does everyone start with a BDD
Turbo Mini Forums

Hi all,
I am playing needle profiles again and using SU Search program.
Does everyone start with the std BDD needle when reprofile a needle?
my last one started life as a BGB and was pretty good, i then refitted the green piston spring popped the oil up with 30/70 engine oil and it was way to rich, put the BDD back in and its pretty sweet.
seems that the 5/30 oil i was using just keeps disapearing through the little port thingamabobs.

any thoughts or suggestions would be great as i just cant seem to get the AFR's right at idle, it seems to jump around a bit and reads 89-20 and at light throttle (2000rpm) cruise its pretty lean at mid 20's as soon as i touch the throttle it drops to 15,14,13 and settle around there which is fine but light throttle cruise is a little concern as it idle.

any thoughts guys?

thanks as always

Grant

179hp on 12psi 1293cc of pure A series
14.0et @101 mph

Grant you need to give that needle in that fuelling range where its lean a. Shave off, a little at at a time ,till you get the fueling cock on,

Use some p600 wet and dry and a pillow drill to profile It in that range you desire, a little. At a time, as you can't replace. What's taken off.

Hope this helps

BDD is a good lean needle to start with you can add fuel but not take it away
if your running a T3 and looking for 12-15psi get your self a 12 ounce spring and a BDL with 20/50 oil

would always recommend a rolling road tune or a wideband and alot of eye balling it to make sure its staying at or richer than 12.5 on boost

if your going the whole hog and doing your own needle i would aim for 15 afr idle with 12-15 deg advance (megajolt ?)


read this if you have not already

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=159683

Yes i moved to the darkside

Instagram @jdm_brett

http://www.mintylamb.co.uk/suneedle/

this is good too

Yes i moved to the darkside

Instagram @jdm_brett

Thanks guys,

I have an innovate wideband kit that sits in the tail pipe so that is all good, also have megajolt and run advance in boost up to 25 degrees, also have a knock box to listen for engine knock and all is ok. just checking to see what you all start with, I have an old old avonbar high boost needle in the box, i might dig it out and see what that runs like as i have not used it in years and never with the wideband.
i am now running a GT2554R with a .49AR exhaust housing and its bang on now since i got a new billet actuator at the right length, i was getting a fair amount of boost creep due to the actuator not opening far enough, i still get a small amount of creep so i think i need to machine the wastgate hole next time she is apart.

Thanks guys

Grant

179hp on 12psi 1293cc of pure A series
14.0et @101 mph

grant , if you are getting readings in the 20's eg 20:1 afr ,then i would check for either an air leak into your exhaust , or , check that the pipe inot the end of the exhaust is going in far enough for the probe to be getting pure exhaust gas , not a mix of exhaust and air . i cannot get my engine to run above 18:1.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

The avon bar hight boost is very similar to the BDL
And as for boost creep get your self a steel bur and tickle the wastegate port i had to open mine up from 14mm to 20/21mm to stop creep issues on my GT20, done it on 2 turbos now solved it both times

What is the spool like on the GT25? I would have thought its similar to a T3's boost threashold

Yes i moved to the darkside

Instagram @jdm_brett

im running a t2/t28 hybrid and started with a BDL needle and it was pritty much bang on untill we brought the boost up beyond 12psi then just the topend needed tweeking
this included the boost transition phase where everyone gets the stutters its spot on.

"Tuning should be a compromise between what is possible and what is necessary"

10)Thou shalt always quest for more power

Thanks Guys,
Robert, you might be right, the pipe only goes up the exhaust around 2 inches, however i have blocked the rest of the exhaust up with a rag and still get simmilar readings at idle around 18. for the BDD to run well it had to be full rich screw could not go in further and it was good but too ruh in to end AFR down to 11 so i polished the first 4 sections and then retested and had to move the screw out 2 turns and it is reall sweet now light throttle cruise at 14 to 15 and as soon as i touch the throttle it dros to 13,12.
does everyone block off the part throtttle lean hose? i had previously but then took out the ball, i have added it now and will road test again to see how it is.

Brett, with the current.49 housing it spools well, starts to spool at about 2800 in top gear.
next road test i might get the go pro onto it and see how i go.


thanks agaom guys

Grant

179hp on 12psi 1293cc of pure A series
14.0et @101 mph

i blocked the part throttle off initially but i had a lean spot with larger changes of the throttle, ie flooring it
long story short, you get an immediate mass of fuel with it ( as at full throttle its not leaning it off )
helps because my GT20 is almost immediately on boost,
on mine station 2.8 is 70mph cruise and if i plant it by station 4.5 i can be on boost
just looked back at logs i hit 10psi boost before ive got to 50% throttle

Edited by Brett on 25th Nov, 2012.

Yes i moved to the darkside

Instagram @jdm_brett