Gearing new car
 

505 BBC, 12:1, Dart 340 heads, Dart Intake, Demon 1295, 150 shot of spray .750 lift cam, 1.76 glide (May switch to a 1.80) 32x14.5 in a 2900lb car. Trying to get it set up for quarter mile and was wondering what gear everyone suggest ?

What rear end ya got ?

i was gonna ask that too.... plus..... what converter is he running :wink:

oh gawd !!!...that 150hp shot changes everything....

He will need to be given two sets ups..one for the all motor and one for the NOS..You can't have the best of both worlds.....

there is not enough information in My opinion to give a NOS gear set up.
lobe sep on cam, ring gap,tire roll out size, converter,NOS spread, Nos fuel pressure, external fuel supply system, or one big pump, method of timing retard,......just getting started !

this can turn down so many rabbit holes when you throw NOS in the Mix.

In other words, NOS or NOT ! :shock:

http://i233.photobucket.com/albums/e...LENGINE2-2.jpg

RPM Formula
 

what about max RPM at the stripe? expected MPH?

MPH x Gear x 336 divide by Tire Diameter in Inches plus Slippage= RPM

9 inch rear end. Nitrous is just for help its being mainly built for a N/T car nitrous will not be used every pass. Like I said this is a brand new car rpm range is around 7500. converter I have two a 5000 and a 5500.

As far as the nitrous I am not worried about that rit now due to the fact it will not be used rite now cause its a new car and just want to get the feel for it before I get into that. I set the car up for a 2 fuel system with a bg280 pump. As far as that goes I am hearing more and more people just say run straight up motor so now the gears are turning again!

no you have brought up a good topic and I am glad you did. DD hit it on the head Nos or Not. you just can't have best of both worlds..I understand about the extra 150 shot in a grudge race but even at a 150 shot the engine prep work such as, ring gap, lope speration on cam, tighter converter and a higher gear,we can get into many other things but I think you get the point.. what I mentioned above will cause you to lose a good bit on the motor side of the run...and its mandatory minimum stuff for running NOS effective and efficent or you run a great chance of hurting your equipment with not a lot of ET there to gain to start with

understand Big CI engines with exotic Big chief heads etc...Can handle 200hp shot and down and be a little more forgiving..in other words you can cheat it up a little on the cam etc...as long as you stay small on the NOS hit...with that said your 505ci is not considered a large ci engine, your also running conventional heads so you really need to treat it as a large small block IMO, When it comes to NOS..Again ( jmo)

If I were you since you mentioned N/T I assume you are setting up some grudge races...right ??? If so I would concentrate on being all HP and put more effort on losing weight and learning to conceal the weight loss and swear its 3800lbs no mater what !!!!!!! 8)

lol... i wish i had taken some pics :wink:

Rite on ill forget the spray with this motor and I shouldnt have a problem with consealing weight due to the fact that most impalas are a helluva lot heavier than mine. But anyway ya its being built for grudge racing.

Well just to give you something to compare to, here is my combo.

'65 Nova, 540BBC 12.6 comp Reher- Morrison cam .808int .765ex, Turbo 400, Dana 60 4.56, Hughes 9" conv 5800 stall, 2870lbs with me in it.
Has run a best of 8.99@ 149. Crosses the stripe at 72-7300. I run a 33x16.5 tire now thinking of going to a little shorter tire on the next set.

Just something to think about.

why no duration specs? lobe sep? fuel?

nice power, performance btw

How short ya Going Beast, Your rpms sound close...how much you want to turn that 540 ?

Didn't have my cam card in front of me at the time but here are the specs: .808int .765ex dur @.050 284int 298ex 112 lobe sep.
I'm running a Quickfuel 1250
Oh and I'm running Brodix BB2X that flow just over [email protected]

Probably to a 14x32 or 14.5 x32 got to check the rollout #'s

Well B I was thinking 250-300 more at the stripe. I really need to get the thing on a dyno and find out what it makes and at what rpm.

-thanks Beast! i like the numbers! :wink: nice combination

dyno's are a good thing...to tune..not all the numbers they put out are realistic in a car,,,but you know this already...I think your doing the right thing...put a 32 on it and check the Roll out 1st to make sure they are shorter then what you have and run it....nothing will tell you more then the seat of your pants and The ET/MPH just back up what you feel,,,when it comes to gearing situations anyway..all the 4 and 6 speeds I ever owned and even a few automatic's (without electronics) I always shifted with what My a$$ was feeling...and that was normally just before the car nosed over... 8)