well it has been since last year late oct. or so since i ran my bbc z28...car went thru some changes.....old best e.t. was 14.47@98 mph with 2.15 60 ft thru the mufflers and on street tires.

changes: 2.73 posi from a 2.41 posi,2100 stall to 2800 stall,new exhaust all the way out 2.5" with 2 1/4" tail pipes,advanced cam 4*,added rhoads lifters,recurved hei,reworked heads,roller tip rockers,raised compression .3 of a point, new rear tires(same size as old)

1st pass right off the highway (1 hour and 1/2 drive)no cool down went to tech and staged.

2.22 60ft
9.225 660
14.062 @ 102.959 mph
shifted at 6,000 rpms

2nd pass 22 min later engine still to hot for my likings.

2.248 60 ft
9.260 660
14.090 @ 102.736 mph

shifted at 6,000 rpms-no changes on tune

3rd pass 47 min later engine cool now
changed #71 front jets to #73 shifted at 6200rpms
launched at 1400 rpms full throttle/no spinning

2.201 60 ft
9.141 660
13.931 @ 103.948 mph

4th pass 41 min cool down ,changed to 6300 shift point, put in a modified squirter (drilled bigger then the stock #25) 1400 rpm launch full throttle no spinning

2.213 60 ft
9.143 660
13.925 @ 104.135

5th pass 55 min cool down ,changed 73 front jets to 75 and changed rear from 75 to 76/77 staggered (77 jet went to the 5-7 cylinders)....same launch ,same shift point 6300

2.219 60 ft
9.171 660
13.957 @ 104.063 mph

6th 38 min cool down,changed 75 front jets back to 73.....no other changes

2.237 60 ft
9.192 660
13.975 @ 104.142 mph

7th pass 29 min cool down, changed purple secondary spring to tall yellow spring. put back the stock #25 squirter......no other changes same launch and 6300 rpm shift point.

2.223 60 ft
9.16 660
13.936 @ 103.823 mph

8th pass,26 min cool down ,put back purple spring, loaded rpms against convertor, blew the tires off the line. 6300 rpm shift point.

2.367 60 ft
9.289 660
14.060 @ 104.415 mph


maybe i can get some fed back on some thoughts for next time out......maybe some tunning tips and ideas.....maybe another set of eyes or two can see something im missing.....thanks

Nice job..very impressive with 2.73's/396 graemlins/thumbsup.gif
Sticky tires and your deep into the 13's
You're running a Torker,correct?

thanks.......but its not a traction issue....its the lack of low end torque that is hurting......i can stage the car at 1400 rpms and mash the gas to the floor and it wont spin at all.....the convertor before the heads was reworked was stalling at 2800 rpms now it only stalls at best 2500 rpms........and it flashes to 2500 rpms when i leave the line from 1400 rpms.......the only reason i blew the tires on that last run is i had the car fully extended and at 2500 rpms and it was almost a power brake type take off.....

im thinking of changing the intake to a rpm eddy so that maybe i can gain some low end torque over the torker 2 intake single plane thats on there now..................

Interesting comparison here. We both have 396 based motors. (408 vs 414) Different set ups though. What cam are you running? I run a Crane Powermax 286 (226/236 on 112 LSA) with dual plane. 9.7CR, oval ports, 3000 stall & 3.73's. On 275-60 street tire, I can burn the tires out of the hole for 100' right through first and into second - no powerbrake, just side step the brake and nail the throttle from idle (850 - 900 rpm) I almost think I need to kill some bottum end.

Incidentally, I also installed the yellow spring, thought maybe I could get the carb to open sooner and kill some bottum end with a little bog, no difference though.

Either accept bad gas mileage and get 3.42-3.73 or get those gears and an overdrive, you could prolly drop nearly a second off of your time.

Originally posted by GRN69CHV:
Interesting comparison here. We both have 396 based motors. (408 vs 414) Different set ups though. What cam are you running? I run a Crane Powermax 286 (226/236 on 112 LSA) with dual plane. 9.7CR, oval ports, 3000 stall & 3.73's. On 275-60 street tire, I can burn the tires out of the hole for 100' right through first and into second - no powerbrake, just side step the brake and nail the throttle from idle (850 - 900 rpm) I almost think I need to kill some bottum end.

Incidentally, I also installed the yellow spring, thought maybe I could get the carb to open sooner and kill some bottum end with a little bog, no difference though. im running a custom grind from delta cams.....i informed the owner of what i was doing with this project.....and he ground me a cam with 233/239 @ .050 with .547/.551 lift on a 111 lsa

out on the street if i just bring the rpms up against the convertor and mash it they will go up in smoke thru first and 1/2 thru second.....but at the track it's alittle different its more sticky and they way i have my car set up with it at rest with 1400 rpms and nail it then the body goes into full motion and really lifts the front end up high...but not the tires.....the rear dont sqwat it raises just as well and plants the tires.....but if i bring the car up against the stall the car raises all around and if i try leave that way it just spins for awhile....

