Printable View
got the car set up for nitrous this yr. need advise on timing retard and hp settings. car; 90 coupe, 302 , forged pistons, scat rods, crank polished oil holes chamfered. studs on mains and heads. world sr heads 2.05/1.60 valves, TFS 3 cam. funnel web intake 750 dp. c4/4000. 4.30/spool/31spl. axles.26x10 MT slicks. separate fuel system for nitrous, msd 6al/3 step retard... 12.80@109n/a.. any thoughts???
Seems like you could/should be going 4 or 5 tenths faster NA then you already are. I think id work on that before spraying it.
Also with a 26" tire, a 4.30 gear, and assuming it actually stalls at 4,000rpm. Id think a 28" tire would suit you much better off the line and keeping the rpm in check at the stripe. Especially when you go to spray it.
I agree with the above, I went 12.30 with a B cam and Gt40 heads. 3.73 gear and 3400 converter. You have way too much gear in the car for spray. Go 3.73 28 or 27 inch tire. I went 10.3x on a 73 jet with my set up. Don't rattle the pistons, it's the death of those motors. 2 degrees timing pulled for every 50 spray is a good starting point.
Add some tire like these guys said. Correct me if i'm wrong but don't you want a slightly tighter converter also?
I think the low compression hurts my times. times are with 275/60 nittos dr's last year. it ran 12.64 with vic jr intake. swapped to a funnel web and slowed to 12.87@108.89. trying 26x10 slicks this yr. still have nittos if it needs more tire ht.. sold the vic jr already. stuck with current combo for now. had 4.56's, ran same #'s noticed the rpm's going thru the traps seem low. only plan to use nos sometimes. sunday brackets at Milan. I'm ok with the n/a times. built to be streetable and faster than the muscle car of the past.
a few yrs back, I had an identacle shortblock with a comp street roller cam(760-8... .586/.586 246*@.050") car ran better than now. 12.40@110 mph with 26x8.5 dirt tires. block cracked, rear cam bearing popped loose tearing up the last lobe on the cam. dam! went with the tfs 3 cam. it had 4.10's then.. rpm thru traps were 5600-5800. shifted at 6800 rpm. i miss that motor. drove on freeway(3500 @ 65) good cam.
flash rpm is approx. 4000 rpm. at the track, it wants to break the tires at 2600-2800 rpm. any higher, the breaks can't hold it still. would like to try a trans brake. can't leave hard enough. not a slug at all, but could be better.
I should have the rpm band to go as fast as 119 mph(6612rpm). motor spins to 6900-7000 easily.even with converter slip, it should be safe. remember 11.50 is my limit(no cage)