wraith Posted October 19, 2018 Share Posted October 19, 2018 Do the gsxr750 flatslid carbs off a slabside work on a b12? Quote Link to comment
Ben Slabby Posted October 25, 2018 Share Posted October 25, 2018 Yeah, got em on a B12 motor. Bored to 33mm they're OK but a bit breathless at the top end. 1 Quote Link to comment
bluedog59 Posted October 26, 2018 Share Posted October 26, 2018 Is that with a stock motor ? Quote Link to comment
Ben Slabby Posted October 26, 2018 Share Posted October 26, 2018 Bog stock, just a 4-2-1 pipe. Quote Link to comment
bluedog59 Posted October 27, 2018 Share Posted October 27, 2018 Strange, I would have thought you'd have got a good few BHP on the top with them, certainly better than stock or stock carbs with dual K+N's and the correct jetting. Quote Link to comment
wraith Posted October 27, 2018 Author Share Posted October 27, 2018 (edited) Just asking as there was a cheep set on that site but I think I will stick with the gsxr 38mm carbs. Nice to know, thanks Edited October 27, 2018 by wraith Add a bit Quote Link to comment
Gixer1460 Posted October 27, 2018 Share Posted October 27, 2018 10 hours ago, bluedog59 said: Strange, I would have thought you'd have got a good few BHP on the top with them, certainly better than stock or stock carbs with dual K+N's and the correct jetting. Why would smaller carbs (bored out to 33mm) be better than the std. 36mm bore carbs - the fella said they were breathless, guess why! Good for a 750 not an 1100/1200 with big lungs! Quote Link to comment
nopokewithoutsmoke Posted October 27, 2018 Share Posted October 27, 2018 I thought that slide carbs generally flow more air than CV's of the same size. So a 33mm slide carb could flow as much air as a 36mm CV. Is that wrong? Quote Link to comment
Gixer1460 Posted October 27, 2018 Share Posted October 27, 2018 The modded 33mm slide carbs have nearly 20% less airflow area - the CV throttle butterfly doesn't get near that as an obstruction hence flow less even though unobstructed - now if it was a 36mm flat slide against the CV - no contest! 1 Quote Link to comment
bluedog59 Posted October 27, 2018 Share Posted October 27, 2018 Interesting. It just shows how much CV and airbox design has come on. Quote Link to comment
nlovien Posted October 28, 2018 Share Posted October 28, 2018 i,ve aye presumed the reasoning behind a CV carb typically being +/- 3mm larger in throat to a direct lift is because the slide is fluttering - not being held open - it will initially lift to full open when you whack open the butterflies, then it finds a position relative to the engine draw - not necessarily full open even if the butterflies are always wanted to see if there is a way to convert a CV to direct lift - to see if you can take away this characteristic and benefit from the bigger throat - probably remain in the bin box of like to do versus ever getting around to it Quote Link to comment
Gixer1460 Posted October 28, 2018 Share Posted October 28, 2018 Got to compare apples with apples! A 33mm anything is never going to match a 36mm anything for N/A airflow - simple physics! Why would anyone bother converting a CV to direct lift when a) it doesn't have an accelerator pump circuit to stop it falling on its arse when the handle is yanked and b) a comparable direct lift carb is available in sizes 34mm - 55mm! Quote Link to comment
bluedog59 Posted October 29, 2018 Share Posted October 29, 2018 On 10/25/2018 at 10:02 PM, Ben Slabby said: Yeah, got em on a B12 motor. Bored to 33mm they're OK but a bit breathless at the top end. Are they at least as good as stock up to the top end ? 4/2/1 pipe , filters/airbox ? what were the setups please ? Quote Link to comment
Ben Slabby Posted October 30, 2018 Share Posted October 30, 2018 GSXR thou K-series stock titanium pipes, Danmoto can and linkpipe. Ramair dual foam filters with silicone pipe reducers to form an intake tract. Can't remember the jetting, from memory they're either 122.5 or 125 mains, I'll look when I take em off again. They're good, nice and crisp most of the way up the rev range but struggle when you work them really hard. If that's a failing of the accelerator pumps or the jetting, I've not sussed out, but there's enough snap to spin the rear out of corners, so that'll do. If I get chance, I'll dyno it to satisfy your curiosity. 1 Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.