Brain Damage @ the track

[cdr]

Yep. History and the data suggest top end fuel delivery.  It looks like your 660' mph is pretty close to normal, right?

What do you think is the root cause?

The 660 was about right, in 2000 da it ran 98 MPH, I pulled out the intank pump to check the wiring, all looked great, some months ago I did a volume test AT 50 psi as Dwayne had suggested & it had plenty of volume, BUT I am going to go to a -8 from a -6 supply & replace the pump even though all looked good, if its not a defective pump it has to be the -6 line is to small I hope LOL

[cdr]

apparently I REALLY under estimated the fuel this motor needs.

[INTMD8]

Hope it works out for you. 

I've ran -6 at well over 1000rwhp.  (And have I believe the same pump with a -6 line on my car at 595rwhp on E85).


If you do have the same pump/tank setup as me (Holley/tanks inc), you aren't going to get anything out of a -8 line over the restriction of the fuel sender that goes in the tank.

I drilled/ported the outlet of that part (that the pump connects to) as I believe it measured more like a -4 internally.

[cdr]

Hope it works out for you.  

I've ran -6 at well over 1000rwhp.  (And have I believe the same pump with a -6 line on my car at 595rwhp on E85).


If you do have the same pump/tank setup as me (Holley/tanks inc), you aren't going to get anything out of a -8 line over the restriction of the fuel sender that goes in the tank.

I drilled/ported the outlet of that part (that the pump connects to) as I believe it measured more like a -4 internally.

Thanks, I had checked all my AN fittings & they were the correct ID, but you are correct on the tanks INC pump module, it has an ID of .240 & a very sharp edge bend, my AN fitting is .270 id, will that fix it LOL, all I can do is try it with the new pump, thanks again .

Just went out & drilled it to .290, it gets pretty thin, took a ball bur & radiused the turn, waiting on the new pump then back together. 

[INTMD8]

Just went out & drilled it to .290, it gets pretty thin, took a ball bur & radiused the turn, waiting on the new pump then back together. 

I don't recall what size I drilled but did the same, radiusing with a ball carbide. Can only help I think 

[cdr]

Hope it works out for you. 

I've ran -6 at well over 1000rwhp.  (And have I believe the same pump with a -6 line on my car at 595rwhp on E85).


If you do have the same pump/tank setup as me (Holley/tanks inc), you aren't going to get anything out of a -8 line over the restriction of the fuel sender that goes in the tank.

I drilled/ported the outlet of that part (that the pump connects to) as I believe it measured more like a -4 internally.

My question to you & NOT meant in a smart ass way, BUT these cars with 595 rwhp & over 1000, running -6 lines have they run a 1/4 mile at the track, I could run mine on a chassis dyno all day long & my fuel problem would not show up. 

[INTMD8]

You could or you did?

I've not ran my Charger at the track since it's in the body shop. It got rear ended on the way home from dyno tuning it.

Even if my car had a problem at the track it wouldn't be due to the fuel line (a fuel line isn't going to flow perfectly on the dyno and be restrictive at the track)

But yes, I work at a performance shop for the last 21 years building/calibrating cars.  So, long ago when we did more 4th gen F-body's we would use the stock fuel line on many twin turbo cars at over 1000rwhp, 8 second, mid to high 150mph trap speeds. Datalogging solid 1-1 boost referenced pressure.

Ran a -6 line on my twin turbo LT1 1996 camaro.  Stick shift car that ran 9's in the quarter, just under 150 traps and just under 200 in the standing mile.

Tons of naturally aspirated customer cars at 500-600rwhp.

With EFI fuel pressures I wouldn't personally bother with changing a -6 feed line unless I was targeting 1200-1600hp.

[INTMD8]

Here are some mopar examples-

https://board.moparts.org/ubbthreads/ubbthreads.php/topics/604960/how-much-hp-will-3-8-fuel-line-handle.html


A 3/8 line supports quite a bit even in carbureted/low pressure applications.  It can support much more at EFI pressures.

If you want to test if it's the line just put another pressure sender or pressure gauge right at the sender outlet.  Compare pressure at the tank vs at the rail. (you'll see it's dropping as well, not just losing 30-40psi across the line).

[cdr]

You could or you did?

I've not ran my Charger at the track since it's in the body shop. It got rear ended on the way home from dyno tuning it.

Even if my car had a problem at the track it wouldn't be due to the fuel line (a fuel line isn't going to flow perfectly on the dyno and be restrictive at the track)

But yes, I work at a performance shop for the last 21 years building/calibrating cars.  So, long ago when we did more 4th gen F-body's we would use the stock fuel line on many twin turbo cars at over 1000rwhp, 8 second, mid to high 150mph trap speeds. Datalogging solid 1-1 boost referenced pressure.

Ran a -6 line on my twin turbo LT1 1996 camaro.  Stick shift car that ran 9's in the quarter, just under 150 traps and just under 200 in the standing mile.

Tons of naturally aspirated customer cars at 500-600rwhp.

With EFI fuel pressures I wouldn't personally bother with changing a -6 feed line unless I was targeting 1200-1600hp.

I dont have as much experience as you BUT I have been doing efi since the 80's, I have seen lots of stuff NOT show up on an engine or Chassis dyno, but rear its ugly head up at the track & the other way also, no I have not had my car on a dyno, a SHORT balst on the dyno will not show anything of the problem I have, all that said is mute, but I think your are onto something with the pump module fitting size ,all I can do right now is make some changes & see what happens, I am VERY sorry to hear your car got run into, that just sucks !!!!! keep me posted on the progress

[cdr]

Here are some mopar examples-

https://board.moparts.org/ubbthreads/ubbthreads.php/topics/604960/how-much-hp-will-3-8-fuel-line-handle.html


A 3/8 line supports quite a bit even in carbureted/low pressure applications.  It can support much more at EFI pressures.

If you want to test if it's the line just put another pressure sender or pressure gauge right at the sender outlet.  Compare pressure at the tank vs at the rail. (you'll see it's dropping as well, not just losing 30-40psi across the line).

I have done the volume test at 50 psi & it flowed IIRC 110 gph @12 volts, what can I say LOL I will retest when I get it back together

[INTMD8]

The only difference I've seen between dyno and track with fuel delivery is slosh uncovering the pump or pickup. 

It's flowing within a couple percent of the same fuel on the dyno as it does at the track so if the line is fine on the dyno it will be fine at the track.

For comparison, my Charger peaked at 492lb/hr fuel flow on the dyno.

If you don't think several seconds of wide open throttle in high gear on the dyno isn't going to show you any problems may I suggest you give it a try?

I see fuel delivery issues on the dyno on -nearly- a daily basis so certainly useful for diagnosing such things.

The test I'm proposing wasn't a volume test, it was moving your pressure sensor to the sending unit (which when it drops as well would rule out the fuel line as the problem)

Of course it's your car to do as you like with, I just think your problem lies elsewhere.

[cdr]

I pulled the fuel pump & found nothing wrong with the wiring or pump, went ahead & got a larger volume pump & drilled out the sending unit pump line connection as it was much smaller id than -6 should be at the recommendation of Member INTDM8 as he was correct on that info for the Tanks Inc set up,I also was using a stock 3/8 steel line that has all the tight bends in it, I already had some new -6 efi hose so I replaced the factory steel line with it so no more bent up steel tubing,did a volume test @ 50 psi & it flows about 120 GPH now @ 12volts ,will make it back to a track rental soon.

[BSB67]

Great.  Keep us posted.