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Discussion Starter #1 (Edited)
At last weekends NHRA Sport compact (Import Mostly) race, I entered in the Quick-16 class. Up to this point the car has been running consistantly in the 11s. Since it rained Saturday and early on Sunday, there was only 1 qualifying round. In qualifyling, the car launched hard, because I followed the rubber that the pro cars laid down. Got a 1.82 sixty foot and then the car fell flat on its face.

Couldn't figure out the problem at the track as I thought that some late minute changes that I made were screwing with the computer. Logs showed that it leaned out to 18 to 1 Air/fuel at 29psi, but this was only for a split second before it lost boost.

Anyway, the problem turned out to be that the return fuel line, right outside the fuel tank had collapsed. This caused high pressure in the fuel system and caused the rubber fuel pump line to blow off inside the tank. Whats more intersting is that the car drove normally except under high boost. Even though the line blew off, it is a very short line and still remained in place so it still produced 50psi of fuel pressure, but no more. When I got it home, I put the puel pressure guage on the rail and pumped the regulator up with a bicycle pump. It would not make more than 50psi. So I took out the fuel pump and found the hose blown off.

Lessons learned:
1) Turbo Dodge cars don't like full stands of spectators and announcers building up expectations of how fast your car is going to be.
2) If not for the alcohol injection, I suspect it would have blown up.
3) There is no raised end on the Walbro 255 pump output nipple to keep the hose from sliding off, so at the worst time, the hose will slide off and we must check these every so often.
4) Return fuel hoses need to be maintained well, even though they don't carry pressure.

Once I reconnected the hose, the car was fine. Went to E-town for a checkout run and ran a 11.583 @ 119.19 with a 1.810 short time (DOT BFGs)

Also, during checkout, I was trying raising and lowering the boost levels. The sweet spot for boost level for this car is 28psi, When I raise it higher (29-30), the MPH and ET drops. I always thought that raising the boost would keep gaining power, (eventually it would not gain as much), but it appears that you actually lose power and efficiency at some point that overcomes the gains from the higher boost.
 

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Flying on those DOT's!!!

Congrats.
 

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DblTrbl said:
Lessons learned:
1) Turbo Dodge cars don't like full stands of spectators and announcers building up expectations of how fast your car is going to be.
2) If not for the alcohol injection, I suspect it would have blown up.
3) There is no raised end on the Walbro 255 pump output nipple to keep the hose from sliding off, so at the worst time, the hose will slide off and we must check these every so often.
4) Return fuel hoses need to be maintained well, even though they don't carry pressure.

Once I reconnected the hose, the car was fine. Went to E-town for a checkout run and ran a 11.583 @ 119.19 with a 1.810 short time (DOT BFGs)

Also, during checkout, I was trying raising and lowering the boost levels. The sweet spot for boost level for this car is 28psi, When I raise it higher (29-30), the MPH and ET drops. I always thought that raising the boost would keep gaining power, (eventually it would not gain as much), but it appears that you actually lose power and efficiency at some point that overcomes the gains from the higher boost.

Rule #1 is so true, blew my turbo trying to make a 13sec pass, with all my friends watching :bang head

Interesting info about the turbo though.

Way to kick ass, thats awesome! :D
 

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DblTrbl said:
3) There is no raised end on the Walbro 255 pump output nipple to keep the hose from sliding off, so at the worst time, the hose will slide off and we must check these every so often.
I swear that there was a lip on the walbro 255 I just install in my car the other week.

Nice times with the car! Flying w/o slicks!
 

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TrboVan said:
Flying on those DOT's!!!

Congrats.
Yes he is. But I plan on giving him a run for his money soon!! His car is very impressive!!
 

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Discussion Starter #7 (Edited)
89daytonaTII said:
I swear that there was a lip on the walbro 255 I just install in my car the other week.

Nice times with the car! Flying w/o slicks!
I hope you don't mind me bringing back this old thread, but I have two more comments.

Yes there was a metal lip on the end of the Walbro, but I found out that it is a small aluminum press on ring and it fell off and ended up stuck in the fuel line, so i didn't see the ring till the second time the line fell off.

Also I found a video of the run where this happend. It's the first pass in this video. If you look carefully, my car is in the far lane. If I remember correctly, I beat the AWD DSM at the line and to 60 foot, but then the fuel line fell off and I was no longer in the picture

http://www.thespeedlounge.com/video/2005SpringNationals.mov

Carl
 

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Brian Putman said:
Yes he is. But I plan on giving him a run for his money soon!! His car is very impressive!!


It's more impressive for the fact that it is a pretty basic car... most of Carl's stuff is homemade and the little tricks he has up his sleeves shave serious time off the launches. The mystery lean spike is finally solved... I'm looking forward to seeing him run again at the strip!
 
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