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Aves
03-29-2010, 06:45 PM
Ok just a bit of background. Truck is running out of fuel around 4800 in 3rd gear. The stock pump was dropping about 5 psi so I decided to try to install A TRE performance 377H fuel pump hoping it would be a cheap fix. Well with the stock returnless regulator the pump would drop 10 psi when going WOT. So tried removing the stock regulator and making a small return loop at the tank. Now I have base pressure at 60 psi but now drops 20 to 25 psi. I have restricted the return line down to 1/8" but had no effect on the pressure drop. It is causing me to go extremely lean( 14.5/1).
The truck was making 427 rwhp @ around 11psi on Vortech. I guess the question I have has anyone had any luck with an intank pump at this power levels? If not looks like it is time to go full return system and fuel cell :boohoo:




Troy

SB440R/T
03-29-2010, 06:58 PM
Ok just a bit of background. Truck is running out of fuel around 4800 in 3rd gear. The stock pump was dropping about 5 psi so I decided to try to install A TRE performance 377H fuel pump hoping it would be a cheap fix. Well with the stock returnless regulator the pump would drop 10 psi when going WOT. So tried removing the stock regulator and making a small return loop at the tank. Now I have base pressure at 60 psi but now drops 20 to 25 psi. I have restricted the return line down to 1/8" but had no effect on the pressure drop. It is causing me to go extremely lean( 14.5/1).
The truck was making 427 rwhp @ around 11psi on Vortech. I guess the question I have has anyone had any luck with an intank pump at this power levels? If not looks like it is time to go full return system and fuel cell :boohoo:




Troy

Running a 255lph pump with a full return system. Don't see any loss in pressure and I am running about 49-50psi with an aeromotive FPR.

Aves
03-29-2010, 10:46 PM
Still in tank? If so do you know what brand and part number?



Troy

RawR/T
03-29-2010, 11:45 PM
Still in tank? If so do you know what brand and part number?



Troy

Walbro 255lph fuel pump. Replaces the stock fuel pump in the tank, and stays in the tank. I have seen them for as low as 100bux from various retail vendors I know.

http://store.driftmotion.com/static/i-walbrofuelpumpfor84-92supra.php

This is what I have in my tank right now, but I am going with a cell and an aeromotive A1000 pump soon.

Aves
04-01-2010, 03:54 AM
Supposedly the tre 377h was a 255lph pump equlivant to the walboro. Might just nit the bullet and do a full system and maybe convert to e-85 same time.

Troy

WhiteRT
04-01-2010, 04:04 AM
Ok just a bit of background. Truck is running out of fuel around 4800 in 3rd gear. The stock pump was dropping about 5 psi so I decided to try to install A TRE performance 377H fuel pump hoping it would be a cheap fix. Well with the stock returnless regulator the pump would drop 10 psi when going WOT. So tried removing the stock regulator and making a small return loop at the tank. Now I have base pressure at 60 psi but now drops 20 to 25 psi. I have restricted the return line down to 1/8" but had no effect on the pressure drop. It is causing me to go extremely lean( 14.5/1).
The truck was making 427 rwhp @ around 11psi on Vortech. I guess the question I have has anyone had any luck with an intank pump at this power levels? If not looks like it is time to go full return system and fuel cell :boohoo:




Troy

Your problem is the size of the stock fuel lines feeding the rails, they are like stirring straws.....if you were able to convert to a -8an feed and -6an return with a regulator inline, the 255lph should feed your setup fine.

I have a mallory EFI FPR here you can have for cheap if you want it to get you started.

Todd

Aves
04-12-2010, 05:46 PM
Well it is not a permant fix or a good fix, but it seems to be working. Just for future reference TRE performance 255lph fuel pumps are junk. Friend had an extra Walboro pump laying around so installed it in tank and kept my redneck engineered return loop at the tank. I am sure my limiting factor now is the rest of the stock lines but hopefuly holds til next winter.
Took truck to the dyno and it is making 435 rwhp and 440 ftlb. Slightly lean in mid range when fuel pressure drops but not too bad(12.4/1) but finishes out in boost @ 11.9/1.
Going to try to to get bed on and get ready for tnt Friday night. If it doesn't get in the 12's this time I am going to set it on fire.


