRC slides. As these have the concave bottoms, if I were to change over to the standard needles, would this set up have any affect on the fuel air mix?

Re: HRC Carbs

Posted: Sun May 06, 2012 8:05 pm
by lukemillar
Not worth the expense! You'll notice no difference, and just spend $$.

Re: HRC Carbs

Posted: Mon May 14, 2012 7:56 pm
by jb1000rr
It wouldn't be expensive, just take a small amount of time to do, that's all.

Re: HRC Carbs

Posted: Mon May 14, 2012 9:15 pm
by lukemillar
jb1000rr wrote:It wouldn't be expensive, just take a small amount of time to do, that's all.
I mean just fitting the slides and nothing else. The full setup is definitely worth it

Re: HRC Carbs

Posted: Wed May 16, 2012 6:57 pm
by jb1000rr
Have any of you race and track day bikers run your NC30's with HRC carb set ups but with the airfilter still fitted instead of the drilled and modified carb bracket and HRC air scoop tray?

Re: HRC Carbs

Posted: Wed May 16, 2012 7:31 pm
by CMSMJ1
I have run with the scoop and a filter - the air scoop, IMO, cools the carbs and prevents heatsoak from the motor.

Don't bother going halfway - either do it or get it standard. The end of the day, these bikes are not going to ever knock out 65+ bhp without stretching them and the associated service and risk.

Pukka race bike, racing only, refreshed every season - get it sorted
pretend racing, trackdays - still with V5 and daylight MOT - standard but dynoed and setup right.

Re: HRC Carbs

Posted: Wed May 16, 2012 8:58 pm
by lukemillar
jb1000rr wrote:Have any of you race and track day bikers run your NC30's with HRC carb set ups but with the airfilter still fitted instead of the drilled and modified carb bracket and HRC air scoop tray?
I run mine with the scoop and no filter. Setup is pretty much bang on now. This is a race bike though, and clocks a fair fewer miles than a road or even track day bike.