i finished porting the heads out and had some more machine work done and after i did that i lost alot of the low torque...i believe i lost the air/fuel velocity that it had before........and the torker 2 intake being a bad design anyways makes it even worse.....so i think at the lower rpm range below 3000 it just aint moving the air/fuel mixture......on top of that im trying to push almost 4000 lbs of the line with 2.73 gears........

so it appears that the heads improved the top end a great deal but it's suffering down low.....and i think im on the edge of lean anyway and the tall yellow spring makes it worse (more air)as before it has always helped.....but i had bigger jets in there too......

i put the rhoads lifters in the engine to help bottom end(after the head work) there was a better seat of the pants feel but i guess not enough to make the car faster in the 60 ft times........

with 2.41 gears and 2100 stall i was getting 2.15 60 ft times.......but that was before the head work as well......

change one thing at a time.

well i bought me a edelbrock rpm intake for the engine.....i am going to make this fit under the stock hood of my camaro.....i'm sure glade i have the cold induction hood scoop this....checked a few measurements (put clay on my set up now and shut the hood) looks as thou i will be just at the limit of clearence i might have to cheat the hood up about 1/8" but its going to fit......i will have to modify the stock air cleaner as well some.......

this should help out the bottom end alot compared to the torker intake......

i found a used intake and paid 150 bucks shipped to my door .........i dont think that was so bad since i saved about 60 bucks over a new one....

ddeennis,keep us posted..I have swapped from a Performer to an RPM..no track times yet though.

ddennis, Check you space above the carburetor very carefully as this needs to be about 2" for the air to go into the engine properly. I had a 454 in a early (1968) Camaro once and adding a hood with a scoop picked up 2 tenths and 3 1/2 MPH over the flat hood which was a very close fit.

Originally posted by Harold Sutton:
ddennis, Check you space above the carburetor very carefully as this needs to be about 2" for the air to go into the engine properly. I had a 454 in a early (1968) Camaro once and adding a hood with a scoop picked up 2 tenths and 3 1/2 MPH over the flat hood which was a very close fit. yes good point.....i'm still running the factory cold air induction air cleaner assy......i put in a factory replacement K&N filter just for that model.......i have the choke horn cut off and everything smoothed on top of the carb. theres around 3 to 3 1/2" of room.....the intake will send the air filter all the way thru the hood to the bottom of the factory hood scoop......i will have to modify the base of the air cleaner assy some maybe cut it down around the edges and put new rubber seal around it to keep the seal to the hood.......its going to be a tight fit for sure.........

Originally posted by mr 4 speed:
ddeennis,keep us posted..I have swapped from a Performer to an RPM..no track times yet though. sure will for the most part im not going to change nothing but the intake so this will be a back to back test of the intakes......the only real difference will be the weather..it was very hot the day i got those times mid after noon and right at 100 degrees out.....boy did i get fried......

i kinda decided to go with the rpm because of the hot rod testing they did.........it looks to me i could be picking up about 30 ft lbs of torque at 2500 rpms and about 20 ft lbs at 3000 by looking at there graphs.......so i should be able to "feel" that. and the car should see some better 60 ft times........

i almost went with the performer since its shorter but i was afraid it might kill the top end pull this things got.....since im turning 6300 rpms i figured the performer might give some up.......i dont want to lose any on top.....just gain some on bottom........we should soon see.........

Probably the most consistant big block car on true street radials i've ever seen. graemlins/thumbsup.gif You could try buying/borrowing some sticky tires like some Drag Radials or whatever, and play around with your launch RPM to see how it reacts, and if u dont like it, get more gear. 3.31s or 3.42s are still pretty tame on the street. You could do about 60 mph @ 2500 with a 27" tire. I think the gain in acceleration will make up for the loss in fuel efficiency.

..the article in "Hot Rod" made me decide to swap it out too..the RPM was worth 29 HP and 20 ft/ft. lbs of torque at 4000..the RPM and Performer are equal at 3300,which is also the torque peak for the Performer..but at 4000,the RPM is making 20 lbs. more and that is the RPM's torque peak,at 4000
I can't "feel" anything in the seat of the pants aftre the swap..but thats OK..thats what timeslips are for.

well the rpm intake is on and working very well......it was a very tight fit....i was able to use everything as before ......there is no room left under the hood of the 80 z28 the factory air cleaner from K&N is 3 1/2" tall and i had to squeeze it down to just over 3 1/4" to make it fit.....the base of the factory air cleaner was trimmed down about 2" and the rubber seal was reglued to it....and i had to remove some support webing on the factory hood scoop and move the soleniod that opens the flapper door 1/2" closer to the winshield under the hood scoop....

bottom line......the car picked up .5" of idle vacuum due to the carb responded to a 1/4 turn in on the idle mixture screws......the idle went up just slightly but i didnt touch it....and timming is still 38* total......the bottom end is alot more responsive i can "feel" the difference but in the upper rpms i cant feel nothing different so the intake inproved the idle more and throttle response to 3000 rpms...

so the only change was the intake and this will be a good back to back test......im going to the WIR track on the 15th to see how it does......