Thread: 1/4 mile time thoughts ?

Hi Everyone, had vk dyno'd on Saturday up Bendigo way, after lots of stuffing around got it close to where we want it. running a 650 ultra hp dam thing would not idle nice tried different ultra with same results. we ended up drilling small holes in butterflys to help it out and fixed the problem but not 100%. dyno man said a qf carb will fix all my issues out. car made 339rwhp

stayed up there an went to test n tune yesdy @ Heathcote, drizzled most of the day but we got 4 runs in track was shocking but i managed a Pb 12.5@111mph 1.93 60ft so id like to think i can clean that up, with that mph its should be good for a High 11.

5k stall so whats everyones thoughts on leaving the Line ? i tried to stall it up but just broke traction, the tried bit less say around 3000rpm mark was bit better.
or next time to i just punch it off idle ? what do most people do when staging ?


Cheers

Originally Posted by GASSD6

Hi Everyone, had vk dyno'd on Saturday up Bendigo way, after lots of stuffing around got it close to where we want it. running a 650 ultra hp dam thing would not idle nice tried different ultra with same results. we ended up drilling small holes in butterflys to help it out and fixed the problem but not 100%. dyno man said a qf carb will fix all my issues out. car made 339rwhp

stayed up there an went to test n tune yesdy @ Heathcote, drizzled most of the day but we got 4 runs in track was shocking but i managed a Pb 12.5@111mph 1.93 60ft so id like to think i can clean that up, with that mph its should be good for a High 11.

5k stall so whats everyones thoughts on leaving the Line ? i tried to stall it up but just broke traction, the tried bit less say around 3000rpm mark was bit better.
or next time to i just punch it off idle ? what do most people do when staging ?


Cheers

Really depends on grip at the track any give day, I usually get best results by just preloading at around 2,200-2,500rpm (that's with a 4200rpm converter) and then send it and let the converter flare a little, but I use N20 so probably different!
cheers

Boppo

Originally Posted by HGPV

Really depends on grip at the track any give day, I usually get best results by just preloading at around 2,200-2,500rpm (that's with a 4200rpm converter) and then send it and let the converter flare a little, but I use N20 so probably different!
cheers

Boppo

Yeah i did find it abit better when i only loaded it up around 2500-3000 anymore just wheel spun as there no grip

Originally Posted by EVL253

also that carb should idle no problems its just a matter of finding out why it wont idle & correcting it

i leave at idle & mat it on the last yellow.

on dyno we tried 1'' spacer didnt like it. 2'' spacer worse, tried no spacer and it was heaps better all through rev range so we left it at that. it does idle but only up around 1200rpm mark. we tried 2 650 ultra holleys both exact same. im looking into billet meetering blocks so we can refine the idle circuit on it abit more. at idle we cracked open the secondary butterfly a touch and it was heaps better, hence why we drilled small holes in each one which helped alot.

yeah i didnt try leaving line from idle, next time ill give it a go.

I have 5500 RPM worth of stall, I stage with about 1500 RPM then mash it. Seems to 60' best that way.

Those Ultra carbs have a weird tune, it will need work but you can fix it.

JMHO

Dont know anything about the car but made the power.

Put so 60 series rubber micky thompsons

And launch it again.

Wet track, 339whp 12.5 at 111 with a 1.9 60ft. 11's should be a walk in the park. Well done.
Sorry no experience/advice with an auto trans.

One of my old engines was a 355, 3500 stall, 3.55's 288rwhp on dyno dynamics, ran 12.32 @ 111mph.
51hp difference on different dynos?

I leave at idle...leave the pump shot for the 60'

very low 12s is what I would expect @ 111 maybe just squeak into the 11s

Originally Posted by desoto30

very low 12s is what I would expect @ 111 maybe just squeak into the 11s

I would think the same. My bike (400kg) runs 108mph for a 12.0
A heavier vehicle should mph higher for the same times, so pretty close there.

Originally Posted by struggler

I have 5500 RPM worth of stall, I stage with about 1500 RPM then mash it. Seems to 60' best that way.

Those Ultra carbs have a weird tune, it will need work but you can fix it.

JMHO

yeah we played around all day on dyno to get it right, suggested to get new billet meetering blocks or look for a quick fuel to fix my problem. the ultra has 3 emulsion channels which 2 are blocked off and the other one is non adjustable new billet ones are all adjustable with jets so it can be refined in the tune.

yeah next time i will try few different launches an see what the car likes.

Originally Posted by m016922

Dont know anything about the car but made the power.

Put so 60 series rubber micky thompsons

And launch it again.

yeah was using a worn pair of MT 235 radials with about 12 psi to get some grip, dyno man suggested a full sick on a marginal race track will help me alot better then a radial will.

Originally Posted by GASSD6

yeah was using a worn pair of MT 235 radials with about 12 psi to get some grip, dyno man suggested a full sick on a marginal race track will help me alot better then a radial will.

Get some refresh ones on that psi,
You will be fine,

Also get jet extensions they do wonders

No big burnout also

What pt no is the Holley , Did you try and play with the emulsions at all . As struggler has said it can be fixed and it will be with little outlay . Also leave on about 2000 to 2500 on the stall and let it flash .
350lj

Originally Posted by GASSD6

yeah we played around all day on dyno to get it right, suggested to get new billet meetering blocks or look for a quick fuel to fix my problem. the ultra has 3 emulsion channels which 2 are blocked off and the other one is non adjustable new billet ones are all adjustable with jets so it can be refined in the tune.

yeah next time i will try few different launches an see what the car likes.