Originally Posted by TheRabbit
Cool pics BJ.
I'll add one more thing about nitrous. At some point you cross a line and into one side effect of nitrous. You will loose about the same amount of et on motor as you gain on nitrous.
In other words when you add a tall gear and tighter converter to handle the additional hp/ torque to gain an extra 2 tenths you'll loose 2 tenths on motor. Of course the amount you gain could be a lot more or less depending on the set up.
It's way worse for me and my application. I gained 1-2 tenths on nitrous from what I use to be able to run, but have lost 7-8 tenths on a motor pass. My motor want turn more than 5500 -5700 on motor alone and it takes FOREVER to do that. lol
to chime in with Rabbit on the lose of et motor vs. spray pass....My car has a pretty big 7/4 swap..don't have cam card in front of me but wanting to say its 116 or 118 lobe speration 100% Nitrous grind...the converter is soo tight there is NO FLASH what so ever bringing it up on the brake on a motor pass...My tires are 33 inches tall with about 102inch roll out..I run a 3.60 gear..so if you factor in the tire height you looking at 3.30-3.40 gear based on a 30 inch tall tire.
here we go....All motor Pass-ET 5.80'ish 1.32 60ft 126 mph
1 small hit 250-ET 4.92'ish 1.10 60ft 144 mph
2 stages 250/300- 4.68'ish 1.09 60 155 mph ish
see how she comes alive !...My headers are fender well exit but the sound change of the motor from motor to spray sounds totally different in a way I cannot explain...its just freakin mean.
Again Blowers were my first..I have drug the back bumper with my injected set up at 130mph.....but I have to be honest the sudden SHARP TQ curve from the Nitrous Hit is 200x off the chain then the flat TQ curve of the Alcohol injected.....Sort of like jumping in 20 degree water buck naked...YES it will take your breath like this if you have a Big enough shot being dumped in there at one time.....You know your moving when the traps at the end of the 1/8 mile have narrrowed up so much it looks like your trying to drive into a rabbit hole @ 150 mph.
just to show engine comparions
383ci BDS Stage 4 teflon blower,enderle Bird catcher dynoed 1320hp 1100ft lbs of TQ at 26psi sucking in bad air in dyno room.
572ci 1400 series littlefield blower enderle Birdcatcher, promag magneto 2200hp 1600ft lbs TQ
632CI Big Chief EPD fabricated sheet metal intake pair of reed 1200 carbs
engine dynoed by itself 1350..and remember its set up to run Nitrous....the advertised rating on the hp jets 1st stage 260hp 2nd stage 300hp ( probably low on the #'s) but for the sake of argument ad the proven 1350hp plus the rated NOS jets and you got 1910hp.......NOT A CLUE ON TQ....BUT I WILL SAY A BUNCH AT ONCE...
Last Time I said this there were a few that weighed in...First let me say a 60ft time is important in 1/8th and 1/4 mile racing....what I am saying today as I did a few years back is the 1/4 is little more forgiving if you bobble the 60ft, you can somewhat recover..ask any healthy turbo guy...but in the 1/8th mile if you don't pick them up and lay them down like a MADD man in the 60ft you will not have a ET run for Chit..
to prove my point look at my vid below.I left the line on 1 stage and let off.My wife was working the video from the traps..this was a a shake down run for me intentionally meaning to hit it hard at 60 ft and kill it.....I was lined up next to a 5.90et car....I came out hot on 1 gun laid down a 1.11 60ft and around 70ft I let out totally off the gas and costed thru the traps...I still ran like a 7.00et and coasted 2/3rd of the track...the 5.99 car finally caught me at the MPH cone..I was coasting maybe 60 mph by then.. you can hear me coming off the line ( My wife is telling my Daughter here he comes...lol) see me coasting when the 5.90 car just caught me at the end. turn up the volume ...lol
http://www.youtube.com/watch?v=jn0p3Og6d9o
The reason I bring this up is
not to put my Nova on a pedestal...No this is common practice around here...most of your Quick cars run like this...all your Outlaw cars do..I use to shake my head when I would go to a Outlaw race and watch them shakedown doing 60ft full power hits shut the car off just past the 60 ft mark..I mean cut it off and coast thru the traps at 50mph with a 5.50et.
Point I am driving home in drag racing you much rather have a Quick car then a fast car...the example I gave you above explains it...I cannot tell you how many cars I have outran in the past pre-outlaw car days that had better MPH then me but I got there before they did....bottom line they were spinning...you can bet if My MPH is up my 60ft is down.
final point; As Rabbit said what you give up in motor you gain in Nos...you can't have the best of the best in both worlds...but you can build one that doesn't kill you either way and you can have decent power on motor and still pick up 3 tenths or so on spray..your engine guy ( if he is good) can help you with this.
As I type this part I am thinking of Logan .....What you would need out of spray is a car set up that could handle a Big shot NOS(250 hit) off the brake...thats hitting it with 250hp out of the hole...if you can get your car to handle this hit without spinning too bad you will only need that 250hit to stay on 1.5-2.0 seconds this will put you out over the 60 ft mark and on the way to a killer run in the 1/8th mile....In my world if I make up 2.2 tenths on the 60ft...I make up 9 tenths on the entire run...I have known people to activate their Nitrous down track...I personally do not recommend this.Hit it leaving the line while the chassis is naturally loading the Nos hit will help this process and help keep it loaded.....My car is more stable to drive under full Nos pass then motor pass... ...if My math is right here This is how I experience my 1/8th mile ride under full power after the 330ft. ...I am traveling approx 171ft per second from 330ft mark thru traps in 1/8th
whewwwwww..ok I am done...sorry so long guys hope someone gets something out of this..did not want the thread to die.