j69camz28

I have a 1969 Camaro w/ a 406--5.7 rods w/ARP bolts, ARP main studs. Pistons are Speed Pro hyper. with the coated anti friction skirts. GM cast crank. Compression is about 9.8:1. 750 Holley DP. I have run a best of 11.89@112.65 on the engine. I've had a NOS Sniper system for about 3 yrs now, brand new in the box. I'm wanting to use it this spring. I believe it adjusts from 100,125, and 150hp. I normally run about 35* timing NA. Will I be ok to use this system all the way up to 150hp, or should I stick with the 100/125? I know about retarding the timing and running colder plugs, is there anything else I should do 1st? Also, and guess on ET improvement based on experience would be cool. Thanks...

ericmac450

What transmission? Rear Gear...car's weight? I'd say you already got a really good suspenion to be run 11's with a 112mph.

Put the 150 on, she'll be alright...just richen up the fuel some. Just be sure not to run platinum plugs.

If you can spray out of the hole I'd say as low as a 10.50 @ 120, I bet it'll really like the spray. Just make sure you don't over run your gear. By that I mean you may be near redline now iwth your 112mph, if your spraying just remember you'll be turning quite a bit more RPMS at the end of the track. I'm sure you've thought about that, just wanted to make sure.

-Eric

tommyt

I would add a MSD 6AL with the adjustable timing computer (its far from a computer, they just call it that). This will serve as a rev limiter, give You an adjustable timing curve, and take care of timing retard when You are spraying, so You won't have to compromise off-bottle performance or mess around with resetting the timing all the time. You may already have this, I just tought I mention it , it works great for me.

j69camz28

I'm running a TH350 with the Street Fighter converter w/ the anti-balloon plate, run a 12-bolt with 3.73s. The car weighs around 3275-3300lbs with me in it. I'm currently running a set of 275/60/15 BFG Drag Radials. My best 60ft time is a few 1.69s. My posi is starting to go out, and I'm replacing it with a stronger Eaton unit. Also am going to experiment with the pinion angle and swap out rear shocks. I'm hoping to lower the 60ft times to low 1.6s and maybe squeeze a 11.79 on the engine. I'm also stepping up to the new MT Drag Radials as soon as I spray it. I already have a Holley Annihilator Ignition system w/bulit in rev limiter, but no timing system. Is it neccessary to go with the MSD system you think, or just more convenient? I currently footbrake the car to about 1600-1800, and mash it from there, shifting at 6K and crossing the line at about 5500-5600. Will the gas throw me over 6K at the line? I'm not wanting to go past 6K, maybe 6100 or 6200 is absoultely necessary. I'm hoping for a 10.99 ET or lower, and you guys think I can hit that?

ericmac450

I'm guessing yes, you'll be over 6k...how far over 6? I'm not sure. Just go to the strip and make a test run...push it as far as your comfortable...if your not to the end of the track just let off go home and get some new gears or taller tires

Are you sure your at 5500-5600? By my calcualations that's 122mph. I'm showing 112mph closer to 5100 (which 112 is an average so I would expect you to actually be quicker at the last beam than you are with the average, but 10mph is a lot)

Like I said before I think you'll be alright. But if you get out there and the run feels wrong then lift...there's no shame in lifting and saving your motor

Have fun, and I wish I had a 69!

j69camz28

ttt

The Doc

I think ericmac450 has a good point. Are you sure the stock tacho isn't over reading?

j69camz28

Its not a stock tach, its an AutoGauge w/shift light(made by Autometer). I'm pretty sure its 5500, I guess I'll pay closer attention when I go out next spring.

j69camz28

Bump

bottledbird68

The MSD isn't neccessary, just more convenient. If you're running the 150 shot I'd pull around 4* of timing to start with and tune your way from there. Just be careful, horsepower wise it sounds like you're starting to get close to the limits of your bottom end already. You may be safer with the 100 horse jets and see if those get you to your goals, they just might. If not then I say spray away. Also, do yourself a favor and get a bottle warmer and a purge. Those were the two best additions I made to my sniper kit in my 68 bird (coming out this winter and a two stage cheater going in, wish me luck ). Make sure bottle pressure is between 900 and 1,000 psi before every run and purge it when you stage. Without the purge you'll get a momentary bog from the extra fuel that dumps in before the air clears out of the nitrous line. Aside from that sounds like you're on the right track. Nice to see another first gen owner around these parts too

unknown_host

iTrader: (1)

On a 150 shot it should do closer to 123/124 mph, probably right around 10.50's.

I think you will be fine for RPM, maybe just a bit over.

Using an online calculator I got 5595 rpm through the traps with your 28" tall tires and 0% slip, so figure in 10% slip in the converter and we are looking at just over 6150 rpm if you trap 125 mph.

I say stick with that gearing/tire combination, and if its too much rpm back down to a 125 or 100 shot.

j69camz28

Thanks for the help guys. I will look into a purge kit and a warmer. Unknown -- thanks for the input on the rpms. I didn't think I could've been that far off on the tach, but wasn't positive. I could live with 6150-6200 I think. I'll start off with the 100shot with the pressure between 900-1000 and see what happens.