Do I need a new converter?

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CopperheadDart

CopperheadDart

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Hey Mopar gurus,
I'm just getting around to running my 67 Dart on the track. So far just 1/8th mile, as that's my local track. It's best ET is 7.68 @ 90.18mph with a 1.70 60' on the following setup:
410 small block with ported Eddy's
TTI step headers
1.5 Crane gold rockers
Hughes hydraulic 246/250 4650ALN-10 cam
Scat 4" crank, Diamond -20cc pistons 0 deck, stud girdle, 10.3:1 compression
port-matched AirGap intake
Fitech EFI 600 unit

727 with manual valve body TF3 kit, bolt in sprag, 4.0lever, deep pan
10" converter that I can hold on the footbrake to about 2500 or so.... I pulled this out of another car and have no idea of its specs or origin.

8 3/4 with 4.30 spool, Dutchman axles, narrowed, mini-tub, inboard springs
295/55/15 MT ET drag radials (27.7" tall, about 10" of tread contacting the ground)
New mono-leaf and Caltrack setup from Calvert

So.... It has hooked well, haven't noticed any spinning, but there's a bit of a lag right off the line, not like it's bogging down, just taking it's time to hit the power band it seems like, before the torque really sets you back. I feel like if I could footbrake to a higher RPM it would rocket out of there. I just think I'm leaving a lot on the table, and this setup should have a much better 60'.
Am I right in thinking this unknown 10" converter is my weak link???

DART.jpg
 
Do this test......
Motor/trans all warmed up.

With the car going along at 10-15mph, trans in high gear, with the motor just above idle(12-1500ish)......... floor the gas.
The tax needle will swing right up to some rpm and then hold steady for a bit.
Whatever that number is, that’s the effective stall speed for that converter, behind that motor, in that car.
The “flash” stall speed.

If I were chasing ET, for that combo I’d want at least 4200-4500 flash stall speed.
It’s going to take a pretty good 9.5” to get you there, and still have decent efficiency out of the converter.
 
What does it weigh? Have you tried leaving at idle or 1500 or so? I think a good converter would be a good investment. I also think a good single plain intake would help.

Years ago I ran a 340 in my 69 Dart, it ran 7.24 @ 94 mph at 3240# on pump 93. It was .030" over, 11.4-1, Ross flat tops, Eagle SIR rods, ported edelbrocks, Hughes hydraulic, 237/242° at .050, .584/.592" lift with 1.6 rockers, Weiand X-Cellerator with a Quick Fuel Q-750, TTI 1 5/8- 1 3/4 headers, 727 with a CRT reverse manual valve body, a 9 1/2" Edge Racing converter that flashed 5000 using the method Dwayne mentioned above, 8 3/4 with 4.30 gears and 275 M/T radials.
 
there is something seriously wrong with your set up. that combo should be in the teens. that mph to the 1/8 tells the car is making about 350 ish hp
 
I could never get my Fitech to work worth a crap at the track....went back to the holley 750 dp.....probably was just me....

7.68 in 1/8 is around 12 flat in 1/4.....yes...you need a converter
 
Do post 2 test. Agree you are down on power. I'm not familiar with FI but fatten it up till the mph falls off. After you get the mph setting right, see if there is a way to fatten up launch, (accelerator nozzle on a carb, whatever that setting is for FI). I would think a single plane would work better with FI.
 
mderoy340 said:
Do post 2 test. Agree you are down on power. I'm not familiar with FI but fatten it up till the mph falls off. After you get the mph setting right, see if there is a way to fatten up launch, (accelerator nozzle on a carb, whatever that setting is for FI). I would think a single plane would work better with FI.
Click to expand...

Thanks for the replies so far! I ran that test and it actually 'flashed' at somewhere between 4100 and 4200 RPM.. So perhaps its not a tight converter I'm battling, but a lean fuel off the line issue that you're describing. I'm pretty new to FI also, but I know I can data log a run, so I'll try that next to see what is going on.
No idea what car weighs, It's full interior, roll bar, subframe connectors, fiberglass fenders, hood, and bumpers, fuel cell, etc... so pretty light all things considered!
 
Looking at the overall engine “recipe”, aside from the EFI( no real experience at the track with that), and perhaps the hyd lifters not willing to rpm high enough to be able to use up that cam......... it seems like there should be close to 10 second potential there.

Unless it’s way heavier than it looks.

