way too slow at drag strip! what should it run?

-
moparmatt19

moparmatt19

Well-Known Member
Joined
Jan 13, 2014
Messages
135
Reaction score
5
Location
mosheim,tn
OK here is the setup
67 notch weight 3300lbs
Chassis STK ft shocks with /6 tors.
STK rear shocks, /6 leafs with extra leafs added.
NO snubber or traction bars.
B body 8 3/4 with 3.91 sure grip
360 .030 10/10 STK crank
Eagle sir rods
KB 107 pistons .005 positive deck. Out of hole
587 heads with 2.02/1.60 Ferrea race flow valves
Pocket ported, push rod pinch open up
Gasket matched. Polished chambers
Valves UN shrouded and deck, 70cc
True 10.1 to 1 comp
Hughes solid cam HTL4852S
248/252 @.050 .563/.572 106 LSA+3
Hughes 1111 double springs
Iron adj rockers, Crower push rods
Crappy professional products air gap
Holley 770 vac sec street avenger
Pertronix billet flame thrower 3 ready run
727 with turbo action rev vb
Turbo action S800 3500 stall
MT 29/10.5/15 slicks.
On got 2 passes. Spur of moment last race of year kinda thing and just install engine in car.
Only ran 12.7@104 SLOW!!
Cut out and popped going down track would not pull. Afterwards found out only had 20deg timing max!! And only 5psi fuel pressure.
What should this run after tuned right??
Also will be going to 4.88 spool with 29 tire and a dynamic 8" 4500 stall. Was ran on 100 Oct turbo blue
 
How well do those heads flow? I really wouldn't know what it "should" run but I'll guess it "will" run mid-high 11's at 115 mph. I'm probably way off but it's a total guess from a noob.
 
Idk the actual flow on heads... My guess probably around 230-240 cfm on intake. I done all the work to the heads in my garage and machine shop. But no flow bench :(
 
Popping and not pulling certainly sounds like a fuel issue. What were the 60 ft times?
 
Traps was like 4400 . 60ft was like 1.8. I forgot to mention that it didn't hook up at all. Left at 3000 and it just blew the tires off but once it got traction it didn't really pull. I have since fixed the fuel and timing issues, but haven't ran it at the track. Feels much much stronger on street now tho. I knew that I needed much more gear for this engine setup but its what I had ATM. I'm just wondering what I should expect this to run when I take it back to the track and have a chance to jet it and dial it in better. I built this expecting to run in the 11's
 
Also to add.. This is a street car. Drove it to work for 2mths strait. But I will be pulling it out of the cuda and putting it in a Dakota drag truck. Weighs right at 3,000 with small block and me in it, that's when I will be running the 4.88's and 8" 4500 stall... I just impatient on running it again lol and hoping my 11's expectations isn't too high
 
Ditch the vac sec carb and bolt a double pumper to that sucker for start.

You've got a pretty decent cam there. Vac secondaries are great for the street but not so good at the track in my experience.

But as long as it's running clean through the traps it sounds like it should be an 11sec car.
 
You can make all the horsepower you want, but if you can't get the car to hook you are lost. Look at better shocks ( adjustable) and either caltracks or at least an adjustable pinion snubber. Get the car to leave and you might be VERY surprised. Get the suspension working and THEN look at more power. JMO
 
Get the timing adjusted to 30-34, fuel pressure up to 7 (some gages will read low once they get warmed up, so check your pressure again cold), and try leaving at idle or a lower RPM. I have the same converter, and my car does better leaving between idle and 2k than if I try to leave at higher RPMs. Once you've done that, start looking at getting the suspension dialed in. The spring eye should be right below or slightly to the rear of the chassis mount. A snubber or caltracs would also help. You should be pulling 1.6X 60' times. As already stated, 4.88 gears won't help you in the 1/4 with that size tires. Stick with the 4.10's, and 4500 stall is also a bit much for what you have. You'll get no difference with race gas over pump gas unless you have the timing bumped way up. I ran back to back pump gas and race gas for S&G, and got the same ET with both. I shaved .25 off my 1/8 mile time just by getting the suspension dialed in, and I'm not running caltracs or a snubber, but have SS springs and a Dana 60. Ditching the 770 vac secondaries and going with a Holley 850 HP will help.

