Posted By: dart443
this thing should mph better? - 09/13/09 11:54 AM
newbee 68 dart 440 ez headed hughes cam 613&626 250 256, 410 gear.ran yesterday 1.47 60 out the door at 11.26 119. what wrong with this combo 
this thing should mph better?
Posted By: Quicktree
Re: this thing should mph better? - 09/13/09 12:28 PM
Welcome 
really need more info, tire size,converter,weight etc. 60' looks good it's not making top end HP unless theres a problem elsewhere.
really need more info, tire size,converter,weight etc. 60' looks good it's not making top end HP unless theres a problem elsewhere.
Posted By: dart443
Re: this thing should mph better? - 09/13/09 12:39 PM
quicktree, 325 et streets,3500 stall, 3400 lbs me in.850 mighty demon,indy-2 manifold
Posted By: Quicktree
Re: this thing should mph better? - 09/13/09 12:46 PM
looks like it's just not making the power it should. I would have a bigger converter but you can't complain about the 60'. check timing and see if you can borrow a bigger carb. play with shift points.
Posted By: Quicktree
Re: this thing should mph better? - 09/13/09 12:47 PM
are the heads ported? if not that should be the next thing you do.
Posted By: dart443
Re: this thing should mph better? - 09/13/09 12:50 PM
the heads are ported. i tried shifting between 6500&7000 no change.
Posted By: Quicktree
Re: this thing should mph better? - 09/13/09 12:54 PM
check and make sure the throttle is open all the way. you have 60' for mid 10s. if your sure about the igniton and timing I would be looking at the carb maybe.
Posted By: dart443
Re: this thing should mph better? - 09/13/09 12:59 PM
timing at 39 degrees ignition all msd no missfire
Posted By: Quicktree
Re: this thing should mph better? - 09/13/09 01:10 PM
try 34-36 just to see what happens.
Posted By: Bad340fish
Re: this thing should mph better? - 09/13/09 01:14 PM
If all else is in line its time for leakdown and compression checks.
Posted By: dart443
Re: this thing should mph better? - 09/13/09 01:27 PM
checked throttle,tried 34 no change, fresh motor.25passes
Posted By: 408Dust
Re: this thing should mph better? - 09/13/09 01:39 PM
Fuel system up to par? Have a fuel pressure gauge on it?
Posted By: rickstershemi
Re: this thing should mph better? - 09/13/09 01:41 PM
Quote:
newbee 68 dart 440 ez headed hughes cam 613&626 250 256, 410 gear.ran yesterday 1.47 60 out the door at 11.26 119. what wrong with this combo
Actually I would be looking for a better ET with a 60' of 1.47.....119mph for an 11.26et is very good IMHO
Rickster
Posted By: dart443
Re: this thing should mph better? - 09/13/09 01:45 PM
holley blue,fuel gauge under hood set at 7 lbs.is a blue pump enough volume?
Posted By: Garceau
Re: this thing should mph better? - 09/13/09 01:54 PM
Whats the compression?
Way too big a cam for a 3500 stall converter. Im guessing that cam doesnt really come on to 5500 or so.
You have a 3500 stall converter and shifted at 6500 or 7K?
Bump that converter up to 4500 or higher (need all the facts). By the time the engine is making power your half way down the track.
1.47 is not great 60, but may be tire limited.
I think your combo is just too far apart on a few different areas.
Way too big a cam for a 3500 stall converter. Im guessing that cam doesnt really come on to 5500 or so.
You have a 3500 stall converter and shifted at 6500 or 7K?
Bump that converter up to 4500 or higher (need all the facts). By the time the engine is making power your half way down the track.
1.47 is not great 60, but may be tire limited.
I think your combo is just too far apart on a few different areas.
Posted By: dart443
Re: this thing should mph better? - 09/13/09 02:02 PM
compression 10.66,had the car on the chassis dyno peak torque at 5200 408
Posted By: Garceau
Re: this thing should mph better? - 09/13/09 02:04 PM
I definatly think your combo is a bit out of sorts.
I really dont like that carb.
Definatly need a looser converter.