Assuming 500 STP fwhp, 10% loss in the car, 3400lbs at the line....... should be at the bottom of the 11’s(7.0’s 1/8).
 
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MOPARCODY said:
there is something seriously wrong with your set up. that combo should be in the teens. that mph to the 1/8 tells the car is making about 350 ish hp
Click to expand...

My 3550lbs '71 340 Cuda ran 12.4'@108 in 1/4 back in '86..which equates to something like >
60 Foot E.T. : 1.72
1/8 Mile E.T. : 7.82
1/8 Mile Trap Speed : 86.88
not that far off yours with more weight and a crap 340 motor compared.....the motor was stock bottom end (under 10:1), stock 2.02 heads (215cfm?) made a true 368fwhp, .590" sft cam, 850DP, 4.30's and a 4200 stall. That doesn't help you any because its hard to diagnose anything, but you can see how bad things are with your combo, around 100hp down?.....I would get the EFI sorted or go back to a carb for starters.
 
I am not a politician. Lol
Its a dog for an eddie stroker.
My stock stroke 360 is 4/5 tenths quicker and i doubt is lighter( i am 320 driving it).
First 3 things i would look at to get it to run better
1. Put an 8 Inch convertor in it( have one in mine and drive it everywhere). It will be way more effecient than that 10 inch. Trust me.
2 throw that cam in the garbage can.
3. Open up heads( and check them)
A stroker motor being raced deserves a flat tappet cam. I would step up to something AT LEAST in the mid 250’s at 50. Something like you have i would probably recommend the exact same cam i am running in my stock stroke( hair big for what i have but was on the shelf) 260/264 565/565 with 1.5 rockers
I replaced a cam like you have with the one above. Had my eddies whittled on a little, and milled them, and swapped from a convertor like you have to a real convertor and went from 12.20’s to a new best of 11.26. From 107 mph in the 1/4 to 119 best.
Cam and convertor first. Open up the heads some next.
Should run ultra low 11’s, 7 teens at worst. This all assumes you are getting fuel and the fuel delivery isn't junk( carb/ fuel injection)
The 60 foot will pick way up, as will the rest of the incrementals
With a bone stock shortblock 360( stock rods, pistons and crank) I have been 1.52 60 foot. Usually 1.54/55
You are giving up a ton there. A ton. 1.70 is horrible not spinning. Should be 1.50 ish all day
 
B3422w5 said:
I am not a politician. Lol
Its a dog for an eddie stroker.
My stock stroke 360 is 4/5 tenths quicker and i doubt is lighter( i am 320 driving it).
First 3 things i would look at to get it to run better
1. Put an 8 Inch convertor in it( have one in mine and drive it everywhere). It will be way more effecient than that 10 inch. Trust me.
2 throw that cam in the garbage can.
3. Open up heads( and check them)
A stroker motor being raced deserves a flat tappet cam. I would step up to something AT LEAST in the mid 250’s at 50. Something like you have i would probably recommend the exact same cam i am running in my stock stroke( hair big for what i have but was on the shelf) 260/264 565/565 with 1.5 rockers
I replaced a cam like you have with the one above. Had my eddies whittled on a little, and milled them, and swapped from a convertor like you have to a real convertor and went from 12.20’s to a new best of 11.26. From 107 mph in the 1/4 to 119 best.
Cam and convertor first. Open up the heads some next.
Should run ultra low 11’s, 7 teens at worst. This all assumes you are getting fuel and the fuel delivery isn't junk( carb/ fuel injection)
The 60 foot will pick way up, as will the rest of the incrementals
With a bone stock shortblock 360( stock rods, pistons and crank) I have been 1.52 60 foot. Usually 1.54/55
You are giving up a ton there. A ton. 1.70 is horrible not spinning. Should be 1.50 ish all day
Click to expand...

I figured I'd go 1.50's 60' with this combo too.. I'm pretty new to racing so all of this is a learning curve for me. I'm going to start with fuel delivery to make sure there isn't anything drastically wrong there...Then invest in a converter. I was surprised to see after doing the test in post #2, that it flashed at 4100ish. Is it normal for a converter that loose to not be able to hold with footbraking above 2400ish RPM?
 