Are you running 1.5 rockers, or 1.6?
 
You're wasting your time trying to dial in a car that is not hooking; you'll be chasing your tail. Fix your traction issue and then start dialing it in by making small changes. Try to only change one thing at a time between runs so you can see if it improved or hurt your times.

You don't need traction bars, but get an adjustable pinion snubber. It's not like they cost that much; I see them advertised used all the time.
 
Well the reason I ran race fuel is BC I'm running around 188-190 cold cranking psi . I broke the engine in on 93 Oct and could only set timing by ear bc my timing light had the wires pulled out of it. ( someone left the wire in a alt belt). After a day or so of driving I checked plugs. Started to show little black spots so I ran 50/50 93/100 to be safe..
Traction. Yes your right about that. The Dakota will be running caltracs and mono's with 29/14.5/15 slicks.
So I should be able to hook up.
The reason. For the 4.88's is BC that would put me mid to low 11's mph going through traps at 6500-6600 rpm .
This won't be any street.. Only bracket raced and trailered. And I figured I can always run a 31-32 slick if needed.
The 8" 4500 was recommend to me by the tech at Dynamic converters. Oh and rockers are 1.5 ratio
 
20* of timing - hitting it with a 200+shot?

Popping/crapping - fuel delivery... why 5 psi?
 
moparmatt19 said:
This won't be any street.. Only bracket raced and trailered.
Click to expand...

Definitely ditch the vac-sec carby then.

Get a good carby you understand whether it be an Edelbrock or Holley, get a timing light that works and make sure the engine is running right.

You're doing something wrong if you can't get it to hook with 10.5in slicks. Look at some Caltracs for sure, but even just start with tire pressure. How much are you running?

Traction is important, but so is a clean pass.
 
crackedback said:
20* of timing - hitting it with a 200+shot?

Popping/crapping - fuel delivery... why 5 psi?
Click to expand...

Lol, that would be low enough timing for at least 300 shot lol.... The 20° timing wasn't on purpose.. I set it by ear BC no light. And this dizzy has start retard so I couldn't set it by the way it started. After the run at the track I got a timing light on it and found out it was only pulling 20° max. The dizzy had limiter put in it. It was setup for 28° initial and 6° mechanical advance and all to come in around 2200rpm. Which would have been fine for this engine IMO if I would have had a light and actually had the initial set at the 28° at idle.. But apparently I had it set by ear at 14° at idle and it only advanced up to 20°. Oh and the 5psi was from a bad fuel regulator.
 
I also agree on the carb.. But I basically got it from holley for free lol... I bought the 770 street avenger back in 2006 when they first came out. Well they had some metering block probs.. Long story short my carb ate itself from inside out after 8 months.. Well 8 yes later after it set in a box I found out holley had a warranty recall and would replace it for free... Well they did. Sent me a brand new one even after 8yrs later. So I used it... I'm going to get a HP series DP from them. I'm thinking 750 but maybe 850. Not sure yet. Also I ran the first run with 15psi in slicks then went down to 8psi no change. I know the suspension is crap on the 67. It was a work in process but the plans changed and the engine will go into the Dakota now.. I'm confident I will hook up with it. I'm just curious on what this engine should run when running correctly in a 3000lb chassis. Like what I should expect or work towards by tuning. And I'm curious on why the 4.88 with 29 would be too much? I'm asking BC I really want to know. By the calculated gear and tire it should be like 117mph at 6600rpms... That should be mid to low 11's which is what I want. Wouldn't that be using the whole engine HP to make the quickest time possible without waisted or unused rpm? If I hit the rev limiter before going through traps then I could go taller tire and would mean that it possibly could run faster right? This is race car 1/4 only.. What I'm asking or saying is if I went to say 4.10's as suggested and only pulling 5800-6000 through traps and the engine pulls hard to 6500-6600 wouldn't that be leaving some ET/ mph on the table to be had??
 
Get it running right and hooking up before you change gears, that way you should know whether 4.56 or 4.88 will work better.

You need hard clean data, until then everything else is a guess.
 
The thing is I have to get gears either way. I'm keeping the 3.91's with the barracuda. I haven't bought any for the Dakota which is where the engine is going to. So either way I have to buy a set. I see that most people that run in the 11's run anything from 4.30-4.88 so maybe I will just cut that in the middle and go with 4.56's I can always change them later if need be, but I have to start somewhere.
 
