1) Not enough fuel- No matter how much fuel my tuner seemed to throw at it in the tune, AFR climbs steadily starting around 5000~5500 all the way up to 6500. The duty cycle of the injectors at the table setting of 1.5 (commanding AFR of ~9.8) was only about 82%, so its not the injectors. And the fuel pressure was maxed out on the 1:1 referenced FPR at 70 (saw ~15psi of boost, and have 58psi baseline at 0 vac/boost). So I know the delta across the injectors was only 55psi, but that shouldn't cause much of a problem should it? My fuel setup now is dual in-tank walbros using the stock 3/8" feed line along the frame rail, and then that goes to a -6 braided line into the fuel rails, and I'm using the EVAP hard line as a return. Is it possible I just am not getting enough volume? I really don't understand how I could have pleanty of pressure, but not enough volume. But if that is the case, what do I need to do to correct this? Run a -8 feed line maybe and then use the stock 3/8" feed as a return? Will that be enough, or do I need bigger? Surely the two 255 walbros are enough?

2) Head gasket checked out- I was running the older 3 layer version 6.0L MLS gaskets. Will a set of the new 6.0/6.2L 5 layer gaskets solve this problem? I also did not coat the 3 layer ones with that copper coating when I put them on. Should I do that with the new gaskets I get? I also remember that when I was installing the ARP head studs I tightened them all the way and bottomed them out on the block. I didn't know until afterwards you were only supposed to tighten them by handuntil they bottom out, then back them off a turn. I will definitely back them off a turn when I put on the new gaskets.

I know there are plenty of people in here running in the 650~700rwhp range. What are you all doing for fuel and head gaskets?

We only got to make 2 pulls. The first one, the boost went to about 14psi and then went back down to 10. I thought the belt was slipping, but the dyno operator said that he thought it spun on the dyno. He tightened the straps, and I tightened the belt a bit, and it hit 15psi the next run and didn't fall off, so whatever the problem there was, it was solved. I don't have my graph print out with me, but IIRC, it was 651rwhp STD. I don't remember what the SAE #'s were, but I do know that the F1 chart with the hat and filter on was higher than my P1 chart with the hat and filter off which was the 632# in my sig.

With the head gasket giving me the finger, we didn't even get to play around with the meth on the dyno this time Hoping to pick up a few more ponies once I get these other problems ironed out...

Any help I can get here guys would be great

 

congrats on nothing blowing up... =) It seems like you may have to upgrade the lines because it would seem to me as if they are a restriction...

 

Thanks LOL ya, if you consider blowing a head gasket now blowing up Oddly enough, both pulls had 0 KR even when it went lean

 

Wow, 0 KR when it went lean I would think you should do a -8an for your feed line and -6 return. You should have enough pump with two for supporting 700 plus, I would think ? I'm inclined to agree there might be a slight restriction. Good numbers for the day Chad !! Now post a video of the beast on the rollers......

 

CHAD,

if you're makeing 15 psi from the F1 you should be making more like 800+ rwhp or on the way to making that power once the motor is happy.... the fuel system sounds ok....but you will need more injectors

 

so whats actually wrong with your head gaskets?

 

Mike- I'll post a vid as soon as I can get my brother to load it onto his computer and e-mail to me. It sounds wicked!

You sure its the injectors Tiago? I have 60's right now, and they are only 82% duty cycle... You were the one who told me how to set my fuel system up like this tho... Didn't you say you used this setup up to 750rwhp?

I am also making 15 psi because I have some very (relatively) restrictive heads. They are stock 6.0L heads- no porting or anything and with stock valve sizes. If I was running AFR's or something and making 15psi, I may then be expecting 800, but for now, I think once I can get the engine prepped to handle the pressure, and utilize the meth system I'm thinking 700rwhp range?

 

The drivers side is leaking out the side near the front side around cyl#3. It could be due to my idiotic installation, or the pressure. I've heard of the heads lifting under boost, so it could be either one, or both.

 

Are you doing an SD tune?

 

No, its MAF. After the MAF maxes out (around 4500 RPM) it keeps adding fuel based on RPM.