On a side note also got the TSM rear brake conversion done also and it finally hold to 2800 for nice launch. :burnout:

Troy

Aves
04-17-2010, 04:52 AM
Well made it back to track this evening and truck ran better but it still has the stumble in third gear. I am starting to think maybe not a fuel issue by itself. Every data log shows the exact same tip right after the shift to 3rd gear. Right around 4600 rpm or so it feels like a bog drops about 300 rpm and then tries to regain rpm. Here is the graph for one pass.

http://i817.photobucket.com/albums/zz98/Yort72/drag416.jpg


Did finally make the 12's on every pass. Best one was :
1.8455 60'
8.1698 1/8
84.51 mph
12.7676 1/4
108.56 mph

More I been thinking about it does it seem to anyone that it could be floating the vavles?

Troy

Addicted2Blue00
04-17-2010, 06:45 AM
dont see any stumble on 3rd, afr will be better with more tunin, more fuel for idle, are you manual shiftin or shiftin with the gas pedal?

valve float issue, is it poppin or droppin on its face etc in higher rpms?

Aves
04-17-2010, 07:01 AM
dont see any stumble on 3rd, afr will be better with more tunin, more fuel for idle, are you manual shiftin or shiftin with the gas pedal?

valve float issue, is it poppin or droppin on its face etc in higher rpms?

You can see it on graph it is the third spike after shift into 3rd. As far as idle the truck seems to like to idle a bit leaner if that makes since. Shifts are done manually. No poppin just seems to fall on its face and it drops 300 or soo rpm before it starts to recover


Troy

WhiteRT
04-17-2010, 07:10 AM
Sounds like belt slip to me - JMO. Do you have any datalogs of boost, I want to bet at the upper RPM range it is slipping and gripping again.

Todd

Aves
04-17-2010, 07:20 AM
Sounds like belt slip to me - JMO. Do you have any datalogs of boost, I want to bet at the upper RPM range it is slipping and gripping again.

Todd

Bottom red line is MAP signal in Kpa. Don't have it logged in vacuum/boost.
Added another idler pulley before S/C and running about 270* of belt wrap. Since adding the that It didn't have the belt slip issues I had in the past. But, that stumble has always been there.


Troy

Aves
04-17-2010, 06:02 PM
Checked belt today to look for signs for slip. Is brand new belt and no signs of slip on belt like old belts use to show.

Has no one else ran into this problem before? Have changed torgue convertor, transmission, ran different pulleys at different boost levels, and still always have the stumble at same place. Glad it is finally in 12's but just feel it should have atleast a few more mph in it if it didn't drop rpms in third.

Troy

PeteRT
04-17-2010, 10:39 PM
If it doesn't get in the 12's this time I am going to set it on fire.

Troy

you should be damn near 12's with way less than 11lbs... geeze, where are you racing?
pete

Any R/T's
04-17-2010, 10:41 PM
Looks like a lean stumble. Log shows lean before the stumble. Should see 11.6AF or lower when pcm goes into open loop and stay below that.

Aves
04-18-2010, 03:29 PM
you should be damn near 12's with way less than 11lbs... geeze, where are you racing?
pete

Have bad 60' from spinning and I think I am losing a few mph at top with stumble. Would love to be @12 :burnout:


Troy

Aves
04-18-2010, 03:33 PM
Looks like a lean stumble. Log shows lean before the stumble. Should see 11.6AF or lower when pcm goes into open loop and stay below that.

I have had this stumble with pig rich tunes and leaner tunes. Going to send logs to Sean have him bump up fuel a bit,but so far truck has really liked this tune.

Also didn't post log from dyno but there is no stumble there so has to be some issue with load?

Troy

Aves
04-20-2010, 07:07 PM
Ok finally think I found some one that can answer my problem. Talked to Martin Saine yesterday by e-mail and he pretty my told me it is the TCC in the trans that can't be tuned out. Have had Sean try to adjust the lockup to different rpm but never made a difference.
Going to go with one of martin Saine's upgraded Valvebodies which elimantes the tcc in third entirely. So hopefully should know something in about 2 weeks.


Troy

Aves
05-08-2010, 07:27 AM
Wooohoo finally fix the bog. Thank you Martin Saine for new Valve body. Plus the transmission is rock solid now with shifts. Makes the ratchet shifter useless now as it shifts right at 5400 rpm every freaking time.

Unfortunatley I made a mistake and orders some 27" tires so crossing the line above power band around 5700rpm.


Troy

Addicted2Blue00
05-08-2010, 04:43 PM
good info to know, you can send the slicks to me if you dont want them lol