As a side note, what are you trapping RPM at, and whats the diameter of your tires, and shift point. Have you checked the converters efficiency?
I really dont like that carb.
Definatly need a looser converter.
As a side note, what are you trapping RPM at, and whats the diameter of your tires, and shift point. Have you checked the converters efficiency?
Posted By: Garceau
Re: this thing should mph better? - 09/13/09 02:06 PM
Quote:Quote:
newbee 68 dart 440 ez headed hughes cam 613&626 250 256, 410 gear.ran yesterday 1.47 60 out the door at 11.26 119. what wrong with this combo
Actually I would be looking for a better ET with a 60' of 1.47.....119mph for an 11.26et is very good IMHO
Rickster
I think its because the converter is so tight. I had to do this once in my dart. Broke a converter through a bone stock one in there. Ran 1/2 second slower and same if not a touch more MPH. Was so tight if I put it in gear it would stall without some fancy footwork.
Posted By: 440Jim
Re: this thing should mph better? - 09/13/09 02:24 PM
325 ET Street radials should be about 28" dia, with that 4.10 gear. I agree the sixty foot is good for the ET, my target sixty foot equation says that is what the following ET should be getting:
Sixty = 0.12xET + 0.17
ET = (Sixty-0.17)/0.12 = 10.83
My other curve fits to general cars in this league inputing 119 mph gives 11.25, so the mph and ET are in line.
More stall speed also improves ET during the shift recovery. Putting an 8" race converter around 5000 rpm would make it feel completely different.
That really isn't very much duration (250), but with your converter and 10.6 CR that is fine. Is that a roller cam? IMO, to take advantage of the heads (assuming decent port work) and the Indy MW intake, you would need to step up the converter and cam, limited by CR.
Sixty = 0.12xET + 0.17
ET = (Sixty-0.17)/0.12 = 10.83
My other curve fits to general cars in this league inputing 119 mph gives 11.25, so the mph and ET are in line.
More stall speed also improves ET during the shift recovery. Putting an 8" race converter around 5000 rpm would make it feel completely different.
That really isn't very much duration (250), but with your converter and 10.6 CR that is fine. Is that a roller cam? IMO, to take advantage of the heads (assuming decent port work) and the Indy MW intake, you would need to step up the converter and cam, limited by CR.
Posted By: dart443
Re: this thing should mph better? - 09/13/09 02:33 PM
440jim its a solid flat,do you think i am maxad out with this cam and convertor
Posted By: BradH
Re: this thing should mph better? - 09/13/09 04:32 PM
Which model of Mighty Demon 850 (downleg or annular boosters)? Has it been tuned at all, or is it "out of the box"?
When you say the heads have been ported, are they still the standard runner size or did they get opened up to MW size?
And maybe I missed it, but what type & size headers do you have?
What RPM are you turning going through the traps?
When you say the heads have been ported, are they still the standard runner size or did they get opened up to MW size?
And maybe I missed it, but what type & size headers do you have?
What RPM are you turning going through the traps?
Posted By: dart443
Re: this thing should mph better? - 09/13/09 04:44 PM
annular boosters 80 90 jets stock air bleeds,ported to max wedge,tti 2 inch
Posted By: Cab_Burge
Re: this thing should mph better? - 09/13/09 05:21 PM
I think the Holley blue pump is the problem 
Been there done that Put a 250 or bigger pump on it My Duster with a set of Eddy RPM standard port heads(518C.I., 10.29to1 comp ratio) and a bigger cam with similar weight(3430 with me in it) runs 10:40 at 128.+ MPH with a 10 inch converter and 3:73 gears with 315x60x15 ET Street Rdials 
I had a Magnafuel 275 pump on it and I could not jet the carbs up enough to slow the car down, I switch to a Magnafuel 300 pump and it slowed down and made the AFR go rich with the same jetting that the car ran 128.+ mph 
this is a street & strip car ran with the exhaust on, air cleaner on and on pump gas 
Been there done that Put a 250 or bigger pump on it My Duster with a set of Eddy RPM standard port heads(518C.I., 10.29to1 comp ratio) and a bigger cam with similar weight(3430 with me in it) runs 10:40 at 128.+ MPH with a 10 inch converter and 3:73 gears with 315x60x15 ET Street Rdials I had a Magnafuel 275 pump on it and I could not jet the carbs up enough to slow the car down, I switch to a Magnafuel 300 pump and it slowed down and made the AFR go rich with the same jetting that the car ran 128.+ mph this is a street & strip car ran with the exhaust on, air cleaner on and on pump gas
Posted By: Dodgem
Re: this thing should mph better? - 09/13/09 06:19 PM
I'm almost think it is fuel too! he left at low RPM first pass bogged 1.57 short and with a 11.3 went 120 then next run he does not bog went 1.47 short and 11.26 @ 119??? When I have a bad 60 the pick up a 1/10th in the 60 next round I usually gain .2 quarter and a mph or two??