 

I would add the larger fuel lines first, and we have found that going with a larger return line seems to keep the fuel cooler. Bob

 

Tiago is right that fuel system will support at least 750 I know personally cause I have run it before, and my black 408 with an F1 is still using a 6 feed and stock return which is real close to what you have. Another thing is lower your base FP to @50psi and then your FPR wont be maxed out at 15 PSI. Are you sure that both pump are working? Also how are they hooked up running all the time or do you have a hobbs switch to activate the second, make sure that is working also as they can go bad pretty frequently. For a test you can wire them both to run all the time for some dyno pulls and while trouble shooting. Also the wire feeding the pump needs to be at least a 10 gauge wire. Also did you make sure your return line it ran right in the back of the car? Just asking a few questions that could get you going. I do believe you could be out of injector, but not 100% sold on it as I know of people making more on the same injector, but different cars act different. Head gaskets I just used L19's torqued to 100 and stock MLS head gaskets no coating I did use Yama bond on them before and it works, but its a PITA to mess with. Good luck.
Jeff
P.S. A larger fuel line is better, but I don't believe it is your issue yet. Volume does a lot like Bob says keeps fuel cooler and works the pumps less and in a sense is more presure. Pounds per square inch so the line is larger so there is more presure really FYI.

 

what size injectors are you running I can't seem to find that info???

 

Dont wory about what is 'commanded,' just keep adding to the PE until you get to 100% DC, THEN you are out of fuel.

I assume 60lb injectors..

I made plenty of power on the stock lines with dual walbros, just make sure you have good sized power and ground wires going to them and a voltblaster doesnt hurt either.

 

Thanks for the input guys. Yes, they are 60# Mototron/ Siemens (flow matched)...

I am pretty sure both pumps are working. The 2nd one is boost activated, but I could easily hook them both up to run at the same time. I would assume they are both working tho since the fuel pressure raises easily it seems. The first pump just has the factory wiring, and the second pump has 10gauge wire. I guess I could add a BAP to the first pump as well if that is a problem, but I thought with the second one being a 10 gauge direct line from a relay it would not have been an issue. I am 100% sure the return line is hooked up correctly. I just made a shopping list of the parts I'd need to run a -8 feed line, and I'd really prefer not to spend about $250 if that won't solve my fuel problems...

 

For most street car builds around 650-700hp here, i tend to use a -8an feed and using the stock feed as a return. The 60lbs will tend to die around 750ish hp so be ready for a aem box and some 83s .

Congrats on the F1, now the power steering is really making noise

 

Voltblaster is 80.00, takes 10 minutes to install and raises the voltage to everything at WOT, they work very well and the increased voltage also helps for a hotter spark.

 

Thanks guys.

KP- where can I get a voltblaster? Is that the actual name of the unit, or just a general name? Who makes them? Sorry for all the questions, never heard of that before.

*edit: I think I found it. Is this what you are talking about?

http://www.exoticperformanceplus.com....html?item=718

 

Speed inc sells them, Casper electronics makes them and you can buy them right from them. I have had one on this car for a couple years now with both the stock PCM and BS3 and never had any issues with anything because of it.

 

2) Head gasket checked out- I was running the older 3 layer version 6.0L MLS gaskets. Will a set of the new 6.0/6.2L 5 layer gaskets solve this problem? I also did not coat the 3 layer ones with that copper coating when I put them on. Should I do that with the new gaskets I get? I also remember that when I was installing the ARP head studs I tightened them all the way and bottomed them out on the block. I didn't know until afterwards you were only supposed to tighten them by handuntil they bottom out, then back them off a turn. I will definitely back them off a turn when I put on the new gaskets.


Never heard of this before....

Copper coating should only be necessary if the surface finish of the block and head are not adequate, otherwise I would not recommend it - isn't going to help with sealing cylinder pressure, only coolant.

Sound like detonation or inadequate clamp load, possibly from not enough stretch being aplied to the fasteners.

Hope you get it figured out, I have a similar set-up I want to put in my car at some point. How do you like the F1?