[hal101]

this is my sons car
1980 ta
455 40 overstock rods arp bolts (was put together atleast 5 years ago)
trw forged i think flattop
6x4 heads ported to 260 cfm
sd 236/245 .570/.574 HR
70 ci intake
Q-Jet
1-5/8 headers 3" exast
th 400 with heues 2500 stall concerter
now for the killer 2.56 posi

he went to the track for his first time last sunday

he made 3 or 4 runs best of 14.090 @ 99.67

what dose everybody think about a holley street dominator ? and will it fit under the scoop ?

[grandville455]

That old faithful roller wants more than a 2500 conv for sure, also with the gear did he leave it in second? or did he shift to 3rd? I would say its down on power big time somewhere? Convertor slipping? What was the top RPMS at stripe? That combo alone even with that gear should run 13's easy and more mph. whats the fuel system like?

[ta man]

I agree ...I expected to see a low 13 time with a decent mph..I wonder about the convertor too..especially with a 2.56 gear.It could be slipping pretty good.I used to shift my old T/A with 2.56 gears into drive at 100mph or so.

[hal101]

Originally Posted by grandville455

That old faithful roller wants more than a 2500 conv for sure, also with the gear did he leave it in second? or did he shift to 3rd? I would say its down on power big time somewhere? Convertor slipping? What was the top RPMS at stripe? That combo alone even with that gear should run 13's easy and more mph. whats the fuel system like?

yea i know the 2500 is not enough but it is what i had left over from the firebird

he said he shifted to 3rd right at or slightly before the finish line

i told him to shift at 4500 for starters so i juess it was 4500 in second at the line

the fuel sys is compleatly stock so im sure it will need to be addressed

i know it needs a lot of upgrades but i just wanted to see him go down the track he has been waiting so long and the smile on his face made it all worth it

[hal101]

Originally Posted by ta man

I agree ...I expected to see a low 13 time with a decent mph..I wonder about the convertor too..especially with a 2.56 gear.It could be slipping pretty good.I used to shift my old T/A with 2.56 gears into drive at 100mph or so.

yea i was hoping for that too

i think the QJet with stock fuel sys was hurting it a lot

well he shifted into drive at the finish line 99 mph so that is about right rite

[71 Ventura II]

No mention of the tires being used, how bad was the 60' times? Definitely leave the tranny in 2nd gear it will help drop .02 to .03 off the ET. Even with the 2.56 I'd think mid to high 13's are possible.

We built a 455 with less than he has so I know it has potential. Ours was a .030 over 455, unported 6X-4 heads, Lunati Bracket Master II hyd cam, stock iron intake, Factory #6213 spreadbore 800 dp, Summit headers, TCI 2000 stall, 3.73 gears. It went 13.20's @103 mph in a full weight 1976 Firebird w/asphault Goodyear circle track tires.

[rad400]

Hal i am glad your son had fun racing. I think the intake and carb are fine try moving shift points to 4800-5000 and see what happens. Could have been his nerves too.

[hal101]

Originally Posted by 71 Ventura II

No mention of the tires being used, how bad was the 60' times? Definitely leave the tranny in 2nd gear it will help drop .02 to .03 off the ET. Even with the 2.56 I'd think mid to high 13's are possible.

We built a 455 with less than he has so I know it has potential. Ours was a .030 over 455, unported 6X-4 heads, Lunati Bracket Master II hyd cam, stock iron intake, Factory #6213 spreadbore 800 dp, Summit headers, TCI 2000 stall, 3.73 gears. It went 13.20's @103 mph in a full weight 1976 Firebird w/asphault Goodyear circle track tires.

the tires are 215 60 14 et streets

i think there is a fuel suply prob he said sometimes it feels like it is slowing down at the finnish

60' ..2.001
330 .5.914
1/8 .9.129
mph 78.59
1000 11.823
1/4 . 14.090
mph 99.67

[hal101]

Originally Posted by rad400

Hal i am glad your son had fun racing. I think the intake and carb are fine try moving shift points to 4800-5000 and see what happens. Could have been his nerves too.

hey thanks
yea wee have a lot of work ahead all it takes is that first time down the track
but he had a great time and that is what counts

[Brent Flynn]

Originally Posted by hal101

this is my sons car
1980 ta
455 40 overstock rods arp bolts (was put together atleast 5 years ago)
trw forged i think flattop
6x4 heads ported to 260 cfm
sd 236/245 .570/.574 HR
70 ci intake
Q-Jet
1-5/8 headers 3" exast
th 400 with heues 2500 stall concerter
now for the killer 2.56 posi

he went to the track for his first time last sunday

he made 3 or 4 runs best of 14.090 @ 99.67

what dose everybody think about a holley street dominator ? and will it fit under the scoop ?

I wouldnt put another intake on it with that gear... i'd think you would lose some low end for sure...need you some 3.55's in there! With the weight of that car, no converter or gear, those intake ports are a little on the big side... Id just put some more gear in there .... i do believe holley street dom will fit under TA scoop... but it wont be faster than the cast intake

[Dragncar]

Its fuel. Take off the brass filter and put a in line 3/8ths canister in there.
That, and take the sock off in the tank and replace with a like length rubber hose and a 80 gph mech pump will get you to 12 flat.

