First time out.... waa waa waa waaaaaaaa !

Thanks guys lots of great information ....tonight I put 28 and 28 squirters in there I had laying around to go to the other extreme down from (42 and 31) to see if it helps the launch (if you can call it that with a 2:56 ) ......its too late to take it out tonight and try it .....but I will keep you informed on track results next time out in a few weeks. Thanks to all for the advice and I will keep updating the thread with progress - changes and looking for more valuable tips. I think I read one car on V8 here on motor HAS hit 12's with a 2 series gear and no headers so it can be done..... J

 

The bug has bitten!

 

Back to the track with a smaller 750 Speed Demon down from the Holley 850 D.P. I was running and I just missed hitting my 12's goal. Car ran a personal best today at 13.157 at 104.45. I ran 13.51 at 103 last time out with the 850 back to back. So I picked up a little et and 1.45 mph. My car still will not 60 ft. My best today was a 2.070. Heres one of my runs tonight (a slower one 13.286 at 101-announcer mis states my time) where a Camaro eats me out of the hole but I caught them and won. It weird the 850 felt like it pulled noticeably harder on the top end but the 750 produces better all around 60ft,mph and e.t. Thats a weird one I cant figure out. Butt dyno says one thing e.t.'s show the opposite is true.

http://www.youtube.com/watch?v=P7i2EmHxG5Q

My car still isnt picking up 22mph like other guys running 12's from the 8th to 1/4...I did creep up a little at gaining 20 mph today but still havent gotten to gaining 22 mph. I had a full spare in the trunk, a loose tire and a 50 lb weight lifting plate and my soft side tool bag all over the passenger side as well. I didnt spin much tonight but that has to be at least 200 lbs back there. I also launched higher at 1800 and got away with it. Anybody got any ideas for picking up anything - on what to try next ? I want to run a 12 with a 2:56 gear and manifolds and I dont want to stop until I hit it. Its been fun.

I was all over the place tonight mph wise ?

13.15 at 104.45
13.28 at 101.72
13.39 at 101.58
13.46 at 102.22

 

Hey there-

I haven't really been following this thread, but I probably should have been as a fellow 2.56er.

My personal best was a 12.79 @ 110, so a 12-second run CAN be done with 2.56. However, you have another obstacle as well - exhaust manifolds. When I switched from full-length headers to shorty headers, I figure that cost me about 0.3 seconds & 3 MPH. I haven't made a 12-second run without full-length headers, my personal best is 13.15 @ 107 with shorties.

Our cars have several other differences, but the thing that brought me from my previous best 13.27 to the 12.79 in one fell swoop was mixture - I think I wasn't getting enough fuel, and when I changed that around the car picked up a lot.

I don't know if you can hit 12's without full-length headers, but there is no doubt they would make a difference. I bet that would change your 20 MPH to the 22 that you think it should run.

60' has always been my problem too- not because of a lack of torque (455s should have plenty of torque) but lack of traction. I have always had to feather it out of the hole. Like I said I haven't been keeping up with this thread, but I bet that if you go back to the 850 carb and back off the accelerator pump a bit it will give you a better ability to control your launch. (Don't back it off to the point of bogging, but back it off to the point of feeling a bit less "responsive").

The other thing I found, and I have no idea why, is that without my rear sway bar I will launch slightly better. I just pulled it off of the car and I don't use it any more.

Airbag in the passenger side rear spring will also help the launch.

One other thing that helped me too was Rhoades lifters. My theory was that they would help my MPG without hurting my ET, but it actually helped my ET too. Of course this depends a LOT on the rest of your combo, and I don't know enough about it to comment, but I believe that Rhoades lifters will only help in certain combinations.

-BC

 

Thanks Bob.....yes I kind of figured at this point headers will do it...I just have been kind of reluctant and thought it would be neat to get it through manifolds. So you went from manifolds to FLH and got you .3 and 3mph ? I guess thats what all the Dynos and Jim W. has said too - they get you +25 to 30hp and the same gain in torque.

What gain did you get with the shorties ? I didnt know shorties would fit a 65 ? I guess they dump right at the same points as the manifolds for hookup ? What cam and carb are you running with your Rhoades ? Whats your average 60 ft ?

First I figure I would go up a jet or 2 sizes up in the back only of this Speed Demon to see if I pickup any mph next time I go out. I dont want to give up on it yet. I just really like the way this carb feels right out of the box so far and havent even begun to really tweak it yet. But you are right maybe another shot with my 850 tweaked as you say -may get it right where it needs to be. I tried going up and down with squirters all the way to 42's with the 850 but always left the pink cams in there and could never get rid of the lean spot on launch...... .. this smaller Barry Grant squirter sized exactly the same as the best setting on my 850 (31 31) never bogs no matter how I launch it-its very tolerant. Thanks for the tips -look forward to your reply....

