majortom4 Posted October 18, 2017 Posted October 18, 2017 Soooooo I have been riding the bandito for a while now. I knew it was running rich and it hits a wall at 6-7000rpm. Just replaced all fuel lines and tidied a few things up and though it was time for a dyno run. It was extremely rich!! (Forgot to take pic of page) but was a huge rich spike...... Couldn't do a full run as wouldn't rev out. Just hit a wall. Main jets are 125. 3psi base fuel pressure Pitot is 8mm i/d in line with air flow and pipe from pitot is 7mm id to carbs and f.p.r What would I need to alter to get this richness smoothed out. Jet size smaller?? Restrictor in the pitot tube to restrict pressure? Less base fuel pressure? See video attached for dyno run. Quote
Kid Kearsley Posted October 18, 2017 Posted October 18, 2017 What sized carbs are you running? 36mm stock bandit? Float height? Needle height? Quote
majortom4 Posted October 18, 2017 Author Posted October 18, 2017 Stock carbs, can't remmebr float height :-( Needles in middle. Quote
FJD Posted October 19, 2017 Posted October 19, 2017 can´t really help you, but i guess i´d try needle position first, then MJ. Fuel level would also affect lower rpm Funny shoe btw ;-) Quote
MeanBean49 Posted October 21, 2017 Posted October 21, 2017 With my td04 before i put the VF23 on I had 110 mains in and ran 2.5psi base. Float heights set at 16mm. I would say main jet is too big. It does have an effect like a rev limiter if your too lean or too rich. Quote
Gixer1460 Posted October 21, 2017 Posted October 21, 2017 Agreed - a blow thro only needs slightly bigger MJ's than for NA. And very surprised if std miki's are holding 3 psi fuel pressure - most leak / pass fuel anything approaching 2psi LOL! And the the fuckin back end of the bike strapped on the dyno - that was plain dangerous! Quote
colinworth79 Posted October 21, 2017 Posted October 21, 2017 I've found the pitot tube design has a large effect on the size of jets you run . I originally ran 115 mains on my bandit then altered the size of the boost pipe and it then wouldn't rev past 5k with that jetting . I would try lower base fuel pressure and drop mains and needle slightly . Really you need to invest in a AFR meter like an innovate lm2 , that way you can connect it all up and take the bike for a run and check which way the fueling is going . If its really rich or lean its not going to run but slightly lean and you are going to end up melting something . Sounds like the clutch was slipping on the dyno ? Quote
majortom4 Posted October 21, 2017 Author Posted October 21, 2017 2 hours ago, Gixer1460 said: Agreed - a blow thro only needs slightly bigger MJ's than for NA. And very surprised if std miki's are holding 3 psi fuel pressure - most leak / pass fuel anything approaching 2psi LOL! And the the fuckin back end of the bike strapped on the dyno - that was plain dangerous! My first statement to the guy was shouldn't the back end be strapped down....... I have ordered some 110 jets and 115 to try. Along with a turn to close valve for in line with the pitot to give it some adjustability if that's the problem. Dobt think Clutch was slipping as it running lock up. The back end was spinning tho as wasn't tied down..... Quote
majortom4 Posted October 21, 2017 Author Posted October 21, 2017 I probably should have invested in a afr meter a while ago but thought that taking it on a dyno, setting it up there so not running too lean, then leaving it would be a better option as I don't fancy giving it full throttle whilst watching a gauge to see what's happening haha Quote
colinworth79 Posted October 22, 2017 Posted October 22, 2017 On 21/10/2017 at 11:29 AM, majortom4 said: I don't fancy giving it full throttle whilst watching a gauge to see what's happening haha the units have data logging . My LM1 has 45 min you can then plug in the computer and see . 1 Quote
Fula28 Posted October 22, 2017 Posted October 22, 2017 (edited) I'm with mean bean, I ran 34mm tin tops with 95mains and needles fully lean at top clip postion. 15.5 flost height. Good luck. Edited October 22, 2017 by Fula28 Quote
Gixer1460 Posted October 23, 2017 Posted October 23, 2017 9 hours ago, colinworth79 said: the units have data logging . My LM1 has 45 min you can then plug in the computer and see . Ha Ha Ha - perfect for reliving the moment when your engine melted in the comfort of an old arm chair with a mug o' tea! A dyno is definitely the place for WOT tuning turbo's IMO! Quote
colinworth79 Posted October 23, 2017 Posted October 23, 2017 3 hours ago, Gixer1460 said: Ha Ha Ha - perfect for reliving the moment when your engine melted in the comfort of an old arm chair with a mug o' tea! A dyno is definitely the place for WOT tuning turbo's IMO! yeah I agree only if the rear wheel can grip the dyno drum and is strapped down properly. Still think a wide band is useful for checking . Quote
wombat258 Posted October 23, 2017 Posted October 23, 2017 All my tuning is on the race track with a data logger, and an AFR meter in front of me. I start rich and work it back to best power/speed. If I see lean get off the gas and correct it before going back on the track. I can get three track days for the cost of one dyno session, and have a lot of fun on the track even when tuning. With a dyno you are a spectator and hoping that the operator has enough knowledge to not lunch your engine while he learns what to do, and lets face it every dyno operator is learning what your engine needs. I do professional failure analysis on engines for a living, and most of them have failed during or shortly after a dyno session. Quote
majortom4 Posted October 23, 2017 Author Posted October 23, 2017 Thanks for the input guys. Back on the dyno tomorrow with some smaller mains and a few options. Will be starting easy and see what's happening and alter to suit. @wombat258How do you get a few track days for the price of a dyno run? I usually do the jet changes etc myself and just pay for dyno time so works out pretty reasonable. Hoping to get it sorted tomorrow :-) Video will follow Quote
wombat258 Posted October 23, 2017 Posted October 23, 2017 Typical dyno sessions "down under" start at $300. Track days near here are $110 per day, and I get at least 5 x 15 minute sessions. Last time at the track I could pull up on track, adjust the EBC, and get back into it. And when I was finished I went onto the track and went flat out for a few sessions. Doing another track day next week to bed in the new brake discs *wink* Quote
majortom4 Posted October 24, 2017 Author Posted October 24, 2017 So fuelling sorted with 110 jets and 1 clip dropped from middle on needles. What sort of power are people getting from your turbos?? Hitting 160 with 8psi on standard actuators on td04hl16t. Wondering if I'm looking boost from somewhere as thought it could have been more?? Quote
MeanBean49 Posted October 24, 2017 Posted October 24, 2017 Sounds about right, 12psi should see around the 200bhp mark Quote
majortom4 Posted October 24, 2017 Author Posted October 24, 2017 A tad lean on final run so going to go with 112.5 mains to be on the safe side. Runs a lot better now tho 1 Quote
MeanBean49 Posted October 24, 2017 Posted October 24, 2017 36 minutes ago, majortom4 said: A tad lean on final run so going to go with 112.5 mains to be on the safe side. Runs a lot better now tho Looks like a nice smooth curve that does. I would be well happy with that. 112.5 should see a few more ponies. Quote
majortom4 Posted October 24, 2017 Author Posted October 24, 2017 Yer really happy. Going to get the jets ordered and fitted once they arrive. Quote
B2BC Posted December 27, 2017 Posted December 27, 2017 Same situation I'll be in soon with my b12 turbo I'm going with 115 mains 2nd clip from top 2.5 turns on air screws and then see where I'm at my fuel pressureis set to 2psi Quote
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