Red storm dyno - hp on engine

[Stephan]

Dyno before winter upgrade, I know current settings is not ideal, and db killers from exckill killed some ponny. Will see after winter, I plan to do some engine work.

Current setup is:
48 pilots, 2+2.25 screws, 178 180 mains, Factory Pro titanium needles front lowest position, rear one up
Arrow full exhaust with Exckill 48mm db killers
Dr Honda stacks, paper filter with burnie morgan mod

some minor addition could be from ex cams on intake, stick coils, electric water pump.

Power is on engine, rear wheel bhp is about 107 bhp and 91 nm

[lloydie]

Did you get a fuelling graph too ?

[Stephan]

unfortunately not, db killer didn´t allow lambda sensor to go inside. I didn´t want to take run without baffles, as I did some fueling adjustmenst for it. I will have next dyno run, as I will put modified baffles with holes for lambda.

[Stephan]

this one, bike is running little worse, but sound is now affordable. I have another set with just open pipes in the end (still loud), so I will modify them some way. But top end power seemed to me untouched with these.

[Stephan]

Dyno after stage1 and tuning, all details are in pimp my ride section.

Final setting is:
Pipercross filter - seems to be good alternative
48 pilots, 188 main jets
FactoryPro needles - rear in the middle, front 0.5mm leaner
blocked slide hole on each carb
*each cylinder was tuned separately, based on AFR

We experimented with open airbox as well and probably I will try it in the future. It showed massive lean condition everywhere, and for sure hidden power is here or in another airbox configurations.

Pipercross has the same AFR curve as paper filter, it is just leaner, so there was significant gain everywhere expect hole between 4-5, but this is problem of needles.

Finally got 122 bhp, but I will try to do something with mid range, maybe it is time for stock needles, or Dynojet.

final numbers


before and after tuning


before and after stg1

[VTRDark]

Thanks for posting those comparison results Stephen, it's always good to see a before and after.

That's a nice little increase you have got there. How's the bike feel to ride. Keihin needles I think would be worth trying. They also do other sizes, fatter or thinner profiles/leener or richer but I have yet to come across them for the VTR. In an ideal world the HRC would be the ones especially if you want to go open airbox,but you know they are like rocking horse sh1t to get hold of.

(:-})

[Varastorm]

I too am trying to get to the bottom of this 5000rpm rich problem every one has.

I am coming to the conclusion the needles are way too short, around 3mm too short is my reckoning.



I have just raised my DJ needle clip to the second groove from the top (with a 0.7mm washer also) & it's accelerating so hard it surprises me every time.

I have only concentrated on the jetting whilst running the Ducati trumpet mod, so not too sure if this will make a huge difference if you haven't got bigger trumpets.

The dyno runs & ass dyno are with out doubt proving the needles are way too short & each time I have dropped the needles (raised the clip) I can feel significant improvements to the acceleration from 3000rpm up.

I am concentrating on the pilot circuit now as that has suffered badly, & am now using #50's with 2 1/2 turns out & feel it is close to optimal.

It's only taken 4-5 years

Give the needles a go Stephan.

If it's crap just change it back, because your dyno run is also showing way too rich at 5000rpm

[Stephan]

Currently my plan is to put 45 pilots, and stock needles, rear raised 1.5mm, front 1mm.

Yesterday I spend whole day with dynoman, so I have the picture what should be the next step. Unfortunately we decided to tune Fpro needles.
I know few people with lambda sensor, so no need to do another dyno tuning, I will try something and do just control run after.

[Varastorm]

Its not me that's telling you your too rich on the needles (mid range), its your dyno graphs that are.

These have Std needles that are way too short, everybody's graphs are the same.

Its because the The needles are too short.

The bike runs well rich, but brilliant at 13-1.

[Varastorm]

Sorry Stephan, I commented that the needles were too long I meant to say too short.

I have corrected it now, sorry for the confusion

[Stephan]

Varastorm: will see, we tried stock needles and it was not much better, but they dont have so rich profile, I believe correct height can sort it. At 4 rpm, lenght of needles should not be the issue, bu who knows ...

[Varastorm]

Stephan, your problems aren't at 4000rpm though your overly rich problem is between 5000rpm to 6000rpm (needle territory)

What I am saying is though, if you lean the needle off as much as I have, you will have a mega lean issue at the pilot. Which I am trying to sort out at the moment.

They all have a small effect on each zone

One last thing, after reading lots about FIL mods. I recon the reason they work so well for people in the mid range is, it leans out the rich issue there.

So instead of leaning it out with a longer needle, the FIL mod does it, but in another way. But the downside is that it runs crap high in the rev range because it's too lean in that fuelling zone.

What do you recon, am I on to something?

[Stephan]

Problem is not afr itself, but speed of change, it is going rich too qiuckly, and biggest drop is betwen 4.5-5. Though 5-6 is not ideal.

[Varastorm]

Problem is not afr itself, but speed of change, it is going rich too quickly, and biggest drop is betwen 4.5-5. Though 5-6 is not ideal.

Its all about the afr Stephan, nothing else. The reason there is a fast change between 4.5-5 is that your pilot (too rich) & needles (way too lean) are way out.

I recon the Pipercross is leaning everything out also, your mains are right but the piper is making it too lean.

This is what I learnt from changing my jets & needles, & how much a change to the afr makes per clip height & jet size.

I also feel that all the jets have a slight influence on each of the fuelling zone's.

This is approximate but I recon the VTR carb zones pivot at these revs-
Pilot:- 0 - 4500rpm
Needle:- 4500 - 7000rpm
Mains:- 7000 - 10,000rpm

They are approximate, but they will put you in the right ball park.

Using a free flow filter will lean a jet size across the graph, (10 on the afr) but am sure they have a lot to do with air turbulence as well.
1 clip height (1mm) = 10 on the afr.
1 main jet size = 10 on the afr.
1 pilot jet size = 10 on the afr.
Pilot screw, .5 - 3.5 = 10 on the afr.

So from reading your graph, this is what I would try if I was in your shoes

Mains I recon, If you remove the Pipercross your mains will be good.
Midrange I recon, that you rich dip @ 5750rpm might go as low as 8-1, so I would drop the needle about 3mm (maybe more).
Pilot I recon, #52's.
Screw I recon, @2 turns out.

Give it a go, nothing to lose & everything to gain

[NZSpokes]

Problem is not afr itself, but speed of change, it is going rich too qiuckly, and biggest drop is betwen 4.5-5. Though 5-6 is not ideal.

Torich to quick falls in line with my work on FIL. Problem I see is the lack of control on the speed the needles lift. FIL there is not vacuum to pull fuel up from the needle at consistent part throttle. So blocking the air bleed to the main circuit will help. For this situation I would consider blocking both holes in the slide and drill one out to 50% of one original hole. Or pre load the slide spring.