CopperheadDart said:
I figured I'd go 1.50's 60' with this combo too.. I'm pretty new to racing so all of this is a learning curve for me. I'm going to start with fuel delivery to make sure there isn't anything drastically wrong there...Then invest in a converter. I was surprised to see after doing the test in post #2, that it flashed at 4100ish. Is it normal for a converter that loose to not be able to hold with footbraking above 2400ish RPM?
Click to expand...

where a convertor holds against a foot brake is meaningless
Many factors at play, such as how good are your brakes, and many other things. Its zero factor, but i guarantee that 10 inch convertor is killing a good bit of ET. Bet my life on it.
The many cars i have owned and raced i have virtually never seen a difference in 60 foot by leaving at different RPM’s
My current car has 8 inch 5,000 stall convertor
I can foot brake it to 1800,2,000, 2500 or really push my luck and hold it to 3,000 hoping it doesnt roll in the beams and it 60 foots within a hundredth any of those ways. Have played with the 3000 trying to cut a better light on a footbrake pro tree deal i only do once a year( won it last year..lol)
In fact, if the convertor is correct for the car, it will generally 60 foot the same off the foot or a transbrake
I used to have a stroker 9 sec Duster. A Points series i raced in 7 or 8 times a year for years with it had pro tree index races and a footbrake only bracket race. I raced in both on the same night. 1.34/1.35 consistently
I would leave off the transbrake with the chip set at usually 4100-4200, running the pro tree 10 flat index, and leave at 2,000 off the foot in the footbrake bracket race and the car 60 footed and ET’ed identically same each way. Same night, same track

Get a good 8 inch convertor when you get the combo sorted out, leave at a comfortable spot on the tach, to be consistent( which is why i almost anyways leave at 2,000) easy to read the tach needle, and the car is “ relaxed” at 2000 dont have to worry about slipping in the beams.
launch rpm can be moved around to help you if you are having problems hitting the tree, but i prefer changing the car around and leaving the launch rpm alone.... front tire pressure, etc. are better fixes.
You drive how you drive. Adjust the car to take advantage of your habits( be they good or bad)

did you install those heads right out of the box and use the springs they came with?
 
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B3422w5 said:
where a convertor holds against a foot brake is meaningless
Many factors at play, such as how good are your brakes, and many other things. Its zero factor, but i guarantee that 10 inch convertor is killing a good bit of ET. Bet my life on it.
The many cars i have owned and raced i have virtually never seen a difference in 60 foot by leaving at different RPM’s
My current car has 8 inch 5,000 stall convertor
I can foot brake it to 1800,2,000, 2500 or really push my luck and hold it to 3,000 hoping it doesnt roll in the beams and it 60 foots within a hundredth any of those ways. Have played with the 3000 trying to cut a better light on a footbrake pro tree deal i only do once a year( won it last year..lol)
In fact, if the convertor is correct for the car, it will generally 60 foot the same off the foot or a transbrake
I used to have a stroker 9 sec Duster. A Points series i raced in 7 or 8 times a year for years with it had pro tree index races and a footbrake only bracket race. I raced in both on the same night. 1.34/1.35 consistently
I would leave off the transbrake with the chip set at usually 4100-4200, running the pro tree 10 flat index, and leave at 2,000 off the foot in the footbrake bracket race and the car 60 footed and ET’ed identically same each way. Same night, same track

Get a good 8 inch convertor when you get the combo sorted out, leave at a comfortable spot on the tach, to be consistent( which is why i almost anyways leave at 2,000) easy to read the tach needle, and the car is “ relaxed” at 2000 dont have to worry about slipping in the beams.
launch rpm can be moved around to help you if you are having problems hitting the tree, but i prefer changing the car around and leaving the launch rpm alone.... front tire pressure, etc.

did you install those heads right out of the box and use the springs they came with?
Click to expand...


Good info, thanks for the quick reply. These heads were ported by a reputable mopar fella in Nebraska, he installed Hughes valve springs and inspected guides and seats, etc... Port matched and mild port in the AirGap. I trust his work. He sold me on that camshaft size, as I wanted a street/strip combo, and at the time I was leaning towards more of a street combo.... but that has morphed as I have caught the racing bug! I know I cant have the best of both, but I really think there's a lot of potential I'm losing out on with what I already have.
 
