ET Speculation, anyone have desktop dragstrip?

[78spyder]

We are just putting the finishing touches on a 77 Astre. It has a fresh mostly blueprinted 355 with 9.8 compression, vortec heads with 64cc, Performer Rpm intake, Edelbrock Performer 750 carb, hooker Super comp 2135 headers with 2.5" duals running to x pipe and Flowmaster 40's right out the back. Cam is roughly 292/.480 with stock rockers for now. Hei supercoil and recurved Hei dist. Th350 shift kit with 3500 stall converter and 3.42 posi with zelsel torsion posi. 235/60/15 BFG Drag radials. No suspension work yet other then the usual 5 lug front and back, air bags and new shocks. I'd like to hear your speculation as we wont have it on the strip this year.

[cjbiagi]

I would guess mid to high 13's.

[speedphreake]

I run a 355, vortec heads, 9-1 comp, super victor intake, 780 carb, 2129 headers, 3.55's 3,000 stall and 26x10 slicks and went 12.59 coasting the last 300 feet. I think mid to high 12's with traction.

[gerbsinmd]

I would have to say that it should be solidly in the 12's, maybe low 12's with good traction. My dad's Malibu with nearly identical engine build ran high 13's low 14's. take 1000 pounds off that, and it puts you in at least high 12's, lower than that is certainly possible, we never had slicks.

[Ishiftem]

I would like to see that car with a little more lift and more gear. Assuming traction, I would guess solid mid to low 12s.

[chevyart]

im guessing high 13s. bet it will go faster with a smaller carb like around 600 cfm... aprox carb size= cu in x rpms divided by 3456 and to me the rpms means the rpm coming through the traps, not what you wind it up to once and a while example 350 cu in x 6000 rpms (at traps) divided by 3456 = 607 cfms anyone out there overcarburetored? chevy art

[Ishiftem]

I think according to that formula, my lawn mower is over carbureted

[chevyart]

hey ishiftem this is a good formula that really works. look at all the guys that run nhra stock and superstock. they run with real small carbs(the rules) and they go so fast with that small equiptment. one of my buddies that is a winner in nhra stock tells me to give him all small parts and he will show me how to make my car go faster( trick is to match all the parts together). my 67 nova with sbc comes through the traps at 7800rpms (355 cu in) and my carbs flows exactly 760 cfms(flowed on flow bench along with my ported heads) and this is just the perfect carb size for my 525 hp sbc) just telling what works, but not saying anyone has to do this, but it works and you might want to try the smaller carbs chevy art

[78spyder]

Thanks for all the info! I think once we get everything broke in we have an 1/8 mile track near home where you can litteraly get 20 passes in one afternoon. I would love to run it as is, then swap in a 600 of 650 carb and see where it sits. I agree about the gears. its going to be driven on the street quite a bit, so 3.73 may be a possibility if the 3.43's dont make us nuts. Valvesprings will take about .530, so more cam may be in the future too.

[78spyder]

Thanks for all the info! I think once we get everything broke in we have an 1/8 mile track near home where you can litteraly get 20 passes in one afternoon. I would love to run it as is, then swap in a 600 of 650 carb and see where it sits. I agree about the gears. its going to be driven on the street quite a bit, so 3.73 may be a possibility if the 3.43's dont make us nuts. Valvesprings will take about .530, so more cam may be in the future too.

[Ishiftem]

hey ishiftem this is a good formula that really works. look at all the guys that run nhra stock and superstock. they run with real small carbs(the rules) and they go so fast with that small equiptment. one of my buddies that is a winner in nhra stock tells me to give him all small parts and he will show me how to make my car go faster( trick is to match all the parts together). my 67 nova with sbc comes through the traps at 7800rpms (355 cu in) and my carbs flows exactly 760 cfms(flowed on flow bench along with my ported heads) and this is just the perfect carb size for my 525 hp sbc) just telling what works, but not saying anyone has to do this, but it works and you might want to try the smaller carbs chevy art

There is something to be said for the smaller carbs. Those stock class cars amaze me. How a guy can get a 67 camaro with a 302 using stock heads and intake into the low 10s and even dip into the 9 second range I'll never know. If someone can make less work, it's them. When I have a car again that runs I will try the smaller carbs. I have enough of them things laying around.