Larry yes I still have the Nitto NT555r's and my 2:56 rear gear. What is the best 60 ft time a guy can expect with a 2:56 ? You have 3:42's correct ? J

 

I am lost with this car ....I just made several necessary fuel system changes as the car was falling off on the top end ie running out of fuel.....SO I got a robmc 1/2" pickup, the TA 500hp pump, I jetted up both front and rears 2 jet sizes. It runs clean all the way through the traps now. I also got a set of TA shorties and finally got them in my 65. At the track today (first time out since April ) I ran ABSOLUTELY no better than before with all these improvements ? This car for whatever reason WILL NOT 60ft sub 2.0 with this 2:56 . I am beginning to think my trans must be slipping or something off the line. My best run today with headers was a 13.27 at 104 with a 2.19 60 ft down from my all time best of 13.15 at 104 with a 2.00 60 ft via gessler ported manifolds ???????????? My worst of 4 runs I tried as an experiment to power brake it to like 2500 - highest of all time , tires broke loose it spun miserably , I let out of it , got back on it and ran the worst all day 2.879 60 ft 14.18 at 105. Later on I had a 13.33 103.92 and a 13.54 103.36 . From all my last 10 timeslips the car 60's at anywhere from 2.0 to like 2.3 usually. Do you guys think maybe my trans isnt holding as I do - Im lost ? The car also was only gaining 20 mph from 1/8th to 1/4 again ...most guys I see in the 12.xx's gain at least 22 mph in that range. So switching from Gessler manifolds to headers got me nothing mph wise either.

Any thoughts are appreciated ........ J

13.27 at 104.20 2.194- 60
13.54 at 103.36 2.317-60
13.33 at 103.92 2.260-60
14.18 at 105.41 spun real bad got out of it and back on it 2.877- 60

 

i haven't read the entire tread but why do you have those 2.56 gears in there? i don't know what benefit those would give you anywhere except above 90 mph. why not use 3.08 and change the first gear in the tranny to a 2.75?

 

I have drag radials on nitto nt555r's ...

the 2:56 isnt my choice its what was in the car...I just thought from reading on here a 12.xx CAN be done with a lousy gear

 

Jay how old are your tires & how do you store them? When the track looks good and my 60' is hit or miss i know it's tire time.
Jamie

 

Jamie - they are brand new less than 300 miles .......... got an idea what should a lousy gear car average 60 ft at - my friends claim I should be able to get a 1.8-1.9 at least ?

 

It's odd how similar motors need different stuff. As you saw, in Reynolds I ran a bunch of 12.50s with the stock pick up, original fuel lines and a stage 1 pump.

As for your times, your cam is similar to mine but you have much better heads and you're only running a 750. I'm running an 870. Are you sure you don't need a bigger carb? Air in / air out.

Also on the air out side, what is the rest of your exhaust? 2 1/2 mandrell bent? Good mufflers?

Also, with the 2.56s I really don't think you're gonna see much better 60 fts. I was getting 1.85s last year with 3.42s.

 

Hey Mike its pretty much all 2.5 except for the 3 inch header down tubes, mandrell , x pipe ,mufflers are decent brand x.....it was running out of fuel near the finish line back in April on about 1/2 my runs with this 750 ...that is gone now with the new pump and pickup......this car is always flat from 1/8 to 1/4 only gaining 20 mph for some reason...with the better exhaust,fuel pump and pickup it should have picked up "something" -but nothing at all ? So its hit a wall somehow and not responding ...Im crutching the gear and tight converter with the smaller carb......it feels like the right carb. My 850 I couldnt tweak out the lean stumble on launch no matter what I tried,squirters,cams etc. Yes I could have thrown the monster accel pumps on the 850 to cover it up but decided not to ......blah blah blah. Im thinking my motor sits high.... I may not have enough air space above that carb...Im using a really deep drop base just to get a 2.75 inch K+N filter in there. I run without it at the track but there isnt much room above that carb and the 65 hood triangular cutout kind of envelopes the carb area as well. Your 66 might be the same ...so I am going to rig up a ram air setup with pieces I have laying around and see if it picks up "anything" to rule that out ....something basic is still wrong here I just have to find it.

What jetting are you running on your 870 ?

 

I like the ram air idea.If the track was good & you launched the same way maybe trying some air presure adjustments could help your 60.How tall are your tires?
Jamie

 

Out of the box. Paperwork says 78 primary, 80 secondary.

 

Jamie tires are 26 " ...I brought them down to 16lbs each this time - no change in 60 ft...did your car pick up with your scoop ?

Thanks Mike for the jet info......something stupid is wrong here ...I will repost after I rig up a ram air setup and try it.....

What are you guys thoughts on stalling the car to launch it rather than just hitting the accelerator from idle and rolling into it ......currently I stall when leaving - if you can call it that ou: .J

 

Also, I looked at my timeslips and I only pick up 20 mph from 1/8 to 1/4 too.

Planning on doing the ram air as well.

 

Jay my car came with the scoop but a friend of mine went from a 69 GS hood to the stg2 scoop and it helped.Off the top of my head he picked up a tenth & 1/2 maybe a bit more.
My air pressure can't very much more than 1 pound or it won't hook on the slicks.From what I can recall my dot drag radials were with in a pound or maybe 2 and spin if off more than that.
I have a 4500 stall for me it 60's best if i hold it around 1200-1400 then pound it.If I hold it against the brake ( say 2500ish) the front end will rise killing my pitch rotation causing lots of wheel spin.When i had stiffer front springs i could hold it, but flashing was a little faster.The only downside to flashing it is for me it is harder to cut a good light.Maybe I'll fix that with a trans-brake someday.
Jamie