Tim: What "big" fuel pump are you using?

OS Inspector: I plan to shortly run K24/20G (Billet) turbos and have a fuel system in mind, but wanted your opinion: Stock pump + 044 in stock fuel filter location & ID 1kcc injectors on E85, think it'll suffice or will I run out of pump or injector? My goals 750rwhp on E85.

OP: Fantastic thread btw, lots of helpful info here!

 

These numbers never seem to add up quite right. For stock 997tt, injector flow is 543 cc/min @ 3 bar. So if you use the standard equation you referenced and calculate hp based on 543 cc/min flow:

hp*0.65*10.5/6*0.95 = 543

hp = 453 which is short of stock 480 bhp and this is at 95% duty cycle.

 

vntperformance;3194098]Tim: What "big" fuel pump are you using?


Weldon 2345. Same as Powell.

 

I believe the stock fpr on a 997TT is 3.8 bar. So when you plug it all in 480bhp 6 injectors bsfc 0.65 duty cycle of 80% and fp of 56 (3.8bar) lands you with 602cc injector needed. When you take your your 543cc @3 bar injector and run it at 56psi (3.8bar) it now flows 612cc.

 

Good point. Thanks. Many folks with upgraded vtg's with "700" kits don't upgrade fuel system and leave as stock. If you plug in the numbers, bsfc .65, fpr 3.8, 700 bhp, 99% DC, you need 716 cc. Never could resolve this?

 

I went with a dual in-tank after having problems with my secondary inline pump. What I did was design a bracket made out of delrin to hold the 044 pumps in tank replacing the stock basket. The pumps are fed using the factory pick up lines that go to the back of the tank. Lines are -8 feed and -6 return. I am in the works of installing a cooler on the return line as the factory cooler was bypassed. If you run dual in-tank pumps you must have a cooler of some sort to prevent overheating the tank and also to keep the pumps happy, and quiet! My layout is very similar to Evoms setup but with a few improvements and it didnt cost me an arm and a leg

I looked at all different setups and felt this was the way to go. I was not about to install a huge LOUD single pump as this is my DD. I also looked at the dual pumps in the trunk using a sump method but didnt think having external lines outside the tank right behind my front bumper was a good idea on the street.

 

Very interesting setup dgreen!

 

Tim correct me if I am wrong, but I think I recall you mentioning it before. He and I are using the Weldon 2345 pump (good for 2000-2200hp). The 2035 is the next step down but Weldon lists it as an "Intermittent Duty" pump.

750rwhp on E85 is going to be close on the pump setup if you are running stock intank and a 044 inline. I know Chris Green is running a Surge Tank because the fuel supply (not injectors) was not enough. Don (Dgreen) setup is a very good solution!

 

Powell: Are you still in AWD configuration, or rwd?

 

Completely RWD now. I had a few close calls with the guard rail due to torque steer and decided was not going to chance that anymore. I also have a CCW Drag Pack for the car.

 

Understandable. I saw....when I was at TX2K10, your car looked mean with the drag pkg.

 

Dgreen,

Please don't take this the wrong way and I realize my post will be easy to dismiss since I am new here and you don't know me or my experience from Adam.

I have a pretty extensive background in building race cars and have done a lot of development in fuel supply systems for very demanding off road race applications.

In your plumbing pics you have a few 90* fittings that are of the sharp bend design. Those are know to cause cavatation in that application. Simply put. Cavaatation kills pumps. An easy fix is to swap the fittings to the sweeping radius design. I have diagnosed several systems failures due to cavatation attributed to the type of fitting you are using.

Camo

 

If you use a 5bar FPR your 543cc @3 bar flows 700cc. I do not feel that is the right way but you see the ease (low cost max profit) in making power.

 

Yes that is right. Weldon also has a fuel pump controller to help with the noise and help with fuel temps.

 

I do not use the threaded and drilled fitting also, do to the same reason you point out.