So about a two years ago before I left for Afghanistan I rebuilt a Pontiac 400 that is in my 1981 Trans Am, It is bored .030 over with #13 heads that are ported and an edelbrock aluminum intake that is ported to match it. It is supplied by a edelbrock 750 cfm carb, and has an MSD 6AL2 box. I put in a voodoo cam, Hydraulic Flat Tappet, Advertised Duration 268/276, Lift .489/.504, with a 2200 RPM stall converter. Also new edel valves, dish top KB pistons. It has Th-350T transmition, with 3:43 gears in the rear with some 10 inch tires and true posi. Stock 400 crank its in good shape, new timing set. The heads got new springs to match the cam. Stock rods. Maybe I shouldn't be disappointed you tell me. I ran a 14.15 1/4 mile with a reaction time of .7. My 60ft is 2.12, 330ft 5.98, 1/8 9.12 at 78.26 MPH, 1000ft 11.84 at 89.68 MPH. This was my first time at the track. What do you all think?
A few more things it was hard to use the stall effectively because my break petal will go all the way into the floor and not feel like they are locking up in the front, is that caused by a lack of vacuum? And my traction is good I didnt seem to spin much at all at any point during the race. I did have subframes, and new 4 tube headers installed. Also the timing was done by a pontiac mechanic I have.
97.6 MPH at the 1/4 mile
I feel like the cooler the engine was the better it ran, my first run down the track at like 160 degrees i had like a 1 second reaction and ran a 14.6. On a few occasions the motor would bog down after the jump like it had no fuel but at the end of my runs when I would park and open the hood up I could smell gas.
That sounds about right to me, first time out. As long as you had fun, its a win!
What were your expectations?
Well id say my car weighs near 4000 pounds right, at 14.1 that puts my horsepower estimate at like 280 rear wheel horse power, that is garbage for the modifications I have isnt it?????!?!
part of it depends on your elevation and obviously wheel spin. 355 gears might get you down quicker.that cam is a not a monster cam. the next one up will get you there quicker but requires an eddy rpm manifold and 355 - 373 gears imo.a quick fuel annular boost venturti type carb will help also.
Not garbage! If you clean up your launch technique, you are in the high 13s. If you experiment with your car in the pits and find out what tuning and adjustments help, you're mid 13s. Thats good. Heck I shaved .4 once with my heavy car just by going from a 275/60 down to a 255/60 and adjusting the technique. If I'd had a few more passes I'd have gotten high 13s, but it was a handful with a little 2nd gear fishtail that way. Are you dragging a whole quarter mile?
Yeah I am doing the whole quarter mile.
I asked that because I didn't know if maybe you were extrapolating from eighth mile times or something. Are you in third gear when you finish or at the top of second? Playing with tire size doesn't just affect starting line performance, and some TH350s have a kinda long slippy shift from 2nd to 3rd. Taller tires might eliminate a shift, shorter ones might get you farther into third, at the finish. Just something to think about there, you do have a fairly mild setup for dragging but it ought to be very pleasing on the street. Having a pair of different rims/tires for the track is the popular way to have your cake and eat it too. I still don't think you should be too disappointed yet.
I just disliked getting *** on by some stock 5.0 Mustangs, and a stupid modern 6.0 GTO..... With little to no modification when I have put so much work in this car.
if your pistins have a 15 cc dish your compression is around 9.2 at sea level, it drops around 5 psi for every 1000 foot increase in elevation. 9.2 is good for your set up at sea level but a bit low if you are at 1000 feet or more, imo.if your pistons are 20 cc your compression is around 8.82 which would be less than optimum. depending what model of mustang you are racing some are fast, most are modified but you can't easily tell and they will tun 12.8's.if you install an xe 274h cam or comparable lunati and get your compression up it will haul a.your stall is a bit too low for good ets as it is imo. i might run around a 2600 rpm.an xe274h cam likes 350 gears in a 400 also. if your carb is a double pumper it will contribute to bogging if you floor it off the line especially if it is a straight booster and not a downleg or annular type.it would be very helpful to know your timing at idle, and max timing and the rpm at which it reaches max with the dist vac disconnected.spend 300.00 and get it dyno tuned.
Bore (in):4.150 in.Bore (mm):105.410mmPiston Styleish, with two valve reliefsPiston Material:Hypereutectic aluminumCompression Distance (in):1.720 in.Piston Head Volume (cc):+17.00cc
I bought a compression gauge ill have to test it.... ***