1/4 Mile Estimate

[TheRacerDave]

Lift has almost nothing to do with P to V clearance. Especially max lift.

True, but increased rocker ratio also opens the valve a couple degrees sooner and closes it a couple degrees later. The effect is greater approaching max lift, but by then the piston is well out of the way. Probably not a big deal at the (around) 10° either side of TDC when valves and piston are closest except in an already tight P-V situation.

 

[TXOval]

Is the converter tuned for use with nitrous specifically? There's a night and day difference in the difference between a nitrous specific and an N/A converter. Nitrous converters are a lot tighter on flash speed to keep the extra torque from "blowing through the converter."

Converter is a high quality billet converter that was built tighter.

Specifically for nitrous, no.

 

[Swinger 340]

Bowling was my "sport". (And drag racing).
I went golfing once. First time out, at a 3-par. Shot a 72 with borrowed clubs.......




But it got dark after three holes, and I had to quit.

You should have started earlier in the morning.

 

[Jersey Devil]

Looking for opinions/advice. I’ll post my cars specs/setup.

66 Barracuda, full interior, all original sheetmetal.

3.73 gears in an 8-3/4 rearend with Inward leaf spring kit

Full welded in frame connectors

904 trans, built by COPE, but A&A manual valve body

4 wheel power disc setup

340, but stroked/bored to 416. Forged crank, forged h-beam rods, forged Mahle pistons, hydraulic roller cam, Victor 340, Holley Super Sniper setup.

Cam is relatively mild, .578 lift, 230ish at .050. Total duration is 288/280

462hp on dyno

I am installing a Nitrous Express 2-stage setup and will probably start with a 100hp shot on both stages.

I’m afraid my car will not meet track requirements due to potential 1/4 time…no cage

I’m new at this and have no idea what this setup could run. Any help would be appreciated.

17” billet specialties rims…

front MT runners 26x6
Rears are 245/45 drag radials

No line lock setup

Richmond gear calculator ( the most Optimistic)
Say 462hp with 3,000lbs could run a best of 10.47@125.5mph

Drag Performance Calculator

Wallace racing gave a more conservative.
10.87@124.37mph

ET-MPH-HP Calculator

With small drag radials, I am thinking that it will be tough hooking up. I would be happy with 12.0s and expect your mph to be alittle over 120mph.

ET is all about the launch/traction. More often than not the mph is pretty close if you have decent traction.

 

[Alfajim]

I appreciate everyone’s replies!

It seems like 12’s to 11’s depending on chassis/suspension/tires and of course the driver

I believe you will find the 904 tranny will not live long with a lot of strip time you will be stepping up to the 727 larger and stronger internals. Have five years with a 68 Hemi cuda auto not many trans issues even using a 5000 stall 9 inch B&M converter with 4.86's in a 8 3/4" 1.740 pinion sometimes 5.12 at higher altitudes.

 

[furrystump]

If built right( nothing special really) the 904 will live forever in a low 11’s car. You address the converter hub issue, put 5 clutches in it, get multi spring pack or reverse wound spring and take care of the servo pistons. Good bands/strut. Live forever. Most of which you need to do to a 727. Plus 904 is safer to a degree. I’m running Copes DIY 904 kit in my car for 3 years. Change the fluid each year. Comes out bright red and clean.

 

[-Boosted-]

I doubt you will hook up. That being said, my guess is high 12's. Get a tire with more sidewall and you will go quicker.

 

[9secRR]

If built right( nothing special really) the 904 will live forever in a low 11’s car. You address the converter hub issue, put 5 clutches in it, get multi spring pack or reverse wound spring and take care of the servo pistons. Good bands/strut. Live forever. Most of which you need to do to a 727. Plus 904 is safer to a degree. I’m running Copes DIY 904 kit in my car for 3 years. Change the fluid each year. Comes out bright red and clean.

the 904 in my car has been in the 8's for 4 years before i got it and 9's in my car for 8 years. so far it's been flawless

 

[crackedback]

I believe you will find the 904 tranny will not live long with a lot of strip time you will be stepping up to the 727 larger and stronger internals. Have five years with a 68 Hemi cuda auto not many trans issues even using a 5000 stall 9 inch B&M converter with 4.86's in a 8 3/4" 1.740 pinion sometimes 5.12 at higher altitudes.

Back when they were new in the 60-70's, you are spot on.

Now with great parts available, lots of people use 904's in 600+hp applications with trans brakes and launching hard. Plus, 904 front drums don't explode like 727's tend to do every once in a while.

 

[Icetech]

B

Back when they were new in the 60-70's, you are spot on.

Now with great parts available, lots of people use 904's in 600+hp applications with trans brakes and launching hard. Plus, 904 front drums don't explode like 727's tend to do every once in a while.

Bah, that just takes the suspense out of it

 

[furrystump]

and the toes…

 

[TXOval]

I’ll have the nitrous system 100% installed this coming week and play with the settings. Sticking with 100hp shot on first stage. Jet for second stage is 100hp as well, but want to dial in stage 1 first.

 

[TXOval]

Did my first test runs today, not track runs.

Stage 1 and 2 are both 100hp shots.

Stage 1 activates at 3000 rpms and minimum 80% TPS through 5600 rpms. Timing retards 6 degrees and AFR target is 12.0.

Stage 2 kicks in at 90% TPS and the timing drops 4 more degrees. Stage 2 also has a separate activation switch so it will remain inactive most of the time.

Stage 2 hit is noticeable.

Traction out of the hole is going to be difficult. I may add a 4-5 second delay to Stage 1