Slow down and take your time with your changes. If you get upset because a couple of bad runs with traction issues then get it to hook. Then move onto the loss of power with the stuttering or whatever you described it as.

I made the mistake of getting home from the track and changing my timing and tire pressure and carb and rear end. It made me a little faster but once I slowed down and changed things one at a time I began shedding tenths.
 
moparmatt19 said:
OK here is the setup
67 notch weight 3300lbs
Chassis STK ft shocks with /6 tors.
STK rear shocks, /6 leafs with extra leafs added.
NO snubber or traction bars.
B body 8 3/4 with 3.91 sure grip
360 .030 10/10 STK crank
Eagle sir rods
KB 107 pistons .005 positive deck. Out of hole
587 heads with 2.02/1.60 Ferrea race flow valves
Pocket ported, push rod pinch open up
Gasket matched. Polished chambers
Valves UN shrouded and deck, 70cc
True 10.1 to 1 comp
Hughes solid cam HTL4852S
248/252 @.050 .563/.572 106 LSA+3
Hughes 1111 double springs
Iron adj rockers, Crower push rods
Crappy professional products air gap
Holley 770 vac sec street avenger
Pertronix billet flame thrower 3 ready run
727 with turbo action rev vb
Turbo action S800 3500 stall
MT 29/10.5/15 slicks.
On got 2 passes. Spur of moment last race of year kinda thing and just install engine in car.
Only ran 12.7@104 SLOW!!
Cut out and popped going down track would not pull. Afterwards found out only had 20deg timing max!! And only 5psi fuel pressure.
What should this run after tuned right??
Also will be going to 4.88 spool with 29 tire and a dynamic 8" 4500 stall. Was ran on 100 Oct turbo blue
Click to expand...

Combo is all over the place. Race car only? Needs a single plane intake and a mech. secondary carb. Should be 12.0-11.80s maybe with everything working right? I thought my car was slow too - 3,200lbs with me in it, -340/W2, .557" cam, Victor intake, 750 DP, 10" 3,800 converter, 4.10 gear, drag radials, Caltracs, only went 12.20 @ 110. Found out it was only on 7 cylinders, #5 had a broken piston ring. Also might have had some fuel delivery issues, was likely draining the bowls by the end of the run. Car should have been in the 11s.

Like said above, get the thing running right first with the timing, fuel pressure etc. Verify valve lash. Timing>float level>transfer slots>mixture screws>accelerator pump>jets>air bleeds. If you switch to a double pumper, verify engine vacuum and get the right power valve. If you stay with the vacuum carb, get some different springs for the vacuum pod to change the rate opening. What kind of fuel pump is it, mechanical or electric? Maybe get an air/fuel gauge to see where your mixture is at. It's really helpful to be able to see that information. There's a lot of tuning left. One step at a time or you'll never know where you are at.

And as mentioned already, get your chassis sorted out before you swap gears. Better shocks all around, better rear springs with some device to control wrap up. Tire pressure is also a tuning tool. Is it aligned properly? Half of ET is chassis.
 
Sorry, a lot here doesn't make sense to me (I'm a little slow...lol). Your '60 foot times, and your 1/4 times and the mph are right on with each other. Another words, most 12.70 cars will run around 104 mph with a 1.8 60' time. It's not like you cut a 1.5 60' and ran a 12.70, or ran 114 mph at 12.70, but it sounds like your whole ET went hand in hand. And 4400 rpm's is what you crossed the traps???? Really?? With 3.91's and a 3500 stall at 104 mph??? This means you would be cruising 55 mph at about 1700 rpm's down the highway, with that converter and gears??? Is that tach way out of calibration causing you to over rev it by 1000 rpm's, thus causing the break up? And then, I've never had a car have a total advancement target of 28 degrees. I guess I've missed something there too. 37-44 degrees is where I've usually ended up. And also, 5 psi of fuel wouldn't cause it to pop and snap as soon as it hooked up, you wouldn't be out of gas that quickly. A lot here does not add up to me. BUT, I agree, the car should be well into the 11's, and 3.91 gears should get that done with ease. HMmmmmmm
 
You must log in or register to reply here.
-

Back
Top