If the heads have been ported by a reputable person, that makes the numbers ever more hard to understand.
But, the convertor is a good start.
Regards the cam, for a Mopar small block stroker With even modest track results desired, not what i would want.
Not sure how much you street drive, but that hydraulic cam is a pooch. Real similar To the cam i got rid of in my 360.
I had 260/266 600 lift solid in a 416 eddie motor very similar to yours that i drove everywhere, including 70 mile roundtrips to the track. With good heads and convertor that cam will cost that motor lots of power
 
You launch and a bit after the 60 it “comes alive”..... converter converter converter!

im with B3... more camshaft!
If you don’t have a billet front drum in that dump truck trans get one! ....or better yet put that money towards a 904 since you’ll be converter shopping anyways :)

ive so hopelessly ruined my Duster “going faster” that it’s going to cost a ton to go back..... be careful out there :)
 
Frankly...... at this point, I’m more suspicious of the EFI than I am the converter with regards to the 60’ times.

Who has some track experience where they went from a good running carb, to one of these budget style EFI units and has some accurate data to share from the swap?
 
PRH said:
Frankly...... at this point, I’m more suspicious of the EFI than I am the converter with regards to the 60’ times.

Who has some track experience where they went from a good running carb, to one of these budget style EFI units and has some accurate data to share from the swap?
Click to expand...

Even with the “ bog” it should still MPH once it comes on..... that MPH has maybe a 400 horsepower look to it...
 
I ran cheap off the shelf converters for years. Then I invested in 2 custom converters for my 2 cars both are 8in. Best money I ever spend on my cars. 60 ft. was better, e.t. dropped and mph went up, plus way more consistant. Most important part of the car for performance. Call a good company and tell them what you need. Dynamic, Ultimate, Turbo action, Ptc, ATI, etc. all good.
 
PRH said:
Frankly...... at this point, I’m more suspicious of the EFI than I am the converter with regards to the 60’ times.

Who has some track experience where they went from a good running carb, to one of these budget style EFI units and has some accurate data to share from the swap?
Click to expand...
I agree. I would get the bog tuned out and AFR at WOT AFR for best mph fixed before throwing a converter at it. Once the engine is tuned you can calculate converter slip at the stripe and have good data for a new converter if needed.
 
It’s just one of those things “that does not compute” for me.
Hot Ede headed 410”, gears, traction, 4100 stall........ 1.70 60’?

Hardly seems possible.
Sure...... it’s more than likely mostly being lost in the converter.
But maybe there is just some delay in the motor reaching full power quickly with the EFI unit?

Purely speculating....... as said...... zero experience at the track with one of those.

Let me ask one of those obvious questions........ are you sure it’s getting full throttle?
On a few occasions....... the answer has ended up being “no”.
And one of those times there was well over 1 second difference in the ET after correcting it.
 
PRH said:
It’s just one of those things “that does not compute” for me.
Hot Ede headed 410”, gears, traction, 4100 stall........ 1.70 60’?

Hardly seems possible.
Sure...... it’s more than likely mostly being lost in the converter.
But maybe there is just some delay in the motor reaching full power quickly with the EFI unit?

Purely speculating....... as said...... zero experience at the track with one of those.
Click to expand...


Good point... easy enough to toss a carb on and see
 
@CopperheadDart Are you using timing control in the Fitech?
Either way, what's your ignition and timing settings look like right now?

I've found my Fitech (no racing with it though) to be very sensitive to timing changes and settings. I use the timing controls in the Fitech, but knowing what I know now I would never race using fitech controlled timing.
 
PRH said:
It’s just one of those things “that does not compute” for me.
Hot Ede headed 410”, gears, traction, 4100 stall........ 1.70 60’?

Hardly seems possible.
Sure...... it’s more than likely mostly being lost in the converter.
But maybe there is just some delay in the motor reaching full power quickly with the EFI unit?

Purely speculating....... as said...... zero experience at the track with one of those.

Let me ask one of those obvious questions........ are you sure it’s getting full throttle?
On a few occasions....... the answer has ended up being “no”.
And one of those times there was well over 1 second difference in the ET after correcting it.
Click to expand...

Yep I confirmed opon install last summer that I have 100% throttle travel.
 
Phreakish said:
@CopperheadDart Are you using timing control in the Fitech?
Either way, what's your ignition and timing settings look like right now?

I've found my Fitech (no racing with it though) to be very sensitive to timing changes and settings. I use the timing controls in the Fitech, but knowing what I know now I would never race using fitech controlled timing.
Click to expand...
Yes I have it controlling my timing, MSD pro billet dizzy, using MSD 6AL box. Base at 13, all in I think at 34 total. I need to revisit that to confirm.
 
Does you EFI have the capacity to data log?
 
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