Yeah you cannot do 27 psi on the bnr on e-47. Not enough fuel especially in the midrange. The wg dc needs to be reduced a lot.

 

If it turns out that the pump is fine that's exactly my plan.

 

Thanks for your input. I was hoping you would stop by. I know some cars have done it but my car seems a little atypical.

 

Term, what would you recommend. 27 psi on less E or E47 with less boost?

 

you can also duct tape the pressure gauge to the window thats what we do at the shop

 

so,,, just a thought why were my three posts saying this same thing ignored, but term comes in and we agree lol

 

I didn't ignore your input. But my guess is that you're not a tuner so your response was probably taken under "consideration".

 

im not a tuner your right, but a car, or in this instance our fuel system, can only be pushed so far... just because we enter a value in hpt doesnt mean that the car can perform that.. hence fp dropping and inj. duty shooting thru the roof... this means back it down or blow it up (sometimes backing it down makes the car faster since the car isnt over compensating)

 

Bingo! Agreed.

 

i NEVER ONCE SAID REDUCING WGDC isnt a posibility but its not the complete factor... Heres is key point. TEAM SS (BNR2871) RAN E47 24 LBS AND ALSO RAN 27 LBS no issue with fuel. OPs issues isnt throughout midrange (its only for 500-800rpm.)

Alot of cars are different fuel system wise. Alot of them wheich everyone knows. So the tune is dependant on the cars fuel values and etc.


Reducing wgdc is just shadowing the issue, not fixing it. You can run e47 on a bnr with 27lbs, ive done it with keeping correct fp. And 2010ss, you are 100% correct, lowering boost while maintianing good fp will keep idcs low. And yes more power can be gained from this.. But my main thing is

 

not arguing, but its not overshadowing an issue if that is the max that the fuel system can support... 800 isnt really not a lot... 800rpm is 23% of a typical pull 3500-7000rpm

 

I see what you are saying here. I think if the problem goes away when you do what you suggested then that is the fix. Sounds like the problem goes away in that instance.

For my application I'm not sure that is what's needed bc I think he already tried this. I am hoping this fuel psi gauge tells the story.

 

I know your not arguing lol.. What I am saying is when you have droppage and you lower boost in that certain area or just drop boost all together because your psi drop is to much in a certain area. Your just shadowing what should really be done. Honestly op could just go methanol and it will fix a lot of the fueling. Or wait for a port fuel injection mani... .. By lowering the boost it's gonna allow for more psi to come back since it is not being used.... But as op said Ive ramped boost in slowly, I've lowered wgdc quite a bit already. And psi drop is still there..

 

You guys make this way too difficult. If the pressure is lower at peak torque or 3500-4500 RPM, then add hpfp mods such as a larger fuel lobe cam. If the pressure is lower at peak HP, or 5500-6500 RPM, then go after the in-tank pump.

 

Methanol would make it worse sir.

I think I have the drop in the upper rpm area. I think the test that was suggested will confirm if the in tank pump is the issue or not.

 

Methanol kit sir!!!! It won't make it worse lol. Just lol

 

Oh an injection kit! I thought you meant to run methanol as fuel.

 

Lol... Hahahaahaha it's ok, I understand you have a bnr under the hood lol ..

 

Also take notice of how much fuel you have in the tank. I had to run almost 1/2 tank in mine to keep from draining the canister. CMiller had the same situation. If your problems happened at 1/4 tank or less, then try a full tank and see if it's better.

 

Matt,

The lobe that was on your test car and the lobe that is currently being sold to us, Are they the same or has it been changed in size? All I have to say is that for paying the money I did for these cams, all I gained was 11whp not the 25whp you claimed at first. Also the duration change though miniscule, is a change and we can see that up top in the Higher RPM's boost drops to 17psi above 6500(its the turbo I know, but I hope that this goes away with a BNR)




Blue line is the 368whp, Red is the previous dyno of 357whp. There is an improvement in the midrange but I really don't see the Bigger Fuel Lobe solving the Fuel issues or demands of Larger Turbo setups. Just like the Mazda guys, you should persue modifying the Fuel pump. I think a combination of the 2 would be nice.

 

Got some interesting results today. So just to recap, I was having very severe rail pressure drop on WOT with a BNR2871, E47, full bolt ons and 27psi. Initially thought it was the HPFP. Replaced that and the same issue persisted. The next thought was that it could be the in tank fuel pump. Maybe it wasn't supplying enough fuel? In the meantime, I switched back to 93 fuel and dosed SeaFoam a couple of times in the gas tank. I've heard of E85 gumming up people's fuel systems so this was a way for me to try and eliminate that possibility while waiting to test the in tank pump.

Well after rigging up the test gauge, GoPro and flashlight under the hood, I did a data log with E47 back in the tank. I drove on about 6 gals of 93 for a few days and took it to empty and then fillled the tank with 2 gals of E47. Loaded up a previous tune file and went for drive. The video shows that (apparently) the in tank fuel pump is maintaining just fine.

Cobalt SS Turbo Fuel Pressure Test - YouTube

Here's the weird part, I no longer have the severe rail pressure drop either! It went away! A buddy of mine suggested that I switch back to 93 for a few days just to see if it would help. I really didn't think it would do much b/c I couldn't imagine that whatever residue could have built up would have caused THAT bad of a pressure drop. Looks like it just may have. I will have James dial me back in and see how long it lasts. I may start dosing SeaFoam in the gas tank every now and then. Who knows, maybe that helps too?

I'll keep this updated in case the problem comes back. For all I know, this could be a glitch or something temporary. Or maybe the mix I ran wasn't quite E47 (eventhough I did 1gal of each E85 and 93).

 

Well, that's good to hear man. Hope that was all she wrote. Keep us posted.

 

Yeah. It almost seems too good to be true. Time will tell. I guess I can send back this 320 lph in tank pump I bought.

DW300 Fuel Pump Tech | DeatschWerks.com

 

That kind of stinks that your results are a bit skewed by the simple fact that the issue basically went away, BUT at least you now know that the supply pump (in-tank pump) is still holding pressure fine.

pfft.... the blind leading the blind my ass..

 

I have been claiming 10-12whp gains for our cams for quite some time, so your results are where they should be.

The fuel pump lobe on the cams that we sell is .050" larger than stock. HPFP flow is increased nearly 20%. We have pushed customer cars close to 450whp on straight E85 and our 256 turbo kit. We couldn't get past 380 on the stock cams.

This is really a topic for a different thread, though.

Frogs- how much gas do you think you had left in the tank when you switched back to E47? The first fill-up can be skewed a lot more than you would expect, putting your E percentage pretty low. You also might have had a higher % ethanol in your E85 last time. We have measured as high as 92% ethanol in E85 from Mobil.