[hal101]

Originally Posted by Brent Flynn

I wouldnt put another intake on it with that gear... i'd think you would lose some low end for sure...need you some 3.55's in there! With the weight of that car, no converter or gear, those intake ports are a little on the big side... Id just put some more gear in there .... i do believe holley street dom will fit under TA scoop... but it wont be faster than the cast intake

thanks
yes i to think it needs gear but for now im going to swap some parts a already have

[hal101]

Originally Posted by Dragncar

Its fuel. Take off the brass filter and put a in line 3/8ths canister in there.
That, and take the sock off in the tank and replace with a like length rubber hose and a 80 gph mech pump will get you to 12 flat.

yes i do think it has a fuel prob already took the brass filter off replaced with a in line canister filter now ill have to check the sock and upgrade the pump

[ta man]

I ran mid 114's with stock 3/8 lines no sock and a Mallory 140.Now almost 117 with same pump RobbMc 1/2 inch pickup all 8AN lines and fittings no other changes.

[hal101]

http://www.youtube.com/watch?v=biZ-POrva7A

looking at the time slips it looks like starting with a full carb it makes it to the 60'
consistantaly but then the fuel delivery prob kicks in and then it is all over the place

sound about right

andy
12:28 9/oct/20011 12:56

rt ...1.095 rt …
60' … 2.169 60' … 2.005
330 … 6.397 330 … 5.588
1/8 … 9.953 1/8 … 8.984
mph … 69.31 mph … 67.08
1000 … 13.005 1000 … 12.134
¼ … 15.636 ¼ … 14.768
mph … 84.58 mph … 86.85

12:38
rt … .608
60' … 2.001
330 … 5.914
1/8 … 9.125
mph … 78.59
1000 … 11.823
¼ … 14.090
mph … 99.67
12:47
rt … .056
60' … 2.072
330 … 5.815
1/8 … 8.861
mph … 81.30
1000 … 11.733
¼ … 14.648
mph … 69.12

[hal101]

made it back to the track with a few changes

replaced the 6x4 heads ported to 260 cfm with #12 heads ported to 280 cfm

replaced the CI intake with a performer RPM

replaced the Q-jet with a holley 870 cfp street avenger

added an electric fuel pump back by the tank to assist the stock pump

last year it did a best of 14.09@99 mph

this year it went 12.77@100.4

and i asked someone if the speed was low for the et he said yes it needs more jet
sound right ?

so what should be the next change more converter or gear (it has cast rods)


http://youtu.be/YQaC8-Lg4Cs

[prostreet64]

Nice improvement. I would lean toward more gear depending on how much street time the car sees. Both of our cars have 3.73s but that is a bit much for highway driving. As you already know, one change usually leads to others. If you go with more gear or more converter you will probably create a traction issue that will then need attention. What 60' time did he run with that 12.77 pass? And it does look like the motor is falling off at the top end; maybe a fuel delivery issue or need more jetting. I think 12.77 should translate to around 105 or better mph. Anyway, it looks like you are well on your way and I know your son must be loving it.

[ponjohn]

I think the biggest restriction is the small headers.

[Slick]

Respectfully, I wouldn't change any more parts (converter, gear, etc.) until you figure out where the MPH went. The heads, cam, intake, even the 1-5/8" headers/3" exhaust system will support way more HP than the MPH indicates. The MPH is even lower than a stock 400 Ram Air III Firebird, so something is definitely wrong.

Therefore, I'd suspect either ignition or fuel. I missed any mention of timing or the ignition system. Check that out, be sure you have something like 36*-40* total depending on actual compression/fuel/etc. and that it is not misfiring at high RPM.

If that all checks out okay (the "ping" test for maximum advance will work absent strip testing or a chassis dyno), then look to fuel delivery. FIRST be sure fuel is getting to the carburetor. You can temporarily rig a hand-held diagnostic vacuum gauge as a pressure gauge using clamped lines into an 1/8th inch fitting in the fuel line at the carburetor; just rig it up onto the cowling (again, temporary) but not inside the car. If over 4PSI is available in third gear at full throttle after being in first and second at full throttle, THEN look to jetting.

One easily missed item is throttle blade opening. When your son's foot is on the floor, is the throttle full open? Simply check the throttle arm to be sure.

Changing gears will hardly affect MPH, changing converters might lower it. That Holley Street Dominator you mentioned will kill MPH and ET unless it is heavily modified. Even then, it requires a lot of gear.

Best of luck to you, the time you put in now will reap more rewards than just "changing parts"

Stuart

[BruceWilkie]

The 2.56 in 2nd is same as running 3.78 rear in high... your not helping ET with the 2.56's but your mph should be higher unless your holding in 2nd gear too far above your power peak and not getting into high before/thru the lights. The HSD isnt going to help the 2.56 gear either.

However all indications are you are running out of fuel whether its a supply problem or jetting or both. Your mph is slow for the ET and gear. You should be going near 104 or more for a 12.77

I got stuck at a 12.60 wall once... adding more and more jet eventually slowed me down but plugs were NOT telling me that. I upgraded to bigger fuel line(1/2'') a Carter race electric pump, holley regulator for each bowl and ditched the mechanical pump. Ist passes heavy black exhaust all the way and et in 12.50's mph 106... jetting down eventually 12.10's 110 mph. It had been starving for fuel yet always sounded clean/miss free going down track.

That was a long time ago and had myself and others scratching our heads as it sounded just fine and plugs never looked too lean unless we leaned enough to slow down. When we decided to jet rich till it slowed down we eventually realized the plugs werent going as dark as they should have. We got it to start to puff black on launch and a clean shutoff and plug check at end of pass looked no different than a pass with less jet.

You definately want 5+ lbs with a Holley thru the entire run...(7 is good if you dont have needle/seat issues with any carb) volume needs to be there with that psi and your jetting needs to be adequate.

You may find this useful if you follow instructions http://www.wallaceracing.com/plug-reading-lm.html