It's almost like the better he launches the less it pulls??
It's almost like the better he launches the less it pulls??
Posted By: 72Challenger
Re: this thing should mph better? - 09/13/09 07:26 PM
I would guess it would pick up ET when you get bigger in the fuel pump, carb and convertor department. Your 60ft tells to run high 10's so for your launch the convertor can't be bad but the cam would like you to be sooner at higher rpms I guess.
So basicly as most others suggested
So basicly as most others suggested
Posted By: BradH
Re: this thing should mph better? - 09/13/09 09:07 PM
Various thoughts here...
- it may be a fuel supply issue, but I think it's more likely a combination issue
- Max Wedge-size Indy heads on 440-ish combinations don't work well from what I've been seeing, unless you spin the snot outta 'em (and your cam and intake choice don't suit that approach)
- Demon 850 annular carb is an odd beast... pulls a lot of fuel through those boosters down low, then seems to choke at higher rpm
- it may be a fuel supply issue, but I think it's more likely a combination issue
- Max Wedge-size Indy heads on 440-ish combinations don't work well from what I've been seeing, unless you spin the snot outta 'em (and your cam and intake choice don't suit that approach)
- Demon 850 annular carb is an odd beast... pulls a lot of fuel through those boosters down low, then seems to choke at higher rpm
Posted By: Quicktree
Re: this thing should mph better? - 09/13/09 09:10 PM
Quote:
Various thoughts here...
- it may be a fuel supply issue, but I think it's more likely a combination issue
- Max Wedge-size Indy heads on 440-ish combinations don't work well from what I've been seeing, unless you spin the snot outta 'em (and your cam and intake choice don't suit that approach)
- Demon 850 annular carb is an odd beast... pulls a lot of fuel through those boosters down low, then seems to choke at higher rpm
Posted By: BDS871Cuda
Re: this thing should mph better? - 09/13/09 11:14 PM
Quote:
the heads are ported. i tried shifting between 6500&7000 no change.
How about shifting it from 5900 to 6400. Short
shifting can do wonders at times. I would think
a 4500 stall but your 60 is good. I think the
825 Race Demon would be a better carb.
What is the RPM at the traps?
To me, it seems like a top end thing. Out of power
in the high rpm range? Maybe a 3.90 gear would be
better. Just some Ideas.
Posted By: Cab_Burge
Re: this thing should mph better? - 09/14/09 12:18 AM
Before I would change anything I would try and figure out what the main problem is 
I would(if you can) take it back to the track and jet it up to see if you can jet it fat enough to slow the 1/4 MPH down, if you can't fix that first If you can jet it up enough to slow it down then your on your own on whats wrong and what to fix Never give up, you know there is a problem, thats the easy part usually, figuring out what is causing it can be the hard part 
Let us know what you find and do
I would(if you can) take it back to the track and jet it up to see if you can jet it fat enough to slow the 1/4 MPH down, if you can't fix that first If you can jet it up enough to slow it down then your on your own on whats wrong and what to fix Never give up, you know there is a problem, thats the easy part usually, figuring out what is causing it can be the hard part Let us know what you find and do
Posted By: dart443
Re: this thing should mph better? - 09/14/09 12:29 AM
thanx for all the replies, ill be going back in two weeks,
Posted By: Garceau
Re: this thing should mph better? - 09/14/09 02:05 AM
Everyone is always down on the holley blue. I think people forget it was the standard forever. Lots of them running much faster vehicles than this guy has.