[chevyart]

hey ishiftemkeep us posted on any swaps and changes, no matter how small, that works. check this my buddy runs a 68 camaro, SS/G or SS/H depending on adding weight it is a 350 cu in, factory rated at i think 3o5 hp. factory compression was 10-1 and ran a quadrajet carb. SS rules let you run any cam and intake you want, but the heads had to be the snmall valve heads(not the 202s) and you had to run stock size valves and stock compression and the carb had to bbe the stock one(quadrajet). weel he has one of the specialists build tha engine for that class( there are guys out there that build the engines for all the different classes) usually around 20 -25 grand and that camaro runs a 9.89 et with a glide. how they do it with all stock GM cast parts we will never know. thats why they keep getting the big bucks because they never tell their secrets) also if you want the motor freshened or if something goes wrtong and they ne4ed to fix it, they want the motor back, UNOPENED. YOU CANT LOOK IN. if you do they wont work on it. probably all the guys are like that but some are. chevy art

[monzabill]

cast parts are lighter than forged , but they dont hold up as long they say? a cast sbc crank is 5 lbs lighter if i remember correctly.

[chevyart]

hey monzabill when i said cast fsctory parts i meant steel parts instead of aluminum(ie aluminum heads vs steel heads. i know for a fact that one ofthe guys in the stock class(runs real fast) has a 375 hp camaro(l-78 engine) and he tatke out the forged steel factory crank and puts in the fsctory cast iron crank just to save weight as you say. everyone wants the forged cranks, but not these guys. all kinds of tricks up their sleeves chevy art

[Bob Gumm]

hey ishiftemkeep us posted on any swaps and changes, no matter how small, that works. check this my buddy runs a 68 camaro, SS/G or SS/H depending on adding weight it is a 350 cu in, factory rated at i think 3o5 hp. factory compression was 10-1 and ran a quadrajet carb. SS rules let you run any cam and intake you want, but the heads had to be the snmall valve heads(not the 202s) and you had to run stock size valves and stock compression and the carb had to bbe the stock one(quadrajet). weel he has one of the specialists build tha engine for that class( there are guys out there that build the engines for all the different classes) usually around 20 -25 grand and that camaro runs a 9.89 et with a glide. how they do it with all stock GM cast parts we will never know. thats why they keep getting the big bucks because they never tell their secrets) also if you want the motor freshened or if something goes wrtong and they ne4ed to fix it, they want the motor back, UNOPENED. YOU CANT LOOK IN. if you do they wont work on it. probably all the guys are like that but some are. chevy art

Art, I don't quite understand the "don't open the engine" comment. If you are challenged by another driver as to the legality of your motor you can be made to tear down your motor for inspection to check CID, stroke, bore, etc.. If a shop that built it wouldn't touch it after it was open I'd say they are not being realistic.

There are probably a 1,000 or more things that can be done to make a motor better. A lot of the power can be determined by the cam which is dialed in to the RPM range, CID, CFM, and fluid dynamics of the engine. The intake charge of a normally aspirated engine can be made more than 100% efficient by timing the valve opening to the intake and head and intake runner cc. At peak RPM the induction charge is cut off when the intake valve closes and the air is going so fast it begins to stack up behind the intake valve and works its way back to the common plenum of the intake. If it reaches the plenum it will start a reverse pressure wave that will quickly bleed off the induction pressure wave. By syncing the cam and RPM so that the intake valve opens just before the pressure wave reaches the plenum you get the benefit of that pressure wave working for you to force the air stacked in the intake port and runner into the cylinder much faster than the piston can suck it in, making the motor better than 100% efficient.


Thanks,