Not to say its not going bad.
Hell I used to run 9.2s with a carter electric.
Not to say its not going bad.
Hell I used to run 9.2s with a carter electric.
Posted By: 451Mopar
Re: this thing should mph better? - 09/14/09 05:22 AM
Quote:
newbee 68 dart 440 ez headed hughes cam 613&626 250 256, 410 gear.ran yesterday 1.47 60 out the door at 11.26 119. what wrong with this combo
I think with the dual plane intake, you really need a larger carb. My 451 with a 252/252 cam, 0.613" lift was using a M1 single plane intake, a 1" open spacer, and a Holley HP 1,000 cfm carb. Before I got the HP carb, I ran a Holley 850, and I had to really richen it to tune it, and this is at Denvers 5,800 ft altitude. The 1,000 cfm carb was jetted pretty close out of the box and the car was faster by about 0.2 second, and a few MPH.
I am not sure what altitude you are racing at, but the altitude here in Denver really slows my car down. The lowest altitude I have run at was Las Vegas, and the car wan 11.80's @ 115 MPH. Not great, but it is a #4,150 street car and I launch pretty easy for traction reasons stock suspension, with the large torsen bars, so not much weight transfer or traction.
Posted By: 440Jim
Re: this thing should mph better? - 09/14/09 02:33 PM
Quote:
indy-2 manifold
If that is the Indy 440-2 intake, it is a single plane, max-wedge ports, 4150 single four barrel.
Posted By: 64ssmax
Re: this thing should mph better? - 09/14/09 03:02 PM
Quote:
compression 10.66,had the car on the chassis dyno peak torque at 5200 408
1.More compression works wonders on mopars. 2.What is the cam installed at?
3.Never liked any of demon carbs. borrow a different brand.
4.Call ATI and talk to tech dept. ask them what convertor might be needed.
5.I would think shifting anything over 6500 with this combo the tongue is hanging out of the car.
lots of good advice from previous replys.
Posted By: BradH
Re: this thing should mph better? - 09/14/09 03:24 PM
Quote:Quote:
indy-2 manifold
If that is the Indy 440-2 intake, it is a single plane, max-wedge ports, 4150 single four barrel.
Ooops... I was thinking the same thing ("-2" = 2-plane).
Still, if he does have that big single-plane intake, it's not helping the torque in the range where his cam is best suited. I'm actually surprised it 60-fts as well as it does w/ the rest of the parts mentioned.
Posted By: dart443
Re: this thing should mph better? - 09/14/09 04:17 PM
cam is installed at 104.5,single plane manifold
Posted By: Dodgem
Re: this thing should mph better? - 09/14/09 05:27 PM
He has a 3/8 fuel line and pick up which I thought should be larger. maybe something to the lean as even though it has pretty big jets it showed lean on the plugs a few races back?
with that big intake and max wedge port EZ's I'd be shifting it 7200 to 7400!!
with that big intake and max wedge port EZ's I'd be shifting it 7200 to 7400!!
Posted By: 451Mopar
Re: this thing should mph better? - 09/14/09 08:18 PM
Quote:
cam is installed at 104.5,single plane manifold
Sorry, I mis-read the intake type.
I was running a 250 GPH pump and 1/2" (-8 AN) fuel line. On the Chassis Dyno the 451 HP peak was at 6100 RPM, so I usually shifted at 6500 RPM.
Posted By: BobR
Re: this thing should mph better? - 09/14/09 08:33 PM
Quote:
He has a 3/8 fuel line and pick up which I thought should be larger. maybe something to the lean as even though it has pretty big jets it showed lean on the plugs a few races back?
with that big intake and max wedge port EZ's I'd be shifting it 7200 to 7400!!
Needs more fuel. Start here before doing anything else.
Posted By: BSB67
Re: this thing should mph better? - 09/14/09 11:07 PM
I suggest that you first check your fuel pressure going through the traps. Pump type and idle fuel pressure is not enough information to determine if you have adequate fuel delivery all of the way down the track.